Abstracts
Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis, applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg-1). There was a differential absorption of Pb and Cd by M. arvensis mainly concentrated in the roots. Pb was found in small amounts in the leaves while Cd largely exceeded the safety limit without symptoms of toxicity. The ultrastructural analysis revealed the metal accumulation on vesicles surrounding the mitochondria and the presence of electron dense deposits surrounding the mitochondria, nucleus and chloroplasts. Little changes caused by Pb and Cd application were not enough to affect the growth and essential oil yield and composition of M. arvensis
contamination; heavy metals; medicinal plant; menthol
A contaminação de plantas medicinais com Pb e Cd pode afetar o crescimento e a produção de óleo essencial das plantas e representa um risco para quem as consome como medicamento. Este estudo teve como objetivo avaliar os efeitos da absorção e localização de Pb e Cd sobre o crescimento das plantas, aspectos ultraestruturais de folhas e sobre o rendimento e composição química do óleo essencial de M. arvensis, os quais foram aplicados ao solo em concentrações crescentes (8, 16, 32, 64 and 128mg kg-1). Houve absorção diferencial de Pb e Cd por M. arvensis, que se concentraram principalmente nas raízes. O Pb foi encontrado em baixas concentrações nas folhas, enquanto o Cd excedeu largamente o limite de segurança sem demonstrar sintomas de toxicidade. As análises ultraestruturais revelaram o acúmulo de metais em vesículas ao redor de mitocôndrias e a presença de depósitos eletrodensos ao redor de mitocôndrias, núcleo e cloroplastos. As pequenas mudanças causadas pela aplicação de Pb e Cd não foram suficientes para afetar o crescimento das plantas e o rendimento e composição química do óleo essencial de M. arvensis
contaminação; metais pesados; planta medicinal; mentol
INTRODUCTION:
Contamination of soils by heavy metals is the most serious environmental problem and has
significant implications for human health. Medicinal herbs may be easily contaminated
during cultivation and harvesting. After drying and processing the heavy metals confined
in plants enter in the human body and may disturb the normal functions of central
nervous system, liver, lungs, heart, kidney and brain, leading to hypertension,
abdominal pain, skin eruptions, intestinal ulcer and different types of cancers (JÄRUP, 2003JÄRUP, L. Hazards of heavy metal contamination. British Medical
Bulletin, v. 68, p. 167-182, 2003. Available from:
<http://bmb.oxfordjournals.org/content/68/1/167.full.pdf+html>. Accessed May
04, 2013. doi: 10.1093/bmb/ldg032.
http://bmb.oxfordjournals.org/content/68...
).
Herbal plants are dried parts of plants widely used as raw materials for pharmaceutical preparations and for "self-medication" especially of the poorest population. WHO (1998)WHO. Quality control methods for medicinal plant materials. Geneva, Switzerland, 1998. p 62-63. recommends that medicinal plants which form the raw materials for the finished products may be checked for the presence of heavy metals, further regulating the maximum permissible limits of toxic metals like cadmium and lead, which amount to 0.3 and 10ppm, respectively (WHO, 1998WHO. Quality control methods for medicinal plant materials. Geneva, Switzerland, 1998. p 62-63.).
Pb is considered an important environmental pollutant, widely found in batteries,
paints, glasses, pipes and chemical fertilizers, mainly the phosphatic fertilizers
(CASAS & SORDO, 2006CASAS, J.S.; SORDO, J. (eds.) Lead: chemistry, analytical aspects,
environmental impact and health effects. The Netherlands: Elsevier, 2006.
354p.). Soils contaminated
with this metal can cause severe reductions in crop productivity (SHARMA & DUBEY, 2005SHARMA, P.; DUBEY, R.S. Lead toxicity in plants. Brazilian Journal of
Plant Physiology, v.17, p.35-52, 2005. doi:
10.1590/S1677-04202005000100004.
https://doi.org/10.1590/S1677-0420200500...
), affecting the essential oils production
and composition (ZHELJAZKOV et al., 2006ZHELJAZKOV, V.D. et al. Effects of Cd, Pb, and Cu on growth and
essential oil contents in dill, peppermint, and basil. Environmental and Experimental
Botany, v.58, p.9-16, 2006.doi:10.1016/j.envexpbot.2005.06.008.
https://doi.org/10.1016/j.envexpbot.2005...
