title: Toxicological studies on procyanidin B-2 for external application as a hair growing agent.
abstract: Procyanidin B-2 [epicatechin-(4beta --> 8)-epicatechin] is one of condensed tannin that exists widely in plants. We have reported previously that procyanidin B-2 possesses hair epithelial cell growth-promoting activity and stimulates anagen induction in hair cycle progression. To evaluate the safety of topical procyanidin B-2 as a hair growing agent, we examined the mutagenicity, acute subcutaneous injection, primary irritation, skin sensitization, and eye irritation of this compound. Mutagenicity tests using bacteria showed procyanidin B-2 to be non-mutagenic. Chromosomal aberration tests using CHL cells indicated that procyanidin B-2 caused polyploidy but no structural aberrations. In micronucleus tests for mutagenicity using mice, procyanidin B-2 was negative. Acute subcutaneous injection study using rats revealed no symptoms of significant injury. The lethal dose of procyanidin B-2 is greater than 2000 mg/kg (subcutaneous injection). Primary irritation tests using rabbits indicated that procyanidin B-2 containing preparation shows no primary irritation. In the guinea pig maximization test, there was no evidence of sensitization to procyanidin B-2. In primary ocular irritation tests using rabbits, procyanidin B-2 containing preparation and vehicle showed slight irritation of conjunctivae which is assumed to be caused by ethanol. It is suggested that topical procyanidin B-2 is safe and acceptable from the series of toxicological tests.
authors.affiliation: Tsukuba Research Laboratories, Kyowa Hakko Kogyo Co., Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoo
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: A
authors.initials: A
authors.lastname: Ishii
mesh_terms: D000287:Administration, Topical; D000818:Animals; D044946:Biflavonoids; D002392:Catechin / Q000633:toxicity*; D005260:Female; D006197:Hair / Q000254:growth & development*; D006203:Hair Preparations / Q000633:toxicity*; D007279:Injections, Subcutaneous; D007509:Irritants / Q000633:toxicity; D008297:Male; D051379:Mice; D009152:Mutagenicity Tests / Q000379:methods; D044945:Proanthocyanidins; D011817:Rabbits; D051381:Rats; D018675:Toxicity Tests
chemical_list: D044946:Biflavonoids; D006203:Hair Preparations; D007509:Irritants; D044945:Proanthocyanidins; C479578:procyanidin B; C017674:procyanidin; D002392:Catechin