COMPARATIVE EFFECTS OF SANDPAPER (FICUS SPP.) LEAVES VARIETIES ON SOME ENZYMES RELEVANT TO VASODILATION IN HYPERTENSIVE AND ERECTILE DYSFUNCTIONAL RATS

Abstract

Hypertensive patients have a 50 % chance of having impaired penile blood flow and erectile dysfunction (ED). Individuals suffering from the comorbidities of hypertension and erectile dysfunction also battle with complications such as hyperlipidemia, obesity, inflammation and challenges arising from the use of antihypertensive drugs. Therefore, this study sought to assess the effects of common varieties of sandpaper [(Ficus exasperata (FE), Ficus asperifolia (FA), Ficus mucuso (FM) and Ficus capensis (FC)] leaves on some enzymes and genes linked to hypertension and erectile dysfunction. The total phenol and total flavonoid contents, in-vitro antioxidant property (ferric reducing antioxidant power (FRAP) assay, ABTS (2,2’- azino-bis (3- ethylbenzothiazoline-6-sulfonic acid) bleaching assay, DPPH (α, α- diphenyl-β-picrylhydrazyl) radical scavenging ability, lipid peroxidation, fenton reaction, Fe2+ radical chelating ability and in vitro enzyme inhibitory properties [angiotensin-converting enzyme (ACE-1), arginase, phosphodiesterase-5 enzyme (PDE-5) activity] were determined. Thereafter, the sandpaper varieties were fed to normal Wistar rats, Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME)- induced hypertensive and erectile dysfunctional rats were fed with dietary inclusion of sandpaper leaves cookies for 14 days. The hemodynamic parameters (systolic blood pressure, diastolic blood pressure and heart rate) and sexual behavioural tests (intromission number and latency, mounting number and latency) were evaluated. The hearts, lungs and penile tissues were excised and the antioxidant enzyme activities namely catalase (CAT), superoxide dismutase (SOD), glutathione-s-transferase, reduced glutathione (GSH), and malondialdehyde (MDA) levels were assessed and key vasodilatory enzyme assays of angiotensin-converting enzyme (ACE-1), arginase, phosphodiesterase-5 enzyme (PDE-5) and nitric oxide (NO) levels were carried out. The levels of hormones (testosterone, follicle stimulating hormone and luteinizing hormone), lipid profile and histopathological analyses of the heart, lungs and penile tissues of the experimental animals were determined. Also, the gene expression levels of ACE-1, SOD, tumor necrosis factor (TNF-α) and endothelial nitric oxide synthase (eNOS) in the heart were quantified using quantitative real-time polymerase chain reaction (RT-qPCR). FC showed the best in-vitro antioxidant properties [DPPH*, ABTS*, Fe2+- induced lipid peroxidation, nitric oxide radical scavenging ability] and enzyme inhibitory activities on ACE-1, arginase and PDE-5 enzymes when compared with the other sandpaper leaves. FM showed the highest ability to increase SOD, GST activities, GSH level, NO level, testosterone level, arginase and PDE-5 inhibition and sexual behavioural function in L-NAME exposed rats. FC-treated rats showed the least structural aberration from histology screens in the heart, lungs and penile tissues. Furthermore, there was a significant reduction at P< 0.05 in body weight gain and the expression of TNF-α genes with an increase in the expressions of SOD and eNOS genes in the heart of FM-treated rats. FC-treated rats showed a significant reduction in diastolic blood pressure, heart rate, lowdensity lipoprotein (LDL)-cholesterol and an increase in high-density lipoprotein-cholesterol, ACE-1 and arginase enzyme inhibition. Conclusively, the results in this study revealed the antihypertensive and aphrodisiac potential of these sandpaper leaves through the modulation of enzymes’ activities and expression of genes linked to both degenerative conditions.