),
besides promotes ultrastructural changes as chloroplast dilatation and membranes rupture
(HU et al., 2007HU, J.Z. et al. Effects of Pb2+ on the active oxygen-scavenging enzyme
activities and ultrastructure in Potamogeton crispus leaves. Russian Journal of Plant
Physiology, v.54, p.414-419, 2007. doi: 10.1134/S1021443707030181.
https://doi.org/10.1134/S102144370703018...
). Cd is considered a heavy
metal found naturally in the soil by mineralization processes of some rocks, but it is
widely released into the environment through waste incineration, urban traffic,
phosphate fertilizers contamination, among others things. High concentrations of this
metal can interfere with plant growth as well as morphological and ultrastructural
aspects of its organs (TUNG & TEMPLE, 1996TUNG, G.; TEMPLE, P.J. Uptake and localization of lead in corn (Zea mays
L.) seedlings, a study by histochemical and eletron microscopy. Science of the Total
Environmental, v.188, p.71-85, 1996. doi:
10.1016/0048-9697(96)05156-X.
https://doi.org/10.1016/0048-9697(96)051...
).
Medicinal plants exposed to heavy metals can differ in production of secondary
metabolites, either suppressing or stimulating production (NASIM & DHIR, 2010NASIM, S.A.; DHIR, B. Heavy metal alter the potency of medicinal plants.
Reviews of Environmental Contamination and Toxicology, v.203, p.139-149, 2010. doi:
10.1007/978-1-4419-1352-4_5.
https://doi.org/10.1007/978-1-4419-1352-...
).
In Brazil, Mentha spp. grown in gardens, ensure its popular use as a medicinal alternative for antiemetic, nasal decongestant and flu purposes. The commercial cultivation of Mentha arvensis L. was enhanced in Brazil mainly for menthol exportation, its majoritary oil compound, which is demanded by pharmaceutical, food, cosmetics and perfumery industries.
Despite the large amount of investigations on heavy metal contents in medicinal plants
(ABOU-ARAB et al., 1999ABOU-ARAB, A.A.K. et al. Quantify estimation of some contaminants in
commonly used medicinal plants in the Egyptian market. Food Chemistry, v.67,
p.357-363, 1999. doi: 10.1016/S0308-8146(99)00082-5.
https://doi.org/10.1016/S0308-8146(99)00...
; ABOU-ARAB & ABOU
DONIA, 2000; CALDAS & MACHADO, 2004CALDAS, E.D; MACHADO, L.L Cadmium, mercury and lead in medicinal herbs
in Brazil. Food and Chemical Toxicology, v.42, p.599-603, 2004. doi:
10.1016/j.fct.2003.11.004.
https://doi.org/10.1016/j.fct.2003.11.00...
), there is
little information regarding the effects on the secondary metabolite production and
ultrastructural aspects. This study aimed to evaluate the effects of absorption and
localization of Pb and Cd, applied with increasing concentrations in soil, on the
growth, ultrastructural aspects of leaves and the essential oil production and quality
of Mentha arvensis.
MATERIAL AND METHODS:
M. arvensis L. propagated by stem cuttings was grown in plastic pots with 5kg of soil homogenized and physico-chemically analyzed before the application of treatments registering the following values: pH 5.3, Al 1.3mmol dm-3, Ca 107mmol dm-3, Mg 45mmol dm-3, K 6mmol dm-3, P 169 mg dm-3, S-SO4-2 10mg dm-3, Fe 283mg dm-3, Mg 21.1mg dm-3, organic matter 86g dm-3, Pb 14mg kg-1, Cd 0.2mg kg-1, thick sand 392g kg-1, fine sand 212g kg-1, silt 259g kg-1, total clay 137g kg-1, natural clay 33g kg-1.
The experiment was conducted in a completely randomized design with eleven treatments (two metals and five concentrations + control) with five repetitions. The data were submitted to analysis of variance (ANOVA) and regression analyses. The models were selected based on significance (P≤0.05) of F-test.
The seedlings were grown under greenhouse conditions with the metals Pb (NO3)2 and CdCl2.5/2H2O applied separately, at concentrations of 0, 8, 16, 32, 64 and 128mg kg-1 of soil, thirty days after planting. Forty days after the treatments application, the plants were harvested for chemical composition, growth, leaf ultrastructure and essential oil production analyses.
