HPLC analysis and in vitro antioxidant mediated through cell migration effect of C.hystrix water extract on human keratinocytes and fibroblasts

Citrus hystrix or kaffir lime is a native tropical plant containing a high level of phenolic and flavonoid compounds. Its fruits are used as a food ingredient to enhance the sour-sweet scent and flavor in many dishes. Due to its polyphenol-containing, it has also been used as traditional medicine for health benefits including oral and gum health, stress relief, hair care, and skincare. In this study, we demonstrated the antioxidant activity of C. hystrix water extract and its effect on human keratinocyte and fibroblast migration. The extract showed a high amount of phenolic and flavonoid contents. The HPLC analysis indicated the presence of gallic acid, catechin, caffeic acid, rutin, and quercetin. We showed that C. hystrix water extract exhibited free radical scavenging capacity, determined by DPPH assay, with IC(50) of 14.91 mg/mL, and nitrite radical scavenging capacity, determined by NO assay, with IC(50) of 4.46 mg/mL. The C. hystrix water extract displayed unnoticeable toxicity at all tested doses. We showed that the treatment of water extracts as low as 50 μg/mL decreased the reactive oxygen species (ROS) from H(2)O(2)-induced ROS formation in both cell lines. Besides, C. hystrix water extract promoted cell migration in a dose-dependent manner. Together, these results demonstrated the positive benefit of C. hystrix water extract as a wound-healing accelerator. Its health benefits may be due to the antioxidant capability of its phytochemical compounds contained in C. hystrix water extract that enhances the migration of two major cell types: fibroblast and keratinocytes, responsible for the proliferation and remodeling phase of wound healing.