Araçá (Psidium cattleianum Sabine): bioactive compounds, antioxidant activity and pancreatic lipase inhibition

Araçá (Psidium cattleianum Sabine): compostos bioativos, atividade antioxidante e inibição da lipase pancreática

Elisa dos Santos Pereira Juliana Rocha Vinholes Taiane Mota Camargo Chirle de Oliveira Raphaelli Núbia Marilin Lettnin Ferri Leonardo Nora Márcia Vizzotto About the authors

ABSTRACT:

“Araçá” has been reported with different biological activities such as antioxidant, antiproliferative and antimicrobial as well as inhibitors of digestive enzymes. The digestive pancreatic lipase enzyme plays a fundamental role in lipid metabolism, and its inhibition has been studied as a target for obesity treatment. This study quantified the bioactive compounds present in different parts of “araçá” fruit and evaluated their antioxidant activity and lipase inhibition properties. Three samples were analyzed for total anthocyanins, total phenolic content, antioxidant activity and pancreatic lipase inhibition. Anthocyanins were reported only in pulp-peel of red “araçá” sample. Phenolic compounds concentration was higher in pulp-peel than in seeds for all samples. The antioxidant activity followed the same trend. A positive correlation was observed between total phenolic content and both antioxidant activity and lipase inhibition. Lipase inhibition activity was higher for pulp-peel compared to the seeds. Overall, the results showed that “araçá” fruit extracts could be beneficial for the treatment of obesity.

Key words:
anthocyanins; phenolic compounds; pulp-peel; seed; native fruit

RESUMO:

A fruta araçá tem sido destacada por suas diferentes atividades biológicas como antioxidante, antiproliferativa e antimicrobiana, além de inibidores de enzimas digestivas. A enzima digestiva lipase tem papel fundamental no metabolismo lipídico, e sua inibição tem sido estudada como alvo para o tratamento da obesidade. Este estudo teve como objetivo quantificar os compostos bioativos presentes em diferentes partes do fruto do araçá e avaliar sua atividade antioxidante e propriedades de inibição da lipase. Três amostras foram analisadas quanto a antocianinas totais, compostos fenólicos totais, atividade antioxidante e inibição da lipase pancreática. Antocianinas foram encontradas apenas na polpa-casca da amostra de araçá vermelho. A concentração de compostos fenólicos foi maior na polpa-casca do que nas sementes para todas as amostras. A atividade antioxidante seguiu a mesma tendência. Os compostos fenólicos totais, a atividade antioxidante e a inibição da lipase apresentaram uma correlação positiva. A atividade de inibição da lipase foi ligeiramente superior para a polpa-casca em comparação com as sementes. No geral, os resultados revelaram que os extratos da fruta do araçá podem ser benéficos para o tratamento da obesidade.

Palavras-chave:
antocianinas; compostos fenólicos; polpa-casca; semente; fruta nativa

INTRODUCTION:

“Araçá” (Psidium cattleianum Sabine) is a native Brazilian fruit from the Myrtaceae family originating in the south of Brazil, that is harvested between January and May (PEREIRA et al., 2018PEREIRA, E. Dos S. et al. Psidium cattleianum fruits: A review on its composition and bioactivity. Food Chemistry, v. 258, p. 95-103, 2018. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814618304394 >. Accessed: March. 05, 2021. doi: 10.1016/j.foodchem.2018.03.024.
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). “Araçá” peel colour can be yellow or red, and its pulp is mucilaginous, aromatic, and contains many seeds (MEREGALLI et al., 2020MEREGALLI, M. M. et al. Conventional and ultrasound-assisted methods for extraction of bioactive compounds from red araçá peel (Psidium cattleianum Sabine). Arabian Journal of Chemistry, v. 13, n. 6, p. 5800-5809, 2020. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S1878535220301234 >. Accessed: March. 20, 2020. doi: 10.1016/j.arabjc.2020.04.017.
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). Psidium cattleianum is known by different names such as “araçá”, “araçá-rosa”, “araçá-de-comer”, “araçá-da-praia” and “araçá-coroa” (PEREIRA et al., 2018PEREIRA, E. Dos S. et al. Psidium cattleianum fruits: A review on its composition and bioactivity. Food Chemistry, v. 258, p. 95-103, 2018. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814618304394 >. Accessed: March. 05, 2021. doi: 10.1016/j.foodchem.2018.03.024.
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) and is consumed in natura, and preserved as jams, jellies, and juices (REISIG et al., 2016REISIG, G. N. et al. Bioactive compounds in conventional and no added sugars red strawberry guava (Psidium cattleianum Sabine) jellies. Revista Brasileira de Fruticultura, v. 38, n. 3, p. 1-7, 2016. Available from: <Available from: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452016000300901 >. Accessed: Aug. 19, 2020. doi: 10.1590/0100-29452016062.
https://www.scielo.br/scielo.php?script=...
). Due to its high content of vitamin C and bioactive compounds with an array of properties (e.g. antioxidant, anticarcinogenic, analgesic, and antimicrobial), it also merits exploration by the pharmaceutical industry (ALMEIDA LOPES, DE; SILVA, E. De O., 2018ALMEIDA LOPES, M. M. et al. Araçá-Psidium cattleyanum Sabine. Exotic Fruits, Elsevier, 2018. 466p. ; MEDINA et al., 2011MEDINA, A. L. et al. Araçá (Psidium cattleianum Sabine) fruit extracts with antioxidant and antimicrobial activities and antiproliferative effect on human cancer cells. Food Chemistry, v. 128, n. 4, p. 916-922, 2011. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S030881461100536X >. Accessed: March. 22, 2020. doi: 10.1016/j.foodchem.2011.03.119.
https://www.sciencedirect.com/science/ar...
; PEREIRA et al., 2018PEREIRA, E. Dos S. et al. Psidium cattleianum fruits: A review on its composition and bioactivity. Food Chemistry, v. 258, p. 95-103, 2018. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814618304394 >. Accessed: March. 05, 2021. doi: 10.1016/j.foodchem.2018.03.024.
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). In vivo research has shown that “araca” can improve blood glucose levels, reduce low-density lipoprotein (LDL), and total blood cholesterol levels, and decrease fat deposition in the liver when administered in the diet of rats (DALLA-NORA et al., 2014DALLA-NORA, C. et al. Protective effect of guabiju (Myrcianthes pungens (O. Berg) D. Legrand) and red guava (Psidium cattleyanum Sabine) against cisplatin-induced hypercholesterolemia in rats. Brazilian Journal of Pharmaceutical Sciences, v. 50, n. 3, p. 483-492, 2014. Available from: <Available from: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502014000300483 >. Accessed: July. 25, 2020. doi: 10.1590/S1984-82502014000300006.
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).

