The present study investigated the antiobesity and
lipid lowering effects of an ethanolic extract of leaves obtained from Orthosiphon stamineus (200 and 400 mg/kg) and its major compound (
rosmarinic acid, 10 mg/kg) in obese mice (C57BL/6) induced by a high-fat diet. Continuous supplementation with O. stamineus extract (200 and 400 mg/kg) for 8 weeks significantly decreased
body weight gain (p < 0.05). However, supplementation with
rosmarinic acid, a constituent in the extract, produced only a slight reduction in
body weight gain compared to the high-fat diet control group. Food intake between the treatment and the high-fat diet groups was similar, which suggested that the
plant extract did not suppress food intake. Further,
body weight reduction of the treatment groups was not due to a decreased reduction in energy intake. Compared to the high-fat diet-fed group, serum
triglycerides, total
cholesterol, and
low-density lipoprotein cholesterol levels were significantly reduced in the treated groups, while
high-density lipoprotein cholesterol levels were not significantly altered. Accumulation of hepatic lipid droplets induced by a high-fat diet was markedly inhibited by O. stamineus extract. In addition, O. stamineus significantly diminished liver
malondialdehyde production, and significantly elevated the activities of hepatic superoxidase dismutase. The present study showed that an ethanolic extract prepared from the leaves of O. stamineus can significantly reduce a gain in
body weight, enhance
antioxidant activity, and possess hypolipidemic and antiobesity effects, thereby protecting against the adverse effects of high-fat diet-induced
obesity.