Accessibility / Report Error

The impact of long-term consumption of diets enriched with olive, cottonseed or sesame oils on kidney morphology: A stereological study

Abstract

Abstract: To date, most of studies have only focused on metabolic effects of dietary oils while recent evidence proposes that they can influence kidneys structure. Therefore, the aim of this study was to evaluate the impact of long-term consumption of olive, cottonseed and sesame oils on renal morphology in rats. 70 male Wistar rats randomly assigned into seven equal groups and treated with standard diet (control), the standard diet enriched with 10% or 20% (W/W) of either olive oil (OLI10%, OLI20%), cottonseed oil (COT10%, COT20%) or sesame oil (SES10%, SES20%) for 5 months. Quantitative features of the kidney including kidney and cortex volumes and the number of glomeruli were analyzed stereologically. Moreover, kidney sections histologically were evaluated. All of the studied oils in low concentration had no devastating effects on renal morphology and also its pathological features. However, only in SES20% group, kidney volume as well as, cortical volume was higher than the control group. Besides, accumulation of carbohydrate macromolecules and renal fibrosis were markedly increased in SES20% group compared to the control. The results suggest that sesame oil, especially at high concentration, may lead to renal deformities as a result of histopathological changes such as dilatation, fibrosis, and tubular defects.

Key words
cottonseed oil; histopathology; kidney; olive oil; sesame oil; stereology


INTRODUCTION

A bulk of evidence shows that dietary fats/oils play important roles in health and disease. Over the past 5 decades, the subject of biological effects of dietary oils/fats has been one of the most researched topics among biomedical studies (RamsdenRAMSDEN CE, ZAMORA D, MAJCHRZAK-HONG S, FAUROT KR, BROSTE SK, FRANTZ RP, DAVIS JM, RINGEL A, SUCHINDRAN CM and HIBBELN JR. 2016. Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73). BMJ 353: i1246. et al. 2016). Subsequently, the landscape of edible oils extensively has changed. However, to date, most of clinical and experimental research has focused on the effects of edible oils/fats in metabolic and cardiovascular functions. Less is known about the health risks of dietary oils on renal function mainly its structure (SvenssonSVENSSON M and CARRERO JJ. 2017. n-3 Polyunsaturated Fatty Acids for the Management of Patients With Chronic Kidney Disease. J Ren Nutr 27: 147-150. and Carrero 2017).

The kidney is a structurally complex organ that has evolved to subserve a number of important functions: excretion of the waste products of metabolism, regulation of body water and salt, maintenance of appropriate acid balance, and secretion of various hormones and autacoids (KumarKUMAR V, COTRAN R and ROBBINS S. 1997. The kidney and its collecting system. Basic Pathology, 6th ed., Philadelphia. WB Saunders Co, p. 439-469. et al. 1997). The results of recent studies demonstrated that fatty acids appear to play a pivotal role in kidney diseases. Accordingly, n-3 and n-6 polyunsaturated fatty acids (PUFA) contribute to preserving kidney health (SyrenSYREN ML, TUROLO S, MARANGONI F, MILANI GP, EDEFONTI A, MONTINI G and AGOSTONI C. 2018. The polyunsaturated fatty acid balance in kidney health and disease: A review. Clin Nutr 37: 1829-1839. et al. 2018). Taken together, these results put forward the hypothesis that different dietary oils might have different effects on kidneys.

Olive oil because of its prominent role in the Mediterranean diet is one of the most popular edible oils in the world. It is a liquid fat obtained from olives (the fruit ofOlea europaea; family Oleaceae), a traditional tree crop of the Mediterranean Basin. The oil is produced by pressing whole olives (Syren et al. 2018). Olive oil generally has the highest percentage of monounsaturated fatty acids (MUFA) between edible oils (AssyASSY N, NASSAR F and GROSOVSKI M. 2010. Chapter 126, Monounsaturated Fat Enriched with Olive Oil in Non-alcoholic Fatty Liver Disease. In: Preedy VR and Watson RR (Eds), Olives and Olive Oil in Health and Disease Prevention. San Diego: Academic Press, p. 1151-1156. et al. 2010).

