Antioxidant and Cytotoxicity Potential of Six Synthesized Chalcones

Background: Chalcones are open-chain flavonoids which display a large number of pharmacological activities such as cytotoxic, anti-inflammatory including antioxidant. The objective of this study was to assess antioxidant and cytotoxic activity of six synthesized chalcones. Methodology: For the current experiments, 1,3-diphenylpropenone (compound R) was used as molecular model to synthetize six compounds, namely three benzyl-benzimidazolyl-chalcones (U1, U2, WAC1) and three imidazopyridinyl-chalcones (V1, V2, V3). All the compounds were evaluated for their ability to scavenge the stable free ABTS.+ radical cation, according to the method develop by Choong et al. In addition, the cytotoxicity test described by Price et al., was performed using healthy human cell line, then in human malignant cell lines (HEP-2, A549). Results: All synthesized chalcones reduced the ABTS.+ radical cation. Indeed, benzyl benzimidazolyl compounds WAC1, U1, U2, by developing respectively 39.61%, 66.09%, and 84.20% percentages of reduction, showed an antioxidant effect 6, 11 and 14 times greater than the compound R (6.14%). As a result, imidazopyridinyl-chalcones compounds, namely V1, V2 and V3 reduced the ABTS.+ radical cation at 91.62%, 99.84% and 97.45% respectively, being 15 and 16 times more active than the compound R. About cytotoxicity, V2 inhibited not significantly HEP-2 malignant cells growth at 48.64%, compared to the standard product, i.e. doxorubicin that inhibited the growth of the same cells at 42.37%. WAC1 inhibited significantly the growth of A549 malignant cells at 89.53%, more than doxorubicin which percentage of growth inhibition was 71.58%. Conclusion: The presence of the α, β-unsaturated carbonyl system (or 1,3-diphenylpropenone) along with a benzimidazole or imidazopyridine heterocyclic ring is likely to contribute to both cytotoxic and antioxidant activities of these compounds.

Acute Toxicity and Antipyretic Activities of a Methanolic Extract of Alchornea cordifolia Leaves

Alchornea cordifolia (Euphorbiaceae) is a very prized plant among traditional healers in Africa. Its leaves are used for its antipyretic properties in traditional areas. The aim of our study is to determine the acute toxicity and the antipyretic activity of a methanolic extract of Alchornea cordifolia leaves. Acute toxicity was assessed by measuring mortality, changes in body weight, spontaneous movements, and normal rectal temperature in mice. Antipyretic activity was evaluated by brewer’s yeast-induced hyperpyrexia in rats according to Teotino method (1963). The antipyretic effect of methanolicextract of Alchornea cordifolia leaves was compared with paracetamol (100 mg/kg bw) orally. Groups of mice treated with doses of 6500;3250;1625 and 812.5mg/kg of the extract did not show any mortality, nor significant alteration of body weight, nor alteration of spontaneous movements. However, incomplete reversed dose-dependent hypothermic activity was observed with doses of 50.78;101.56;203.12;406.25;and 812.5 mg/kg p.o. of the extract, showing acute toxicity of this plant. In the antipyretic assay, the extract with doses of 50.78;101.56;203.12;406.25;and 812.5 mg/kg p.o. exhibited a significant dose-dependent antipyretic activity similar to paracetamol (100 mg/kg bw) in rats. Thus Alchornea cordifolia may inhibit prostaglandins-biosynthesis from hypothalamus. Our results support claims on its traditional uses in management of fever. However Alchornea cordifolia may affect hypothalamus not only during fever but also when body temperature is normal.