Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

BACKGROUND: Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption

Weight reducing and hypocholesterolemic effects of aqueous extract of the leaves of Tridax procumbens Linn on sub-chronic salt-loaded rats

The effects of aqueous extract of Tridax procumbens on the weight gain and organ weights, plasma lipid profiles and atherogenic indices were studied in sub-chronic salt-loaded Wistar rats. The control group received a diet consisting 100% of the commercial feed, while the four test groups received a diet consisting 8% salt and 92% commercial feed all through, except for the reference treatment group that had its salt-loading discontinued after six weeks. The extract was orally administered daily at 150 and 200 mg/kg body weight; while the test control, reference and control groups received appropriate volumes of water by the same route. Compared to test control, the treatment produced lower (significantly, P<0.05) mean daily weight gain, plasma LDL and non-HDL cholesterol, and (non-significantly) atherogenic indices, plasma triglyceride, total- and VLDL-cholesterol; and higher plasma HDL cholesterol, without significant alterations in organ weights and sizes. These results indicate a likely dose dependent cardio-protective potential of the extract on the hypertensives