The fifth most produced vegetable oil is cottonseed oil (WassefWASSEF EA, SHALABY SH and SALEH NE. 2015. Cottonseed oil as a complementary lipid source in diets for gilthead seabream Sparus aurata juveniles. Aquac Res 46: 2469-2480. et al. 2015). Cottonseed oil is a cooking oil extracted from the seeds of cotton plants of various species, mainlyGossypium hirsutumandGossypium herbaceum, that are grown for cotton fiber, animal feed, and oil. Cottonseed has a similar structure to other oilseeds such as sunflower seed, having an oil-bearing kernel surrounded by a hard outer hull; in processing, the oil is extracted from the kernel. Cottonseed oil is used for salad oil, mayonnaise, salad dressing, and similar products because of its flavor stability (LuLU J, BANKOVIC-CALIC N, OGBORN M, SABOORIAN MH and AUKEMA HM. 2003. Detrimental effects of a high fat diet in early renal injury are ameliorated by fish oil in Han:SPRD-cy rats. J Nutr 133: 180-186. et al. 2003).

Sesame oil is an edible vegetable oil derived from sesame seeds. Besides being used as a cooking oil in South India, it is used as a flavor enhancer in Middle Eastern, African, and Southeast Asian cuisines. It has a distinctive nutty aroma and taste (BarnwalBARNWAL B and SHARMA M. 2005. Prospects of biodiesel production from vegetable oils in India. Renew Sust Energ Rev 9: 363-378. and Sharma 2005). Sesame oil is a good mixture of PUFA and MUFA (OrsavovaORSAVOVA J, MISURCOVA L, AMBROZOVA JV, VICHA R and MLCEK J. 2015. Fatty Acids Composition of Vegetable Oils and Its Contribution to Dietary Energy Intake and Dependence of Cardiovascular Mortality on Dietary Intake of Fatty Acids. Int J Mol Sci 16: 12871-12890. et al. 2015). The oil is popular in Asia and is also one of the earliest-known crop-based oils, but worldwide mass modern production continues to be limited even today due to the inefficient manual harvesting process required to extract the oil. Nevertheless, a recent review of the literature on biological effects of sesame oil found that it can decrease high levels of cholesterol and inflammation which makes it effective for reducing atherosclerosis and the risk of cardiovascular disease (HsuHSU E and PARTHASARATHY S. 2017. Anti-inflammatory and Antioxidant Effects of Sesame Oil on Atherosclerosis: A Descriptive Literature Review. Cureus 9: e1438. and Parthasarathy 2017).

As mentioned before, our knowledge about the effects of dietary vegetable oils on kidney structure is very limited. Consequently, the aim of the research was to evaluate long-term consumption effects of olive oil, cottonseed oil, and sesame oil on the renal structure of healthy rats.

MATERIALS AND METHODS

OILS PREPARATION AND FATTY ACID DETERMINATION

Commercial grades of dietary olive oil (OLI), cottonseed oil (COT) and sesame oil (SES) were purchased from the local market in Birjand, Iran. Fatty acid profiles of the oils, as well as the standard diet (Javaneh-Khorasan, Iran) were determined using a gas chromatograph (YL 6000, Korea) equipped with a CP-Sill 88 capillary column (60m, 25 µm i.d., 0.2 µm film) blindly at the Standard Research Institute, Karaj, Iran. Fatty acid methyl esters were identified on the basis of ISO 5508 (ISIR 4090) and analyzed according to the ISO 5509 (ISIRI 4091) (Hassanzadeh-TaheriHASSANZADEH-TAHERI M, JAHANI F, HASSANZADEH-TAHERI M, DOOSTABADI M, DOOSTABADI H and HOSSEINI M. 2018a. The impacts of yoghurt butter oil on rat testicular morphology and sexual hormones in a 150-day study. Comp Clin Path 27: 959-965. et al. 2018a).

