Effects of rose-hip and grapeseed dietary supplementation on serum oxidative stress parameters in dogs before and after physical exercise

The aim of this study was to evaluate the effects of 60 days of rose-hip\nand grapeseed dietary supplementation of a balanced home-cooked diet on\nserum oxidative stress parameters: ROMs, MDA and FRAP in army service\ndogs before and after regular physical exercise. The dogs were fed a\nbalanced cooked diet as instructed by army standards until the initial\nblood sampling in June. Thereon the dogs were randomly allotted to 4\ngroups according to the dietary regime: dogs maintained on a balanced\ncooked diet according to army standards, branded dry dog food, cooked\ndiet with added 500 mg rose-hip extract, and cooked diet with added 100\nmg grapeseed extract for a 60 day period from June to September after\nwhich all 4 groups were fed the standard cooked meal diet. Sampling was\nperformed at the beginning of the experiment (June), 60 days from the\nstart of the treatment (September) and finally 60 days after the end of\nsupplementation (November). Statistical analysis of the results included\ndescriptive statistical parameters: mean (M), standard deviation (SD),\nand variation coefficient (CV%). In order to test the statistical\nsignificance of the differences between treatments a multifactor\nvariance test (ANOVA) was performed for ROM, MDA and FRAP and the\ncombined effects of diet, exercise and time period were observed. The\ninitial (in June) increase in MDA and ROMs after exercise indicates the\npresence of oxidative stress 30 minutes after exercise. However, the\nantioxidative effects of rose-hip and grapeseed extracts are not\nconclusive, as multifactor ANOVA testing of time, diet, and exercise\nfactors did not reveal for MDA statistically significant differences\neither at 60 days of supplementation nor 60 days after withdrawal of the\nsupplements. Only one distinct exception was recorded for the prolonged\nantioxidative effects reflected in significantly decreased (p < 0.01)\nROMs before and after exercise in dogs fed the branded dry food 60 days\nafter the end of such dietary regime (November). FRAP values tend to be\nhigher (p > 0.05) after exercise compared to before exercise in all\nexperimental groups in November, indicating on a possible redistribution\nand upregulation of endogenous antioxidants during the experiment.