Characterization of Anticancer Principles of Celosia argentea (Amaranthaceae).

BACKGROUND: An Indian origin, Celosia argentea is a weed growing during rainy season traditionally claimed for treating several ailments. Early researches on C. argentea were focused on the anti-cancer screening of seeds, with few reports on aerial parts. OBJECTIVE: To isolate and characterize bioactive compounds of aerial parts of C. argentea and evaluate their anticancer potential. MATERIALS AND METHODS: The methanolic aerial part extract was fractionated on column chromatography using chloroform: methanol mixture. The fractions; 80:20 and 95:5 were purified on MCI-HP20 HPLC column. Chromatographically pure compounds were pooled, concentrated and characterized spectroscopically. The compounds were further screened for anti-oxidant and cytotoxic potential. RESULTS: Isolated compounds were confirmed as: (1) Luteolin-7-O-glucoside and (2) phenolic, 1-(4-hydroxy-2-methoxybenzofuran-5-yl)-3-phenylpropane-1,3-dione. Both exhibited significant antioxidant potential with IC50 values of 20.80 and 21.30 µg/ml for 2,2-diphenyl-1-picrylhydrazyl assay (***P < 0.001) and significant Trolox equivalent antioxidant capacity (TEAC) values for 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (*P < 0.05) and ferric reducing antioxidant potential assay (****P < 0.0001). In 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay, Compound 1 and 2 showed potent cytotoxicity against SiHa, HCT, MCF-7 cancer cell lines at 20 µg/ml (****P < 0.0001) and 18 µg/ml (**P < 0.01), respectively, without affecting the normal Vero cells. Both compounds enabled maximum reduction in cell viability at 50 µg/ml against HT-29 (***P < 0.001) and MCF-7 cell lines (**P < 0.01) in try pan blue viability assay. Apoptosis occurred at concentrations of 47.33 ± 0.8 µg/ml and 56.28 ± 1.2 µg/ml for Compound 1 and 35.15 ± 0.4 µg/ml and 28.05 ± 0.3 µg/ml for Compound 2 for HT-29 and MCF-7 respectively. CONCLUSION: A novel anticancer phenolic compound; (1-(4-hydroxy-2-methoxybenzofuran-5-yl)-3-phenylpropane-1,3-dione), isolated from aerial parts of C. argentea was a valuable finding of the research. SUMMARY: The present study validated the potential of the plant C. argentea as an antioxidant, and anticancer remedy with two valuable isolations. Although one of them is a known compound: Luteolin 7-0 glycoside, the other isolated phenolic compound;-{1-(4-hydroxy-2-methoxybenzofuran-5-yl)-3-phenylpropane-1,3-dione}, is the first to be reported and thus can be considered as a valuable outcome of this research work.

Antiepileptic activity of lobeline isolated from the leaf of Lobelia nicotianaefolia and its effect on brain GABA level in mice.

OBJECTIVE: To investigate the anticonvulsant activity of the lobeline isolated from the Lobelia nicotianaefolia in chemoconvulsant-induced seizures and its biochemical mechanism by investigating relationship between seizure activities and altered gamma amino butyric acid (GABA) in brain of mice in Pentylenetetrazol (PTZ) seizure models. METHODS: The anticonvulsant activity of the isolated lobeline (5, 10, 20 and 30 mg/kg, i.p.) was investigated in PTZ and strychnine induced seizures in mice and the effect of isolated lobeline on brain GABA level in seizures induced by PTZ. Diazepam was used as reference anticonvulsant drugs for comparison. RESULTS: Isolated lobeline (10, 20 and 30 mg/kg, i.p.) significantly delayed and antagonized (P < 0.050-0.001) the onset of PTZ-induced seizures. It also antagonized strychnine induced seizures. The mortality was also prevented in the test group of animals. In biochemical evaluation, isolated lobeline (5, 10 and 20 mg/kg, i.p.) significantly increased the brain GABA level. And at dose of 30 mg/kg GABA level showed slight decrease in PTZ model. CONCLUSIONS: In our findings, isolated lobeline (20mg/kg) exhibited potent anticonvulsant activity against PTZ induced seizures. Also a biochemical evaluation suggested significant increase in barain GABA level at 20 mg/kg i.p. of isolated lobeline. Hence, we may propose that lobeline reduces epileptic seizures by enhancing the GABA release supporting the GABAergic mechanism.

Fluorinated 2'-hydroxychalcones as garcinol analogs with enhanced antioxidant and anticancer activities.

Chalcones are involved in the synthesis of flavonoids and are themselves known to exhibit multiple pharmacological properties. However, compared to other structurally similar phytochemicals like garcinol and curcumin, the therapeutic use of chalcones is limited because of their lower bioavailability and rapid metabolic clearance from biological system. In the present work, we have attempted to overcome these limitations in case of 2'-hydroxychalcones through bioisosteric substitution of fluoro groups in place of phenolic hydroxyls. The fluorinated chalcones were found to be more potent antioxidant and anti-proliferative compounds than their hydroxyl counterparts indicating the influence of metabolically stable C-F bonds towards bioavailability. The difluoro derivatives were found to be most effective against human pancreatic BxPC-3 cancer cells which possess up-regulated COX-2 expression and also showed activity against human breast cancer BT-20 cells with triple negative phenotype, suggesting that these compounds will have broader application in the future.