METHODS: In the current study, the crude methanol and fractionated extract of the rhizomes of Alpinia pahangensis were investigated for their antioxidant activity using four different assays namely, the DPPH scavenging activity, superoxide anion scavenging, β-carotene bleaching and reducing power assays whilst their phenolic contents were measured by the Folin-Ciocalteu's method.In vitro neutral red cytotoxicity assay was employed to evaluate the cytotoxic activity against five different cancer cell lines, colon cancer (HCT 116 and HT-29), cervical cancer (Ca Ski), breast cancer (MCF7) and lung cancer (A549) cell lines, and one normal cell line (MRC-5). The extract that showed high cytotoxic activity was further investigated for its chemical constituents by GC-MS (gas chromatography-mass spectrometry) analysis.
RESULTS: The ethyl acetate fraction showed the strongest DPPH radical scavenging (0.35 ± 0.094 mg/ml) and SOD activities (51.77 ± 4.9%) whilst the methanol extract showed the highest reducing power and also the strongest antioxidant activity in the β-carotene bleaching assays in comparison to other fractions. The highest phenolic content was found in the ethyl acetate fraction, followed by the crude methanol extract, hexane and water fractions. The results showed a positive correlation between total phenolic content with DPPH radical scavenging capacities and SOD activities. The hexane fraction showed potent cytotoxic effect against KB, Ca Ski and HCT 116 cell lines with IC₅₀ of 5.8 ± 0.1 and 9.1 ± 2.0 ug/ml, respectively. The major components of hexane fraction analysed by GC-MS analysis were mostly methyl esters.
CONCLUSIONS: The current study suggests that the methanol extract and ethyl acetate fraction of A. pahangensis is a potential source of natural antioxidant for protective as well as prevention of life-threatening diseases. The hexane fraction of A. pahangensis may have the potential to be developed into therapeutic option for treating cancer.
OBJECTIVE: In the present study, we investigated the cytotoxic effect of 80% ethanol extract of P. amarus and its marker constituents (phyllanthin, hypophyllanthin, gallic acid, niranthin, greraniin, phyltetralin, isolintetralin, corilagin and ellagic acid) on HCT116 and their underlying mechanisms of action.
METHODS: Their antiproliferative and apoptotic effects on HCT 116 were performed using MTT assay and flow cytometric analysis, respectively, while caspases 3/7, 8 and 9 activities were examined using the colorimetric method. The expression of cleaved poly ADP ribose polymerase enzyme (PARP) and cytochrome c proteins was investigated by the immune-blot technique.
RESULTS AND DISCUSSION: HPLC and LC-MS/MS analyses demonstrated that the extract contained mainly lignans and polyphenols. The plant samples markedly suppressed the growth and expansion of HCT116 cells in a concentration- and time-dependent manner with no toxicity against normal human fibroblast CCD18 Co. P. amarus extract, phyllanthin and gallic acid induced mode of cell death primarily through apoptosis as confirmed by the exteriorization of phosphatidylserine. Caspases 3/7, 8, and 9 activities increased in a concentration-dependent manner following 24h treatment. The expressions of cleaved PARP (Asp 214) and cytochrome c were markedly upregulated.
CONCLUSION: P. amarus extract, phyllanthin and gallic acid exhibited an apoptotic effect on HCT116 cells through the caspases-dependent pathway.
OBJECTIVE: The present study was aimed to synthesize and evaluate antimicrobial and anticancer activities of Schiff bases of 2-mercaptobenzimidazole.
METHODS: The Schiff bases of 2-mercaptobenzimidazole were synthesized from 4-(2-(1H-benzo[d]- imidazol-2-ylthio)acetamido)benzohydrazide. The synthesized compounds were evaluated for antimicrobial and anticancer activities by tube dilution method and Sulforhodamine-B (SRB) assay, respectively.
RESULTS: Compounds 8 (MICpa, an = 2.41, 1.20 µM/ml), 10 (MICse, sa = 2.50 µM/ml), 20 (MICec = 2.34 µM/ml) and 25 (MICca = 1.46 µM/ml) showed significant antimicrobial activity against tested bacterial and fungal strains and compounds 20 (IC50 = 8 µg/ml) and 23 (IC50 = 7 µg/ml) exhibited significant anticancer activity.
CONCLUSION: In general, the synthesized derivatives exhibited moderate antimicrobial and anticancer activities. Compounds 8 and 25 having high antifungal potential among the synthesized compounds may be taken as lead molecules for the development of novel antifungal agents.
AIM OF STUDY: Although anticancer activity has been reported for the plant, the goal of the study was designed to isolate and characterize the active metabolites from G. mangostana and measure their cytotoxic properties. In this research, the mechanism of antiproliferative/cytotoxic effects of the tested compounds was investigated.
MATERIALS AND METHODS: The CHCl3 fraction of the air-dried fruit hulls was repeatedly chromatographed on SiO2, RP18, Diaion HP-20, and polyamide columns to furnish fourteen compounds. The structures of these metabolites were proven by UV, IR, 1D, and 2D NMR measurements and HRESIMS. Additionally, the cytotoxic potential of all compounds was assessed against MCF-7, HCT-116, and HepG2 cell lines using SRB-U assay. Antiproliferative and cell cycle interference effects of potentially potent compounds were tested using DNA content flow cytometry. The mechanism of cell death induction was also studied using annexin-V/PI differential staining coupled with flow cytometry.
RESULTS: The CHCl3 soluble fraction afforded two new xanthones: mangostanaxanthones V (1) and VI (2), along with twelve known compounds: mangostanaxanthone IV (3), β-mangostin (4), garcinone E (5), α-mangostin (6), nor-mangostin (7), garcimangosone D (8), aromadendrin-8-C-β-D-glucopyranoside (9), 1,2,4,5-tetrahydroxybenzene (10), 2,4,3`-trihydroxybenzophenone-6-O-β-glucopyranoside (11), maclurin-6-O-β-D-glucopyranoside (rhodanthenone) (12), epicatechin (13), and 2,4,6,3`,5`-pentahydroxybenzophenone (14). Only compound 5 showed considerable antiproliferative/cytotoxic effects with IC50's ranging from 15.8 to 16.7µM. Compounds 3, 4, and 6 showed moderate to weak cytotoxic effects (IC50's ranged from 45.7 to 116.4µM). Using DNA content flow cytometry, it was found that only 5 induced significant cell cycle arrest at G0/G1-phase which is indicative of its antiproliferative properties. Additionally, by using annexin V-FITC/PI differential staining, 5 induced cells killing effect via the induction of apoptosis and necrosis in both HepG2 and HCT116 cells. Compound 3 produce necrosis and apoptosis only in HCT116 cells. On contrary, 6 induced apoptosis and necrosis in HepG2 cells and moderate necrosis in HCT116 cells.
CONCLUSION: Fourteen compounds were isolated from chloroform fraction of G. mangostana fruit hulls. Cytotoxic properties exhibited by the isolated xanthones from G. mangostana reinforce the avail of it as a natural cytotoxic agent against various cancers. These evidences could provide relevant bases for the scientific rationale of using G. mangostana in anti-cancer treatment.