The biological activities reported for “araçá” are related to phenolic compounds and carotenoids reported to be present in “araçá” fruits (ALMEIDA LOPES et al., 2018ALMEIDA LOPES, M. M. et al. Araçá-Psidium cattleyanum Sabine. Exotic Fruits, Elsevier, 2018. 466p. ; CORRÊA et al., 2011CORRÊA, L. C. et al. Antioxidant content in guava (Psidium guajava) and araçá (Psidium spp.) germplasm from different Brazilian regions. Plant Genetic Resources, v. 9, n. 3, p. 384-391, 2011. Available from: <Available from: https://www.cambridge.org/core/journals/plant-genetic-resources/article/abs/antioxidant-content-in-guava-psidium-guajava-and-araca-psidium-spp-germplasm-from-different-brazilian-regions/88598D94E8A1E1FA99EC2DBF33521713 >. Accessed: Aug. 18, 2020. doi: 10.1017/S1479262111000025.
https://www.cambridge.org/core/journals/...
). Consumption of foods rich in phenolic compounds is associated with reduced risk of health disorders due to their neutralization of excess free radicals and reactive oxygen species (BELISÁRIO et al., 2020BELISÁRIO, C. M. et al. Carotenoids, sugars, ascorbic acid, total phenolics, and antioxidant activity of murici from Brazilian Cerrado during refrigerated storage. Ciência Rural, v. 50, n. 4, p. 1-8, 2020. Available from: <Available from: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782020000400751 >. Accessed: Aug. 05, 2020. doi: 10.1590/0103-8478cr20180620.
https://www.scielo.br/scielo.php?script=...
; SHAHIDI & AMBIGAIPALAN, 2015SHAHIDI, F.; AMBIGAIPALAN, P. Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects - A review. Journal of Functional Foods, v. 18, p. 820-897, 2015. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S1756464615003023 >. Accessed: Aug. 29, 2020. doi: 10.1016/j.jff.2015.06.018.
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). Phenolic compounds can also inhibit specific digestive enzymes (WU et al., 2020WU, D.-T. et al. Phenolic compounds, antioxidant activities, and inhibitory effects on digestive enzymes of different cultivars of okra (Abelmoschus esculentus). Molecules, v. 25, n. 6, p. 1276, 2020. Available from: <Available from: https://www.mdpi.com/1420-3049/25/6/1276 >. Accessed: March. 12, 2021. doi: 10.3390 / moléculas25061276.
https://www.mdpi.com/1420-3049/25/6/1276...
). Pancreatic lipase acts in the breakdown of fats, including triglycerides and phospholipids, playing an important role in lipid metabolism. Thus, inhibitors of this enzyme represent a potential therapeutic route for obesity due to their reduction of lipid digestion and absorption at the peripheral level. Considering that 50-70% of total dietary fat hydrolysis is performed by pancreatic lipase, inhibition of this enzyme is a potential stand alone treatment for obesity (ALIAS et al., 2017ALIAS, N. et al. Anti-obesity potential of selected tropical plants via pancreatic lipase inhibition. Advances in Obesity, Weight Management & Control, v. 6, n. 4, 2017. Available from: <Available from: https://medcraveonline.com/AOWMC/AOWMC-06-00163.pdf >. Accessed: March. 22, 2021. doi: 10.15406 / aowmc.2017.06.00163.
https://medcraveonline.com/AOWMC/AOWMC-0...
). Orlistat, obtained from Streptomyces toxytricini, is currently the only pancreatic lipase inhibitor approved for clinical use (FINER et al., 2000FINER, N. et al. One-year treatment of obesity: A randomized, double-blind, placebo-controlled, multicentre study of orlistat, a gastrointestinal lipase inhibitor. International Journal of Obesity, v. 24, n. 3, p. 306-313, 2000. Available from: <Available from: https://pubmed.ncbi.nlm.nih.gov/10757623/ >. Accessed: July. 31, 2020. doi: 10.1038 / sj.ijo.0801128.
https://pubmed.ncbi.nlm.nih.gov/10757623...
; ZHANG et al., 2018ZHANG, C. et al. The free, esterified, and insoluble-bound phenolic profiles of Rhus chinensis Mill. fruits and their pancreatic lipase inhibitory activities with molecular docking analysis. Journal of Functional Foods, v. 40, p. 729-735, 2018. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S1756464617307429 >. Accessed: July. 22, 2021. doi: <https://doi.org/10.1016/j.jff.2017.12.019>.
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). It can produce side effects including flatulence, oily spots, abdominal cramps, urgency, faecal incontinence, and steatorrhea (CHAPUT & TREMBLAY, 2007CHAPUT, J.; TREMBLAY, A. Currently available drugs for the treatment of obesity: Sibutramine and Orlistat. Mini-Reviews in Medicinal Chemistry, n. 418, p. 3-10, 2007. Available from: <Available from: https://pubmed.ncbi.nlm.nih.gov/17266632/#:~:text=The%20currently%20available%20drugs%20for,at%20least%201%2D2%20years >. Accessed: Aug. 01, 2020. doi: 10.2174/138955707779317849.
https://pubmed.ncbi.nlm.nih.gov/17266632...
) that reduce patient compliance with treatment regimens. Alternatives are needed, potentially including the use of natural products.

