title: Xenobiotics in vitro: the influence of L-cystine, pantothenat, and miliacin on metabolic and proliferative capacity of keratinocytes.
abstract: To investigate the effect of cell growth-stimulating agents on human epidermal keratinocytes, we exposed monolayers of normal human keratinocytes derived from foreskin to different concentrations of the amino acid L-cystine, the member of the vitamin B family D-pantothenat, the phytosterol miliacin, and a combination thereof in keratinocyte growth medium. As a test system for the metabolic capacity, we used the activity of mitochondrial deyhdrogenases as measured by XTT, and for the cell proliferation, we determined the BrdU-uptake. The additives, active ingredients of the hair growth drug PRIORIN, were added in the presence of fully supplemented keratinocyte growth medium or a deficient medium without L-cystine, L-methionine, L-histidin, D-pantothenat, epidermal growth factor, and bovine pituary gland extract. Deficient medium itself reduced the metabolic capacity of keratinocytes to 35% compared with keratinocytes in fully supplemented growth medium. In deficient medium cell, proliferation was not measurable. Increasing doses of L-cystine restored the reduced metabolic capacity from 46% (0.009 mg/L) to 54% (0.09 mg/L) and 92% (0.45 mg/L) in deficient medium. Addition of D-pantothenat (0.43 mg/L) enhanced the metabolic capacity to 150% only in fully supplemented growth medium, compared with untreated controls with growth medium. Miliacin (6 mg/mL) increased not only the metabolic capacity (162%) but also stimulated cell proliferation (215%) as measured by BrdU-uptake in growth medium. The combination of all three additives increased the metabolic capacity (245%) synergistically in growth medium. We were able to show effects of D-panthenol, L-lysine, and miliacin on proliferation and metabolic capacity of keratinocyte monocell culture, which was further increased by combination of the three substances. These basic results suggest a beneficial effect on keratinocyte growth and stimulation by products combining these substances (e.g., Priorin). Furthermore, this work emphasizes the suitability of keratinocyte monolayers for pharmacological testings.
authors.affiliation: Department of Dermatology and Allergology, University Clinic RWTH, Aachen, Germany.
authors.forename: D Hoeller
authors.initials: DH
authors.lastname: Obrigkeit
authors.forename: T
authors.initials: T
authors.lastname: Oepen
authors.forename: F K
authors.initials: FK
authors.lastname: Jugert
authors.forename: H F
authors.initials: HF
authors.lastname: Merk
authors.forename: J
authors.initials: J
authors.lastname: Kubicki
mesh_terms: D001973:Bromodeoxyuridine / Q000378:metabolism; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003553:Cystine / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010205:Pantothenic Acid / Q000494:pharmacology*; D013778:Tetrazolium Salts / Q000378:metabolism; D014315:Triterpenes / Q000494:pharmacology*; D014803:Vitamin B Complex / Q000494:pharmacology*; D015262:Xenobiotics / Q000494:pharmacology
chemical_list: D013778:Tetrazolium Salts; D014315:Triterpenes; D015262:Xenobiotics; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide; D014803:Vitamin B Complex; D010205:Pantothenic Acid; D003553:Cystine; C031972:miliacin; D001973:Bromodeoxyuridine