Protective effects of rice bran hydrolysates on heart rate variability, cardiac oxidative stress, and cardiac remodeling in high fat and high fructose diet-fed rats

Abstract

Objective: To examine the ameliorative effect of rice bran hydrolysates (RBH) on metabolic disorders, cardiac oxidative stress, heart rate variability (HRV), and cardiac structural changes in high fat and high fructose (HFHF)-fed rats. Methods: Male Sprague-Dawley rats were daily fed either standard chow diet with tap water or an HFHF diet with 10% fructose in drinking water over 16 weeks. RBH (500 and 1 000 mg/kg/day) was orally administered to the HFHF-diet-fed rats during the last 6 weeks of the study period. At the end of the treatment, metabolic parameters, oxidative stress, HRV, and cardiac structural changes were examined. Results: RBH administration significantly ameliorated metabolic disorders by improving lipid profiles, insulin sensitivity, and hemodynamic parameters. Moreover, RBH restored HRV, as evidenced by decreasing the ratio of low-frequency to high-frequency power of HRV, a marker of autonomic imbalance. Cardiac oxidative stress was also mitigated after RBH supplementation by decreasing cardiac malondialdehyde and protein carbonyl, upregulating eNOS expression, and increasing catalase activity in the heart. Furthermore, RBH mitigated cardiac structural changes by reducing cardiac hypertrophy and myocardial fibrosis in HFHF-diet-fed rats. Conclusions: The present findings suggest that consumption of RBH may exert cardioprotective effects against autonomic imbalances, cardiac oxidative stress, and structural changes in metabolic syndrome.

Effects of Riceberry Rice Bran Oil Supplementation on Oxidative Stress and Cardiovascular Risk Biomarkers in Older Adults with Prehypertension

“…In this study, neither HRV nor BP variables were statistically significantly improved in either the RBO or RRBO groups, although previous studies have reported that supplementation with rice bran and its antioxidant compounds phenols and anthocyanin enhanced HRV by reducing sympathetic activity, restoring sympathovagal balance, and alleviating vagal nerve inflammation ( Bruno and Ghiadoni, 2018 ; Behl et al, 2021 ; Senaphan et al, 2021 ). Senaphan et al (2021) , in their study on rats fed a high-fat and high-fructose diet, demonstrated that rice bran hydrolysates restored HRV by reducing the low frequency/high frequency ratio and improved blood lipids, insulin sensitivity, hemodynamic variables, cardiac oxidative stress, and cardiac structural changes. Typically, in addition to the cardiac autonomic nervous system, BP control is associated with several influencing factors, including baroreflex sensitivity, endothelial function, and the renin-angiotensin system ( Asemu et al, 2021 ).…”

Effects of Riceberry rice bran oil supplementation on oxidative stress, cardiovascular risk biomarkers, and cardiac autonomic nervous system activity in older adults with prehypertension

“…In this study, we did not observe any statistically signi cant improvement in either HRV or BP outcomes in either the RBO or RRBO groups, although previous studies have reported that supplementation with rice bran and its antioxidant compounds, phenols and anthocyanin, improved HRV by reducing sympathetic activity, reestablishing sympathovagal balance, and alleviating vagal nerve in ammation [16,52,53]. A study by Senaphan et al [53] in rats fed a high fat, high fructose diet showed that rice bran hydrolysates restored HRV by decreasing the LF/HF ratio and improved lipid pro les, insulin sensitivity, hemodynamic parameters, cardiac oxidative stress (decreased MDA and protein carbonyl, upregulated eNOS expression, and increased catalase activity), and cardiac structural changes (reduced cardiac hypertrophy and myocardial brosis).…”

Supplementation with rice bran hydrolysates reduces oxidative stress and improves lipid profiles in adult dogs

“…RBH was obtained from the faculty of Agro-Industry, Chiang Mai University (Chiang Mai, Thailand). RBH preparation is described in a previous study [ 38 ]. The composition of RBH was: protein content: 27.47% (wet basis), fat: 3.45%, and moisture: 1.44%.…”

“…During the 30 days of the supplement, all dogs in this RBH supplemented group were given 500 mg/kg of RBH mixed with a meal per day. The doses of RBH were chosen based on the results of preliminary observations and previous studies [ 37 , 38 ]. BW was measured every week and the RBH supplement dose was adjusted.…”

“…This indicates that rice bran was primarily used as an animal feed and it is gaining importance commercially in human diets due to the beneficial nutritive and biological effect. Rice bran hydrolysates (RBH) which is prepared from defatted rice bran and possesses antioxidant, anti-inflammatory and angiotensin converting enzyme inhibiting (ACEi) activity [ 37 , 38 ]. Previous studies have reported the beneficial effects of RBH in hypertension, insulin resistance and metabolic syndrome in rats by moderating hypertension and mitigating cardiovascular risk factors through vasodilatory, antioxidant activities, an ACEi property, ameliorating dyslipidemia, insulin resistance, anti-inflammation, reduction of oxidative stress, cardiac autonomic dysfunction, cardiovascular remodeling and arterial stiffness [ 3 , 4 , 5 , 37 , 38 ].…”