Antioxidant compound content is dependent on the part of the fruit analyzed. Some phenolic compounds are present in greater quantities in the pulp and bark than in the seeds of Momordica cochinchinensis and other exotic fruits from Colombia (CONTRERAS-CALDERÓN et al., 2011CONTRERAS-CALDERÓN, J. et al. Antioxidant capacity, phenolic content and vitamin C in pulp, peel and seed from 24 exotic fruits from Colombia. Food Research International, v. 44, n. 7, p. 2047-2053, 2011. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0963996910004357 >. Accessed: Aug. 21, 2020. doi: 10.1016/j.foodres.2010.11.003.
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; KUBOLA & SIRIAMORNPUN, 2011KUBOLA, J.; SIRIAMORNPUN, S. Phytochemicals and antioxidant activity of different fruit fractions (peel, pulp, aril and seed) of Thai gac (Momordica cochinchinensis Spreng). Food Chemistry, v. 127, n. 3, p. 1138-1145, 2011. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814611002226 >. Accessed: Oct. 18, 2020. doi: 10.1016/j.foodchem.2011.01.115.
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). Genetic variability of this fruit should also be considered, because there are variations in alleles within the species, both between different populations of the same species, and within single populations (GRIFFITHS et al., 2000GRIFFITHS, A.; MILLER, J.; SUZUKI, D. An introduction to Genetic Analysis. 7. ed. New York: Elsevier, 2000. 860 p.). These factors may influence fruit composition and biological activity. Thus, this study verified the potential of different genotypes, and different parts of “araçá” fruit to inhibit pancreatic lipase activity, and to broadly assess “araca” bioactive compound and antioxidant activity content.

MATERIALS AND METHODS:

Standards and reagents

Reagents were purchased from various suppliers. Phosphate buffer (pH 7.0), 2,2-diphenyl-1-picrylhydrazyl (DPPH) D9132, cyanidin-3-O-glucoside, Folin-Ciocalteu reagent V0S0427, chlorogenic acid C3878, sodium carbonate, and Lipase kit MAK046 were purchased from Sigma-Aldrich (St. Louis, MO, EUA). Ethanol, methanol, and hydrochloric acid were purchased from VETEC (Duque de Caxias, RJ, Brazil).

“Araçá” samples

Three samples of “araçá” were obtained from the Active Germplasm Bank of native fruits at Embrapa Clima Temperado (31°40′47”S, 52°26′24”W, RS, Brazil, accession numbers AC 44 and AC 87 (red genotype), and Bicudo cultivar (yellow genotype)). Several fruits from three plants of each cultivar or accession (a new plant variant obtained via tissue culture, chemical treatment, or any classical breeding practice, not yet characterized, but assigned an accession number) were harvested when ripe between March and April of 2016. Samples were transported to the laboratory in boxes at 25°C, within 30 min. Pulp-peel were manually separated from the seeds, and both were frozen at -20ºC. Samples were lyophilized and ground (particles diameter < 5 μm) under liquid nitrogen using a ball mill, and stored at -80°C until analyzed.

Total anthocyanin content

Total anthocyanin content was measured as described (FULEKI & FRANCIS, 1968FULEKI, T.; FRANCIS, F. J. Quantitative methods for analysis. Journal of Food Science, v. 33, p. 72-77, 1968. Available from: <Available from: https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1968.tb00887.x >. Accessed: march 22, 2021. doi: 10.1111/j.1365-2621.1968.tb00887.x.
https://onlinelibrary.wiley.com/doi/10.1...
). Briefly, 250 mg of freeze-dried “araçá” sample was mixed with 10 mL of extraction solvent [85:15 ethanol (95%): hydrochloric acid (1.5 M)] and stirred for 5 min. Samples at a concentration of 25 mg/mL were filtered (paper filter Whatman no4), and absorbance was measured at 535 nm. Results were expressed as equivalents of cyanidin-3-O-glucoside, based on a cyanidin-3-O-glucoside (-0-0.4 mg/mL) standard curve (y = 0,0451x + 0,0006 r² = 0,9964).