ANIMALS AND DIETS

Healthy male Wistar rats (60 days old) were purchased from laboratory animal facility in Birjand University of Medical Sciences, Birjand, Iran. The rats were housed in a temperature-controlled room (22±2 °C) with a 12h light/dark cycle. All animal procedures were conducted and approved in accordance with the guide for the laboratory animals’ care and usage of Birjand University of Medical Sciences, Birjand, Iran (Ethic code: Ir.bums.REC.1396.94). All efforts were made to minimize animal suffering and to reduce the number of animals used. The animals were divided randomly into seven equal groups (n = 10) with the mean body weight of 251.41 ± 17.37 g. The groups were fed with the following diets for 5 months:

Group 1 (Control): received a standard diet (containing 3% fat)

Group 2 (OLI10%): received a standard diet 10% (w/w) supplemented with olive oil

Group 3 (OLI20%): received a standard diet 20% (w/w) supplemented with olive oil

Group 4 (COT10%): received a standard diet 10% (w/w) supplemented with cottonseed oil

Group 5 (COT20%): received a standard diet 20% (w/w) supplemented with cottonseed oil

Group 6 (SES10%): received a standard diet 10% (w/w) supplemented with sesame oil

Group 7 (SES20%): received a standard diet 20% (w/w) supplemented with sesame oil.

The concentrations and study period were according to our previous study in which the impact of long term consumption of 6 different dietary fats have been studied (Hassanzadeh-TaheriHASSANZADEH-TAHERI M, HASSANZADEH-TAHERI M, JAHANI F and HOSSEINI M. 2018b. Effects of yoghurt butter oils on rat plasma lipids, haematology and liver histology parameters in a 150-day study. Int J Dairy Technol 71: 140-148. et al. 2018b). The animals had ad libitum access to their respective food and tap water throughout the study.

HISTOLOGICAL EVALUATION

At the end of the study (after 5 months), the rats were anesthetized with ketamine-xylazine (65:10 mg/kg IP) (Hassanzadeh-TaheriHASSANZADEH-TAHERI M, HASSANPOUR-FARD M, DOOSTABADI M, MOODI H, VAZIFESHENAS-DARMIYAN K and HOSSEINI M. 2018c. Co-administration effects of aqueous extract of turnip leaf and metformin in diabetic rats. J Tradit Complement Med 8: 178-183. et al. 2018c), and fixed by intracardiac perfusion with 4% paraformaldehyde in 0.01M phosphate buffered saline. Both kidneys of each animal were rapidly removed, weighed, and then post-fixed in the same fixative for 48 h at 4 °C. The kidneys were processed by routine histological methods and embedded in paraffin blocks. The tissues were sectioned serially and coronally, using a sliding microtome (Leitz, Italy) at the thickness of 5μm for histopathological evaluation (left kidney) or 10 μm thickness with 250 μm intervals for stereology (right kidney) (UlubayULUBAY M, YAHYAZADEH A, DENIZ OG, KIVRAK EG, ALTUNKAYNAK BZ, ERDEM G and KAPLAN S. 2015. Effects of prenatal 900 MHz electromagnetic field exposures on the histology of rat kidney. Int J Radiat Biol 91: 35-41. et al. 2015).

To evaluate kidney structure and pathological lesions, tissue sections (5 μm) were prepared for staining with hematoxylin and eosin, periodic acid-Schiff (PAS) and Masson’s trichrome. To study histological changes in the renal tissue, three random sections from each rat were scanned under a light microscope (UPLAN FI, Japan) and analyzed using Image J software (NIH, Bethesda, USA). Pathological features including degeneration, congestion, infiltration and hemorrhage were assessed and scored for each microscopic field of kidney sections according to a scoring checklist (0= none, 1= mild, 2= moderate, 3= severe) as previously described (Hassanzadeh-TaheriHASSANZADEH-TAHERI M, HOSSEINI M, HASSANPOUR-FARD M, GHIRAVANI Z, VAZIFESHENAS-DARMIYAN K, YOUSEFI S and EZI S. 2016. Effect of turnip leaf and root extracts on renal function in diabetic rats. Orient Pharm Exp Med 16: 279-286. et al. 2018d). The PAS score is defined as 0= no deposits of PAS-positive material, 1= up to one third, 2= one-third to two-thirds, and 3= more than two-thirds of glomerular section positively stain with PAS (Hassanzadeh-Taheri et al. 2016, WuWU D, GAO B, LI M, YAO L, WANG S, CHEN M, LI H, MA C, JI A and LI Y. 2016. Hydrogen Sulfide Mitigates Kidney Injury in High Fat Diet-Induced Obese Mice. Oxid Med Cell Longev 2016: 2715718. et al. 2016). Also, interstitial fibrosis in Masson’s trichrome stained sections was scored by the following criteria: 0= absent, 1= less than 25% of the area, 2= 25-50% of the area and 3= more than 50% of the area (Wu et al. 2016). The percentage of collagen fibers deposition was measured with the directionality plugin in Fiji– ImageJ (SchindelinSCHINDELIN J et al. 2012. Fiji: an open-source platform for biological-image analysis. Nat Methods 9: 676-682. et al. 2012).

