Spirulina platensis prevents oxidative stress and inflammation promoted by strength training in rats: dose-response relation study.

The purpose of this study was to evaluate the effects of Spirulina Platensis supplementation on selected blood markers of oxidative stress, muscle damage, inflammation, and performance in trained rats. Rats (250 g - 300 g) were submitted to a strength training program (eight weeks), divided into four groups: control (GT) (trained without supplementation), trained with daily-supplementation of 50 mg/kg (GT50), 150 mg/kg (GT150) and 500 mg/kg (GT500). Training consisted of a jump protocol in PVC-cylinder containing water, with increasing load over experimental weeks. We evaluated the markers of oxidative stress (malondialdehyde - MDA and antioxidant capacity) and inflammation (C-reactive protein) at the end of the training. Among groups submitted to strength training, concentration of C-reactive protein decreased after 8 weeks of intervention in the trained group and GT500. Strength training enhanced plasma MDA concentration of malondialdehyde with supplementation of S. platensis in GT150 and GT500. In plasma analysis, strength training enhanced the percentage of oxidation inhibition, with spirulina supplementation in rates of 150 and 500 mg/kg. Spirulina supplementation for 8 weeks (in a dose-effect manner) improved antioxidant capacity as well as attenuated exercise-induced increases in ROS and inflammation. As a practical application, the use as high doses did not cause a reduction in positive physiological adaptations to exercise training. Additional studies are necessary to test the application of Spirulina Platensis in other contexts, as collective sports (basketball, football, soccer).

Supplementation with Spirulina platensis Modulates Aortic Vascular Reactivity through Nitric Oxide and Antioxidant Activity.

The possible mechanism is involved in the effects of Spirulina platensis on vascular reactivity. Animals were divided into sedentary group (SG) and sedentary groups supplemented with S. platensis at doses of 50 (SG50), 150 (SG150), and 500 mg/kg (SG500). To evaluate reactivity, cumulative concentration-response curves were constructed for phenylephrine and acetylcholine. To evaluate the involvement of the nitric oxide (NO) pathway, aorta tissue was preincubated with L-NAME and a new curve was then obtained for phenylephrine. Biochemical analyses were performed to evaluate nitrite levels, lipid peroxidation, and antioxidant activity. To contractile reactivity, only SG500 (pD2 = 5.6 ± 0.04 vs. 6.1 ± 0.06, 6.2 ± 0.02, and 6.2 ± 0.04) showed reduction in phenylephrine contractile potency. L-NAME caused a higher contractile response to phenylephrine in SG150 and SG500. To relaxation, curves for SG150 (pD2 = 7.0 ± 0.08 vs. 6.4 ± 0.06) and SG500 (pD2 = 7.3 ± 0.02 vs. 6.4 ± 0.06) were shifted to the left, more so in SG500. Nitrite was increased in SG150 and SG500. Lipid peroxidation was reduced, and oxidation inhibition was increased in all supplemented groups, indicating enhanced antioxidant activity. Chronic supplementation with S. platensis (150/500 mg/kg) caused a decrease in contractile response and increase in relaxation and nitrite levels, indicating greater NO production, due to decreased oxidative stress and increased antioxidant activity.

Whole Red Grape Juice Reduces Blood Pressure at Rest and Increases Post-exercise Hypotension.

OBJECTIVE: The objective of this study was to evaluate the effect of whole red grape juice (juice) on blood pressure (BP) at rest and on the magnitude of post-exercise hypotension (PEH). METHODS: This double-blind, randomized controlled study was performed with 26 individuals with hypertension (40 to 59 years old) who were divided into experimental (n = 14) and control (n = 12) groups. Subsequently, the experimental group was subdivided according to the initial BP values. The subjects performed 2 sessions of aerobic exercise on a treadmill (60 minutes, 60%-85% maximum heart rate), separated by a 28-day period of supplementation with a daily dose of juice (150 ml for men and 100 ml for women) or a control drink. BP was measured before, during, and immediately after each exercise session as well as every 10 minutes during the 60-minute post-exercise recovery period. RESULTS: The BP at rest did not change in the experimental group, but when this group was subdivided by initial BP, the subjects with controlled initial BP (EGCP) achieved a significant reduction (133.3 ± 5.6 to 114.6 ± 12.2 mmHg, p = 0.02); in contrast, the experimental group with borderline hypertensive BP values (EGBP) did not. Intervention with juice did not modify PEH in the experimental group, but when this group was divided as a function of the initial BP, PEH was potentiated at some times in EGCP. CONCLUSIONS: We conclude that juice promotes a reduction in BP at rest and is also capable of improving PEH in individuals with hypertension, but these effects are dependent on the initial BP values.