Abstract:
CONTEXT: Scyphiphora hydrophyllacea is a shrub mangrove plant of the family Rubiaceae and not yet been studied for anti-hepatocarcinogenic effects. OBJECTIVES: We investigated possible in vitro anti-hepatocarcinogenic and antioxidant properties of S. hydrophyllacea. MATERIALS AND METHODS: Dried leaves of S. hydrophyllacea were sequentially extracted into hexane, chloroform, ethyl acetate, and methanol and tested for cytotoxicity on HepG2 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and sulforhodamine B assays, and for antioxidant activities by the free radical 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays. Total phenolic and flavonoid contents were estimated in all four extracts. The hexane and chloroform extracts were tested for pro-apoptotic properties in HepG2 cells, and bioactive components were identified by gas chromatography-mass spectrometry (GC-MS) analysis. RESULTS: The hexane and chloroform extracts showed dose-dependent and time-dependent cytotoxic effects. Morphological changes observed under fluorescence microscope related to apoptosis, and significant (P < 0.001) increases in caspase 3 and 9 levels were observed in hexane and chloroform extract-treated cells. Slight DNA fragmentation was observed only in response to the chloroform extract. mRNA expressions of p53 and Bax were significantly upregulated by low doses of hexane and chloroform extracts. Highest antioxidant activity was observed in the methanol extract. GC-MS profiles identified 24 and four major compounds in the hexane and chloroform extracts, respectively. These included some known anticancer compounds such as lupeol. CONCLUSION: Cytotoxicity, antioxidant effects, and apoptosis-related changes exerted by hexane and chloroform extracts of S. hydrophyllacea concluded that these two extracts are good source for isolation of possible anticarcinogenic compounds. SUMMARY: The hexane and chloroform extracts of Scyphiphora hydrophyllacea showed dose-dependent and time-dependent cytotoxic effects.Morphological changes related to apoptosis and significant (P < 0.001) increases in caspase 3 and 9 levels were observed in hexane and chloroform extract-treated cells.mRNA expressions of p53 and Bax were significantly upregulated by low doses of hexane and chloroform extracts.Highest antioxidant activity was observed in the methanol extract.GC-MS profiles identified 24 and four major compounds in the hexane and chloroform extracts, respectively. Abbreviation used: DPPH: 1,1-diphenyl-2-picryl-hydrazyl, ABTS: 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonic acid, GC-MS: gas chromatography-mass spectrometry, DNA: deoxyribonucleic acid, HCC: Hepatocellular carcinoma, GAE: gallic acid equivalents, SRB: sulforhodamine B, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, AO/EB: acridine orange/ethidium bromide, GAPDH: Glyceraldehyde 3-phosphate dehydrogenase, IC50: half maximal inhibitory concentration; QE: quercetin equivalents, HE: hexane extract, CE: chloroform extract, EAE: ethyl acetate extract, ME: methanolic extract, TPC: total polyphenol content, TFC: total flavonoid content, ANOVA: Analysis of variance.