The effect of Inula Viscosa extract on inflammation, microbial growth, glycemia, and blood lipid profile. (c2005)

Abstract

The present study evaluates the effects of a one month period of chronic consumption of water, methanol, and petroleum ether extracts of Inula viscosa on fasting blood lipid profile, sugar level, and liver enzymes in rats receiving a regular fat diet. The present investigation also included the antimicrobial and anti-inflammatory effect of the plant extract. A general fasting hypoglycemic effect was only observed with chronic intake of water extract. This hypoglycemic effect was accompanied with a significant increase in serum insulin concentration. Both methanol and petroleum ether extracts of Inula viscosa, showed a potential antimicrobial activity on gram-positive and gram-negative bacteria as well as antifungal effects. A dose dependent antimicrobial inhibition trend in both methanol and petroleum ether extracts was observed. In the acute inflammation induced by carrageenan, Inula viscosa water extract showed an anti-inflammatory effect with the 500 and 1000mg/kg B.W. doses, in a dose dependent manner. The 1000 mg/kg B.W. dose and diclofenac showed similar inflammatory inhibition (36% us 39%). In the chronic inflammatory study, Inula viscosa water extract showed a consistent dose dependant anti-inflammatory effect on formalin induced paw-edema. The 1000mg/kg B.W. dose had similar anti-inflammatory effect (44%) compared with diclofenac (44%). Water, methanol, and petroleum ether extracts contributed to substantial changes in the blood lipid profile. Although no significant changes in the concentration of circulating TAG was observed among the different groups, all extracts reduced significantly serum total cholesterol, LDL cholesterol and LDL/HDL cholesterol ratio with respect to the control group. Only the methanol group showed a significant decrease in the concentration of HDL-cholesterol with respect to all other groups. VLDL apolipoprotein B100 (apo B100) showed no significant differences among the different groups. Determination of SGOT, SGPT and LDH activities showed similar values in all groups except with LDH where the activities were significantly lower than the control group. In conclusion, Inula viscosa methanol and petroleum ether extracts appeared to have important anti-bacterial and anti-fungal activities. Water extract seems to be a very effective anti-inflammatory drug that may be used for both acute and chronic inflammation. The water extract is also effective in reducing serum glucose level via possibly promoting insulin secretion by the pancreas. Both water and petroleum ether extracts appear to be effective in reducing blood cholesterol level through enhanced lipoprotein metabolism and clearance. No liver damage has occurred during the study period with all extract used.