STREOLOGY

The right kidney of animals was cut in 10 μm thickness with 250 μm intervals for stereological study. The volume of the cortex and whole kidney were estimated by using the Cavalieri’s principle and the point counting method (NyengaardNYENGAARD JR. 1999. Stereologic methods and their application in kidney research. J Am Soc Nephrol 10: 1100-1123. 1999). For this approach 15-20 sections for each rat were used. The point density of the point-counting gird was specified according to a pilot study that included two kidney specimens of adult rats. A grid of points was laid over the image of the section and the points hitting it were counted and the area sum of the cortex and medulla were calculated separately. The volume of kidney cortex, medulla and glomeruli were determined by applying the following formula:

V o l u m e ( V ) = t × a ( p ) × P

Where ‘t’ is the thickness of the section, ‘a/p’ is the interpoint area, and ‘∑p’ is the number of points hitting the object of interest in the section. After applying this formula to all samples, the total volume to be estimated from the following formula:

T o t a l v o l u m e : V 1 + V 2 + + V n .

To estimate the numerical density of glomeruli and the total number of glomeruli, physical dissector pairs were applied. Serial sections were taken with a systematic unbiased sampling. One of the two sections was selected as a reference and the other as a look-up. Both of the sections were photographed at a magnification of 100X and 400X. An unbiased counting frame was placed on the reference and the look-up sections on the screen of the computer (20*20 cm) to perform the counting according to the dissector method. Afterwards, the numbers of glomeruli seen in the reference section but not in look-up section were counted. The numerical density of glomeruli per volume (cm3) (Nv) was estimated using the following formula:

N v = Q / ( t × A )

Where, ∑Q- is the total number of glomeruli counted in the reference section, t is the mean section of thickness (10μm), and A is the area of the unbiased counting frame. Finally, the total number of kidney glomeruli (TN) was estimated by the following formula:

T N = N v × K i d n e y v o l u m e

STATISTICAL ANALYSIS

Results are expressed as mean ± SD in all groups. Variance in data was checked for homogeneity by Kolmogorov–Smirnov test. Statistical differences between groups were detected by one-way ANOVA test followed by Dunnett’s test. Furthermore, histopathological grading scores were analyzed between the groups using Kruskal-Wallis test. Statistical significance was inferred at p<0.05. The SPSS software, version 22 was used for all analyses.

RESULTS

FATTY ACID COMPOSITION

The fatty acid composition of all the three oils, as well as standard diet (consist of 3% fat) is presented in Table I. Accordingly, the OLI, COT and SES consisted of 20.7, 33.3, and 20% saturated fatty acids and 67.8, 28.8, and 42% MUFAs respectively. The levels of PUFAs were 10.9, 37.3, and 37.6% of total fatty acids corresponding to OLI, COT, and SES.

TABLE I
Fatty acid composition of the oils and standard diet.

TOTAL ENERGY INTAKE AND KIDNEY-BODY WEIGHT RATIO

Based on monitoring of 5-month total food consumption, total energy intake of each rat during the study period was calculated (1g of standard diet: 3.59 kcal; 1g of 10% enriched diet: 3.94 kcal; and 1g of 20% enriched diet: 4.44 kcal). The results of total energy intake, final body and kidney weights, and kidney to body weight ratio are shown in Table II. Accordingly, there was no significant difference in total energy intake between the studied groups. The mean of body weight of the animals treated with all of the experimental diets (except SES10%) was significantly higher than the control group (p<0.05). Compared to the control and other experimental groups, the kidney weight significantly increased only in the SES20% group (p<0.001). Likewise, the ratio of kidney weight to body weight only was greater in SES20% group than control, significantly (p<0.001).

TABLE II
Total energy intake, body and kidney weights, and kidney to body weight ratio.

