The Polysulfide Containing Medicinal Plant Parkia speciosa Hassk. has Both Antioxidant and Cardioprotective Activity

The aim was to investigate any cardioprotective potential of hydrogen sulfide (H₂S) released by oil extracted from Parkia speciosa Hassk. seeds (PsH). To achieve this, an in vivo heart failure model in Wistar rats was induced by daily administration of isoproterenol (ISO, 5 mg/kg) for a week. In preliminary experiments, three organocyclic polysulfide H₂S donors (1,2,4-trithiolane, 1,3,5-trithiane, and 1,2,4,6-tetrathiepane) were identified in PsH by gas chromatography-mass spectrometry, then the in vitro 2,2-diphenyl-1-picrylhydrazyl assay verified antioxidant activity for PsH. In the heart failure model, markers of cardiac damage, lipids, and antioxidants plus urinary and serum H₂S were measured, and cardiac tissues were also histopathologically scrutinized. In vivo, PsH restored ISO-suppressed serum and urinary H₂S levels and reversed ISO-elevation of: the serum lipid profile (total cholesterol, triglycerides, and low-density lipoprotein), cardiac oxidative stress (using malondialdehyde, superoxide dismutase, and reduced glutathione), and serum markers of cardiac damage (lactate dehydrogenase, creatine kinase-myocardial band, and troponin-1). The findings were supported by histopathology (PsH reversed ISO-induced Zenker's type tissue degeneration and hemorrhage) along with congruent activities of three positive controls (sodium hydrosulfide, vitamin C, and digitalis). It was concluded that PsH has the potential as an H₂S donating nutraceutical in reducing biochemical aspects of heart failure.