Antihypertensive Effect and Safety Evaluation of Rice Bran Hydrolysates from Sang-Yod Rice.

Rice bran hydrolysates contain highly nutritional proteins and beneficial phytochemicals. Sang-Yod rice bran hydrolysates (SRH) extracted from red pigmented rice is a rich source of nutrients and phenolic compounds. The present study evaluated the antihypertensive effect of SRH and its safety in Sprague-Dawley rats. Hypertension was induced in male rats by administration of L-NAME (50 mg/kg/day) in drinking water for three weeks, and the antihypertensive effect of SRH was evaluated. Treatment of SRH (250 or 500 mg/kg) significantly reduced arterial blood pressure and improved hemodynamic parameters. The antihypertensive effect was associated with decreased oxidative stress, suppressed p47phox NADPH oxidase expression, increased nitric oxide bioavailability and decreased angiotensin II level and ACE activity. The SRH was shown to be safe after feeding male and female rats with a rodent diet containing 1.5% SRH for 90 days. Overall, these findings suggest that SRH is safe and may help to prevent hypertension.

Effects of arm swing exercise training on cardiac autonomic modulation, cardiovascular risk factors, and electrolytes in persons aged 60-80 years with prehypertension: A randomized controlled trial.

PURPOSE: This study aimed to investigate the effect and carry-over effect of arm swing exercise (ASE) training on cardiac autonomic modulation, cardiovascular risk factors, and blood electrolytes in older persons with prehypertension. METHODS: Subjects were 50 individuals with prehypertension (aged 66.90 ±â€¯5.50 yr, body mass index 23.84 ±â€¯3.65 kg/m2). They were randomly assigned into ASE group and control group. Subjects in the ASE group underwent an ASE training program for 3 months at a frequency of 30 min/day, 3 days/week. Subjects in the control group maintained their daily routine activities minus regular exercise. Blood pressure, heart rate variability (HRV), cardiovascular risk factors including blood glucose, lipid profile, high-sensitive C-reactive protein (hsCRP), and electrolytes were evaluated on 3 occasions: before and after the 3-month intervention, and 1 month after intervention ended. RESULTS: Following the 3-month intervention, systolic blood pressure (SBP) and serum hsCRP concentration were significantly lower, while serum high-density lipoprotein (HDL)-cholesterol, potassium (K+), magnesium (Mg2+) concentrations, standard deviation of normal R-R intervals (RMSSD) and high frequency (HF) power values were higher in the ASE group when compared with the control group (p < 0.05). At the 1-month follow-up interval, SBP and serum hsCRP concentration remained lower while serum HDL-cholesterol and K+ concentrations remained higher in the ASE group as compared to the control group (p < 0.05). CONCLUSION: ASE training decreased SBP and serum hsCRP concentration, increased serum HDL-cholesterol, K+, and Mg2+ concentrations and increased RMSSD and HF power values in older persons with prehypertension. In addition, there were carry-over effects of ASE training i.e. decreased SBP and serum hsCRP concentration as well as increased serum HDL-cholesterol and K+ concentrations.

Curcumin improves endothelial dysfunction and vascular remodeling in 2K-1C hypertensive rats by raising nitric oxide availability and reducing oxidative stress.

Oxidative stress plays a role in maintaining high arterial blood pressure and contributes to the vascular changes that lead to hypertension. Consumption of polyphenol-rich foods has demonstrated their beneficial role in the prevention and treatment of hypertension. Curcumin (CUR), a phenolic compound present in the rhizomes of turmeric, possesses cardiovascular protective, anti-inflammatory and antioxidant properties. The present study was designed to investigate the protective effect of CUR on 2kidney-1clip (2K-1C)-induced hypertension, endothelial dysfunction, vascular remodeling and oxidative stress in male Sprague-Dawley rats. Sham operated or 2K-1C rats were treated with CUR at a dose of 50 or 100 mg/kg/day (or vehicle). After 6 weeks of treatment, CUR ameliorated hemodynamic performance in 2K-1C hypertensive rats (P< 0.05), by reducing blood pressure, increasing hindlimb blood flow and decreasing hindlimb vascular resistance. Hemodynamic restoration was associated with a reduction in plasma angiotensin converting enzyme level. Endothelium-dependent vasorelaxation, in response to acetylcholine, of aortic rings isolated from 2K-1C hypertensive rats-treated with CUR was significantly increased (P< 0.05). CUR also attenuated hypertension-induced oxidative stress and vascular structural modifications. These effects were associated with elevated plasma nitrate/nitrite, upregulated eNOS expression, downregulated p47phox NADPH oxidase and decreased superoxide production in the vascular tissues. The overall findings of this study suggest the mechanisms responsible for the antihypertensive action of CUR in 2K-1C hypertension-induced endothelial dysfunction and vascular remodeling involve the improvement NO bioavailability and a reduction in oxidative stress.

