Anti-inflammatory effect of sea-buckthorn fruit in vivo

Abstract

Fruits of Hippophae rhamnoides L. has recently become a popular medicinal and nutritional herbal drug due to its beneficial constituents, mainly the high concentration of vitamin C, flavonoids, phytosterols, and carotenoids. Sea-buckthorn has been used in traditional medicine for treatment of asthma, skin diseases, gastric ulcers and lung disorders [1]. Preparations of the fruit are used nowadays in Hungary to treat allergic symptoms. To support traditional uses of sea-buckthorn berry we have investigated the in vivo anti-inflammatory effect of different extracts of the fruits and their active constituents were investigated by bioactivity-guided isolation. Aqueous and methanol extracts of the whole fruit and methanol extracts of different parts of the berries (peel, pulp, seeds) were tested on induced paw oedema test in rats. The 70% methanol peel extract was found to be the most potent, and it was further examined in different acute inflammation models induced by carrageenan, histamine, dextran, bradykinin, serotonine and by 48/80 substance to approach the mechanism of action. The extract inhibited only the 48/80 induced inflammation. The peel extract was subjected to liquid-liquid partitioning to yield chloroform, ethyl acetate, n-butanol and water soluble fractions. Only the chloroform soluble fraction was found to be active in 48/80-induced paw oedema test. The chloroform fraction was subjected then to vacuum liquid chromatography resulting 7 subfractions. In the most active subfraction high amounts of oleanolic acid (31%) and ursolic acid (19%) were detected. Both triterpenes display anti-inflammatory activity in 48/80-induced paw oedema test. Our results suggest that oleanolic acid and ursolic acid may be responsible unequivocally for the anti-allergic effect of the sea-buckthorn fruit peel extract due to their membrane stabilising effect.