Abstract:We investigated the lipid-lowering effects of methanolic extract of Vernonia amygdalina (VA) leaves in rats fed an high cholesterol diet, and compared with a standard hypolipidemic drug, Questran (Qu). The effects of VA on the lipid profi le were assessed by measuring the levels of total cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, lipid peroxidation (LPO), phospholipid, and glutathione (GSH) in the plasma and liver of the rats. Administration of cholesterol at a dose of 30 mg/0.3 ml, fi ve times in a week for nine consecutive weeks resulted in a signifi cant increase (p Ͻ 0.05) in plasma and post mitochondrial fraction (PMF) cholesterol levels by 33% and 55%, respectively. However, treatment with extract of VA at doses of 100 and 200 mg/kg caused a dose dependent reduction in the plasma and PMF cholesterol by 20%, 23% and 23%, 29%, respectively. Similar reduction in cholesterol levels was obtained in Qu-treated rats. Furthermore, VA at 200 mg/kg decreased the plasma and PMF LDL-cholesterol levels by 23% and 49%, and also decreased plasma and PMF triglyceride levels by 29% and 28%, respectively. Also, VA at 100 and 200 mg/kg caused a dosedependent increase in plasma HDL-cholesterol levels by 41% and 59%, respectively. However, there were no signifi cant differences (p Ͼ 0.05) in the PMF HDL-cholesterol and phospholipid levels of the treated rats when compared to hypercholesterolemic rats. There were signifi cant decreases (p Ͻ 0.05) in the LPO levels of extract-treated rats. Precisely, VA at 100 and 200 mg/kg decreased the levels of plasma and PMF LPO by 38%, 42% and 35%, 45%, respectively. In addition, VA augmented the cholesterol-induced decrease in PMF glutathione levels of the rats. Taken together, these results suggest the lipid-lowering effects of VA and, probably serve as a new potential natural product for the treatment of hyperlipidemia.

Telfairia occidentalis (fluted pumpkin) is one of the commonly consumed leafy vegetables in Nigeria. In order to justify its inclusion in herbal preparations in African traditional medicine, the possible hypolipidemic effect of this vegetable was investigated in rats fed a cholesterol-rich diet. The ability of Questran, a hypolipidemic drug, to attenuate hypercholesterolemia was also examined. Rats were fed with either a basal diet containing cholic acid (0.2%) or a supplemented diet with T. occidentalis at the 3% and 6% levels. Oral administration of cholesterol for 9 consecutive weeks resulted in a significant increase (P < .001) in the relative weight of the heart of cholesterol-fed rats. However, supplemented diets significantly (P < .001) ameliorated the cholesterol-induced enlargement of the heart. Rats fed on supplemented diets had a dose-dependent reduction in plasma and postmitochondrial supernatant fraction (PMF) cholesterol levels. In particular, supplemented diets containing 3% and 6% T. occidentalis decreased plasma and PMF cholesterol levels by 20% and 30% and by 30% and 45%, respectively. A similar decrease in plasma and PMF cholesterol levels was obtained in Questran-treated hypercholesterolemic rats. Furthermore, 3% and 6% T. occidentalis-supplemented diets significantly (P < .05) decreased the cholesterol-induced increase in plasma and PMF low-density lipoprotein (LDL) cholesterol levels by 24% and 48% and by 28% and 52%, respectively. In contrast, there was no significant difference (P > .05) in plasma and PMF triglyceride levels of rats fed on supplemented diets when compared with cholesterol-fed rats. There were significant decreases (P < .05) in lipid peroxidation levels in rats fed on the supplemented diets. Specifically, 3% and 6% T. occidentalis-supplemented diets decreased plasma and PMF lipid peroxidation by 24% and 20% and by 42% and 21%, respectively. This study demonstrates that T. occidentalis may be a useful therapy for hypercholesterolemia through reducing oxidative stress and cholesterol levels.

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Background: Mitochondrial-mediated cell death begins with opening of mitochondrial membrane permeability transition (mPT) pore and medicinal plants contain phytochemicals that modulate the mPT pore. Hypothesis and Purpose: We investigated the modulatory effects of crude methanol extract of Daniellia oliveri leaves (CMDO) on mPT pore in vitro. Study Design and Methods: Phytochemical screening and antioxidant activities of crude methanol extract of Daniellia oliveri leaves (CMDO) were evaluated according to standard procedures. CMDO was partitioned into chloroform fraction (CFDO), ethyl acetate fraction (EFDO) and methanol fraction (MFDO) by Vacuum liquid chromatography (VLC). Effects of CMDO, CFDO, EFDO and MFDO on mPT pore were assessed by spectrophotometry. Effects of the most potent fraction on mitochondrial ATPase, Fe-induced lipid peroxidation and cytochrome c release were assessed by spectrophotometry. CMDO was subjected to GC-MS analysis to identify the bioactive compounds present. Results: CMDO contains phytochemicals and showed appreciable total flavonoid content (0.483±0.02 QE mg/100g), total phenolic content (0.886±0.12 GAE mg/100g), total antioxidant capacity (0.039±0.001 AE mg/100 g), ferric antioxidant reducing power (IC50=350 µg/ml) and 2, 2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging activity (IC50=166 µg/ml). The maximum induction of mPT pore opening in the absence and presence of calcium, respectively, were as follows: CMDO (10.11 folds, 5.18 folds), CFDO (19.9 folds, 16.3 folds), EFDO (7.5 folds, 23.2 folds), MFDO (22.2 folds, 31.3 folds). The most potent mPT pore-opening fraction (MFDO) enhanced mitochondrial ATPase activity, inhibited Fe-induced lipid peroxidation and caused cytochrome c release. GC-MS analysis of CMDO revealed the presence of bioactive compounds including methyl propanamide, Dibutyl phthalate, saturated and unsaturated fatty acids. Conclusion: Methanol fraction (MFDO) of CMDO most potently induced mPT pore opening via enhancement of mitochondrial ATPase activity, which was substantiated by the release of cytochrome c (in vitro). This includes MFDO as a candidate pharmacologic remedy for diseases associated with insufficient apoptosis.

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