Elastic band resistance combined with modified Thai yoga exercise to alleviate oxidative stress and airway inflammation in type 2 diabetes mellitus.

The objective of this study was to investigate the effects of the combination of elastic band resistance exercise (EBRE) with modified Thai yoga on the alleviation of blood glucose and oxidative stress in type 2 diabetes mellitus (T2DM). Forty-two patients with T2DM were enrolled and allocated to an exercise or control group (n=21/group). The exercise group participated in EBRE combination with modified Thai yoga for 40 min, 5 days/wk, for 12 consecutive weeks. Blood glucose, oxidative stress markers, antioxidants, pulmonary function, respiratory muscle strength, and airway inflammation were measured before and after the 12 weeks. The results showed that the exercise group had a significant reduction in fasting blood glucose and glycated hemoglobin. Moreover, T2DM patients in the exercise group showed a significant reduction in plasma malondialdehyde, while superoxide dismutase and catalase were significantly increased. The exercise group also observed a significant improvement in pulmonary function; forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow, and forced midexpiratory flow as well as respiratory muscle strength. Interestingly, the combination of EBRE with modified Thai yoga markedly improved airway inflammation through the reduction in fractional exhaled nitric oxide. In conclusion, these findings suggest that the combination of EBRE with modified Thai yoga improves blood glucose, oxidative stress, antioxidants, pulmonary function, respiratory muscle strength, and airway inflammation in T2DM patients. Hence, it could be considered as a possible exercise program for T2DM patients.

Oxidative stress associated with impaired autonomic control and severity of lung function in chronic obstructive pulmonary disease patients.

Oxidative stress has been suggested to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study aimed to investigate a link between malondialdehyde (MDA) levels, pulmonary function, and cardiac autonomic control in patients with COPD. Plasma levels of MDA, heart rate variability, and pulmonary function were measured in 50 clinically stable COPD patients and 50 normal male controls. COPD patients exhibited lower means of the standard deviations of all normal to normal (NN) intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD), and high frequency (HF). Nevertheless, they presented greater low frequency (LF) and low frequency/high frequency ratio (LF/HF ratio) in supine and head-up tilt positions than controls (P<0.001). More-over, a negative correlation between MDA levels with SDNN (P<0.001) and a positive correlation with LF (P<0.01) and LF/HF ratio (P<0.05) were observed in both positions. In COPD patients, plasma MDA levels were 2.3 times greater than controls (4.33±2.03 µM vs. 1.89±0.39 µM, P<0.001), and they were inversely correlated with forced vital capacity, forced expiratory volume in 1 sec, midexpiratory flow, and peak expiratory flow (P<0.001). Our findings suggest a potential role for oxidative stress in impaired cardiac autonomic control and clinical relevance of plasma MDA levels as a predictor of severity of COPD in COPD patients.

Effects of sleep deprivation and 4-7-8 breathing control on heart rate variability, blood pressure, blood glucose, and endothelial function in healthy young adults.

