Bioactive compounds and antioxidant properties of Houttuynia cordata for hair cosmetic application

Abstract

Houttuynia cordata or “Plu Kaow“ in Thai, a perennial herb, has been used as an edible vegetable and traditional medicine plant due to its health benefits such as anti-inflammatory, antiviral, antioxidants, and skin disease. The aims of this study were to evaluate bioactive compounds (total phenolic (TPC), flavonoid (TFC), proanthocyanidins (TPAC) contents and antioxidant properties (ABTS, DPPH and FRAP activities) of Plu Kaow for used in hair cosmetic applications. Plu Kaow powder was extracted with three different solvents including DI water, 70% methanol and 70% ethanol, using an incubator shaker at 150 rpm for 6 h. The results showed that the highest yield was found in the methanolic Plu Kaow extract (8.73%). The methanolic of Plu Kaow extract had statistically the highest TPC and TPAC (128.27±8.45 mg GAE/g extract, 206.67±21.80 mg CE/g extract, p<0.05, respectively). Although, TFC showed no statistical difference between these three extracts, the methanolic Plu Kaow extract exhibited the highest TFC (70.74±17.31 mg QE/g extract). In the antioxidant study, the significantly highest antioxidant activities in DPPH and ABTS were found in the methanolic Plu Kaow extract (0.54±0.04 and 0.88±0.01 mg TEAC/g extract, p<0.05, respectively). In the FRAP assay, the result showed that the statistically highest was found in the ethanolic Plu Kaow extract (0.95±0.00 mg TEAC/g extract, p<0.05). According to the results, the methanolic extract Plu Kaow exhibited higher contents in bioactive compounds and antioxidant activities than other solvents. Thus, the methanolic Plu Kaow extract should be used as an active ingredient in a hair tonic formulation. Hair tonic were made by 1% and 5% methanolic Plu Kaow extract (concentration 1 mg/mL) and other ingredients such as 95% ethanol, propylene glycol, menthol, DMDM hydantoin, sodium metabisulfite. Moreover, these hair tonics were stable through Freeze-thaw cycle testing and suitable to use on scalp due to pH of products (pH 5.5). Hair tonic with 1% methanolic Plu Kaow extract was satisfied in terms of good characteristic and good feeling after use with a light texture. Results suggested that Plu Kaow extract (especially the methanolic extract) can be used as natural antioxidant for preventing anti-aging including hair aging (hair loss, or gray hair).