Role of Herbal Extracts of Catechu from Uncaria gambir in the Treatment of Chronic Diabetic Wounds

Catechu is a dried decoction from twigs with the leaves of Uncaria gambir. Its antioxidant, anti-inflammatory, and antimicrobial activities have been previously reported because of its high catechin and epicatechin content (>21%). It is also one of the components used in traditional Chinese herbal medicine, “Jinchuang Ointment,” which has excellent efficacy in treating chronic diabetic wounds. An in vivo zebrafish embryo platform and an in vitro cell-based tube formation assay were used to measure the angiogenic activity of catechu extracts. Interestingly, for the first time, catechu extracts stimulated angiogenic activity on both platforms. The expression of the IL-8 gene was induced in HMEC1 cells after treatment with catechu extracts for 1 h only. In contrast, the upregulation of FGFR2, FGFR3, NF-κB, STAT3, and vimentin persisted for 24 h. A summary of the possible mechanisms underlying the angiogenic activity of catechu extracts in HMEC1 cells is shown. Unexpectedly, catechu extracts inhibited the migration of HaCaT cells. These results can account for the intense blood flow flux in porcine excisional wound sites in our previous studies, which provides insights into the therapeutic activity of catechu extract in chronic diabetic wounds.