title: Ethanol extract of Piper longum L. attenuates gentamicin-induced hair cell loss in neonatal cochlea cultures.
abstract: Piper longum L. (PL), also as known as long pepper, a well-known spice and traditional medicine in Asia and Pacific islands, has been reported to exhibit wide spectrum activity including antioxidant activity. However, little information is available on its protective effect on gentamicin (GM) induced ototoxicity which is commonly regarded as being mediated by reactive oxygen species and reactive nitrogen species. This study was undertaken to investigate the protective effect of PL ethanol extract on gentamicin-induced hair cell loss in neonatal cochlea cultures. Cochlea cultures from postnatal day 2-3 mice were used for analysis of the protective effects of PL against gentamicin-induced hair cell loss by phalloidin staining. E. coil cultures were used to determine whether PL interferes with the antibiotic activity of GM. Nitric oxide (NO)-scavenging activity of PL was also measured in vitro. GM induced significant dose-dependent hair cell loss in cochlea cultures. However, without interfering with the antibiotic activity of GM, PL showed a significant and concentration-dependent protective effect against GM-induced hair cell loss, and hair cells retained their stereocilia well. In addition, PL expressed direct scavenging activity toward NO radical liberated within solution of sodium nitroprusside. These findings demonstrate the protective effect of PL on GM-induced hair cell loss in neonatal cochlea cultures, and suggest that it might be of therapeutic benefit for treatment of GM-induced ototoxicity.
authors: Medical Science Research Institute, Department of Otorhinolaryngology - Head and Neck Surgery, Dongguk University Ilsan Hospital, Gyeongg, Korea.
authors: Xiao Fei
authors: XF
authors: Du
authors: Jae-Jun
authors: JJ
authors: Song
authors: Seungug
authors: S
authors: Hong
authors: Jihye
authors: J
authors: Kim
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count; D002478:Cells, Cultured; D003051:Cochlea / Q000166:cytology* / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D000431:Ethanol; D016166:Free Radical Scavengers; D005839:Gentamicins / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D006198:Hair Cells, Auditory / Q000187:drug effects* / Q000473:pathology; D051379:Mice; D008813:Mice, Inbred ICR; D009569:Nitric Oxide / Q000378:metabolism; D009924:Organ Culture Techniques; D031701:Piper / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000633:toxicity*; D012997:Solvents
chemical_list: D016166:Free Radical Scavengers; D005839:Gentamicins; D010936:Plant Extracts; D011500:Protein Synthesis Inhibitors; D012997:Solvents; D009569:Nitric Oxide; D000431:Ethanol