Gender difference following high cholesterol diet induced renal injury and the protective role of rutin and ascorbic acid combination in Wistar albino rats

Lipids in Health and Disease Gender difference following high cholesterol diet induced renal injury and the protective role of rutin and ascorbic acid combination in Wistar albino rats Salim Salih Al-Rejaie 0 Hatem Mustafa Abuohashish 0 Osama Abdelrahman Alkhamees 2 Abdulaziz Mohammed Aleisa 0 Abdulaziz S Alroujayee 1 0 Department of Pharmacology and Toxicology, College of Pharmacy , P.O. Box 2457 , King Saud University , Riyadh 11451 , Saudi Arabia 1 College of Medicine, Al-Imam University , Riyadh, PO Box 11623 , Saudi Arabia 2 Department of Pharmacology, College of Medicine, Al-Imam University , Riyadh, PO Box 11623 , Saudi Arabia Background: An increased interest is given to the impact of high fat diet on health worldwide. Abnormalities in lipid metabolism induced by high cholesterol diet (HCD) were reported to exacerbate renal diseases via oxidative stress pathways. Rutin and ascorbic acid showed a protective role against oxidative stress-mediated diseases. Furthermore, both lipid metabolism and tissue response to oxidative stress damage was found to vary according to animal gender. Thus, the objective of this work was to examine possible gender-related differences and the possible protective effects of rutin and ascorbic acid supplementation on high cholesterol diet induced nephrotoxicity. Methods: 96 young male and female Wistar albino rats were used. HCD supplemented animals were treated with rutin alone or in combination with ascorbic acid for 6 weeks. Creatinine plasma level was estimated. Furthermore, kidney levels of nucleic acids, total protein, malondialdehyde (MDA), reduced glutathione (GSH), total cholesterol, and triglycerides were determined. Finally, kidney tissues were used for histopathological examination. Results: HCD supplementation decreased kidney level of nucleic acids, which was more prominent in female animals. Both vitamin combination significantly attenuated HCD induced decrease in nucleic acids. Moreover, kidney level of MDA was significantly altered by HCD in both genders, which was inhibited by rutin and ascorbic acid alone or in combination in male groups and by both vitamins in female groups. There was a reduction in kidney level of GSH by HCD, especially in male groups, which was attenuated by rutin and ascorbic acid combination. Kidney levels of total cholesterol and triglycerides were significantly increased by HCD supplementation in both genders. Coadministration with rutin and/or ascorbic acid protected from such increase, which was more obvious in both vitamins combination. Histopathological investigation supported vitamins protective effect, which was more prominent in male vitamins combination group. Conclusions: HCD-induced renal injury in female was higher than in male animals, suggesting a better antioxidative stress defense response in male's kidney. Moreover, the antioxidant and reno-protective effects of rutin and ascorbic acid were augmented following their combination. High cholesterol diet; Nephrotoxicity; Renal injury; Gender difference; Rutin; Ascorbic acid - Introduction It is well known that lifestyle and diet play a role in the development of kidney disease. Several studies indicated that abnormalities in lipid metabolism can often accompany and exacerbate renal disease [1,2]. Hypercholesterolemia is well-known to be an independent risk factor for renal injury [3] and to aggravate the pathogenesis of a variety of clinical and experimental renal diseases [4-6]. High cholesterol diet (HCD) was found to increase blood pressure and to induce renal injury [7]. Moreover, many accumulating evidences support the idea that HCD exacerbates kidney damage in animal models of kidney disease [8]. Previous data showed that even a short exposure to HCD supplementation is associated with an increase in oxidative stress and renal inflammation [9]. Indeed, HCD supplementation to animals was reported to significantly increase kidney oxidative stress parameter and to significantly reduce kidney antioxidant parameters [10]. Therefore, the inhibition of oxidative stress under hypercholesterolemic conditions is considered to be an important therapeutic approach for kidney related diseases. Rutin (RT), a quercetin-3-rutinosid or vitamin-P, is considered as one of flavonoid glycosides, which is found in onions, apples, tea and red wine [11]. Rutin is well known to exhibit multiple pharmacological activities including antibacterial, antitumor, anti-inflammatory, anti-diarrheal, antiulcer, anti-mutagenic, vasodilator and immunomodulator [12]. Furthermore, rutin showed an inhibitory effect against membrane lipid peroxidation [13]. Rutin was found to have renalprotective effects via its antioxidant activities which suggest its protective role in oxidative stress-mediated diseases [13-15]. Vitamin C is a water-soluble enzyme cofactor, abundantly present in different plants and some animals. It is present in two chemical forms: the reduced form (ascorbic acid; AA) and the oxidized form (dehydroascorbic acid; DHA). AA is the most predominant form in the human body and is involved in tissue growth and repair. AA has a potent antioxidant activity and is well known to protect tissues from oxidative injury through efficiently quenching the damaging free radicals produced by many biological processes [16,17]. Gender difference currently plays an important role in the etiology of hyperlipidaemic-induced disorder including cardiovascular diseases (CVD). For instance, men are more susceptible to coronary heart disease than agematched women. However, postmenopausal women have an equal chance of CVD with men [18,19]. The underlying mechanisms for this difference are related to the known effects of estrogens of lipid metabolism, such as a decrease in HDL catabolism via a decrease in hepatic lipase activity and an increase in LDL catabolism via an increase in the number of LDL receptors [20]. Moreover, the severity of oxidative stress tissue damage and injury may vary according to gender difference. Hepatic oxidative stress and inflammatory response in acute uremia after bilateral nephrectomy was shown to be more significant in female than male rats [21]. Sex dimorphism in pancreas oxidative stress as response to HCD was also reported, where female rats were protected against oxidative damage [22]. Furthermore, application of chronic mild stress to male and female rats was shown to induce different oxidative stress and compensatory responses, which was suggested to be due to differences in the mechanisms regulating oxidant/ antioxidant pathways [23]. The current study was designed with major two goals; (1) to investigate gender-related differences in response to high cholesterol diet induced nephrotoxicity using Wistar albino rats as an animal model; (2) to evaluate the potential beneficial effects of rutin and/or ascorbic acid supplementation on high cholesterol diet induced nephrotoxicity. Materials and methods Materials Animals Young male an (...truncated)