Total phenolic content

Total phenolic content was measured using the Folin-Ciocalteu method adapted from SWAIN & HILLIS (1959SWAIN, T.; HILLIS, W. E. The phenolic constituents of Prunus domestica. I.-The quantitative analysis of phenolic constituents. Journal of the Science of Food and Agriculture, v. 10, n. 2, p. 33, 1959. Available from: <Available from: https://onlinelibrary.wiley.com/doi/10.1002/jsfa.2740100110 >. Accessed: July. 18, 2020. doi: 10.1002/jsfa.2740100110.
https://onlinelibrary.wiley.com/doi/10.1...
). Briefly, 250 mg samples of each freeze-dried powder was stirred for 5 min in 10 mL methanol (1:40 w/v) and filtered (paper filter Whatman nº4). A 250 μL aliquot of each sample (25 mg/mL) was combined with 4 mL of water and 250 μL of Folin-Ciocalteu reagent (0.25 N). After a 3 min incubation, 500 μL of Na2CO3 (1 N) was added, and mixtures were incubated for 2 h at room temperature. Absorbance was measured at 725 nm, and results were expressed as chlorogenic acid equivalents (CAE g/100 g fresh weight) using a chlorogenic acid (-0-0.5 mg/mL) standard curve (y = 0,5825x - 0,0101 r² = 0,9907).

Antioxidant activity using DPPH

Antioxidant activity was measured using a method described by THAIPONG et al. (2006THAIPONG, K. et al. Comparison of ABTS, DPPH, FRAP, and ORAC assays for estimating antioxidant activity from guava fruit extracts. Journal of Food Composition and Analysis, v. 19, n. 6, p. 669-675, 2006. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0889157506000081 >. Accessed: March. 10, 2020. doi: 10.1016/j.jfca.2006.01.003.
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). Lyophilized “araçá” samples (250 mg) were stirred for 5 min in 10 mL methanol (1:40 w/v) and filtered (paper filter Whatman nº4). A 200 µL aliquot of each sample (25 mg/mL) was mixed with 2.8 mL of 0.10 mM methanolic DPPH solution (THAIPONG et al., 2006). Reactions were incubated in the dark at room temperature for 24 h, and absorbance was measured at 515 nm. Results were expressed as Trolox equivalents (Trolox equivalents µg/g of dry weight) using a Trolox (0-0.5 mg/mL) standard curve (y=235.89x˗6.2846, r²=0.9916).

Nitric oxide radical inhibition

Nitric oxide radical scavenging activity was measured using a previously described method (VINHOLES et al., 2017VINHOLES, J. et al. In vitro assessment of the antihyperglycemic and antioxidant properties of araçá, butiá and pitanga. Food Bioscience, v. 19, p. 92-100, 2017. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429217300019 > Accessed: Feb. 15, 2021. doi: 10.1016/j.fbio.2017.06.005.
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). Lyophilized “araçá” samples (62.5 mg) were stirred for 5 min in 10 mL of 50% ethanol (1:40, w/v). Samples were filtered (paper filter, Whatman no4) and stored at -20°C until analyzed. A 50 µL aliquot of each extract (6.25 mg/mL) or the 50% ethanol control were mixed with 50 µL of 20 mM sodium nitroprusside, and incubated for 60 min at room temperature under light. Fifty microliters of Griess reagent (0.1 % naphthylethylenediamine dihydrochloride and 1 % sulphanilamide in 2% phosphoric acid) was then added, and mixtures were incubated at room temperature in the dark for 10 min. Absorbance at 562 nm was measured, and results were expressed as percent inhibition (I%) using equation 1:

I%=Acontrol-AsampleAcontrol x 100 (1)

where Acontrol is absorbance of the control reaction (all reagents, except the extract), and Asample is absorbance of the dissolved “araca” extract.

Pancreatic lipase inhibition

Lipase inhibition was measured using the procedure described in the Lipase Activity Assay Kit (MAK046; Sigma-Aldrich). Lyophilized “araçá” samples (250 mg) were stirred for 5 min in 10 mL of ethanol (50 %) (1:40, w/v). Samples were filtered (paper filter, Whatman no4) and stored at -20°C until analyzed. Extract samples (2.5 mg/mL) were added separately to the lipase mixture. Absorbance was recorded in a microplate reader and compared with that of the lipase mixture without extract (control). Absorbance was measured at 570 nm at T1 to read A1 and at T2 after incubating the reaction at 37°C for 40 min. Change in A570 Between T1 and T2 (A2−A1) represents glycerol oxidation. Lipase activity was calculated using equation 2,

Lipase activitymUmL=B-dilution factorT2-T1x V (2)

in which B is the glycerol concentration in the standard curve (nmol), V is the pre-treated sample volume (mL) added to each reaction well, T1 is the time of the initial reading (A1) (min), and T2 is the time of the second reading (A2) (min). One unit is defined as the amount of lipase needed to hydrolyse triglycerides at a rate yielding 1.0 μmol of glycerol per min at 37°C. Orlistat (Xenical) at a final concentration of 0.24 mg/mL was used as a positive control for lipase inhibition, based on a value reported in the literature (CHATER et al., 2016CHATER, P. I. et al. Inhibitory activity of extracts of Hebridean brown seaweeds on lipase activity. Journal of Applied Phycology, v. 28, n. 2, p. 1303-1313, 2016. Available from: <Available from: https://link.springer.com/content/pdf/10.1007/s10811-015-0619-0.pdf >. Accessed: Aug. 06, 2020. doi: I 10.1007/s10811-015-0619-0.
https://link.springer.com/content/pdf/1...
). Percent inhibition of lipase extracts was calculated using equation 3:

