Development of Rice By-Products Based Hair Tonic Mixed with Traditional Thai Herbal Extracts: A Sustainable Approach for Hair Care

Previously, byproducts from Thai rice mill industry including crude riceberry oil (CRO) and broken riceberry (BRB) showed antioxidant and tyrosinase-stimulating activities. This work aimed to develop 5 hair tonic formulae by mixing CRO (0.2-1.0%) and BRB (0.4-2.0%) with three Thai traditional herbal ethanolic extracts (2.0%) of Catunaregam tomentosa (CT), Acacia concinna (AC) and Tinospora crispa (TC) in 4:3:3 (v/v). The results showed that formula 5 (F5) containing 2% BRB, 1.0% CRO and 2% herbal extracts exhibited the highest antioxidant activity (DPPH scavenging capacity at 16.6 TEAC mg/g, FRAP value at 1.18 FeSO4 mg/g, and ABTS value at 14.9 TEAC mg/g) and tyrosinase-stimulating activity of 38%. This hair tonic was safe to use based on skin irritation test, and stable over 8-week storage at room temperature. Hence, F5 hair tonic (coded (R)) was tested on 20 subjects divided in 2 groups (older and younger age groups) with 10 individuals each in a randomized, double-blind, placebo-controlled experimental design with split-head method where treatments were conducted as intra-individual trial for 10, 20 and 30 days. The hair tonic coded C (Control without BRB, CRO or herbal extracts) and the commercial hair tonic coded G were tested for comparison. Adverse reactions were not noticed during the study. The hair tonic R was able to reduce hair loss by 48-71% in 2 groups with no significant difference from the commercial hair tonic. In comparison with the efficacy in the reduction of gray hair of the 2 groups at each time interval, the 2experimental (R) hair tonic product was found to be more effective in group 2 (younger age). However, the efficacy in the reduction of gray hair was lower than that in the reduction of hair loss. The experimental hair tonic R was more effective in dandruff reduction in group 1 (older age). The R hair tonic product received a satisfactory score of 6.79±0.32 out of 9.0 (moderate-to-high likeness) with the highest score from the aroma and the lowest score from the opaque color resulting from mixing aqueous herbal extract and oil. This is a sustainable way to add value to byproducts from rice mill industry and Thai traditional herbs as cosmetic elements in the formulation of hair products.