This study investigated the effects of sleep deprivation on heart rate variability (HRV), blood pressure (BP), fasting blood glucose (FBG), and endothelial function as well as the immediate effects of 4-7-8 breathing control on HRV and BP. In total, 43 healthy participants aged 19-25 years were classified into two groups: Twenty two in the with sleep deprivation group and 21 in the without sleep deprivation (control) group. Resting heart rate (HR), BP, HRV, FBG, and endothelial function were examined. Subsequently, participants practiced 4-7-8 breathing control for six cycles/set for three sets interspersed between each set by 1-min normal breathing. Thereafter, the HR, BP, and HRV were immediately examined. The HRV, HR, and BP variables and FBG were not significantly different between the two groups. However, endothelial function was significantly lower in the sleep deprivation group than that in the control group (p < 0.05). In response to 4-7-8 breathing control, low- and very-low-frequency powers significantly decreased (p < 0.05), whereas high-frequency power significantly increased (p < 0.05) in the control group. Moreover, time domain, total power, and very-low-frequency power significantly decreased (p < 0.05) in the sleep deprivation group. Both groups had significantly decreased HR and systolic BP (p < 0.05). HRV, HR, and BP variables showed no significant differences between the groups. Healthy young adults with and without sleep deprivation may have similar HRV, BP, and FBG values. However, sleep deprivation may cause decreased endothelial function. Furthermore, 4-7-8 breathing control can help participants improve their HRV and BP, particularly in those without sleep deprivation.

Effects of Long-Term Regular Continuous and Intermittent Walking on Oxidative Stress, Metabolic Profile, Heart Rate Variability, and Blood Pressure in Older Adults with Hypertension.

It is documented that regular exercise is beneficial for improving the antioxidant system, metabolic system, cardiac autonomic function, and blood pressure in those with hypertension. In this regard, low-intensity exercise is recommended for older adults, particularly those with chronic diseases. This study aimed to compare the effects of long-term regular continuous walking with intermittent walking on oxidative stress, metabolic profile, heart rate variability, and blood pressure in older adults with hypertension. Forty-three participants with hypertension aged 60-80 years were randomly divided into the continuous or intermittent walking (CON or INT) groups. Participants in the CON group walked for 30 min, 3 days/week for 12 weeks. Participants in the INT group split 30 min walking into 3 identical sessions punctuated by a 1 min rest after each session, 3 days/week for 12 weeks. Antioxidant and oxidative stress markers, metabolic markers, heart rate variability, and blood pressure were evaluated before and after the exercise program. Glutathione (GSH), GSH to GSH disulfide (GSSG) ratio, and total GSH increased significantly, and GSSG and malondialdehyde decreased significantly in both groups (p < 0.05) without significant differences between groups. Triglycerides, ratio of total cholesterol to high-density lipoprotein cholesterol, and atherosclerogenic index were significantly lower in the CON group than those in the INT group (p < 0.05). The standard deviation of the NN intervals and root mean square of the successive differences were significantly higher, and low-frequency power was significantly lower in the INT group than that in the CON group (p < 0.05). No significant changes in blood pressure were noted in both groups, and nor were there any significant differences between groups. Long-term regular continuous and intermittent walking may comparably increase antioxidants, reduce oxidative stress, and be beneficial for improving important blood pressure-related outcomes, including metabolic profile or cardiac autonomic function in older adults with hypertension.

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

We investigated the changes in the oxidative stress and cardiovascular disease risk biomarkers, including the activity of the cardiac autonomic nervous system, in older adults with prehypertension following Riceberry rice bran oil supplementation. A total of 35 women aged 60 to 76 years with prehypertension were randomly allocated to two groups, one of which was supplemented with rice bran oil (n=18) and the other with Riceberry rice bran oil (n=17) at 1,000 mg daily for 8 weeks. Prior to and after the supplementation, oxidative stress and cardiovascular risk biomarkers (primary outcomes), heart rate variability, and blood pressure (secondary outcomes) were investigated. Results showed that plasma malondialdehyde, blood glutathione disulfide, and tumor necrosis factor-alpha levels were significantly decreased, and the ratio of reduced glutathione to glutathione disulfide significantly increased in both groups after supplementation (all P<0.05). No significant differences were observed between groups. Heart rate variability and blood pressure did not statistically significantly change subsequent to supplementation in either group and did not differ between groups. In conclusion, Riceberry rice bran oil supplementation for 8 weeks alleviates oxidative stress and inflammation in older adults with prehypertension to a similar extent as rice bran oil supplementation.

The optimal cutoff score of the 2-min step test and its association with physical fitness in type 2 diabetes mellitus.

