title: Smilax China root extract detoxifies nicotine by reducing reactive oxygen species and inducing CYP2A6.
abstract: Resveratrol has a beneficial effect of lowering reactive oxygen species (ROS) and reduces cellular oxidative stress. We hypothesized that ethanol extract of Smilax china root (EESC) rich in resveratrol (RES) and oxyresveratrol (OXY) could reduce ROS caused by nicotine and promoting nicotine turnover by induction of CYP2A6. The amount of cotinine converted from nicotine was quantified by the direct barbiturate assay method. Expression of CYP2A6 was unregulated by RES, OXY, or EESC, respectively. Pretreatment of RES (50, 100, and 250 μM), OXY (50, 100, and 250 μM), and RES+OXY (50 and 100 μM) inhibited cytotoxicity and ROS production caused by nicotine in a dose-dependent manner. EESC pretreatment (1.8 mg/mL) increased cell viability by 1.5-fold higher than the control (nicotine only), and lowered cellular ROS levels. A significant amount of the conversion of nicotine to cotinine was observed in EESC pretreatment by CYP2A6 induction in HepG2 cells. These results suggested that hepatic induction of CYP2A6 and ROS reduction by EESC activate nicotine metabolism and reduce cellular oxidative stress.
  
  
  CONCLUSIONS
  Nicotine exposure due to smoking is very concerning because it is the major factor for lung diseases and cardiovascular disorders. It is necessary to examine natural ingredients that can detoxify from nicotine to cotinine as well as neutralize free radicals induced from nicotine. Results from the current study suggest potential applications of Smilax china root for detoxification of nicotine in the food industry.
authors.affiliation: Dept. of Food Science and Technology, Sejong Univ, 98 Gunja-dong, Seoul, 143-747, Republic of Korea.
authors.forename: Kyeong-Mu
authors.initials: KM
authors.lastname: Kim
authors.forename: Joo-Won
authors.initials: JW
authors.lastname: Suh
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Yang
authors.forename: Bo-Rahm
authors.initials: BR
authors.lastname: Kim
authors.forename: Tae-Sik
authors.initials: TS
authors.lastname: Park
authors.forename: Soon-Mi
authors.initials: SM
authors.lastname: Shim
mesh_terms: D003367:Cotinine / Q000737:chemistry / Q000378:metabolism; D065637:Cytochrome P-450 CYP2A6 / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D009538:Nicotine / Q000737:chemistry / Q000633:toxicity*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D018517:Plant Roots / Q000737:chemistry*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D032281:Smilax / Q000737:chemistry*
chemical_list: D017382:Reactive Oxygen Species; D012313:RNA; D009538:Nicotine; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6; D003367:Cotinine
keywords: CYP2A6; ROS; Smilax china root; cotinine; nicotine