A nitric acid digestion of dried leaves and roots was performed in triplicate, for Pb and Cd determination by optical emission spectrometry with inductively coupled plasma ICP-OES - Varian 710 (Varian, Australia).
The growth variables analyzed were: plant height (PH), stem diameter (SD), leaf area (LA) and number of leaves (NL). The leaf (LDB), stem (SDB), root (RDB) and total dry biomass (TDB) were evaluated and the specific leaf area (SLA = LDB/LA) and leaf area ratio (LAR = LA/TDB) were calculated according to HUNT (1990HUNT, R. Basic Growth Analysis: Plant Growth Analysis for Beginners. Boston and London: Unwin Hyman, 1990. 112p.).
For ultrastructural analysis, the median region of fully expanded leaves were collected from the third node, with four repetitions of each treatment, fixed in glutaraldehyde, post fixed with osmium tetroxide, dehydrated in ethanolic series and embedding in LR White resin. Samples were analyzed from the control treatment and the highest concentration of Pb and Cd (128mg kg-1). Semifine and ultrathin cuts obtained in a UC6 Leica ultramicrotome were observed in a Morgagni 268D Transmission Electron Microscope (FEI Company, Soft Imaging System, Germany), operating at 80kV acceleration voltage.
The essential oil content (100g g-1 dry biomass) and yield (g
plant-1), were obtained by hidrodestilation of dried leaves in a Clevenger
Apparatus in quadruplicate, for an hour. The quantitative oil analysis was performed in
a Varian 3800 Saturn gas chromatograph (Varian, Walnut Creek, CA, USA), equipped with
VF5-ms capillary column (30m x 0.25mm x 0.25μm) and flame ionization detector. The
temperature started at 70°C, then programmed to reach 200°C at 8°C min-1 and
up to 260°C at 10°C min-1, being maintained at this temperature for 5min.
Helium was used as carrier gas with a constant flow of 1.2mL min-1. The
injection volume was 1µL of 10% oil solution in CHCl3, in reason of
split 1:10. Qualitative analysis was carried out in mass
spectrometer Varian Chromopack 2000 (Varian, Walnut Creek, CA, USA) with the same
programming and above-mentioned capillary column. The oil components were identified by
comparing their mass spectrum in the literature (ADAMS,
2007ADAMS, R.P. Identification of essential oils components by gas
chromatography mass spectroscopy. Carol Stream, Illinois: Allured Publishing
Corporation, 2007. 804p.) with the spectra database (NIST105) and, also, by comparing retention
indices with those of literature. Kovats retention indices (KI) were determined using a
homologous series of n-alkanes (C8-C26) injected under the same
chromatographic conditions of samples, using the equation of VAN DEN DOOL & KRATZ (1963VAN DEN DOOL, H.; KRATZ, P.D. A generalization of the retention index
system including linear temperature programmed gas-liquid partition chromatography.
Journal of Chromatography, v.11, p.463-471, 1963. doi:
10.1016/S0021-9673(01)80947-X.
https://doi.org/10.1016/S0021-9673(01)80...
).
RESULTS:
During the experimental period, the plants showed vigorous and uniform growth, without visible symptoms of phytotoxicity. No significant effects were observed (P<0.05) on the growth of M. arvensis with Pb and Cd application to the soil (Table 1).
The Pb content was not detectable in leaves until the maximum dose of 128mg kg-1, when it was possible to quantify an average of 2mg kg-1 Pb in leaf dry biomass. On the other hand, a significant dose dependent response (P<0.05) was verified on M. arvensis roots, reaching a maximum absorption of 50 mg kg-1 Pb at 128mg kg-1 concentration (Figure 1A).
: Content variation of Pb (A) and Cd (B) in leaves ( - ) and roots ( ... ) of M. arvensis in relation to the applied doses of Pb and Cd to the soil.
The Cd content in leaves and roots of M. arvensis was significantly (P<0.05) influenced by the increasing concentration of metal applied to soil, with lower concentrations in leaves than in roots. The largest Cd absorption occurred at 128mg kg-1 soil concentration, with maximum absorption of 12 mg kg-1 on leaf and 78mg kg-1 on root dry biomass (Figure 1B).
