Abstract
Obesity is a consequence of an imbalance between energy intake and energy expenditure. It affects people of both genders and all age groups, ethnicity and socioeconomic groups, and in developed and developing countries. Obesity is often accompanied by the metabolic syndrome (MetS). MetS is characterized by a clustering of cardiovascular risk factors, including high blood pressure, adiposity, dyslipidemia and glucose intolerance, which together increase the risk of atherosclerotic cardiovascular disease, type 2 diabetes mellitus and other causes of mortality. Nowadays, there is a growing interest in the use of plant-based agents instead of synthetic drugs to manage chronic diseases such as MetS; one such example is Berberis vulgaris. B. vulgaris contains isoquinonline alkaloids such as berberine, berberrubine and berbamine. Recent studies have proved that berberine exhibits pharmacological activities and positive effects on the risk factors of obesity and MetS. We have reviewed original articles related to the possible molecular mechanisms of action of berberine on obesity and MetS. Berberine suppresses adipocyte differentiation and decreases obesity. It also regulates glucose metabolism via decreasing insulin resistance and increasing insulin secretion. Other effects of berberine include antihyperlipidemic and antihypertensive activities and endothelial protection.