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Viscum angulatum Heyne ex DC (Viscaceae) is a leafless hemiparasitic shrub traditionally used in Asian countries for the treatment of hypertension. In the present study, the methanol extract of the whole plant was examined for diuretic activity in rats. The activity was evaluated using parameters such as urine volume after 5, 19, and 24 h and urine sodium, potassium, and chloride concentrations. The extract was further scrutinized for polyphenolic compounds and triterpenoids. The extract demonstrated a significant increase in and dose-dependent effect on urine excretion volume in comparison to the normal group in the tested range of 100-400 mg/kg. The extract demonstrated comparable saluretic and higher natriuretic activity (Na(+)/K(+)) compared to the furosemide treated group. However, the Cl(-)/Na(+) + K(+) ratio, which indicates carbonic anhydrase mediated activity, remained unaffected. HPLC and quantitative analysis of the extract revealed that polyphenolic compounds and the triterpenoid, oleanolic acid, are the major phytochemicals, and are proposed to be responsible for the observed diuretic effect. Oleanolic acid has been reported to possess diuretic activity with significant potassium loss in rats. In contrast to pure oleanolic acid, the extract demonstrated a valuable potassium-sparing effect. This suggests modulation of the diuretic effect of oleanolic acid by polyphenolics present in the extract. The observed dose-dependent potassium-sparing diuretic effect is a hereto unreported property of this plant.

Antioxidant and cytotoxic activities of the methanolic and aqueous extracts of Caesalpinia pulcherrima wood were studied in in vitro models. Both extracts exhibited strong antioxidant activity, as evidenced by the low IC50 values in both 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide and superoxide scavenging methods; the values were found to be less or comparable to those of gallic acid, the standard used. To determine the cytotoxic activity, extracts were tested for toxic effects to brine shrimp larvae. In this assay, the methanolic extract had little effect, but aqueous extract was relatively toxic. The antioxidant and cytotoxic activities may be attributed to the total phenolic content in the wood.

The antioxidant activities of the methanol extracts from the wood and pericarp of Caesalpinia decapetala (Roth) Alston (Caesalpiniaceae) were assessed in efforts to validate the herb. The antioxidant activity of the plant has been studied using its ability to scavenger DPPH, superoxide radicals, and nitric oxide radical along with its ability to inhibit lipid peroxidation. The antioxidant activity and phenolic content of the pericarp as determined by the DPPH, superoxide radical, nitric oxide radical, total phenols, the flavonoids, and total flavonols were higher than that of the wood. Analysis of plant extracts revealed a high amount of polyphenols and flavonoids suggesting a possible role of these phytoconstituents in the antioxidant property. Moreover, the results were observed in a concentration and dose dependent manner. Studies clearly indicate that the C. decapetala has significant antioxidant activity. [ABSTRACT FROM AUTHOR]

Present work describes the potent antidiabetic fraction from flowers of Cassia auriculata Linn. Hydromethanolic extract along with its ethyl acetate and n-butanol fractions were evaluated for antidiabetic activity in alloxan-induced diabetes in rats. The n-butanol fraction exhibited significant reduction (p<0.001) in blood glucose levels and was also found effective in restoring the blood lipids and proteins to normal level. The activity was found comparable with standard drug phenformin. The hydromethanolic extract and its fractions were subjected to preliminary qualitative chemical investigations which indicated the presence of phenolic compounds, carbohydrates, tannins, steroids and amino acids. [ABSTRACT FROM AUTHOR]