Vitamin B6 (pyridoxine) vitamins are of interest in preventative and protective strategies in cardiovascular disease. However, the safety and efficacy of vitamin B6 has been questioned. The aim of this study was to study the protective effect of pyridoxine, amlodipine, and their combination against vasopressin-induced angina model in rats. The administration of vasopressin (1 IU/kg, i.v.) to the rats elevated the S-wave level of the electrocardiogram reflecting the presence of subendocardial ischemia, whereas it decreased of the heart rate, resulting in the increase of the cardiac enzymes, creatine kinase MB (CK MB), and lactate dehydrogenase (LDH). In the vasopressin-induced angina model, oral administration of pyridoxine in dose of 5, 7, 10 mg/kg revealed dose-dependent suppression of vasopressin-triggered of ST elevation and in reduced of heart rat. In addition, pyridoxine produced dose-dependent suppression of cardiac enzymes, creatine kinase MB (CK MB), and lactate dehydrogenase (LDH) more than amlodipine and isosorbide; while in contrast, the combination of pyridoxine with amlodipine resulted in a trend towards increased adverse cardiovascular events; pyridoxine in dose 7 mg/kg was found to be more potent than pyridoxine in doses 5, 10 mg/kg, amlodipine and isosorbide on vasopressin-induced angina in rats. Pyridoxine in dose of (5, 7 mg) prevents cardiac necrosis and artery well thickened on vasopressin-induced angina modal. Pyridoxine's protective effects may be mediated by improved endothelial nitric oxide synthase (eNOS) function, reduction of homocysteine levels, and modulation of sympathetic activity. Pyridoxine at optimal doses shows promise as a novel therapeutic agent for coronary heart disease prevention, warranting further investigation into its potential clinical applications.
Averrhoa carambola is a species of tree native to tropical Southeast Asia. It possesses antioxidant and anti-hyperlipidemia effects and has traditionally been used to treat a variety of ailments. However, the presence of oxalic acid in its fruits might restrict its consumption by individuals suffering from kidney disease, and caramboxin can cause neurotoxicity. In this study, we evaluated the acute and sub-chronic toxicity of the methanolic extract of A. carambola leaves (MEAC) in male and female rats. In the acute study, female rats were given a single oral dose of 5000 mg/kg of MEAC and closely examined for distinct indications of toxic effects during the first 4 h, periodically for 48 h, and daily thereafter for 14 days. Rats of both sexes were employed in the sub-chronic investigation for the 28-day repeated dose oral toxicity study. Results of the acute study revealed the safety of MEAC up to a dose of 5000 mg/kg where the rats did not show changes or signs of toxicity. In the sub-chronic toxicity study, MEAC (250, 500, and 1000 mg/kg) administration did not affect the body weight, food, and water consumption, motor coordination, behavior, or mental alertness in the treated rats. In addition, no variations in hematological or biochemical markers were found in MEAC-treated rats. In conclusion, these findings pinpoint the safety of MEAC at doses up to 5000 mg/kg. The leaves of A. carambola could be safely consumed by people with kidney disease to treat other ailments.