% Inhibition of lipase =lipase activity of control-lipase activity of samplelipase activity of control x 100 (3)

Statistical analysis

Analyses were performed in triplicate (n=3) and results (means ± standard deviation) were calculated using Microsoft Excel. Results for total anthocyanin content, total phenolic content, antioxidant activity, nitric oxide radical inhibition, and lipase inhibition were submitted to analysis of variance. Means were compared between “araçá” genotypes and parts (pulp-peel vs. seeds) for each assay by Tukey test at a 0.05 confidence level using WinStat 2.11.

RESULTS AND DISCUSSION:

The increased prevalence of overweight people in the world’s population reinforces interest in identification of foods with high levels of bioactive compounds (INOUE et al., 2018INOUE, Y. et al. Epidemiology of obesity in adults: Latest trends. Current obesity reports, v. 7, n. 4, p. 276-288, 2018. Available from: <Available from: https://pubmed.ncbi.nlm.nih.gov/30155850/ >. Accessed: March. 11, 2020. doi: 10.1007 / s13679-018-0317-8.
https://pubmed.ncbi.nlm.nih.gov/30155850...
). Consumption of foods high in phenolic compounds has been associated with reduced risk for development of chronic diseases such as cancer, cardiovascular diseases, obesity, and atherosclerosis (SHAHIDI & AMBIGAIPALAN, 2015SHAHIDI, F.; AMBIGAIPALAN, P. Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects - A review. Journal of Functional Foods, v. 18, p. 820-897, 2015. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S1756464615003023 >. Accessed: Aug. 29, 2020. doi: 10.1016/j.jff.2015.06.018.
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).

All “araçá” samples afforded considerable amounts of phenolic compounds. Anthocyanins were detected only in the pulp-peel of red genotype “araçá”, with concentrations of 42.2 and 43.7 mg/100 g dried sample (Table 1). This was expected, because these compounds are responsible for the red color of AC 44 and AC 87 samples (VEBERIC et al., 2015VEBERIC, R. et al. Anthocyanin composition of different wild and cultivated berry species. LWT - Food Science and Technology, v. 60, n. 1, p. 509-517, 2015. Available from: <Available from: http://dx.doi.org/10.1016/j.lwt.2014.08.033 >. Accessed: Feb. 15, 2021. doi: 10.1016/j.lwt.2014.08.033.
http://dx.doi.org/10.1016/j.lwt.2014.08....
). Total phenolic content was similar among all genotypes. However, higher content was observed in pulp-peel fractions than in seeds among all genotypes. Values for this parameter varied from 1418.5 to 1533.4 mg/100g in seeds, and 1933.3 to 2088.5 mg/100g in pulp-peel (Table 1). These values are higher than those reported by Denardin et al. (2015DENARDIN, C. C. et al. Antioxidant capacity and bioactive compounds of four Brazilian native fruits. Journal of Food and Drug Analysis, v. 23, n. 3, p. 387-398, 2015. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S1021949815000344 >. Accessed: July. 25, 2020. doi: 10.1016/j.jfda.2015.01.006.
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) (660,19 mg/100g). By contrast, CHAVES et al. (2018CHAVES, V. C. et al. Berries grown in brazil: anthocyanins profiles and biological properties. Food Research International, v. 98, n. 11, p. 4331-4338, 2018. Available from: <Available from: https://pubmed.ncbi.nlm.nih.gov/29430645/ >. Accessed: July. 30, 2020. doi: 10.1002 / jsfa.8959.
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) reported higher concentrations of phenolic compounds in the red genotype (719,00 mg/100g) compared to the yellow genotype (382 mg/100g). Phenolic compounds including catechin and ellagic acid were found in high quantities in pulp-peel extracts of AC44, AC87, and Bicudo, while catechin, ellagic acid, and quercetin were the major compounds in seed extracts (PEREIRA et al., 2020PEREIRA, E. Dos S. et al. Characterization of araçá fruits (Psidium cattleianum Sabine): Phenolic composition, antioxidant activity and inhibition of α-amylase and α-glucosidase. Food Bioscience, p. 100665, 2020. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429219305231 >. Accessed: Feb. 11, 2021. doi: 10.1016/j.fbio.2020.100665.
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).

Table 1
Total anthocyanins content and total phenolic content, antioxidant activity and inhibition of pancreatic lipase of differents “araçá” genotypes [a].