This study was carried out to evaluate sensitivity, specificity, and test cutoff score to predict cardiorespiratory fitness by using the 2-min step test (2MST) in patients with type 2 diabetes mellites (DM). The association of the 2MST and physical fitness tests including a 6-min walk test (6MWT), a 5 time sit-to-stand test (FTSST), and leg strength in the form of a leg performance test were also investigated. This study was cross-sectional and conducted in 100 type 2 DM patients. Patients were screened through health questionnaires, medical illness, general characteristics, and physical fitness tests; 2MST, 6MWT, FTSST, and leg strength. Blood was collected for assessment of fasting blood sugar and lipid profiles. The number of steps in the 2MST was positively correlated with the distance of the 6MWT (r=0.6995, P<0.0001) and leg strength (r=0.4292, P<0.0001). 2MST was negatively correlated with time to perform the FTSST (r=-0.405, P<0.0001). Moreover, this study established the optimal cutoff score of the 2MST at ≤61 steps with 92.24% sensitivity, and 81.36% specificity to predict cardiorespiratory fitness in type 2 DM patients. Our findings indicate that the 2MST may be used as a predictor for walking capacity, leg strength, and ability to change position from sitting to standing in type 2 DM. In addition, this result may imply that patients with type 2 DM performing the 2MST at less than 61 steps was significantly associated with decreased cardiorespiratory fitness.

Upper and lower limb resistance training program versus high-intensity interval training on oxidative stress markers in university athletes.

Highly-intensive exercise occurs in reactive oxygen species which leads to cellular damage as a result of increased oxidative stress markers. An appropriate program design incorporating volume, intensity, and types of exercise may produce different effects amid oxidative status in athletes. Therefore, this study aimed to investigate the outcomes of resistance training (RT) and high-intensity interval training (HIIT) on oxidative stress markers, and physical performance in university athlete subjects. The effect of two different protocol types (RT and HIIT) on oxidative stress and antioxidant status were also compared. Seventy-two university athletes, were recruited and divided into control, RT, and HIIT groups (n=22/group). The RT group were undertaken a resistance exercise training program of the upper and lower body. The HIIT group performed their exercise training on a cycle ergometer. The training program was 30 min/day, 3 days/wk, continuously over 8 weeks. We observed that long-term RT and HIIT improved blood glutathione and glutathione disulfide redox ratio in all athletes. The results demonstrated that only RT training significantly decreased plasma malondialdehyde. Another finding was that RT and HIIT resulted in similar elicitation of physical performance in the post-compared with pretraining exercise. This study revealed that RT and HIIT programs improved antioxidants and physical performance in university sports athletes. However, oxidative markers were only improved following the RT program. This study suggests that RT program is superior to HIIT in improving oxidative stress markers in sport athletes.

Relationships between respiratory muscle strength, chest wall expansion, and functional capacity in healthy nonsmokers.

Chest wall expansion determines lung volume and functional capacity. Factors determining chest wall expansion include respiratory muscle strength. Accordingly, there may be association among respiratory muscle strength, chest wall expansion, and functional capacity. Thusly, this cross-sectional study identified the relationship between respirato-ry muscle strength, chest wall expansion, and functional capacity. Seventy-six healthy male and female participants aged between 20 to 59 years exhibiting a body mass index of 18.5 to 22.9 kg/m2 were enrolled. Inspiratory and expiratory muscle strength were evaluated via maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), respectively. Chest wall expansion was measured through thoracic circumferences at three different levels; upper, middle, and lower levels with diaphragmatic movement also measured utilizing the circumference of the lower edge of the 10th rib. Functional capacity was evaluated through distance obtained from a 6-min walk test. Results showed that both MIP and MEP were significantly correlated with chest wall expansion at the middle (P=0.005 and P=0.006) and lower (P=0.012 and P=0.020) thoracic levels as well as diaphragmatic movement (both P<0.001). Moreover, both MIP and MEP were significantly related amid the 6-min walk distance (P=0.025 and P<0.001). In conclusion, respiratory muscle strength is positively associated with chest wall expansion, diaphragmatic movement, and functional capacity in healthy participants.

Garcinia mangostana pericarp extract protects against oxidative stress and cardiovascular remodeling via suppression of p47phox and iNOS in nitric oxide deficient rats.

