OBJECTIVES: To investigate the cardiovascular effects of a butanolic fraction of Gynura procumbens in rats.

METHODS: Anaesthetized rats were given intravenous bolus injections of butanolic fraction at doses of 2.5-20 mg/kg in vivo. The effect of butanolic fraction on vascular reactivity was recorded in isolated rat aortic rings in vitro.

RESULTS: Intravenous administrations of butanolic fraction elicited significant (p < 0.001) and dose-dependent decreases in the mean arterial pressure. However, a significant (p < 0.05) decrease in the heart rate was observed only at the higher doses (10 and 20 mg/kg). In isolated preparations of rat aortic rings, phenylephrine (1 × 10⁻⁶ M)- or potassium chloride (8 × 10⁻² M)-precontracted endothelium-intact and -denuded tissue; butanolic fraction (1 × 10⁻⁶ - 1 × 10⁻¹ g/ml) induced similar concentration-dependent relaxation of the vessels. In the presence of 2.5 × 10⁻³ and 5.0 × 10⁻³ g/ml butanolic fraction, the contractions induced by phenylephrine (1 × 10⁻⁹-3 × 10⁻⁵ M) and potassium chloride (1 × 10⁻² - 8 × 10⁻² M) were significantly antagonized. The calcium-induced vasocontractions (1 × 10⁻⁴-1 × 10⁻²M) were antagonized by butanolic fraction concentration-dependently in calcium-free and high potassium (6×10⁻² M) medium, as well as in calcium- and potassium-free medium containing 1×10⁻⁶ M phenylephrine. However, the contractions induced by noradrenaline (1 × 10⁻⁶ M) and caffeine (4.5 × 10⁻² M) were not affected by butanolic fraction.

Aim: To evaluate the nephroprotective activity of CAE and its fractions in cisplatin-induced nephrotoxicity and to assess whether they compromise the anticancer efficacy of cisplatin.

Materials and methods: Cisplatin-induced renal damage was induced in Ehrlich Ascites Carcinoma (EAC) bearing mice during mild phase of tumor growth. CAE and its butanol (BF) and aqueous (AF) fractions were administered orally from the 5th day for five days. Nephroprotective potential (serum urea, creatinine, renal histology) and effect of VC on cisplatin anticancer efficacy (tumor volume, viable tumor cells, percentage increase in life span (% ILS)) were calculated.

Result: CAE and its fractions significantly reversed the cisplatin-induced renal damage. CAE and BF treated animals showed regeneration of 50%-75% of proximal tubular cells. Compared to EAC control mice, the % ILS of the cisplatin-treated group was 244% and it was further extended to 379% after CAE administration. The % ILS in the CAE treated group was 1.6 times higher than the cisplatin alone treated group. GC-MS study showed the presence of astaxanthin and betulin.