The palisade parenchyma cells of control plants exhibited nucleus (nuclear membrane, nucleoli) and organelles with normal aspect (Figure 2A). Chloroplasts containing clear and well-structured grana were observed in these cells, located next to the mitochondria walls and surroundings with intact contours and no evidence of changes (Figure 2D). The presence of starch grains (Figure 2F, G, H) and plastoglobules was also verified in some chloroplasts (Figure 2D, E, F, G, H). On the other hand, in the same cells of plants grown with 128mg kg-1 Pb, some changes were observed as invagination of the nucleus (Figure 2B) and cell wall (Figure 2E), disruption of the chloroplast membranes (Figure 2E), in addition to the presence electron dense deposits surrounding the mitochondria (Figure 2H). In plants treated with 128mg kg-1 Cd electron dense deposits were also observed around the nucleus (Figure 2C), chloroplasts (Figure 2F), and vesicles with electron dense contents on mitochondrias (Figure 2I).
: Transmission of electron photomicrographs of palisade parenchyma cells of the mesophyll of M. arvensis without application of Pb and Cd to the soil (A. D. G) and with application of 128 mg kg-1 Pb (B. E. H) and 128 mg kg-1 Cd (C. F. I), showing the ultrastructural changes as chloroplast membrane disruption, invagination of cell wall and nucleus membrane, eletrodenses deposits and vesicles with electrodenses deposit around organelles related to the application of toxic metals. NU: nucleus; CH: chloroplast; SG: starch grain; MT: mitochondria; black thick arrow: invagination of the nucleus membrane and cell wall; white thick arrow: electron dense deposits surrounding chloroplasts and nucleus; asterisk(*): disruption of chloroplasts membranes; white arrowhead: plastoglobules; black arrowhead: vesicles with eletrodense contents surrounding mitochondria.
No significant effects of Pb and Cd application in the soil (P<0.05) were observed on the essential oil content (4.26%) and yield (0.36g planta-1) of M. arvensis. The chemical composition of the essential oil was not expressive, with only minor variations without any clear trend. The chromatographic analysis of the essential oils enabled the identification of nine volatile components, amounting to about 99% of the chemical composition, which were divided into aliphatic hydrocarbons (3-octanol), monoterpenes (limonene), oxygenated monoterpenes (neo-isopulegol, isomenthone, menthone, menthol, pulegone and carvotanacetone) and sesquiterpenes (E-caryophyllene) (Table 2). Menthol was the major component of the essential oil of plants in all treatments, responsible for more than 86% of the chemical composition of the essential oil of M. arvensis. Compared to the control treatment, the concentration varied not more than 2% with the application of toxic metals in the soil.
DISCUSSION:
The heavy metal concentrations in the soil before application of treatments (14mg kg-1 Pb, 0.2 mg kg-1 Cd) is in a normal range, since the worldwide average of soil surface, is 15mg kg-1 Pb and 0.53mg kg-1 Cd (KABATA-PENDIAS & PENDIAS, 2000KABATA-PENDIAS, A.; PENDIAS, H. Trace elements in soils and plants. Boca Raton: CRC, 2000. 331p.). The presence of these heavy metals in the soil may result of irrigation with contaminated water, improper exploitation of natural resources and the application of large amounts of phosphate fertilizers and pesticides (CASAS & SORDO, 2006CASAS, J.S.; SORDO, J. (eds.) Lead: chemistry, analytical aspects, environmental impact and health effects. The Netherlands: Elsevier, 2006. 354p.).
The higher accumulation of Pb in the roots (50mg kg-1) of M. arvensis
in relation to its leaves (2mg kg-1) is sustained by the low mobility
of this metal in plants, resulted in less accumulation in shoot organs (KABATA-PENDIAS & PENDIAS, 2000KABATA-PENDIAS, A.; PENDIAS, H. Trace elements in soils and plants. Boca
Raton: CRC, 2000. 331p.). However, the
limited quantity of this metal that penetrates in the root through the cell wall of
epidermal cells is retained in the cortex cells, being endodermis the main barrier for
limiting Pb translocation to aerial parts (TUNG &
TEMPLE, 1996TUNG, G.; TEMPLE, P.J. Uptake and localization of lead in corn (Zea mays
L.) seedlings, a study by histochemical and eletron microscopy. Science of the Total
Environmental, v.188, p.71-85, 1996. doi:
10.1016/0048-9697(96)05156-X.
https://doi.org/10.1016/0048-9697(96)051...
