Antihypercholesterolemic, antioxidative and anti-inflammatory potential of an extract of the plant Tabernaemontana divaricata in experimental rats fed an atherogenic diet

Abstract

Abstract The present study highlights the putative anti-atherogenic, antioxidative and anti-inflammatory potential of Tabernaemontana divaricata extract (ethanolic) in a Wistar rat model of experimental hypercholesterolemia. The rats were divided into Group I (control), Group II (atherogenic diet-fed, saline-treated) and Group III (atherogenic diet-fed, T. divaricata extract-treated [200\u202fmg/kg/b.wt]). The levels of lipid profile parameters (total cholesterol, triglycerides, high-density, low-density and very low-density lipoprotein cholesterol and atherogenic index) and C-reactive protein (CRP) were investigated in serum samples. The levels of enzymatic and non-enzymatic antioxidants, malondialdehyde and nitric oxide (NO), and gene and protein expression levels of CRP, inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) and gene expression levels of interleukin-1β (IL-1β) were determined in liver tissue samples. Rats of Group II showed significantly heightened mean concentrations of CRP, and lower mean levels of lipid profile parameters, except high-density lipoprotein cholesterol, than control rats; Rats of Group II also exhibited significantly lower mean activities/levels of enzymatic and non-enzymatic antioxidants and heightened mean malondialdehyde and NO content compared to control animals. However, in Group III rats, the values were significantly improved, in contrast to Group II rats. Significantly higher gene expression of IL-1β and significantly higher gene and protein expression of CRP, iNOS and TNF-α occurred in liver samples from hypercholesterolemic rats compared to control rats. In liver samples from Group III rats, gene and protein expression was not markedly elevated. The T. divaricata extract thus exhibited anti-atherogenic potential in hypercholesterolemic Wistar rats due to its hypocholesterolemic, antioxidant and anti-inflammatory effects.