All “araçá” samples showed scavenging capacity towards DPPH radical. However, for all samples, the pulp-peel extracts were more active than the seed extracts. The yellow genotype (Bicudo) and AC 87 showed the highest activity (Table 1). Values for antioxidant activity varied from 154.9 to 330.3 μg/g in seeds, and 1097.7 to 1277.0 μg/g in pulp-peel. The antioxidant activity assay using DPPH• stable radical is widely used to assess native fruits (MEDINA et al., 2011MEDINA, A. L. et al. Araçá (Psidium cattleianum Sabine) fruit extracts with antioxidant and antimicrobial activities and antiproliferative effect on human cancer cells. Food Chemistry, v. 128, n. 4, p. 916-922, 2011. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S030881461100536X >. Accessed: March. 22, 2020. doi: 10.1016/j.foodchem.2011.03.119.
https://www.sciencedirect.com/science/ar...
; VINHOLES et al., 2017VINHOLES, J. et al. In vitro assessment of the antihyperglycemic and antioxidant properties of araçá, butiá and pitanga. Food Bioscience, v. 19, p. 92-100, 2017. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429217300019 > Accessed: Feb. 15, 2021. doi: 10.1016/j.fbio.2017.06.005.
https://www.sciencedirect.com/science/ar...
). “Araçá” showed higher antioxidant activity than “uvaia” or “guabiroba”, with a value of 389.7 µg/g, similar to results observed for seeds in the present study (PEREIRA et al., 2012PEREIRA, M. C. et al. Characterization and antioxidant potential of Brazilian fruits from the Myrtaceae family. Journal of Agricultural and Food Chemistry, v. 60, n. 12, p. 3061-3067, 2012. Available from: <Available from: https://pubs.acs.org/doi/10.1021/jf205263f >. Accessed: Jan. 05, 2021. doi: 10.1021 / jf205263f.
https://pubs.acs.org/doi/10.1021/jf20526...
).

The antioxidant activity in the pulp-peel of “camu-camu” and “araçá-boi” fruits, both from the Myrtaceae family, yielded values of 34.79 µg trolox/g and 6048.26 µg trolox/g dried fruit (NEVES et al., 2015NEVES, L. C. et al. Post-harvest nutraceutical behaviour during ripening and senescence of 8 highly perishable fruit species from the Northern Brazilian Amazon region. Food Chemistry, v. 174, p. 188-196, 2015. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814614016756?via%3Dihub >. Accessed: Aug. 28, 2020. doi: 10.1016/j.foodchem.2014.10.111.
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). The peels of both samples showed higher antioxidant activities than their pulps. In one other study of fruits from the Myrtaceae family, antioxidant activity values were between 3455.85 µg trolox/g and 16997.37 µg trolox/g of fruit (BARROS et al., 2017BARROS, R. G. C. et al. Evaluation of bioactive compounds potential and antioxidant activity in some Brazilian exotic fruit residues. Food Research International, v. 102, p. 84-92, 2017. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0963996917306671 >. Accessed: Oct. 12, 2020. doi: 10.1016/j.foodres.2017.09.082.
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).

Nitric oxide radical (NO•) inhibition was also higher in pulp-peel extracts, but did not differ significantly among genotypes, with inhibition ranging from 72.1% to 73.0%. Inhibition by seed extracts varied from 18.3% to 50.0%, with the yellow genotype (Bicudo) being the most active (Table 1). The NO• radical is a signaling molecule produced in the body that is responsible for different physiological and pathological processes. In pathological conditions, this radical is produced in excess, causing damage such as DNA fragmentation, cell damage, and neuronal cell death. In addition, NO• is neurotoxic, mediating pathological processes such as cerebral ischemia, epilepsy, Alzheimer’s disease, and Parkinson’s disease. Thus, its inhibition is of great importance (RADÜNZ et al., 2020RADÜNZ, M. et al. Antimicrobial potential of spray drying encapsulated thyme (Thymus vulgaris) essential oil on the conservation of hamburger-like meat products. International Journal of Food Microbiology, v. 330, p. 108696, 2020. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0168160520301902 >. Accessed: Jan. 20, 2021. doi: 10.1016/j.ijfoodmicro.2020.108696.
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).

Nitric oxide radical inhibition apparently correlates with levels of bioactive compounds present in “araçá” fruit (VINHOLES et al., 2017VINHOLES, J. et al. In vitro assessment of the antihyperglycemic and antioxidant properties of araçá, butiá and pitanga. Food Bioscience, v. 19, p. 92-100, 2017. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429217300019 > Accessed: Feb. 15, 2021. doi: 10.1016/j.fbio.2017.06.005.
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; VINHOLES et al., (2018)VINHOLES, J. et al. Effect of in vitro digestion on the functional properties of Psidium cattleianum Sabine (araçá), Butia odorata (Barb. Rodr.), Noblick (butiá) and Eugenia uniflora L. (pitanga) fruit extracts. Food and Function, v. 9, n. 12, p. 6380-6390, 2018. Available from: <Available from: https://pubs.rsc.org/en/content/articlelanding/2018/fo/c8fo01329b#!divAbstract >. Accessed: Feb. 15, 2021. doi: 10.1039/c8fo01329b.
https://pubs.rsc.org/en/content/articlel...
. It has been reported that even after gastrointestinal digestion, one-third of the phenolic compounds present in “araçá” extracts remains, suggesting strong prospects for maintaining its antioxidant activity.

The phenolic compounds ellagic acid, gallic acid, epicatechin, catechin, and quercetin, reported as “araçá” constituents (MEDINA et al., 2011MEDINA, A. L. et al. Araçá (Psidium cattleianum Sabine) fruit extracts with antioxidant and antimicrobial activities and antiproliferative effect on human cancer cells. Food Chemistry, v. 128, n. 4, p. 916-922, 2011. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S030881461100536X >. Accessed: March. 22, 2020. doi: 10.1016/j.foodchem.2011.03.119.
https://www.sciencedirect.com/science/ar...
; PEREIRA et al., 2020PEREIRA, E. Dos S. et al. Characterization of araçá fruits (Psidium cattleianum Sabine): Phenolic composition, antioxidant activity and inhibition of α-amylase and α-glucosidase. Food Bioscience, p. 100665, 2020. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429219305231 >. Accessed: Feb. 11, 2021. doi: 10.1016/j.fbio.2020.100665.
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), are capable of maintaining endogenous anti-inflammatory, anticarcinogenic, antimicrobial, and antioxidant defense systems.

