title: Comparison of toad skins Bufo bufo gargarizans Cantor from different regions for their active constituents content and cytotoxic activity on lung carcinoma cell lines.
abstract: BACKGROUND
  The skin of Bufo bufo gargarizans Cantor, rich in bufadienolides, peptides, and alkaloids, has approved pharmacological activity for preliminary anti-liver and lung tumor treatment. However, few studies have systematically focused on the influence of the producing regions on the content and antitumor activity of the active constituents in toad skins.
  
  
  OBJECTIVE
  This study aims to compare toad skins obtained from six different regions in China (Jiangsu, Anhui, Henan, Hebei, Jiangxi, and Shandong province) for their bufadienolide and alkaloid content, and their cytotoxic activity on two lung carcinoma cell lines (SPC-A-1 cells and A549 cells).
  
  
  METHODS
  High performance liquid chromatography (HPLC) was used to quantificationally determine four bufadienolides, which included bufotalin, bufalin, cinobufagin, and resibufogenin in toad skins, from six different regions, respectively. In addition, an ultraviolet (UV) spectrophotometer was also employed to identify the content of the total alkaloids using 5-hydroxytryptamine (5-HT) as the reference substance. An MTT assay was performed to compare the antiproliferative effects of the toad skins' ethanolic extracts from the different regions against SPC-A-1 and A549 cells.
  
  
  RESULTS
  In this study, the toad skins from Jiangsu province had the highest amount of bufadienolides (472.6 μg/g crude drug) and alkaloids (1.51 mg/g crude drug). Meanwhile, according to the extract, it exhibited the strongest cytotoxic effect against the lung carcinoma cell line (SPC-A-1 cells and A549 cells) with IC50 values of 24.82 ± 0.76 and 23.77 ± 0.63 μg crude drug/mL, respectively.
  
  
  CONCLUSIONS
  The toad skins that originated from the Jiangsu province, have comparatively greater advantages over samples from other regions as far as active constituent content and potential anti-lung cancer activity is concerned, suggesting that it can be a promising chemotherapeutic agent in lung cancer therapy, in further studies.
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Meteria Medica, Jiangsu Provincial Academy of Chinese Medicine, 210028, Nanjing, P. R. China.
authors.forename: Congyan
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Pharmaceutics, Jiangsu University, 212013, Zhenjiang, Jiangsu, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Meteria Medica, Jiangsu Provincial Academy of Chinese Medicine, 210028, Nanjing, P. R. China ; Department of Pharmaceutics, Jiangsu University, 212013, Zhenjiang, Jiangsu, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Meteria Medica, Jiangsu Provincial Academy of Chinese Medicine, 210028, Nanjing, P. R. China.
authors.forename: Ding
authors.initials: D
authors.lastname: Qu
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Meteria Medica, Jiangsu Provincial Academy of Chinese Medicine, 210028, Nanjing, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
keywords: Active constituents; Bufo bufo gargarizans cantor; content determination; cytotoxicity; lung carcinoma cell; producing regions; toad skins