In vitro and in vivo anti-inflammatory potential of Cryptolepis buchanani

Cryptolepis buchanani Roem. & Schult. (Asclepiadaceae), a climbing tree, is used as folk medicine in southeast Asia. In Thailand, the stem of this plant is traditionally used for the treatment of inflammation, including arthritis, and muscle and joint pain. In the current study, the potential anti-inflammatory activity of a 50% ethanol extract of this plant was evaluated in a number of experimental models. For anti-acute inflammatory activity, results showed that the extract caused reduction of carrageenan-induced rat paw edema in addition to significant reduction of eicosanoid production from calcium ionophore A23187-stimulated rat peritoneal leukocytes. In a test for anti-chronic inflammatory potential utilizing the cotton thread-induced granuloma, the extract caused significant lowering of granulation tissue formation. The reduction of tumor necrosis factor-α (TNF-α) release from LPS-stimulated human monocytic cell line (THP-1) was also demonstrated in cells that were pre-incubated with the extract. An additional important feature of Cryptolepis buchanani is its low toxicity, especially by oral treatment, which significantly encourages clinical trials of this extract in the human. In conclusion, the results give scientific support to the traditional use of this plant for combating inflammation. Further investigations are required to identify the active constituents responsible for the anti-inflammatory activity of Cryptolepis buchanani. Subacute and chronic toxicological studies in animals are also needed before clinical trials.