Cardiovascular Protective Effect of Lignan Glycosides of Plumeria rubra Leaves

Introduction: Cardiovascular disorders are the most prevalent and life-threatening conditions affecting human beings. Therefore, this study aimed to assess the cardioprotective effect of P. rubra leaves. Aim: Plumeria rubra L. has been used for ages in alternative/traditional systems of medicine for several conditions, such as arthritis, toothache, pruritus, asthma, dysuria, gonorrhoea, diabetes, and various types of inflammation. Methods: Acute toxicity studies were performed using OECD 423 guidelines, and cardiomyopathy was induced in Wistar albino rats through an intraperitoneal injection of doxorubicin hydrochloride. Different groups were established to study the efficacy of doxorubicin-treated P. rubra leaf extract for 7 days. Blood pressure of both systolic and diastolic was recorded with noninvasive blood pressure apparatus, and the mean was considered. Biochemical parameters were analysed for serum and tissue homogenate viz. lactate dehydrogenase (LDH), thiobarbituric acid reactive substance (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). Results: The LD50 cut-off range for the leaf extract was found to be 2,000 mg/kg body weight. P. rubra leaf extract prevented the increase in heart rate (364.8 BPM) and mean blood pressure (122.24 mmHg) and demonstrated good results as an antihypertensive agent. The treatment with the extract was also found to revert the oxidative stress levels, as depicted by the MDA, SOD, and catalase levels in heart tissue in treated rats. Conclusion: P. rubra leaf extract at a higher dose (200 mg/kg) exerted a compelling cardioprotective action against cardiomyopathy induced by doxorubicin in Wistar rats due to the presence of lignan glycoside, liriodendrin.