title: Extracts from Radix Astragali and Radix Rehmanniae promote keratinocyte proliferation by regulating expression of growth factor receptors.
abstract: Chinese herbal medicine has long been used as a treatment for wounds. However, the underlying cellular and molecular mechanisms remain largely unknown. In this study it was shown that the proliferation of keratinocytes, which is known to play an important role in wound healing as the major cell type in the epidermis, was promoted by three herbal extracts/natural compounds: NF3 (an extract from the mixture of Radix Astragali (RA) and Radix Rehmanniae (RR) in the ratio of 2:1), stachyose (an isolated compound from Radix Rehmanniae) and extract P2-2 (a sub-fraction from the extract of Radix Astragali). The effect of the herbal extracts/natural compounds on the growth of keratinocytes was not influenced by a high glucose level, a condition similar to diabetic patients who usually suffer from diabetic foot ulcers. Real time RT-PCR results showed that the expression of epidermal growth factor (EGF) receptor, but not transforming growth factor-β (TGF-β) receptor, was up-regulated by NF3. Moreover, treatments with the EGF receptor kinase inhibitor AG1478 and the MEK inhibitor U0126 resulted in the diminishment of the effect of the three herbal extracts/natural compounds on keratinocyte proliferation, indicating that EGF receptor might have a significant role in this action. This study has further elucidated the molecular mechanism under which herbal extracts/natural compounds exert their effects on the wound healing process.
authors.affiliation: School of Biomedical Sciences, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: J W
authors.initials: JW
authors.lastname: Ren
authors.forename: K M
authors.initials: KM
authors.lastname: Chan
authors.forename: Patrick K K
authors.initials: PK
authors.lastname: Lai
authors.forename: Clara B S
authors.initials: CB
authors.lastname: Lau
authors.forename: H
authors.initials: H
authors.lastname: Yu
authors.forename: P C
authors.initials: PC
authors.lastname: Leung
authors.forename: K P
authors.initials: KP
authors.lastname: Fung
authors.forename: Walter F X
authors.initials: WF
authors.lastname: Yu
authors.forename: C H
authors.initials: CH
authors.lastname: Cho
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects*; D009844:Oligosaccharides / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D032267:Rehmannia / Q000737:chemistry; D015854:Up-Regulation
chemical_list: D004365:Drugs, Chinese Herbal; D009844:Oligosaccharides; D010936:Plant Extracts; D018125:Receptors, Transforming Growth Factor beta; C005695:stachyose; C512478:EGFR protein, human; D066246:ErbB Receptors