). This Pb retention in the root system can act as a protective
mechanism against contamination of the plant shoot (KASTORI et al., 2012KASTORI, R.R. et al. Effect of lead contamination of maize seed on its
biological properties. Zbornik Matice Srpske za Prirodne Nauke, n.123, p.75-82, 2012.
doi: 10.2298/ZMSPN1223075K.
https://doi.org/10.2298/ZMSPN1223075K...
), as was checked for M. arvensis. This low
translocation of Pb to M. arvensis leaves is a positive factor, since,
normally this is the main commercial part used for essential oil extraction.
Furthermore, the amount of Pb in leaves of M. arvensis did not exceed the
limit of 10mg kg-1 specified by the WHO (1998).
Similarly, the Cd also showed much higher concentrations in roots (78mg kg-1)
than in the leaves (12mg kg-1) of M. arvensis, possibly due the
restriction of Cd transport by xylem, which may occur by increased lignin deposition on
these cells (LUX et al., 2011LUX, A. et al. Root responses to cadmium in the rhizosphere: a review.
Journal of Experimental Botany, v.62, p.21-37, 2011. doi:
10.1093/jxb/erq281.
https://doi.org/10.1093/jxb/erq281...
). Premature
lignification of vessel element adds layers of impermeable cells that reduce transport
of both water and metal (LUX et al., 2011LUX, A. et al. Root responses to cadmium in the rhizosphere: a review.
Journal of Experimental Botany, v.62, p.21-37, 2011. doi:
10.1093/jxb/erq281.
https://doi.org/10.1093/jxb/erq281...
).
However, the high Cd concentration in M. arvensis leaves, forbid its
popular use as decoction or infusion, once the plant processing in hot water can extract
the metals for the tea (ABOU-ARAB & ABOU DONIA,
2000ABOU-ARAB, A.A.K. et al. Quantify estimation of some contaminants in
commonly used medicinal plants in the Egyptian market. Food Chemistry, v.67,
p.357-363, 1999. doi: 10.1016/S0308-8146(99)00082-5.
https://doi.org/10.1016/S0308-8146(99)00...
). The Cd concentration found in M. arvensis leaves exceeded
about 40 times the limit of 0.3mg kg-1 established by WHO (1998). This
emphasizes the danger of metal accumulation in M. arvensis without
phytotoxicity symptoms, representing a potential risk for humans and animals (OLIVER, 1997OLIVER, M.A. Soil and human health: a review. European Journal of Soil
Science, v.48, p.573-592, 1997. doi:
10.1111/j.1365-2389.1997.tb00558.x.
https://doi.org/10.1111/j.1365-2389.1997...
).
Although some species (Vetiveria zizanioides, Prosopis juliflora and
Desmanthus virgatus) register reductions on growth and biomass
production in the presence of heavy metals as Pb (ALVES
et al., 2008ALVES, J.C. et al. Absorção e distribuição de chumbo em plantas de
vetiver, jureminha e algarroba. Revista Brasileira de Ciência do Solo, v.32,
p.1329-1336, 2008. doi: 10.1590/S0100-06832008000300040.
https://doi.org/10.1590/S0100-0683200800...
), a possible explanation for the lack of phytotoxicity symptoms
and yield of M. arvensis by Pb and Cd application, would be due to the
greater retention of metals in the roots, which act as a barrier to the transport of
large quantities of metal to the shoot, thus avoiding the toxic effect of such heavy
metals.
Wall invaginations in mesophyll cells of M. arvensis treated with Pb may be
related to an increased strategy surface area as adaptive to provide physiological
benefits to increase the ions transport of water under stress conditions (KURKOVA, 2002KURKOVA, E.B. et al. Responses of Seidlitzia rosmarinus to salt stress.
Biological Bulletin, v.29, p.221-228, 2002. doi:
10.1023/A:1015478329530.
https://doi.org/10.1023/A:1015478329530...
