Royal jelly plus coenzyme Q10 supplementation improves high-intensity interval exercise performance via changes in plasmatic and salivary biomarkers of oxidative stress and muscle damage in swimmers: a randomized, double-blind, placebo-controlled pilot trial

Figures & data

Figure 1. HIIE performance expressed as a number of FINA points at baseline and day 10 of intervention between randomization arms. Data are given as means ± SD and compared by paired Student’s t-test for within-group comparison analysis and by Student’s t-test for independent data for between-group comparison analysis. n = 10 per group. **** – p < 0.0001; * – p < 0.05; ns – not significant (p > 0.05).

Table 1. Plasmatic and salivary biomarkers of oxidative stress and muscle damage before and immediately after high-intensity interval exercise at baseline and day 10 of intervention between randomization arms.

Physical	Day 0		Day 10
Performance variables	Pre-exercise	Postexercise	Pre-exercise	Postexercise
Plasmatic DC levels, a.u.
RJQ	0.30 ± 0.02	0.33 ± 0.02*	0.29 ± 0.01*	0.30 ± 0.01^#†
PLA	0.30 ± 0.01	0.32 ± 0.02*	0.30 ± 0.01	0.32 ± 0.02^#§
Salivary DC levels, a.u.
RJQ	0.28 ± 0.01	0.30 ± 0.02*	0.26 ± 0.02*	0.27 ± 0.02^#†
PLA	0.28 ± 0.01	0.30 ± 0.01*	0.28 ± 0.01	0.30 ± 0.02^#§
Plasmatic SB levels, a.u.
RJQ	101.72 ± 18.02	157.67 ± 34.70*	94.91 ± 12.78*	107.69 ± 20.86^#†
PLA	102.40 ± 16.27	156.88 ± 39.20*	102.41 ± 12.28	160.73 ± 44.59^#§
Salivary SB levels, a.u.
RJQ	85.76 ± 21.33	130.86 ± 47.89*	80.61 ± 15.70	86.35 ± 19.65^#†
PLA	87.06 ± 20.34	133.98 ± 55.50*	91.28 ± 16.03	137.44 ± 49.80^#§
Plasmatic CK activity, U/L
RJQ	52.21 ± 15.91	72.67 ± 20.85*	43.95 ± 21.26*	47.58 ± 23.64^#†
PLA	48.06 ± 10.33	72.45 ± 14.60*	52.35 ± 19.58	74.09 ± 23.03^#§
Salivary CK activity, U/L
RJQ	33.20 ± 14.39	54.80 ± 21.49*	29.30 ± 14.17*	35.70 ± 18.37^#†
PLA	33.70 ± 11.10	57.90 ± 17.77*	34.90 ± 13.05	58.80 ± 18.28^#§

Data are given as means ± SD and compared by paired Student’s t-test for within-group comparison analysis and by Student’s t-test for independent data for between-group comparison analysis. Bonferroni correction was used, if required. n = 10 per group. * – significantly different from pre-exercise value at day 0 (p < 0.05); # – significantly different from pre-exercise value at day 10 (p < 0.05); † – significantly different from postexercise value at day 0 (p < 0.05); § – significantly different from RJQ group (p < 0.05). DC, diene conjugates; SB, Schiff bases; CK, creatine kinase; RJQ, royal jelly plus coenzyme Q10; PLA, placebo.

Figure 2. Generalized pairs plot, including density plot, scatter plot, and correlation matrix, for displaying distribution and relationship between the changes in plasmatic and salivary DC, SB, and CK levels under HIIE conditions in both intervention groups. n = 10 per group. *** – p < 0.001; ** – p < 0.01. Abbreviations: Corr, Pearson’s correlation coefficient for both groups; Placebo, Pearson’s correlation coefficient for PLA group; RJ + CoQ10, Pearson’s correlation coefficient for RJQ group; DC, diene conjugates; SB, Schiff bases; CK, creatine kinase.

Table 2. Modeling the effects of 10-day RJQ supplementation on changes in plasmatic and salivary biomarkers of oxidative stress and muscle damage in response to high-intensity interval exercise.

Response variable (Y)	Intercept (β0)	Regression coefficient (β1)	Multiple R-squared
Plasmatic DC levels, a.u.	0.024***	−0.017***	0.6796
Salivary DC levels, a.u.	0.019***	−0.016***	0.7512
Plasmatic SB levels, a.u.	58.321***	−45.540***	0.5047
Salivary SB levels, a.u.	46.165***	−40.421**	0.4287
Plasmatic CK activity, U/L	21.738***	−18.106***	0.9006
Salivary CK activity, U/L	23.900***	−17.500***	0.785

Data are presented as β₀ (mean changes in athletes treated with PLA) and β₀ + β₁ (mean changes in athletes treated with RJQ). n = 10 per group. *** – p < 0.001; ** – p < 0.01. DC, diene conjugates; SB, Schiff bases; CK, creatine kinase.

Figure 3. Principal component analysis applied to changes in RJQ-dependent variables in both plasma and saliva under HIIE conditions. n = 10 per group. PC1, principal component 1; PC2, principal component 2; DC, diene conjugates; SB, Schiff bases; CK, creatine kinase.

Figure 4. Scattergram of plasmatic and salivary PC1 values and the number of FINA points scored by swimmers during HIIE in both intervention groups. n = 10 per group. PC1, principal component 1; R, Pearson’s correlation coefficient; p, p-value.