Profiling of Polyphenolic Compounds, Antioxidant, Antidyslipidemic and Cardiac Risk Preventive Effect of Keteki Joha and Kola Joha Rice Cultivars Grown in Assam, India: A Comparative Study

Abstract

Background: Food grains' ability to promote health is widely recognized as a result of their rich nutritional profile and presence of antioxidants. Aim: The present study aimed to investigate the antioxidant, antidyslipidemic, and cardiac risk preventive effects of unpolished whole rice extracts of Keteki and Kola Joha of Assam, India, and to profile the polyphenolic compounds present. Methods: Whole unpolished rice samples were extracted with ethanol and the efficacy of the extract of both rice cultivars was evaluated against high-fat and high-sugar induced hyperlipidemia in rats. The effects of extracts on lipid profile, hepatic enzyme, endogenous antioxidants, lipid peroxidation, creatine kinase-NAC, lactate dehydrogenase, C-reactive protein and lipoprotein(s) were evaluated. Atherogenic indices were calculated to find the effect of the extract on cardiac risk. HPLC analysis of whole unpolished rice samples was also carried out to profile the polyphenolics present. Results: HPLC analysis revealed the presence of gallic acid, vanillic acid, caffeic acid, sinapic acid, o-coumaric acid, t-coumaric acid, rosamarinic acid, chlorogenic acid, phytic acid in both rice samples. Protocatechuic acid, syringic acid, and p-coumaric acid were detected in keteki joha, and ferulic acid was detected in kola joha only. Ethanol extracts (200 and 400 mg/kg) of both rice varieties for 30 days significantly averted dyslipidemia, preserved the level of endogenous antioxidants, and prevented lipid peroxidation. Levels of creatine kinase-NAC, lactate dehydrogenase, Creactive protein, and lipoprotein (a) were significantly (P < 0.01) less in the extract-treated group compared to the disease-control group. Extract treatment enhanced ApoA1 level while the reduced level of ApoB. ApoB/ApoA1 ratio was found more in the disease control group, which was significantly reduced in the extract-treated group. The atherogenic index, atherogenic coefficient, and cardiac risk ratio were reduced, while the cardioprotective index was enhanced in treatment groups. Conclusion: This paper profiled polyphenolic compounds for the first time. Keteki joha exhibited better results than Kola joha. Observations offer novel insights into the hypothesis for the first time that unpolished Keteki and Kola Joha rice can be beneficial in averting hyperlipidemia and its associated coronary events.