[Show abstract][Hide abstract] ABSTRACT: Defatted 85% crude hot aqueous methanol extract of Vitex trifolia purpurea (AME) successively extracted with, chloroform and ethyl acetate. Cytotoxicity of (AME), chloroform methanol extract (CE), ethyl acetate methanol extract (EE) and the residue obtained from methanol extract after successive extraction (RME) have been evaluated on brine shrimp (Artemia salina) and Hep-G2 cell lines as well. In brine shrimp lethality bioassay the results revealed that the (RME) is the most potent one with LC50 value 173 microg/ml while LC50 values of (AME), (CE) and (EE) was 180, 199 and 286 microg/ml, respectively. As well as the results of cytotoxic assay against Hep-G2 cell lines are in full agreement with previous results, with IC50 values 6, 10.7, 20.8 and 65.8 microg/ml for (RME), (AME), (CE) and (EE), respectively.
Journal of the Egyptian Society of Parasitology 08/2011; 41(2):409-16.
[Show abstract][Hide abstract] ABSTRACT: In the present study, antioxidant activity of methanolic extracts of the leaves of seven Egyptian Cassia species was investigated using two methods, the phosphomolyb-date method and 1,1 diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity method.· The results revealed that C. glauca is the most potent species and that the activity of other plant species decreases in the following order: C. grandis > C. nodosa > C. fistula > C. didymobtrya > C. occidentalis > C. sophera. Defatted methanolic extract of the most active plant C. glauca was subjected to fractionation using different organic solvents such as CHCl3, EtOAc and BuOH. Antixidant activities of the fractions were investigated and the results showed that ethyl acetate fraction possessed high activity. Total phenolic and flavonoid concentrations of each plant extract were determined using the Folin-Ciocalteu reagent and aluminum chloride. Correlation between radical scavenging capacities of extracts and total phenolic concentration was observed.
[Show abstract][Hide abstract] ABSTRACT: In this study, the total phenolic content of the methanol, methanol-water mixtures and water extracts of the leaves of two plants growing in Egypt; Ficus sycomorus and Azadirachta indica were determined by using Folin-Ciocalteu reagent. Also, the antioxidant activity of these extracts was evaluated by using two methods including DPPH radical scavenging activity assay and total antioxidant capacity using phosphomolybdenum technique .The results showed that the antioxidant activities of the tested extracts were highly correlated with their total phenolic contents. Methanol (70 %) extract of each plant exhibited the highest antioxidant activity compared with other extracts in the two antioxidant methods. Therefore, the defatted methanol (70 %) extract was fractionated with certain organic solvents as CHCL 3 , EtOAc and n-BuOH, and then these fractions were submitted to antioxidant assessment .The butanolic fraction of each plant had the highest activity in the two antioxidant assays. Also, a linear positive correlation existed between the antioxidant activities of these fractions and their total phenolic and flavonoid contents. On the other hand, the effect of different temperatures (27, 50, 70 and 100 0 C), different pH values (3, 5, 7, 9 and 11) and storage in the dark at 10 0 C and 27 0 C on the antioxidant activity of methanol extract of each plant was investigated. The results showed that the antioxidant activity of this extract of the two plants decrease with increasing the temperatures and exhibit the highest activity in neutral and acidic pH.Also storage of the methanol extract of each plant at 27 0 C for one week did not show any significant change in the antioxidant activity whereas the activity decreased at 10 0 C. On the basis of these results, leaves of the two plants proved to be a good source of natural antioxidants due to their marked antioxidant activity.
13- The 1st Euro- Med Conference of ''Plant Natural Products: from Biodiversity to Bioindustry". National Research Center, Cairo, Egypt, 8-10 December, 2009; 12/2009