HISTOLOGICAL EVALUATION

The results of the semi-quantitative histopathological evaluation are presented in Table III. Kruskal-Wallis global comparison revealed a significant difference between the groups in the mean rank of congestion as well as degeneration (p<0.001 each). Kidney sections of SES20% treated group revealed higher mean rank of congestion and degeneration compared to the control group (p<0.001 each). Other experimental groups showed normal kidney architecture without any significant inflammations, hemorrhage, and infiltration or degenerations (Figure 1).

TABLE III
Score of histopathological changes in the kidney section.
Figure 1
Histopathological assessment of the kidney sections of rats in the control (a), Olive 10% (b), Olive 20% (c), Cottonseed 10% (d), Cottonseed 20% (e), Sesame oil 10% (f) and Sesame oil 20% (g, h). The sections were stained with hematoxylin and eosin dyes. The star represents urinary space dilatation and arrow shows a proximal tubule with lysosome accumulation.

PAS-positive staining can be used to stain structures containing a high proportion of carbohydrate macromolecules, such as glycoproteins, glycogen, and proteoglycans. The PAS score comparison revealed that SES20% treated animals had significantly increased (p<0.001) carbohydrate content compared to the control group (Figure 2). The structure of kidneys of the studied groups was depicted in Figure 3.

Figure 2
Quantitative analysis of PAS-positive deposits. Control, Olive 10% (OLI10), Olive 20% (OLI20), Cottonseed 10% (COT10), Cottonseed 20% (COT20). Sesame oil 10% (SES10) and Sesame oil 20% (SES20). Values were presented as mean± SD. * p<0.05 compared with the control group.
Figure 3
Evaluation of carbohydrate content in the kidney of rats using PAS staining. Control (a), Olive 10% (b), Olive 20% (c), Cottonseed 10% (d), Cottonseed 20% (e), Sesame oil 10% (f) and Sesame oil 20% (g, h). The arrow shows thickening of Bowman’s capsule and the star represents carbohydrate accumulation (PAS-positive) in the glomerulus. Generally, the sections of SES20% group have purple appearance while those from the other groups have blue appearance.

Masson’s trichrome is a three-color staining protocol used in the histology, which produced red fibers, blue collagen, pink cytoplasm, and dark brown nuclei. The amount of blue collagen staining was significantly increased (p<0.001) in SES20% treated animal when compared to the control group (Figures 4 and 5).

Figure 4
The extent of renal fibrosis is represented semi- quantitavly by the fibrosis score. Control, Olive10% (OLI10), Olive 20% (OLI20), Cottonseed 10% (COT10), Cottonseed 20% (COT20), Sesame oil 10% (SES10) and Sesame oil 20% (SES20). Values were presented as mean± SD. *p<0.05 compared to the control group.
Figure 5
Evaluation of renal collagen deposition using Masson’s Trichrome staining. Control (a), Olive 10% (b), Olive 20% (c), Cottonseed 10% (d), Cottonseed 20% (e), Sesame oil 10% (f) and Sesame oil 20% (g, h). The arrows clearly show collagen deposition areas (blue fibers) both in glomeruli and interstitium.

STEREOLOGICAL RESULTS

All stereological results are summarized in Table IV. Mean volume of the kidney was significantly increased (p<0.001) in SES20% group in comparison with control group. There was no statistical difference between the other studied groups. The mean cortex volume of SES20% group also were significantly higher (p<0.001) than control as well as other studied groups. There was no significant difference in the total number of glomeruli between the groups (p=0.14).

TABLE IV
Mean volumes of the kidney and cortex and total glomeruli number.

DISCUSSION

The results of the present study revealed that all of the studied oils in low concentration (10% added to the diet) had no devastating effects on renal morphology and also its pathological features. However, in the 20% concentration, kidney of animals treated with sesame oil showed markedly morphological changes and histological alterations. In line with increases in kidney weight, kidney total volume and cortical thickness significantly increased in SES20% treated rats. Moreover, histological evaluation revealed that tubular and glomerular congestion, as well as urinary space dilatation were the most evident alterations in kidney tissues belong to SES20% treated animals. Consistent with histopathological changes, special staining techniques showed that PAS-positive reaction of glomeruli and interstitium -representing carbohydrate accumulation- significantly increased in SES20% group. Moreover, renal collagen deposition assay using Masson’s trichrome staining technique showed that fibrosis score significantly increased in SES20% groups compared to the control and other experimental groups. Our findings reveal that the results of histopathological examinations and stereological quantification confirm each other.