All “araçá” samples were able to inhibit pancreatic lipase, with greater potency in pulp-peel extracts than in seed extracts (except in AC 87), with percent inhibition above 54% (Table 1). Moreover, all samples, except for Bicudo seed extract, showed inhibitory values significantly higher than that of the positive control orlistat (31.2 ± 3.3 %). AC 44, with high enzymatic inhibition, has cyanidin-3-O-glucoside and catechin as major constituents (PEREIRA et al., 2020PEREIRA, E. Dos S. et al. Characterization of araçá fruits (Psidium cattleianum Sabine): Phenolic composition, antioxidant activity and inhibition of α-amylase and α-glucosidase. Food Bioscience, p. 100665, 2020. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429219305231 >. Accessed: Feb. 11, 2021. doi: 10.1016/j.fbio.2020.100665.
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). Bicudo and AC 87 contain high catechin concentrations (PEREIRA et al., 2020).

Myrtaceae fruits showed promising lipase inhibition results (BATUBARA et al., 2009BATUBARA, I.; et al. Screening antiacne potency of Indonesian medicinal plants: Antibacterial, lipase inhibition, and antioxidant activities. Journal of Wood Science, v. 55, n. 3, p. 230-235, 2009. Available from: <Available from: https://jwoodscience.springeropen.com/articles/10.1007/s10086-008-1021-1 >. Accessed: Aug. 21, 2020. doi: 10.1007/s10086-008-1021-1.
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) and some phenolic compounds present in “araçá” are relevant to inhibition of specific enzymes such as the glutathione oxidases (VALKO et al., 2007VALKO, M. et al. Free radicals and antioxidants in normal physiological functions and human disease. International Journal of Biochemistry and Cell Biology, v. 39, n. 1, p. 44-84, 2007. Available from: <Available from: https://pubmed.ncbi.nlm.nih.gov/16978905/ >. Accessed: March. 12, 2021. doi: 10.1016 / j.biocel.2006.07.001.
https://pubmed.ncbi.nlm.nih.gov/16978905...
), and α-glucosidase (VINHOLES, J. et al., 2017VINHOLES, J. et al. In vitro assessment of the antihyperglycemic and antioxidant properties of araçá, butiá and pitanga. Food Bioscience, v. 19, p. 92-100, 2017. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S2212429217300019 > Accessed: Feb. 15, 2021. doi: 10.1016/j.fbio.2017.06.005.
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).

