Effects of 4-Week Tangeretin Supplementation on Cortisol Stress Response Induced by High-Intensity Resistance Exercise: A Randomized Controlled Trial

The impact of tangeretin combined with whey protein on exercise-induced bronchoconstriction in professional athletes: a placebo-controlled trial

BACKGROUND

Exercise-induced bronchoconstriction (EIB) is highly prevalent in athletes. The objective of this study was to assess the therapeutic efficacy of daily tangeretin combined with whey protein supplementation over a period of 4 weeks in professional athletes with EIB.

METHODS

Using a placebo-controlled, double-blind, paired, randomized trial design, a cohort of 30 professional athletes with EIB, consisting of 14 females and 16 males, was divided into two groups: the tangeretin combined with whey protein intervention group (TIG), and the placebo control group (PCG). Both the TIG and PCG underwent exercise challenge tests (ECT) and VO2max tests before (ECT1, V1) and after (ECT2, V2) the intervention. Blood (eosinophils, neutrophils, and basophils) and serum (interleukin-5, IL-5; interleukin-8, IL-8; Clara cell secretory protein-16, CC16; immunoglobulin E, IgE) levels were measured early in the morning of ECT1 and ECT2, respectively. Lung function was assessed immediately before and post-ECT immediately.

RESULTS

Tangeretin combined with whey protein use for 4 weeks attenuated the decrease in forced expiratory volume in 1 s (FEV1) post trials (∆FEV1(ECT1-ECT2): mean (SD) TIG -7.51(6.9)% vs. PCG -2.33(11.49)%, p = 0.013). Tangeretin also substantially attenuated IL-5 concentration (∆IL-5(T1-T5): Tangeretin -19.4% vs Placebo + 8.37%, p = 0.022); IL-8 concentration (∆IL-8(T1-T5): Tangeretin -17.28% vs Placebo + 6.1%, p = 0.012); CC16 concentration (∆CC16(T1-T5): Tangeretin -11.77% vs Placebo + 24.19%); and IgE concentration in the serum (∆IgE(T1-T5): Tangeretin -24.1% vs Placebo -3.9%), and significantly decreased neutrophil count (∆N(T1-T5): Tangeretin -11.34% vs Placebo + 0.3%) and eosinophil count in blood (∆N(T1-T5): Tangeretin -38.5% vs Placebo + 4.35%). Compared with V1, VO2max (p = 0.042) and TLim (p = 0.05) of V2 were significantly increased in the TIG, and there was no significant change in the PCG. Meanwhile, six athletes in the TIG and 0 athletes in the PCG became EIB-negative at ECT2; the overall negative conversion rate of EIB was 40.00% in TCG. Additionally, the number of cough symptoms decreased from 9 to 3 and dyspnea from 4 to 2 in the TIG.

CONCLUSION

After high-intensity exercise, athletes with EIB achieved significant improvements in lung function and blood inflammatory factors by combining tangeretin and whey protein supplementation. EIB athletes also showed longer exercise endurance and VO2max at 4 weeks after TI. In addition, some patient symptoms disappeared after combination supplementation. The effect of this treatment on professional athletes with EIB was beneficial.

The Effects of Antioxidant Supplementation on Soccer Performance and Recovery: A Critical Review of the Available Evidence

Background Soccer is linked to an acute inflammatory response and the release of reactive oxygen species (ROS). Antioxidant supplements have shown promising effects in reducing muscle damage and oxidative stress and enhancing the recovery process after eccentric exercise. This critical review highlights the influence of antioxidant supplements on performance and recovery following soccer-related activity, training, or competition. Methods: English-language publications from the main databases that examine how antioxidant-based nutrition and supplements affect the recovery process before, during, and after soccer practice or competition were used. Results:Coenzyme Q10 (CoQ10), astaxanthin (Asx), red orange juice (ROJS), L-carnitine (LC), N-acetyl cysteine (NAC), beetroot (BET), turmeric root, and tangeretin reduce muscle damage (creatine kinase, myoglobin, cortisol, lactate dehudrogenase, muscle soreness). Tangeretin, docosahexaenoic acid (DHA), turmeric root, and aronia melanocarpa restrict inflammation (leukocytes, prostalagdin E2, C-reactive protein, IL-6 and 10). Q10, DHA, Asx, tangeretin, lippia citriodora, quercetin, allopurinol, turmeric root, ROJS, aronia melanocarpa, vitamins C-E, green tea (GTE), and sour tea (STE) reduce oxidative stress (malondialdehude, glutathione, total antioxidant capacity, superoxide dismutases, protein carbonyls, ascorbate, glutathione peroxidase, and paraoxonase 1). BET and NAC reinforce performance (endurance, jump, speed, strength). Conclusions: Further research is needed to determine the main mechanism and the acute and long-term impacts of antioxidant supplements in soccer.