Several experimental studies demonstrated that rodent diet enriched in fat (more than 30% of energy) considered as a high-fat diet (YangYANG SC, LIN SH, CHANG JS and CHIEN YW. 2017. High Fat Diet with a High Monounsaturated Fatty Acid and Polyunsaturated/Saturated Fatty Acid Ratio Suppresses Body Fat Accumulation and Weight Gain in Obese Hamsters. Nutrients 9: 1148. et al. 2017). In the current study 10 and 20% enriched diets with the oils providing about 22.5 and 40.1% calories, respectively. Moreover, toxicological assessments in experimental animals usually were categorized into four classes: acute, sub-acute, sub-chronic and chronic. Acute toxicity test is defined as a single exposure for less than 24 h, sub-acute toxicity refers to repeated exposures for 1 month or less, sub-chronic toxicity refers to repeated exposures for 1 to 3 months and chronic toxicity assay refers to repeated exposures for more than 3 months (Hassanzadeh-Taheri et al. 2018d). Therefore, in the present study two concentrations of the oils added to normal diets because they are more reassembling to normal and high-fat diets and also we have chosen 5-month investigation to simulate long-term consumption pattern like what happens in real life.

Recently, research demonstrates that high-fat diet may cause renal alterations (Syren et al. 2018). Previous studies demonstrated that chronic administration of dietetic lipids can cause abdominal obesity and significantly alters the renal cortical structure in rats (AltunkaynakALTUNKAYNAK ME, ÖZBEK E, ALTUNKAYNAK BZ, CAN İ, UNAL D and UNAL B. 2008. The effects of high-fat diet on the renal structure and morphometric parametric of kidneys in rats. J Anat 212: 845-852. et al. 2008). There is evidence showing that in chronic kidney diseases, kidney weight increases (LeveyLEVEY AS and CORESH J. 2012. Chronic kidney disease. Lancet 379: 165-180. and Coresh 2012). Similar to our findings, Abdel-RahmanABDEL-RAHMAN MK. 2010. Influence of dietary fat on renal function, lipid profile, sex hormones, and electrolyte balance in rats. Eur J Lipid Sci Technol 112: 1166-1172. and colleagues reported that 12 weeks treatment with a high-fat diet (consist of 20% fat) markedly increased kidney weight in rats (Abdel-Rahman 2010). Evidence also shows that high-fat diet can cause morphological alterations in kidney such as increasing glomerular volume, dilatation in urinary space and increasing in cortical thickness (V MathewMATHEW AV, OKADA S and SHARMA K. 2011. Obesity related kidney disease. Curr Diabetes Rev 7: 41-49. et al. 2011). In the recent study in which nephrectomized rats were evaluated by MRI (Magnetic Resonance Imaging) technique, scientists reported that kidney weight in response to increasing glomeruli volume elevation is increased (BennettBENNETT KM, BERTRAM JF, BEEMAN SC and GRETZ N. 2013. The emerging role of MRI in quantitative renal glomerular morphology. Am J Physiol Renal Physiol 304: F1252-1257. et al. 2013). According to evidence cortical thickness in acute progressive kidney diseases is decreased. On the other hand, in diabetic patients, the cortical thickness is increasing during the disease development (GolalipourGOLALIPOUR MJ, GHARRAVI AM, GHAFARI S and AFSHAR M. 2007. Effect of Urtica dioica on morphometric indices of kidney in streptozotocin diabetic rats - a stereological study. Pak J Biol Sci 10: 3875-3879. et al. 2007).

Histopathological evaluations revealed that in SES20% group, PAS-positive staining in both glomerular and tubular structures significantly increased. Most sugars include at least one glycol formations at positions 2 and 3. The periodate ion (in periodic acid) selectively oxidizes glycols, yielding two aldehyde groups which firmly anchored to the tissue. The aldehydes can be detected with one of several chromogenic reagents like Schiff’s reagent. Schiff’s reagent covalently combines with aldehydes to form a red-purple compound. Thus, PAS-positive tissues indicating the high content of carbohydrate that usually observes in diabetic nephropathy and some other renal diseases (Kiernan 2001). This is in good agreement with Wu et al. study in which 12-week high-fat diet consumption (45% calorie from fat) caused a significant increase in the amount of PAS-positive staining in both glomerular and tubular structures of mice kidneys (Wu et al. 2016).