), since Pb is also related to changes
in the water balance of plants (SHARMA & DUBEY,
2005SHARMA, P.; DUBEY, R.S. Lead toxicity in plants. Brazilian Journal of
Plant Physiology, v.17, p.35-52, 2005. doi:
10.1590/S1677-04202005000100004.
https://doi.org/10.1590/S1677-0420200500...
). It can be also associated with a microtubules disruption which may
alter the shape and the synthesis of cell wall caused by the action of Pb (LIU et al., 2009LIU, D. et al. Pb/Cu effects on the organization of microtubule
cytoskeleton in interphase and mitotic cells of Allium sativum L. Plant Cell Reports,
v.28, p.695-702, 2009. doi: 10.1007/s00299-009-0669-3.
https://doi.org/.1007/s00299-009-0669-3...
). Chloroplast changes observed in
cells of M. arvensis treated with Pb were already described in
Potamogeton crispus treated with Pb, resulting in dilation of
chloroplasts and disruption of their membranes (HU et
al., 2007HU, J.Z. et al. Effects of Pb2+ on the active oxygen-scavenging enzyme
activities and ultrastructure in Potamogeton crispus leaves. Russian Journal of Plant
Physiology, v.54, p.414-419, 2007. doi: 10.1134/S1021443707030181.
https://doi.org/10.1134/S102144370703018...
), possibly by reducing the concentration of membrane lipids caused
by contamination with Pb as noted in the chloroplasts of Lycopersicon esculentum
leaves (DJEBALI et al., 2005DJEBALI, W. et al. Ultrastructure and lipid alterations induced by
cadmium in tomato (Lycopersicon esculentum) chloroplast membranes. Plant Biology,
v.7, p.358-368, 2005. doi: 10.1055/s-2005-837696.
https://doi.org/10.1055/s-2005-837696...
).
It is believed that both granules and vesicles with eletrodense contents around the
organelles are related to the movement limitation of heavy metals in the cells. Granules
with electron dense content around chloroplasts and nucleus of M. arvensis
mesophyll cells treated with Cd, and around M. arvensis mitochondria of
mesophyll cells treated with Pb, were previously observed in Aradopsis
thaliana roots under high concentrations of Cd (BELLENGHEM et al., 2007BELLENGHEM, F.V. et al. Subcellular localization of cadmium in roots and
leaves of Arabidopsis thaliana. New Phytologist, v.173, p.495-508, 2007. doi:
10.1111/j.1469-8137.2006.01940.x.
https://doi.org/10.1111/j.1469-8137.2006...
) and Zea mays roots treated with Pb
(TUNG & TEMPLE, 1996TUNG, G.; TEMPLE, P.J. Uptake and localization of lead in corn (Zea mays
L.) seedlings, a study by histochemical and eletron microscopy. Science of the Total
Environmental, v.188, p.71-85, 1996. doi:
10.1016/0048-9697(96)05156-X.
https://doi.org/10.1016/0048-9697(96)051...
). These structures
were described as granular deposits present in the cortex intercellular spaces or in the
cell wall. The metal would be transported from the apoplast to the symplast, reducing
its movement in the plant (TUNG & TEMPLE,
1996TUNG, G.; TEMPLE, P.J. Uptake and localization of lead in corn (Zea mays
L.) seedlings, a study by histochemical and eletron microscopy. Science of the Total
Environmental, v.188, p.71-85, 1996. doi:
10.1016/0048-9697(96)05156-X.
https://doi.org/10.1016/0048-9697(96)051...
; BELLENGHEM et al., 2007BELLENGHEM, F.V. et al. Subcellular localization of cadmium in roots and
leaves of Arabidopsis thaliana. New Phytologist, v.173, p.495-508, 2007. doi:
10.1111/j.1469-8137.2006.01940.x.
https://doi.org/10.1111/j.1469-8137.2006...
).
Plants exposed to heavy metal stress show changes in production of secondary
metabolites, either suppressing or stimulating production (NASIM & DHIR, 2010NASIM, S.A.; DHIR, B. Heavy metal alter the potency of medicinal plants.
Reviews of Environmental Contamination and Toxicology, v.203, p.139-149, 2010. doi:
10.1007/978-1-4419-1352-4_5.
https://doi.org/10.1007/978-1-4419-1352-...
). Changes in essential oil composition by
heavy metals stress are associated with inactivation of specific enzymes of metabolic
pathways of secondary metabolites (NASIM & DHIR,
2010NASIM, S.A.; DHIR, B. Heavy metal alter the potency of medicinal plants.
