Hair Growth Promotion Activity and Its Mechanism of Polygonum multiflorum

Area of Science:

• Pharmacology and Traditional Medicine
• Dermatology and Hair Biology
• Natural Product Research

Background:

• Polygonum multiflorum Radix (PMR) is traditionally used for hair growth and coloring, but its mechanisms and optimal application require scientific validation.
• Existing clinical applications of PMR face challenges regarding efficacy and mechanistic understanding.
• Scientific evidence for the hair growth promotion and coloring effects of PMR is limited.

Purpose of the Study:

• To investigate the hair growth promotion activity of PMR and Polygonum multiflorum Radix Preparata (PMRP) in C57BL/6J mice.
• To elucidate the underlying mechanisms of hair growth promotion by PMR and PMRP, focusing on key cytokine regulation.
• To compare the efficacy of oral versus topical administration of PMR and PMRP for hair growth.

Main Methods:

• Hair growth was assessed using metrics including hair length, hair-covered skin ratio, follicle count, and hair color in C57BL/6J mice.
• The expression levels of cytokines involved in hair growth, such as FGF-7, SHH, β-catenin, IGF-1, and HGF, were analyzed.
• Comparative study involving oral administration of PMR and PMRP, and topical application of PMRP.

Main Results:

• Oral PMR achieved a 100% hair-covered skin ratio, significantly higher than oral PMRP (48%–88%).
• Topical PMRP demonstrated substantial hair growth promotion with approximately 90% hair coverage.
• Oral PMR's effect is linked to FGF-7 expression, while topical PMRP's effect is associated with SHH stimulation.

Conclusions:

• Both oral PMR and topical PMRP exhibit significant hair growth promotion activities.
• PMR is more suitable for oral administration, whereas PMRP shows greater efficacy when applied topically.
• The distinct mechanisms involve FGF-7 upregulation for oral PMR and SHH stimulation for topical PMRP.