Antiinflammatory activities of flavonoids and a triterpene caffeate isolated from Bauhinia variegata

Abstract

In the continuing search for novel antiinflammatory agents, six flavonoids, namely kaempferol (1), ombuin (2), kaempferol 7,4'-dimethyl ether 3-O-beta-D-glucopyranoside (3), kaempferol 3-O-beta-D-glucopyranoside (4), isorhamnetin 3-O-beta-D-glucopyranoside (5) and hesperidin (6), together with one triterpene caffeate, 3beta-trans-(3,4-dihydroxycinnamoyloxy)olean-12-en-28-oic acid (7) were isolated from the non-woody aerial parts of Bauhinia variegata. Compounds 1-7 were evaluated as inhibitors of some macrophage functions involved in the inflammatory process. These seven compounds significantly and dose dependently inhibited lipopolysaccharide (LPS) and interferon (IFN)-gamma induced nitric oxide (NO), and cytokines [tumor necrosis factor (TNF)-alpha and interleukin (IL)-12]. The concentration causing a 50% inhibition (IC50) of NO, TNF-alpha and IL-12 production by compounds 1, 2 and 7 was approximately 30, 50 and 10 microM, respectively, while at 50, 200 and 40 microM compounds 3, 4, and 5, 6 showed 15-30% inhibition, respectively. On the other hand, compounds 3 and 7 showed no inhibitory effect, while compounds 1, 4-6 reduced by around 10-30% the synthesis of NO by macrophages, when inducible NO synthase was already expressed with LPS/IFN-gamma for 24 h. These experimental findings lend pharmacological support to the suggested folkloric uses of the plant B. variegata in the management of inflammatory conditions.

Evaluation of Bauhinia variegata L. bark fractions for in vitro antioxidant potential and protective effect against H2O2-induced oxidative damage to pBR322 DNA

“…Flavonoids prevent hydroxy radicalinduced damage (Husain et al, 1987) by donating an electron to neutralize the species (Morel et al, 1994). Biological properties of different Bauhinia species have been investigated in numerous experimental in vivo and in vitro models and the results indicate that the reported therapeutic properties are mainly due to the presence of flavonoids (Rao et al, 2008). Results obtained in the present study revealed that there is present a considerable level of total phenolic and flavonoid content in the polar extract/fractions viz., MEB, EAB, NBB and REB of B. variegata bark (Table 1).…”

Antioxidant, Phytotoxic and Antimicrobial Activities of Methanolic Extract of Bauhinia variegata Barks

“…The plates were then left for half an hour with the lid closed so that the extract diffused into media. The plate was incubated overnight at 37 0 C. After proper incubation (18-24 hours) the plates were observed for the zone of inhibition around well (Farrukh et al 2010, Nucrat et al 2006, Rao et al 2008.…”

Inhibitory Effect of the Ethyl Acetate Fraction of Ethanol Extract from Rhus verniciflua Stokes Wood on the Activity of Mushroom Tyrosinase

“…The polyphenolic components, which can be considered as derivatives of phenol, are known to have many physiological functions, and they are also sources of natural tyrosinase inhibitors. They are abundant in the ethyl acetate fractions of plant extracts (Rao et al 2008;Kang et al 2012). Polyphenolic constituents in the ethyl acetate fractions may contribute to the high anti-tyrosinase activity.…”