Can Plant Extracts Help Prevent Hair Loss or Promote Hair Growth? A Review Comparing Their Therapeutic Efficacies, Phytochemical Components, and Modulatory Targets

This review investigates the potential of plant extracts in preventing and treating alopecia by examining their therapeutic efficacies, phytochemical components, and modulatory targets. Various plant extracts, such as those from Camellia japonica, Cucumis melo, Orthosiphon stamineus, and Panax ginseng, have shown promising results in enhancing the proliferation and viability of human follicle dermal papilla cells (HFDPCs) in vitro, promoting hair shaft growth in ex vivo hair follicle cultures, and stimulating hair growth in animal models. Clinical trials have verified the hair growth-promoting efficacy of several plant extracts. Active compounds like phenolic compounds, terpenes, sulfur-containing compounds, and fatty acids promote cell survival, proliferation, and the anagen phase of the hair cycle while reducing oxidative stress, inflammation, cellular senescence, and male hormone activity. Key signaling pathways involved include PKB/AKT, ERK, WNT, and SHH, with suppression of TGF-β and BMP pathways. The findings suggest that targeted therapies for alopecia could be developed from well-selected plant extracts and their active compounds, though further research is needed to fully understand their mechanisms and optimize their use.