To our knowledge, this is the first report of “araçá” (Psidium cattleianum) ability to inhibit this enzyme. Polyphenols are the main class of pancreatic lipase inhibitors (BUCHHOLZ & MELZIG, 2015BUCHHOLZ, T.; MELZIG, M. F. Polyphenolic compounds as pancreatic lipase inhibitors. Planta Medica, v. 81, n. 10, p. 771-783, 2015. Available from: <Available from: https://pubmed.ncbi.nlm.nih.gov/26132857/ >. Accessed: Aug. 22, 2020. doi: 10.1055 / s-0035-1546173.
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) due to chemical characteristics that facilitate bond formation between these compounds and the enzyme (BUCHHOLZ & MELZIG, 2015). Compounds such as myricetin, kaempferol glucosides, catechin/epicatechin, and procyanidins are associated with pancreatic lipase inhibition (BUCHHOLZ & MELZIG, 2015; CAMARGO et al., 2017CAMARGO, A. C. DE; et al. Phenolic profile of peanut by-products: Antioxidant potential and inhibition of alpha-glucosidase and lipase activities. Journal of the American Oil Chemists’ Society, v. 94, n. 7, p. 959-971, 2017. Available from: <Available from: https://link.springer.com/article/10.1007/s11746-017-2996-9 >. Accessed: Aug. 15, 2020. doi: 10.1007/s11746-017-2996-9.
https://link.springer.com/article/10.100...
; GENDARAM et al., 2017GENDARAM, O. et al. Pancreatic lipase inhibitory and antioxidative constituents from the aerial parts of Paeonia lactiflora Pall. (Ranunculaceae). Phytochemistry Letters, v. 21, n. July, p. 240-246, 2017. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S1874390016303378 >. Accessed: March 22, 2020. doi: 10.1016/j.phytol.2017.07.009.
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; YOSHIKAWA et al., 2009YOSHIKAWA, M. et al. Acylated oleanane-type triterpene saponins with acceleration of gastrointestinal transit and inhibitory effect on pancreatic lipase from flower buds of Chinese tea plant (Camellia sinensis). Chemistry and Biodiversity, v. 6, n. 6, p. 903-915, 2009. Available from: <Available from: https://onlinelibrary.wiley.com/doi/abs/10.1002/cbdv.200800153 >. Accessed: Feb. 12, 2021. doi: 10.1002/cbdv.200800153.
https://onlinelibrary.wiley.com/doi/abs/...
; ZHANG, B. et al., 2015ZHANG, B. et al. Phenolic profiles of 20 Canadian lentil cultivars and their contribution to antioxidant activity and inhibitory effects on α-glucosidase and pancreatic lipase. Food Chemistry, v. 172, p. 862-872, 2015. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814614015301 >. Accessed: Jan. 05, 2021. <doi: https://doi.org/10.1016/j.foodchem.2014.09.144>.
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). The antihyperlipidemic action of catechin is due to its inhibition of key enzymes involved in lipid biosynthesis, and its ability to reduce intestinal absorption of lipids (ANANDH BABU; LIU, 2008ANANDH BABU, P.; LIU, D. Green tea catechins and cardiovascular health: An update. Current Medicinal Chemistry, v. 15, n. 18, p. 1840-1850, 2008. Available from: <Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2748751/ >. Accessed: Aug. 02, 2020. doi: 10.2174 / 092986708785132979.
https://www.ncbi.nlm.nih.gov/pmc/article...
). Other studies have reported ellagic acid, quercetin (MARTINEZ-GONZALEZ et al., 2017MARTINEZ-GONZALEZ, A. I. et al. In vitro inhibition of pancreatic lipase by polyphenols: A kinetic, Fluorescence spectroscopy and molecular docking study. Food Technology and Biotechnology, v. 55, n. 4, p. 519-530, 2017. Available from: <Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5848196/ >. Accessed: Aug. 29, 2020. doi: 10.17113 / ftb.55.04.17.5138.
https://www.ncbi.nlm.nih.gov/pmc/article...
), and anthocyanins to be lipase inhibitors (YOU et al., 2011YOU, Q. et al. Inhibitory effects of muscadine anthocyanins on α-glucosidase and pancreatic lipase activities. Journal of Agricultural and Food Chemistry, v. 59, n. 17, p. 9506-9511, 2011. Available from: <Available from: https://pubs.acs.org/doi/10.1021/jf201452v >. Accessed: March. 22, 2021. doi: <https://doi.org/10.1021/jf201452v>.
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). Different biological properties such as thermogenic activity, fat oxidation ability, appetite control, obesity-related hormone level regulation, and inhibition of digestive enzymes involved in the absorption of carbohydrates and lipids are ascribed to the phenolic compounds chlorogenic acid, the catechins, and quercetin, present in “araçá” (SIMÃO et al., 2017SIMÃO, A. A. et al. Aqueous extract of Psidium guajava leaves: Phenolic compounds and inhibitory potential on digestive enzymes. Anais da Academia Brasileira de Ciencias, v. 89, n. 3, p. 2155-2165, 2017. Available from: <Available from: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000502155 >. Accessed: Feb. 26, 2020. doi: 10.1590/0001-3765201720160067.
https://www.scielo.br/scielo.php?script=...
).

Correlation analysis showed that the antioxidant activity, nitric oxide radical inhibition, and lipase inhibition positively correlated with total phenolic content (Table 2). Different pharmacological properties have been ascribed to “araçá” that are associated with its chemical composition. In fact, the Psidium genus has been described as having antioxidant, antidiabetic, anticancer, antimicrobial, anti-inflammatory, and anti-aging activities, among others (PEREIRA et al., 2018PEREIRA, E. Dos S. et al. Psidium cattleianum fruits: A review on its composition and bioactivity. Food Chemistry, v. 258, p. 95-103, 2018. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0308814618304394 >. Accessed: March. 05, 2021. doi: 10.1016/j.foodchem.2018.03.024.
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). These properties showed this fruit’s potential applications in the food and pharmaceutical industries.

Table 2
Correlation between the total phenolic content (TPC), antioxidant activity (DPPH), nitric oxide radical inhibition and pancreatic lipase inhibition of “araçá” genotypes.

Since few drug options exist for treating obesity, and orlistat has side effects, research into, and development of natural products with pancreatic lipase inhibition are an inspiring avenue of research in pursuit of new therapies. Natural products containing phenolic compounds have already shown efficient inhibition of pancreatic lipase. More detailed studies are still needed. This research may provide some guidance in the development of other studies, given the promise of pancreatic lipase inhibitors for treatment of obesity and related disorders.

CONCLUSION:

The present study described bioactive compounds (total anthocyanins and total phenolic content), antioxidant activity, nitric oxide radical neutralization, and pancreatic lipase inhibition of three “araçá” samples. Anthocyanins were present only in red “araçá” genotypes. Total phenolic content was similar among genotypes, but was tissue type dependent within the fruit. Pulp-peel extracts showed higher phenolic content and antioxidant and antiradical activities. This study provided, to our knowledge, the first assessment of pancreatic lipase inhibition by this species. All extracts inhibited lipase more efficiently than orlistat. Thus, “araçá” may provide considerable amounts of phenolic compounds with antioxidant activity and lipase inhibitory properties. Research is being conducted to develop a functional food containing “araçá” extracts, which preserves its biological properties, to aid in controlling and combating obesity.

ACKNOWLEDGEMENTS

The authors would like to acknowledge Fundação Coordenação Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for providing the financial support for the completion of the present work.

REFERENCES

  • CR-2020-0778.R2

Publication Dates

  • Publication in this collection
    21 July 2021
  • Date of issue
    2021

History

  • Received
    20 Aug 2020
  • Accepted
    18 Feb 2021
  • Reviewed
    19 Apr 2021
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