Cat's whiskers flavonoid attenuated oxidative DNA damage and acute inflammation: its importance in lymphocytes of patients with rheumatoid arthritis.

Cleome gynandra L. (Capparidaceae) is one of the vegetables commonly known as 'Hurhur' and 'Karaila' in India, 'Pe Hua Tsai' in China and "Cat's whiskers" in English. Present study was aimed to characterize previously isolated Cat's whiskers flavonoid as 5-hydroxy-3, 7, 4' -trimethoxyflavone (5HTMF) and to evaluate its effect on carrageenan-induced acute inflammation in rats and hydrogen peroxide induced DNA damage in mouse macrophages. The ex vivo effect of 5HTMF upon generation of free radicals in the mononuclear lymphocytes of patients with rheumatoid arthritis (RA) was also evaluated. 5HTMF not only reduce the swelling of hind paw in rats from 1 to 3 h of carrageenan injection but also decreased serum nitric oxide (NO) production. Toxic hydrogen peroxide induced oxidative DNA damage that was significantly decreased by 5HTMF. Though oxidative stress is a potential biomarker for determining disease activity in patients with RA, surprisingly 5HTMF inhibited the superoxide, hydroxyl and NO radicals in the isolated peripheral blood mononuclear lymphocytes of patients with RA. From the above study, it may be concluded 5HTMF attenuated acute inflammation by inhibiting NO and by protecting the oxidative DNA damage due to hydrogen peroxide scavenging property. It was also equally effective in scavenging the free radicals in lymphocytes of patients with RA. Collectively, our results indicate that 5HTMF as well as leafy vegetable of Cat's whiskers may be a promising nontoxic food alternative in attenuating the oxidative stress, meriting further studies on other human inflammatory cells.