Similar to carbohydrate macromolecules accumulation, assessments of renal fibrosis with Masson’s trichrome staining techniques revealed that in SES20% group renal fibrosis markedly increased compared to the control and other studied groups. It is previously reported that imbalance between renal lipogenesis and lipolysis in high-fat treated mice could induce renal fibrosis (KumeKUME S et al. 2007. Role of altered renal lipid metabolism in the development of renal injury induced by a high-fat diet. J Am Soc Nephrol 18: 2715-2723. et al. 2007).

The evidence from this study suggests that sesame oil in long-term and high intake may cause structural and histopathological changes in kidneys. Taken together, our findings confirm that different types of fat regardless their proportion in a diet could influence renal structure differently. We propose that further research using molecular methods and immunohistochemical techniques to put more light on mechanisms behind sesame oil induced kidney damage.

ACKNOWLEGMENTS

This study was financially supported by Birjand University of Medical Sciences (Grant number: 455109). We gratefully acknowledge the help provided by Ms. Sara Nanvazadeh in fatty acids determination.

REFERENCES

  • ABDEL-RAHMAN MK. 2010. Influence of dietary fat on renal function, lipid profile, sex hormones, and electrolyte balance in rats. Eur J Lipid Sci Technol 112: 1166-1172.
  • ALTUNKAYNAK ME, ÖZBEK E, ALTUNKAYNAK BZ, CAN İ, UNAL D and UNAL B. 2008. The effects of high-fat diet on the renal structure and morphometric parametric of kidneys in rats. J Anat 212: 845-852.
  • ASSY N, NASSAR F and GROSOVSKI M. 2010. Chapter 126, Monounsaturated Fat Enriched with Olive Oil in Non-alcoholic Fatty Liver Disease. In: Preedy VR and Watson RR (Eds), Olives and Olive Oil in Health and Disease Prevention. San Diego: Academic Press, p. 1151-1156.
  • BARNWAL B and SHARMA M. 2005. Prospects of biodiesel production from vegetable oils in India. Renew Sust Energ Rev 9: 363-378.
  • BENNETT KM, BERTRAM JF, BEEMAN SC and GRETZ N. 2013. The emerging role of MRI in quantitative renal glomerular morphology. Am J Physiol Renal Physiol 304: F1252-1257.
  • GOLALIPOUR MJ, GHARRAVI AM, GHAFARI S and AFSHAR M. 2007. Effect of Urtica dioica on morphometric indices of kidney in streptozotocin diabetic rats - a stereological study. Pak J Biol Sci 10: 3875-3879.
  • HASSANZADEH-TAHERI M, HASSANPOUR-FARD M, DOOSTABADI M, MOODI H, VAZIFESHENAS-DARMIYAN K and HOSSEINI M. 2018c. Co-administration effects of aqueous extract of turnip leaf and metformin in diabetic rats. J Tradit Complement Med 8: 178-183.
  • HASSANZADEH-TAHERI M, HASSANZADEH-TAHERI M, JAHANI F and HOSSEINI M. 2018b. Effects of yoghurt butter oils on rat plasma lipids, haematology and liver histology parameters in a 150-day study. Int J Dairy Technol 71: 140-148.
  • HASSANZADEH-TAHERI M, HOSSEINI M, HASSANPOUR-FARD M, GHIRAVANI Z, VAZIFESHENAS-DARMIYAN K, YOUSEFI S and EZI S. 2016. Effect of turnip leaf and root extracts on renal function in diabetic rats. Orient Pharm Exp Med 16: 279-286.
  • HASSANZADEH-TAHERI M, HOSSEINI M, SALIMI M, MOODI H and DORRANIPOUR D. 2018d. Acute and Sub-Acute Oral Toxicity Evaluation of Astragalus hamosus Seedpod Ethanolic Extract in Wistar Rats. Pharm Sci 24: 23-30.
