The Effect of a High-Protein Diet Supplemented with Blackthorn Flower Extract on Polyphenol Bioavailability and Antioxidant Status in the Organs of C57BL/6 Mice.

The health benefits of polyphenols are based on their bioavailability, which is why a significant portion of research focuses on factors that affect their bioavailability. Previous studies suggest that the intake of polyphenols along with macronutrients in food represents one of the key factors influencing the bioavailability of polyphenols and, consequently, their biological activity in the organism. Since polyphenols in the human diet are mainly consumed in food together with macronutrients, this study investigated the in vivo absorption, metabolism, and distribution of polyphenolic compounds from the water extract of blackthorn flower (Prunus spinosa L.) in combination with a protein-enriched diet in the organs (small intestine, liver, kidney) of C57BL/6 mice. The bioaccumulation of polyphenol molecules, biologically available maximum concentrations of individual groups of polyphenol molecules, and their effect on the oxidative/antioxidative status of organs were also examined. The results of this study indicate increased bioabsorption and bioavailability of flavan-3-ols (EC, EGCG) and reduced absorption kinetics of certain polyphenols from the groups of flavonols, flavones, and phenolic acids in the organs of C57BL/6 mice after intragastric administration of the water extract of blackthorn flower (Prunus spinosa L.) in combination with a diet enriched with whey proteins. Furthermore, subchronic intake of polyphenols from the water extract of blackthorn flower (Prunus spinosa L.) in combination with a diet enriched with whey proteins induces the synthesis of total glutathione (tGSH) in the liver and superoxide dismutase (SOD) in the liver and small intestine. The results of this study suggest potential applications in the development of functional foods aimed at achieving the optimal health status of the organism and the possibility of reducing the risk of oxidative stress-related disease.

The Effects of Nettle Extract Consumption on Liver PPARs, SIRT1, ACOX1 and Blood Lipid Levels in Male and Female C57Bl6 Mice.

The aim of this study was to evaluate how nettle (Urtica dioica L.) water extract consumption would interact with regulators of peroxysomal lipid oxidation, histone deacetylase, and markers of oxidative stress in the liver and blood lipid levels in male and female C57Bl6 mice. Metabolically unchallenged (healthy) mice (n = 5 per sex) were treated with a nettle extract in a dose of 40 mg of total polyphenols in the extract per kg mice body weight. The nettle extract was applied daily along with normal diet for 15 days. The serum triglycerides, cholesterol, HDL, LDL, and liver PPAR-α, PPAR-γ, PGC-1-α, ACOX1, SIRT1, MDA, SOD, CAT, and GSH were compared between exposed and unexposed (control) animals. In males, the PPAR-α, PGC1-α, and ACOX1 levels together with systemic HDL cholesterol were significantly (p ≤ 0.05) increased while the LDL cholesterol decreased (p ≤ 0.05). In females, no changes in PPAR-α and PGC1-α or serum lipids were noted, but the ACOX1 content in the liver was significantly (p ≤ 0.05) increased. The SIRT1 activity increased (p ≤ 0.05) only in females. In both sexes, the PPAR-γ levels were not significantly (p ≤ 0.05) affected in either sex. The results indicate that nettle plant extract has the potential to modulate selected transcriptional factors and histone deacetylase in vivo, with certain sex differences, which should be studied further in similar models.

Effects of naringin and valproate interaction on liver steatosis and dyslipidaemia parameters in male C57BL6 mice.

Valproate is a common antiepileptic drug whose adverse effects include liver steatosis and dyslipidaemia. The aim of our study was to see how natural flavonoid antioxidant naringin would interact with valproate and attenuate these adverse effects. For this reason we treated male C57BL6 mice with a combination of 150 mg/kg of valproate and 25 mg/kg naringin every day for 10 days and compared their serum triglycerides, cholesterol, LDL, HDL, VLDL, and liver PPAR-alpha, PGC-1 alpha, ACOX1, Nrf2, SOD, CAT, GSH, and histological signs of steatosis. Valproate increased lipid peroxidation parameters and caused pronounced microvesicular steatosis throughout the hepatic lobule in all acinar zones, but naringin co-administration limited steatosis to the lobule periphery. In addition, it nearly restored total serum cholesterol, LDL, and triglycerides and liver ACOX1 and MDA to control levels. and upregulated PPAR-alpha and PGC-1 alpha, otherwise severely downregulated by valproate. It also increased SOD activity. All these findings suggest that naringin modulates key lipid metabolism regulators and should further be investigated in this model, either alone or combined with other lipid regulating drugs or molecules.

