Biological Potential of Polyphenols in the Context of Metabolic Syndrome: An Analysis of Studies on Animal Models

Simple Summary Polyphenols are a family of widespread organic compounds occurring in heterogeneous plants. The antioxidative properties of polyphenols are widely known. However, they also possess unquestionably anti-inflammatory, antiatherosclerotic, anti-microbial, antiallergic, immunomodulatory, anti-carcinogenic, and antimutagenic activity. As evidenced by recent studies, diets abundant in polyphenol-rich plant materials induce positive effects in preventing and treating non-communicable chronic diseases, such as metabolic syndrome, which is currently recognized as a crucial public health problem. This study aims to review the literature on the role of polyphenols in the aspect of metabolic syndrome in studies on animal models and highlight the most promising micronutrients. Positive results in this field can lead to the development of innovative functional food products, which can contribute to the health improvement of the population. Metabolic syndrome (MetS) is a disease that has a complex etiology. It is defined as the co-occurrence of several pathophysiological disorders, including obesity, hyperglycemia, hypertension, and dyslipidemia. MetS is currently a severe problem in the public health care system. As its prevalence increases every year, it is now considered a global problem among adults and young populations. The treatment of choice comprises lifestyle changes based mainly on diet and physical activity. Therefore, researchers have been attempting to discover new substances that could help reduce or even reverse the symptoms when added to food. These attempts have resulted in numerous studies. Many of them have investigated the bioactive potential of polyphenols as a "possible remedy", stemming from their antioxidative and anti-inflammatory effects and properties normalizing carbohydrate and lipid metabolism. Polyphenols may be supportive in preventing or delaying the onset of MetS or its complications. Additionally, the consumption of food rich in polyphenols should be considered as a supplement for antidiabetic drugs. To ensure the relevance of the studies on polyphenols' properties, mechanisms of action, and potential human health benefits, researchers have used laboratory animals displaying pathophysiological changes specific to MetS. Polyphenols or their plant extracts were chosen according to the most advantageous mitigation of pathological changes in animal models best reflecting the components of MetS. The present paper comprises an overview of animal models of MetS, and promising polyphenolic compounds whose bioactive potential, effect on metabolic pathways, and supplementation-related benefits were analyzed based on in vivo animal models.