Aqueous and ethanol extracts prepared from leaves of Olea europaea L. were evaluated for in vitro antioxidant and in vivo hypocholesterolemic effect. The result of administration of O. europaea leaf extracts on serum total cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) in hypercholesterolaemic mice was evaluated. In addition, rutin and luteolin, reported to occur naturally in O. europaea leaves, were docked against HMG-CoA reductase, the rate-limiting enzyme in cholesterol metabolism. Mice treated with both extracts showed reduced total cholesterol (246.6 and 163.4 mg/dl, for mice groups treated with respective extracts) and LDL (150.16 and 81.28 mg/dl, for mice groups treated with respective extracts) levels as compared to the hypercholesterolaemic group (total cholesterol 253.00 mg/dl and LDL 160.00 mg/dl). Mice treated with aqueous extract (200 mg/kg body weight) showed significantly reduced triglyceride and VLDL levels as compared to the group treated with atorvastatine. HDL level of mice administered with O. europaea aqueous extract was comparable to the atorvastatine-treated group. The ethanol extract of O. europeae leaves was a potent antioxidant (IC50 69.15 mg/ml, % inhibition 54.98, 82.63 mg ascorbic acid equivalent/g extract, 7.53 mol of Fe2+/g extract, and % inhibition 49.71, for the DPPH, β-carotene bleaching, total antioxidant capacity, FRAP, and ferric thiocyanate assays, respectively). Docking studies revealed that rutin showed higher binding affinity with HMG-CoA reductase as compared to luteolin. Data gathered from this study support the development of a prophylactic biomedicine from O. europaea leaves for the management of hypercholesterolemia and atherosclerosis.
Background: Morinda citrifolia L. is widely used as a folk medicinal food plant to manage a panoply of diseases, though no concrete reports on its potential anti-obesity activity. This study aimed to evaluate the potential of M. citrifolia leaf extracts (MLE60) in the prevention of weight gain in vivo and establish its phytochemical profile. Design: Male Sprague-Dawley rats were divided into groups based on a normal diet (ND) or high fat diet (HFD), with or without MLE60 supplementation (150 and 350 mg/kg body weight) and assessed for any reduction in weight gain. Plasma leptin, insulin, adiponectin, and ghrelin of all groups were determined. (1)H NMR and LCMS methods were employed for phytochemical profiling of MLE60. Results: The supplementation of MLE60 did not affect food intake indicating that appetite suppression might not be the main anti-obesity mechanism involved. In the treated groups, MLE60 prevented weight gain, most likely through an inhibition of pancreatic and lipoprotein activity with a positive influence on the lipid profiles and a reduction in LDL levels . MLE60 also attenuated visceral fat deposition in treated subjects with improvement in the plasma levels of obesity-linked factors . (1)Spectral analysis showed the presence of several bioactive compounds with rutin being more predominant. Conclusion: MLE60 shows promise as an anti-obesity agents and warrants further research.
Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research.