Flavonoids of Enhydra Fluctuans exhibits analgesic and anti-inflammatory activity in different animal models

Enhydra fluctuans (Compositae), an edible semi aquatic herbaceous vegetable plant, widely used in traditional system of Indian medicine. Total flavonoids of E. fluctuans (TFEF) were screened for analgesic and anti-inflammatory activity. Analgesic activity was studied in acetic acid induced writhing response and by hot plate method in Swiss albino mice. Anti-inflammatory activity was estimated by carrageenan and histamine induced acute inflammation and Freund's complete adjuvant (FCA) induced chronic inflammation in rats. Two flavonoids, baicalein 7-O-glucoside and baicalein 7-O-diglucoside, were isolated from the ethyl acetate fraction. Oral administration of TFEF at the doses of 200 and 400 mg/kg provide 27.05 and 55.49% protection respectively in acetic acid induced writhing method. It also increased the pain threshold in mice evidenced by hot plate method. TFEF showed more potent anti-inflammatory activity. The results of this study may be attributed to high free radical scavenging and antioxidant potential of the flavonoids present in ethyl acetate fraction of Enhydra fluctuans.