Reviews of Environmental Contamination and Toxicology, v.203, p.139-149, 2010. doi:
10.1007/978-1-4419-1352-4_5.
https://doi.org/10.1007/978-1-4419-1352-...
). As there were no changes on M. arvensis essential oil
yield and composition, probably Pb and Cd applied in the soil was not sufficient to
affect these routes of secondary metabolites production. Similarly, the exposition of
Anethum graveolens and Ocimum basilicum to Cd, Pb and Cu
showed no clear trend of variation (ZHELJAZKOV et al.,
2006ZHELJAZKOV, V.D. et al. Effects of Cd, Pb, and Cu on growth and
essential oil contents in dill, peppermint, and basil. Environmental and Experimental
Botany, v.58, p.9-16, 2006.doi:10.1016/j.envexpbot.2005.06.008.
https://doi.org/10.1016/j.envexpbot.2005...
). Moreover, Mentha piperita cultivated with Pb and Cd, under
maximum concentration of 100 and 1500ppm respectively, showed a significant reduction of
essential oil yield, which was mainly associated with the reduction of biomass, number
of leaves and total leaf area (AMIRMORADI et al.,
2012AMIRMORADI, S. et al. Effect of cadmium and lead on quantitative and
essential oil traits of peppermint ( Mentha piperita L.). Notulae Scientia Bilogicae,
v.4, p.101-109, 2012.).
CONCLUSION:
Pb and Cd were absorbed by M. arvensis and concentrated mainly in the roots, but Cd was also translocated to the shoots, exceeding the permissible levels for human consumption. At ultrastrutural level, the metals accumulated on vesicles. The cellular alterations due metals application were not enough to produce phytotoxicity symptoms or affect the growth and essential oil yield of M. arvensis.
- ABOU-ARAB, A.A.K. et al. Quantify estimation of some contaminants in commonly used medicinal plants in the Egyptian market. Food Chemistry, v.67, p.357-363, 1999. doi: 10.1016/S0308-8146(99)00082-5.
» https://doi.org/10.1016/S0308-8146(99)00082-5 - ABOU-ARAB, A.A.K.; ABOU DONIA, M.A. Heavy metals in Egyptian spices and medicinal plants and the effect of processing on their leaves. Journal Agricultural, Food Chemistry v.48, p.2300-2304, 2000. doi: 10.1021/jf990508p.
» https://doi.org/10.1021/jf990508p - ADAMS, R.P. Identification of essential oils components by gas chromatography mass spectroscopy. Carol Stream, Illinois: Allured Publishing Corporation, 2007. 804p.
- ALVES, J.C. et al. Absorção e distribuição de chumbo em plantas de vetiver, jureminha e algarroba. Revista Brasileira de Ciência do Solo, v.32, p.1329-1336, 2008. doi: 10.1590/S0100-06832008000300040.
» https://doi.org/10.1590/S0100-06832008000300040 - AMIRMORADI, S. et al. Effect of cadmium and lead on quantitative and essential oil traits of peppermint ( Mentha piperita L.). Notulae Scientia Bilogicae, v.4, p.101-109, 2012.
- BELLENGHEM, F.V. et al. Subcellular localization of cadmium in roots and leaves of Arabidopsis thaliana. New Phytologist, v.173, p.495-508, 2007. doi: 10.1111/j.1469-8137.2006.01940.x.
» https://doi.org/10.1111/j.1469-8137.2006.01940.x - CALDAS, E.D; MACHADO, L.L Cadmium, mercury and lead in medicinal herbs in Brazil. Food and Chemical Toxicology, v.42, p.599-603, 2004. doi: 10.1016/j.fct.2003.11.004.
» https://doi.org/10.1016/j.fct.2003.11.004 - CASAS, J.S.; SORDO, J. (eds.) Lead: chemistry, analytical aspects, environmental impact and health effects. The Netherlands: Elsevier, 2006. 354p.
- DJEBALI, W. et al. Ultrastructure and lipid alterations induced by cadmium in tomato (Lycopersicon esculentum) chloroplast membranes. Plant Biology, v.7, p.358-368, 2005. doi: 10.1055/s-2005-837696.