Nω-Nitro-l-arginine methyl ester (l-NAME)-induced hypertension and cardiovascular remodeling are associated with oxidative stress and inflammation. Garcinia mangostana Linn., has been reported to have antioxidant and anti-inflammatory properties. This study investigated whether G. mangostana pericarp extract (GME) could prevent l-NAME-induced hemodynamic alterations, cardiovascular remodeling, oxidative stress and inflammation in rats. Male Sprague-Dawley rats were given 40mg/kg/day of l-NAME in drinking water to induce hypertension, and were simultaneously treated with GME at a dose of 200mg/kg/day. Rats that received l-NAME for five weeks had high blood pressure, left ventricular hypertrophy and thickening of aortic wall. Vascular superoxide production, plasma malondialdehyde (MDA), and plasma tumor necrosis factor alpha (TNF-α) were significantly increased in l-NAME-hypertensive rats (p<0.05). This was consistent with up-regulation of the p47phox NADPH oxidase subunit and iNOS protein expression in aortic tissues (p<0.05). Low levels of plasma nitric oxide metabolites were observed in l-NAME hypertension. GME prevented the development of hypertension and cardiovascular remodeling induced by l-NAME with reduced oxidative stress and inflammation. These data suggest that GME had a protective effect against l-NAME-induced hypertension and cardiovascular remodeling via suppressing p47phox NADPH oxidase subunit and iNOS protein expression resulting in enhancing NO bioavailability.

Mamao Pomace Extract Alleviates Hypertension and Oxidative Stress in Nitric Oxide Deficient Rats.

Reactive oxygen species (ROS)-induced oxidative stress plays a major role in pathogenesis of hypertension. Antidesma thwaitesianum (local name: Mamao) is a tropical plant distributed in the tropical/subtropical areas of the world, including Thailand. Mamao pomace (MP), a by-product generated from Mamao fruits, contains large amounts of antioxidant polyphenolic compounds. The aim of this study was to investigate the antihypertensive and antioxidative effects of MP using hypertensive rats. For this purpose, male Sprague-Dawley rats were given Nω-nitro-L-arginine methyl ester (L-NAME), an inhibitor of endothelial nitric oxide synthase (eNOS), in drinking water (50 mg/kg) for three weeks. MP extract was orally administered daily at doses of 100 and 300 mg/kg. L-NAME administration induced marked increase in blood pressure, peripheral vascular resistance, and oxidative stress. MP treatment significantly prevented the increase in blood pressure, hindlimb blood flow and hindlimb vascular resistance of L-NAME treated hypertensive rats (p < 0.05). The antihypertensive effect of MP treatment was associated with suppression of superoxide production from carotid strips and also with an increase in eNOS protein expression and nitric oxide bioavailability. The present results provide evidence for the antihypertensive effect of MP and suggest that MP might be useful as a dietary supplement against hypertension.

Peptides-Derived from Thai Rice Bran Improves Endothelial Function in 2K-1C Renovascular Hypertensive Rats.

In recent years, a number of studies have investigated complementary medical approaches to the treatment of hypertension using dietary supplements. Rice bran protein hydrolysates extracted from rice is a rich source of bioactive peptides. The present study aimed to investigate the vasorelaxation and antihypertensive effects of peptides-derived from rice bran protein hydrolysates (RBP) in a rat model of two kidney-one clip (2K-1C) renovascular hypertension. 2K-1C hypertension was induced in male Sprague-Dawley rats by placing a silver clip around the left renal artery, whereas sham-operated rats were served as controls. 2K-1C and sham-operated rats were intragastrically administered with RBP (50 mg kg(-1) or 100 mg kg(-1)) or distilled water continuously for six weeks. We observed that RBP augmented endothelium-dependent vasorelaxation in all animals. Administration of RBP to 2K-1C rats significantly reduced blood pressure and decreased peripheral vascular resistance compared to the sham operated controls (p < 0.05). Restoration of normal endothelial function and blood pressure was associated with reduced plasma angiotensin converting enzyme (ACE), decreased superoxide formation, reduced plasma malondialdehyde and increased plasma nitrate/nitrite (p < 0.05). Up-regulation of eNOS protein and down-regulation of p47phox protein were found in 2K-1C hypertensive rats-treated with RBP. Our results suggest that RBP possesses antihypertensive properties which are mainly due to the inhibition of ACE, and its vasodilatory and antioxidant activity.