ABSTRACT:
Natural products are recognized for skincare application, and their extracts have provided the essential phytochemical nutrients for skin health. Due to Schumannianthus dichotomus or “Khla” rhizome has been traditionally utilized for treatment of skin diseases, and the ethanol extraction of this rhizome (KE) has chosen to mimic the common method of Thai herbal preparations. The aims of this study were to screen the phytochemicals of KE including total phenolic content (TPC), total flavonoid content (TFC), and common ten phenolic acids and flavonoids i.e. gallic acid, tannic acid, hydroquinin, quercetin, isoquercetin, rutin, kaempferol, apigenin, eriodictyol, and catechin. Furthermore, in vitro biological activities of KE including antioxidants, anti-inflammation, anti-microbial and cytotoxicity were also to evaluate this extract as skincare ingredient. As our results, TPC and TFC were 299.83±6.23 mg GAE/g and 81.10±4.10 mg QE/g, respectively. The catechin and rutin were 22.76 and 3.67 mg/kg, respectively. There was exhibited DPPH and NO radical scavenging activity (SC50 = 0.01±0.0 and 6.49±1.59 mg/ml), and inhibited lipid peroxidation (IPC50 = 0.01±0.0 mg/ml), while lack of metal chelating activity. Anti-bacterial activity of KE against Cutibacterium acnes, the major acne-associated bacteria. Therefore, it is unable to inhibit other skin pathogens including Staphylococcus aureus, Candida albicans and Malassezia furfur. Anti-inflammatory activity of KE (0.1 mg/ml) was reduced NO production from LPS-induced macrophages (24.15±1.45%). KE was a lack of cytotoxicity against mouse macrophages and human skin fibroblasts (up to 1.0 and 0.1 mg/ml, respectively). This finding provided preclinical information on the use of S. dichotomus rhizome on cosmetic purposes.