  • HASSANZADEH-TAHERI M, JAHANI F, HASSANZADEH-TAHERI M, DOOSTABADI M, DOOSTABADI H and HOSSEINI M. 2018a. The impacts of yoghurt butter oil on rat testicular morphology and sexual hormones in a 150-day study. Comp Clin Path 27: 959-965.
  • HSU E and PARTHASARATHY S. 2017. Anti-inflammatory and Antioxidant Effects of Sesame Oil on Atherosclerosis: A Descriptive Literature Review. Cureus 9: e1438.
  • KUMAR V, COTRAN R and ROBBINS S. 1997. The kidney and its collecting system. Basic Pathology, 6th ed., Philadelphia. WB Saunders Co, p. 439-469.
  • KUME S et al. 2007. Role of altered renal lipid metabolism in the development of renal injury induced by a high-fat diet. J Am Soc Nephrol 18: 2715-2723.
  • LEVEY AS and CORESH J. 2012. Chronic kidney disease. Lancet 379: 165-180.
  • LU J, BANKOVIC-CALIC N, OGBORN M, SABOORIAN MH and AUKEMA HM. 2003. Detrimental effects of a high fat diet in early renal injury are ameliorated by fish oil in Han:SPRD-cy rats. J Nutr 133: 180-186.
  • NYENGAARD JR. 1999. Stereologic methods and their application in kidney research. J Am Soc Nephrol 10: 1100-1123.
  • ORSAVOVA J, MISURCOVA L, AMBROZOVA JV, VICHA R and MLCEK J. 2015. Fatty Acids Composition of Vegetable Oils and Its Contribution to Dietary Energy Intake and Dependence of Cardiovascular Mortality on Dietary Intake of Fatty Acids. Int J Mol Sci 16: 12871-12890.
  • RAMSDEN CE, ZAMORA D, MAJCHRZAK-HONG S, FAUROT KR, BROSTE SK, FRANTZ RP, DAVIS JM, RINGEL A, SUCHINDRAN CM and HIBBELN JR. 2016. Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73). BMJ 353: i1246.
  • SCHINDELIN J et al. 2012. Fiji: an open-source platform for biological-image analysis. Nat Methods 9: 676-682.
  • SVENSSON M and CARRERO JJ. 2017. n-3 Polyunsaturated Fatty Acids for the Management of Patients With Chronic Kidney Disease. J Ren Nutr 27: 147-150.
  • SYREN ML, TUROLO S, MARANGONI F, MILANI GP, EDEFONTI A, MONTINI G and AGOSTONI C. 2018. The polyunsaturated fatty acid balance in kidney health and disease: A review. Clin Nutr 37: 1829-1839.
  • ULUBAY M, YAHYAZADEH A, DENIZ OG, KIVRAK EG, ALTUNKAYNAK BZ, ERDEM G and KAPLAN S. 2015. Effects of prenatal 900 MHz electromagnetic field exposures on the histology of rat kidney. Int J Radiat Biol 91: 35-41.
  • MATHEW AV, OKADA S and SHARMA K. 2011. Obesity related kidney disease. Curr Diabetes Rev 7: 41-49.
  • WASSEF EA, SHALABY SH and SALEH NE. 2015. Cottonseed oil as a complementary lipid source in diets for gilthead seabream Sparus aurata juveniles. Aquac Res 46: 2469-2480.
  • WU D, GAO B, LI M, YAO L, WANG S, CHEN M, LI H, MA C, JI A and LI Y. 2016. Hydrogen Sulfide Mitigates Kidney Injury in High Fat Diet-Induced Obese Mice. Oxid Med Cell Longev 2016: 2715718.
  • YANG SC, LIN SH, CHANG JS and CHIEN YW. 2017. High Fat Diet with a High Monounsaturated Fatty Acid and Polyunsaturated/Saturated Fatty Acid Ratio Suppresses Body Fat Accumulation and Weight Gain in Obese Hamsters. Nutrients 9: 1148.

Publication Dates

  • Publication in this collection
    23 May 2019
  • Date of issue
    2019

History

  • Received
    27 Aug 2018
  • Accepted
    29 Oct 2018
Academia Brasileira de Ciências Rua Anfilófio de Carvalho, 29, 3º andar, 20030-060 Rio de Janeiro RJ Brasil, Tel: +55 21 3907-8100 - Rio de Janeiro - RJ - Brazil
E-mail: aabc@abc.org.br