Carnosic acid, a new class of lipid absorption inhibitor from sage

The methanolic extract from the leaves of Salvia officinalis L. (sage) showed significant inhibitory effect on serum triglyceride elevation in olive oil-loaded mice (500 and 1000 mg/kg, p.o.) and inhibitory activity (IC50: 94 μg/mL) against pancreatic lipase, which is participated in digestion of lipids. Through bioassay-guided separation using the inhibitory activity against pancreatic lipase activity, 4 abietan-type diterpenes (carnosic acid, carnosol, royleanonic acid, 7-methoxyrosmanol) and a triterpene (oleanolic acid) were isolated from the active fraction. Among these compounds, carnosic acid and carnosol substantially inhibited pancreatic lipase activity with IC50 values of 12 μg/mL (36 μM) and 4.4 μg/mL (13 μM), respectively. Carnosic acid significantly inhibited triglyceride elevation in olive oil-loaded mice at doses of 5–20 mg/kg (p.o.). However, other constituents (carnosol, royleanonic acid, oleanolic acid) did not show any effects at a dose of 200 mg/kg (p.o.). Furthermore, carnosic acid (20 mg/kg/day, p.o.) reduced the gain of body weight and the accumulation of epididymal fat weight in high fat diet-fed mice after 14 days.