» https://doi.org/10.1055/s-2005-837696 - HU, J.Z. et al. Effects of Pb2+ on the active oxygen-scavenging enzyme activities and ultrastructure in Potamogeton crispus leaves. Russian Journal of Plant Physiology, v.54, p.414-419, 2007. doi: 10.1134/S1021443707030181.
» https://doi.org/10.1134/S1021443707030181 - HUNT, R. Basic Growth Analysis: Plant Growth Analysis for Beginners. Boston and London: Unwin Hyman, 1990. 112p.
- JÄRUP, L. Hazards of heavy metal contamination. British Medical Bulletin, v. 68, p. 167-182, 2003. Available from: <http://bmb.oxfordjournals.org/content/68/1/167.full.pdf+html>. Accessed May 04, 2013. doi: 10.1093/bmb/ldg032.
» https://doi.org/10.1093/bmb/ldg032» http://bmb.oxfordjournals.org/content/68/1/167.full.pdf+html - KABATA-PENDIAS, A.; PENDIAS, H. Trace elements in soils and plants. Boca Raton: CRC, 2000. 331p.
- KASTORI, R.R. et al. Effect of lead contamination of maize seed on its biological properties. Zbornik Matice Srpske za Prirodne Nauke, n.123, p.75-82, 2012. doi: 10.2298/ZMSPN1223075K.
» https://doi.org/10.2298/ZMSPN1223075K - KURKOVA, E.B. et al. Responses of Seidlitzia rosmarinus to salt stress. Biological Bulletin, v.29, p.221-228, 2002. doi: 10.1023/A:1015478329530.
» https://doi.org/10.1023/A:1015478329530 - LIU, D. et al. Pb/Cu effects on the organization of microtubule cytoskeleton in interphase and mitotic cells of Allium sativum L. Plant Cell Reports, v.28, p.695-702, 2009. doi: 10.1007/s00299-009-0669-3.
» https://doi.org/.1007/s00299-009-0669-3 - LUX, A. et al. Root responses to cadmium in the rhizosphere: a review. Journal of Experimental Botany, v.62, p.21-37, 2011. doi: 10.1093/jxb/erq281.
» https://doi.org/10.1093/jxb/erq281 - NASIM, S.A.; DHIR, B. Heavy metal alter the potency of medicinal plants. Reviews of Environmental Contamination and Toxicology, v.203, p.139-149, 2010. doi: 10.1007/978-1-4419-1352-4_5.
» https://doi.org/10.1007/978-1-4419-1352-4_5 - OLIVER, M.A. Soil and human health: a review. European Journal of Soil Science, v.48, p.573-592, 1997. doi: 10.1111/j.1365-2389.1997.tb00558.x.
» https://doi.org/10.1111/j.1365-2389.1997.tb00558.x - SHARMA, P.; DUBEY, R.S. Lead toxicity in plants. Brazilian Journal of Plant Physiology, v.17, p.35-52, 2005. doi: 10.1590/S1677-04202005000100004.
» https://doi.org/10.1590/S1677-04202005000100004 - TUNG, G.; TEMPLE, P.J. Uptake and localization of lead in corn (Zea mays L.) seedlings, a study by histochemical and eletron microscopy. Science of the Total Environmental, v.188, p.71-85, 1996. doi: 10.1016/0048-9697(96)05156-X.
» https://doi.org/10.1016/0048-9697(96)05156-X - VAN DEN DOOL, H.; KRATZ, P.D. A generalization of the retention index system including linear temperature programmed gas-liquid partition chromatography. Journal of Chromatography, v.11, p.463-471, 1963. doi: 10.1016/S0021-9673(01)80947-X.
» https://doi.org/10.1016/S0021-9673(01)80947-X - WHO. Quality control methods for medicinal plant materials. Geneva, Switzerland, 1998. p 62-63.
- ZHELJAZKOV, V.D. et al. Effects of Cd, Pb, and Cu on growth and essential oil contents in dill, peppermint, and basil. Environmental and Experimental Botany, v.58, p.9-16, 2006.doi:10.1016/j.envexpbot.2005.06.008.
» https://doi.org/10.1016/j.envexpbot.2005.06.008
Publication Dates
-
Publication in this collection
Mar 2015
History
-
Received
19 July 2013 -
Accepted
29 May 2014