Pinus thunbergii bark extract rich in flavonoids promotes hair growth in dorsal skin by regulating inflammatory cytokines and increasing growth factors in mice

Abstract

Korean maritime pine bark ( Pinus thunbergii ) has been used as an alternative medicine due to its beneficial properties, including anti-inflammatory effects. To date, the anti-inflammatory and hair growth-promoting effects of Pinus densiflora bark extract have remained elusive. Therefore, in the present study, Pinus thunbergii bark was extracted with pure water (100°C) and the extract was examined to determine its polyphenol and flavonoid content. C57BL/6 mice were used to assess the effects of the extract to promote hair growth. The extract (1, 2 and 4%) was topically applied onto shaved dorsal skin and hair growth was observed for 17 days. A significant increase in hair growth was observed with 2 and 4% extract. Based on this finding, the optimal dose of the extract for effective hair growth promotion was determined to be 2%. The mechanisms of hair growth promotion were investigated via immunohistochemical analysis of changes in inflammatory cytokines and growth factors in the hair follicles following treatment with 2% extract. The treatment reduced the levels of TNF-α and IL-1β, which are pro-inflammatory cytokines, while it enhanced the levels of IL-4 and IL-13, which are anti-inflammatory cytokines, in the hair follicles. In addition, elevated insulin-like growth factor I and vascular epidermal growth factor were detected in hair follicles following treatment. Based on these findings, it was suggested that the extract of Pinus thunbergii bark may be utilized for hair loss prevention and/or hair growth promotion.

Flavonoids in safflower extract reduce cisplatin-induced damage to human follicle dermal papilla cells by inhibiting DNA damage and Rad17/Chk1/Cdc25C signaling

“…Among these, flavonoids have been found to be the most effective in promoting hair regeneration in BalB/c mice (Rambwawasvika et al, 2019). In vivo experiments have shown that flavonoids, such as the flavonoid-rich extract of Pinus thunbergii bark, can also promote hair regeneration, which promotes hair growth in C57BL/6 mice by regulating the expression of inflammatory substances and promoting growth factors (Her et al, 2022). Similarly, the addition of flavonoid-rich extract of Equisetum hyemale L. was found to promote hair regrowth in Sprague Dawley rats with chemically-induced alopecia (David et al, 2019).…”

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

“…Some extracts alleviated inflammatory response determined by the expression levels of inflammatory cytokines, such as tumor necrosis factor-alpha (TNFα), interleukin (IL)-1β, and IL-6 [59,65,67,98], or cellular senescence determined by the expression level of senescence-associated β-galactosidase (SA-β-gal) [61,65,67] in cells stimulated with phorbol-12-myristate 13-acetate (PMA) plus calcium ionophore A23187 [50], H 2 O 2 [59,61,65], or androgen [67]. The anti-inflammatory effects of extracts of Angelica gigas and Pinus thunbergii were shown by the reduced levels of pro-inflammatory cytokines (TNF-α and IL-1β) and increased levels of anti-inflammatory cytokines (IL-4 and IL-13) in the dorsal skin of mice [50,108]. In silico molecular docking analysis of phytochemical components of Leea indica resulted in the identification of several compounds with high ligand efficiencies towards prostaglandin D 2 synthase, implicating their potential anti-inflammatory activity [103].…”

Biomolecules of Fermented Tropical Fruits and Fermenting Microbes as Regulators of Human Hair Loss, Hair Quality, and Scalp Microbiota

“…As a general mechanism, many herbs, higher plants, and their active constituents used for the management of alopecia target the hair cycle - keratinocyte proliferation, apoptosis, angiogenesis, microcirculation around hair bulb, hormones, and inflammation [ 21 ]. Numerous secondary metabolite-enriched extracts of plants/algae, such as Serenoa repens [ 22 , 23 ], Panax ginseng Mayer [ 24 ], bergamot [ 25 ], Pinus thunbergii [ 26 ], Crataegus pinnatifida [ 27 ], Aconiti Ciliare Tuber [ 28 ], Caesalpinia sappan L. [ 29 ], Ecklonia cava [ 30 ], and many others have been investigated in preclinical studies for their hair growth-promoting or hair loss-inhibiting actions. Among the biologically active substances, plant polyphenols, alkaloids, terpenoids have been identified, along with lipids and fatty acids, reviewed in [ 31 , 32 ].…”