Phytotoxic activity and chemical composition of Cassia absus seeds and aerial parts

Allelopathic activity and chemical constituents of extracts from roots of Euphorbia heterophylla L

Euphorbia heterophylla L. is regarded as a major weed worldwide. Its high aggressiveness in agricultural environment prompted us to investigate the allelopatic activity and chemical constitution of extracts from roots of this plant. Hexane extract showed low phytotoxic activity. Methanol extract at 2.0 mg mL-1 inhibited 100% of germination, root and shoot growth of the indicator plants Sorghum bicolor and Lactuca sativa. β-sitosterol, stigmasterol, and esters of lupeol, germanicol, taraxasterol, pseudotaraxasterol, α-amyrin and β-amyrin were isolated from the hexane extract and their structures elucidated on the basis of MS and 1H, 13C and DEPT-135 NMR data. GC-MS analysis of the derivatized methanol extract allowed for identifying a series of allelopathic organic acids potentially involved in allelopathic interactions of E. heterophylla. This is the first study on the allelopathic activity of extracts and identification of metabolites from roots of E. heterophylla.

Neuroprotective effects of Cassia tora against paraquat-induced neurodegeneration: relevance for Parkinson's disease

The aim of the present study was to determine whether Cassia tora extracts could reverse the oxidative stress-induced neurodegeneration in a Parkinson's disease in vitro model. The leaves were treated with ethyl acetate (CtEA) or methanol (CtME). The extracts were first analysed by HPLC for their phenolic content and then tested for their neuroprotective effects in human SK-N-SH neuroblastoma cells. Cells were pre-treated with various concentrations of extracts followed by incubation with paraquat (14 μM). Firstly, pre-treatment of SK-N-SH cells with 100 μg/mL of CtEA or CtME significantly reduced the paraquat-induced production of reactive oxygen species. Furthermore, both CtEA and CtME reduced the paraquat-induced apoptosis. Moreover, there was a significant reduction of paraquat-induced DNA damage in SK-N-SH cells pre-treated with CtEA or CtME. Finally, both extracts significantly inhibited paraquat-dependent lipid peroxidation. Altogether, these in vitro data establish C. tora as a possible anti-Parkinson natural remedy.

Phytochemical and antioxidant properties of some Cassia species

In this study, the antioxidant activity of aqueous and ethanol extracts of four plants from the genus Cassia were evaluated by various antioxidant assays, including ferric reducing antioxidant power (FRAP), DPPH free radical scavenging, metal chelating activity, phosphomolybdenum reducing power, hydrogen peroxide radical scavenging, hydroxyl radical scavenging, deoxyribose degradation and β-carotene bleaching assay. The various antioxidant activities were compared to standard antioxidant such as ascorbic acid. All the extracts showed antioxidant activity in the tested methods. Among the four species, Cassia auriculata has been found to possess highest activity in most of the tested models. In addition to the antioxidant activity, the total phenolics and flavonoids were measured in the extracts. The ethanolic extract exhibited highest phenolics and flavonoid contents and had also shown potent antioxidant activity in comparison to the aqueous extracts. The possible antioxidant mechanism of the ethanol extract can be due to its hydrogen or electron donating and direct free radical scavenging properties. Hence, the ethanol extract represents a source of potential antioxidants that could be used in pharmaceutical industries.