Objective: To study the effect of the extracts

Nocturnoside B

from cestrum nocturnum Linn. on doxorubicin-induced(DOX) myocardial injury in Wistar rats. Method: Nocturnoside B(NNS B) from the leaves and shoots of cestrum nocturnum

was separated by solvent silica gel extraction

column chromatography and preparative HPLC

and their structures were elucidated on the basis of chemical and spectral analysis. Myocardial injury model in Wistar rats was induced by DOX injection intrapertoneally. Rats were randomly divided into four groups:normal group

DOX group (2.5 mg·kg-1)

DOX+NNS B(4.0

2.0 mg·kg-1) group. Rats were killed 14 days after treatment to observe general state

ascites and rat mortality. Heart rate

waveform

the whole heart index and left ventricular index were calculated from the electrocardiogram. The serum creatine kinase(CK)

lactate dehydrogenase(LDH)

aspartate transaminase(AST) and superoxide dismutase(SOD)

glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in myocardial tissue were determined. The changes in myocardial cells and fibers in the left ventricular were investigated pathologically. The cytotoxic effect of DOX+NNS B on tumor cells was evaluated in vitro. Result: Treatment with NNS B could significantly protecte the rat model from DOX-induced cardiotoxic effects as evidenced from lower mortality(%)

less ascites

lower levels of lipid peroxidation

normalization of antioxidant enzymes and ultrastructural studies showing minimal damage to the heart. In vitro cytotoxic studies using BEL-7404

Hela

K562 cells lines demonstrated that NNS B could compromise the anti-tumor effect of DOX. Conclusion: NNS B has a protective effect against cardio-toxicity induced by DOX. The mechanisms may depend on the effect of NNS B on scavenging oxygen free radicals in the rat heart

inhibiting lipid peroxidation.The combined treatment of DOX and NNS B holds promise as a safe and effective chemotherapeutic strategy.