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Centipeda minima has been used since centuries as a traditional medicinal plant in treating a number of disease conditions, the bioactive components responsible for its anti-inflammatory and anti-arthritis activity have not been identified. The present study was planned to isolate flavonoids fractions from Centipeda minima leaves extracts, and assessed anti-inflammatory and anti-arthritis activity in rats. The hydroalcoholic and aqueous extracts of Centipeda minima leaves were prepared and evaluated for in vitro antioxidant activity namely DPPH, total polyphenol content, total flavonol content and reducing power assay. The different fractions were isolated from hydroalcoholic extracts by using column chromatography. The Flavonoids fractions were investigated for anti-inflammatory and anti-arthritis activity in carrageenan rat induced paw oedema, cotton pellet-induced granuloma model and adjuvant induced chronic arthritis in rats. The findings of in vitro antioxidant activity confirmed that hydroalcoholic extracts expressed higher antioxidant activity compared to aqueous extract, and hence hydroalcoholic extracts was further selected for the isolation of various fractions. The results of phytochemical study suggest that FCM6, FCM7 and FCM8 exposed the presence of polyphenol and flavonoids. The fraction FCM6, FCM7 and FCM8 (25 mg/kg) exhibits significant antiinflammatory and anti-arthritis activity. The outcomes suggest that the anti-inflammatory and anti-arthritis activity of isolated fraction was due to presence of flavonoids and polyphenols.

Double exchange (DE)-mediated ferromagnetism in manganites, in which the Zener pair (Mn3+/Mn4+) is a key factor, is marked by the coexistence of the magnetic transition and the metal-insulator transition, thus distinguishing itself from superexchange (SE)-mediated ferromagnetism. Through detailed magnetization, transport and XAS studies, it was proposed by some of us that a unique magnetic pair-making effect occurs in Ru-substituted La0.6Pb0.4Mn1-xRUxO3 by virtue of variable valency of Ru and Mn. Ru ion, exhibiting a variable valency of Ru4+ and Ru5+, governs the DE-mediated coupling by initiating a magnetic pair-making effect with Mn3+ and Mn4+ states. Neutron diffraction measurements carried out on these compounds in the temperature range 4.2-500 K reveal the microscopic nature of magnetic ordering. Data obtained, in conjunction with data from other experimental techniques above, show that (i) Ru participates in the DE interaction with Mn for x 0.4, and (iii) SE ferromagnetic interactions are favored for x > 0.4. (c) 2006 Elsevier B.V. All rights reserved.