The Potential of Resveratrol-Rich Peanut Callus Extract in Promoting Hair Growth and Preventing Hair Loss

Resveratrol has been found to stimulate the growth of human dermal papilla cells (hDPCs) and protect them from oxidative damage. The topical application of resveratrol effectively enhanced hair growth and stimulated the transition of the hair cycle from the resting phase (telogen) into the active growth phase (anagen phase). The aim of this study was to examine the effects of resveratrol-rich peanut callus and sprout extracts on promoting hair growth and anti-hair loss effects in hDPCs and then select the most effective extract (callus) for further assessment in clinical applications. The peanut sprout and callus were produced from plant seeds and extracted with ethanol. Resveratrol was identified as the major constituent in the extracts obtained using the HPLC approach, although no resveratrol was found in the original seed extract. Hair cell proliferation, growth factor expression, and 5α-reductase (5-AR) inhibition assays were used to examine the extracts’ promotion of hair growth and inhibition of anti-hair loss in an in vitro hDPCs model, and standard resveratrol served as a positive reference. Initially, the cytotoxicity of the samples was assessed, revealing that 2.5% of all extracts and 0.02% of resveratrol exhibited a non-cytotoxic effect to hDPCs. The 50% cytotoxic concentration of peanut callus extract (15.50 ± 0.05%) was significantly less cytotoxic to hDPCs than sprout (12.30 ± 0.14%) and seed (11.69 ± 0.26%) extracts (p < 0.05). In vitro experiments indicated that peanut callus extract had the greatest proliferated hDPCs (20.44 ± 0.78%), increased the expression of growth factors (IGF-1, KGF, and HGF) and inhibited 5AR (27.83 ± 2.48%). Then, the callus extract and resveratrol as the positive standard were separately incorporated into a hair serum base and assessed for anti-hair loss effect in a randomized, double-blind, placebo-controlled clinical trial on 60 subjects, and the daily hair shedding count, one-minute combing, and forcible hair pluck tests were monitored for 12 weeks. The clinical study showed that the hair serum containing peanut callus extract and resveratrol were effective in reducing hair shedding (66.98% and 61.47%), decreased hair fall from combing by (83.92% and 68.19%), and increased the ratio of the anagen/telogen by (3.3 and 2.8, respectively). The results suggest that peanut callus extract has a significant amount of resveratrol and the potential to stimulate hair growth and prevent hair loss, making it an alternative bioactive option for cosmetic applications.