Research background. P. granatum and Rh. rosea – as well as a number of other species of medicinal plants – exert an array of biological effects: adaptogenic, antioxidant and anti-inflammatory. However, there are not enough contemporary studies of their influence on metabolic processes, especially in cases of imbalanced diet. Lipid dysregulation is the main reason for many diseases, including obesity, cardiovascular disorders, non-alcoholic fatty liver disease, hypertension, atherosclerosis and insulin resistance. Recently, a growing amount of evidence suggests the positive effects of certain natural nutrients on lipid metabolism. The work aims to define the general effect of Rh. rosea and P. granatum fruit peel on physiological activity and metabolic processes in model animals fed with excessive fat diet. This study is relevant for the
development of drugs and food additives for treatment and prophylaxis of metabolism disorders.
Experimental approach. In a 30-day experiment, we determined the effect of Rhodiola rosea L. rhizomes and Punica granatum L. fruit peel on the physiological activity and metabolic processes of 24 laboratory rats consuming a high-fat diet. The physical activity was evaluated according to the mass gain of animals and change in the relative mass of the internal organs, and also the functional condition of the central nervous system, as demonstrated by the indicators of the locomotor activity and emotional status, determined in the Open Field test. The influence on the metabolic processes was revealed by biochemical and clinical blood analyses.
Results and conclusions. Body mass of rats fed with Rh. rosea reached 125.8 % of the initial body mass; when fed on P. granatum, it reached 123.9 %; and in the control group, only 111.5 % of the initial body mass. The rhizomes of Rh. rosea in the diet of male rats during the month of the experiment did not cause significant changes in the relative organ mass, and the peel of P. granatum fruits led to a decrease in the thymus relative mass, as well as liver, and brain. Rh. rosea rhizomes in the rats' diet led to an increase in the activity of alkaline phosphatase, and also to a decrease in the concentration of urea and urea nitrogen. Diet supplemented with Rh. rosea also contributed to a strong decrease in plasma concentrations of bilirubin and triglycerides (up to 57.0 % compared with the concentration in the control group). The rhizomes of Rh. rosea contributed to an unreliable decrease in the atherogenicity index. The fruit peel of P. granatum also strongly has increased alkaline phosphatase activity and reduced plasma triglyceride concentrations. In addition, in rats consuming the peel of P. granatum, blood glucose concentration decreased. Under the influence of P. granatum, a strong increase in the atherogenic index (up to 518.6 % of the control) was observed because of a decrease in the high-density lipoproteins’ concentration (up to 57.1 %) and a simultaneous elevation of low-density lipoproteins’ concentration (up to 158.3 % of the control). Open field test between groups remained without significant changes.
Novelty and scientific contribution. The results indicate that the roots of Rh. rosea
and peel of P. granatum are safe as food additives to high-fat diet and cause no pathological changes and side-effects, and at the same time significantly influences the metabolic processes (lipid and carbohydrate). Our study theoretically substantiates the use of Rh. rosea roots and P. granatum peel for the production of nutraceutical and pharmacological products for the correction of metabolic disorders of people and animals. Doses and periods of their application require further research.