Beneficial Effects of Laurel (Laurus nobilis L.) and Myrtle (Myrtus communis L.) Extract on Rat Health.

Polyphenols of Laurel and Myrtle exhibit structural diversity, which affects bioavailability, metabolism, and bioactivity. The gut microbiota plays a key role in modulating the production, bioavailability and, thus the biological activities of phenolic metabolites, particularly after the intake of food containing high-molecular-weight polyphenols. The aim of this study was to investigate whether the polyphenolic components of Laurel and Myrtle aqueous extract have beneficial effects on rat health. The growth of lactic acid bacteria (LAB), ß-glucuronidase, ß-glucosidase, ß-galactosidase activity, pH value, body weight change and food efficacy ratio after intragastric treatment of rats with Laurel and Myrtle extract at doses of 50 and 100 mg/kg for two weeks were investigated. The endogenous populations of colonic probiotic bacteria (Lactobacilli and Bifidobacteria) were counted on selective media. According to the obtained data, Laurel extract in the applied dose of 50 and 100 and Myrtle extract (100 mg/kg) positively affects the rats health by increasing the number of colonies of Lactobacilli and Bifidobacteria compared to the control group, causes changes in glycolytic enzymatic activity and minor change in antioxidative tissue activity. In addition, high doses of Laurel increase food efficiency ratio, while Myrtle has the same effect at a lower dose.

Blackthorn Flower Extract Impact on Glycaemic Homeostasis in Normoglycaemic and Alloxan-Induced Hyperglycaemic C57BL/6 Mice.

RESEARCH BACKGROUND: The use of plants and their extracts in treatments of chronic diseases is widely known in traditional medicine. The aim of this study is to determine the effects of 10-day consumption of blackthorn (Prunus spinosa L.) flower extract on blood glucose, glycaemic load, serum α-amlyase activity and insulin concentration in normoglycaemic and hyperglycaemic (alloxan-induced) mice model. EXPERIMENTAL APPROACH: Normoglycaemic and hyperglycaemic (treated with alloxan, 150 mg per kg body mass) C57BL/6 mice were administered daily, during 10 days, blackthorn flower extract by gavage. The sugar mass concentration within the extract was determined by HPLC analysis. In mice, blood and serum blood glucose concentrations, and oral glucose tolerance test were determined by blood glucometer. Serum insulin concentration was determined by ELISA assay and α-amylase activity by colourimetric assay. RESULTS AND CONCLUSIONS: The blackthorn flower extract increased glucose concentrations in normoglycaemic mice by 30% after the 1st and 5th day and by 17% after the 10th day of consumption. It is a consequence of released sugars because sugar analysis revealed 59.8 mg/L monosaccharides, mainly fructose (55.7 mg/L) and glucose (24.3 mg/L) in the extract. On the contrary, the extract consumption reduced serum blood glucose in hyperglycaemic mice by 29% after 10 days of treatment. Oral glucose tolerance test also confirmed that in the hyperglycaemic group treated with blackthorn flower extract glucose homeostasis was improved and showed decrease in blood glucose. Serum insulin concentration increased by 49% and serum α-amylase activity by 46% after 10 days of treatment with blackthorn flower extract in hyperglycaemic group. Thus, it can be concluded that blackthorn flower extract improved glucose tolerance, enhanced insulin secretion and lowered serum α-amylase activity. NOVELTY AND SCIENTIFIC CONTRIBUTION: The obtained results show for the first time the potential of blackthorn (Prunus spinosa L.) flower extract in hyperglycaemia management.