Hypoglycemic and hypolipidemic effects of fermented milks with added roselle ( Hibiscus sabdariffa L.) extract

Fermentation-enriched quinoa β-glucan ameliorates disturbed gut microbiota and metabolism in type 2 diabetes mellitus mice

Quinoa β-glucan (QBG) has shown potential benefits in treating type 2 diabetes mellitus (T2DM); however, comprehensive evaluations of its effects remain limited. This study investigates the impact of QBG-derived from hot water extraction (Q-) and microbial fermentation enrichment (Q+)-on serum glucose levels, lipid profiles, appetite-regulating hormones, fecal short-chain fatty acids (SCFAs), and gut microbiota composition and function in streptozotocin/high-fat diet (STZ/HFD)-induced T2DM mice. The results indicate that QBG treatment significantly reduced fasting blood glucose, insulin levels, triglycerides (TG) and total cholesterol (TC), while concurrently increasing high-density lipoprotein cholesterol (HDLC) levels. Additionally, liver and pancreatic function improved, as evidenced by decreased levels of malondialdehyde (MDA), aspartate transaminase (AST), and alanine transaminase (ALT). SCFA levels were significantly higher in QBG-treated groups compared to MC group. QBG treatment also reduced the abundance of Firmicutes and Patescibacteria, along with the Firmicutes/Bacteroidota ratio, while increasing levels of Bacteroidota and Actinobacteria. These findings suggest that QBG can regulate the dysbiosis of SCFAs production in T2DM mice and may indirectly modulate the secretion of appetite-regulating hormones by influencing gut microbiota composition. Furthermore, PICRUSt analysis revealed that QBG treatment, particularly Q + _H, could enhance disrupted metabolism and improve gut microbiota functions, helping restore normal physiological function.

Hibiscus sabdariffa in Diabetes Prevention and Treatment—Does It Work? An Evidence-Based Review

Diabetes is currently a global health problem that is already reported as an epidemic. This metabolic disease, characterized by a disturbance in the carbohydrate, protein, and lipid metabolism, is often accompanied by disorders of several organs. Its treatment is expensive and often difficult to control. Therefore, it seems necessary to search for new drugs and solutions to facilitate therapy and reduce treatment costs. Herbal medicines are becoming more and more popular. Hibiscus sabdariffa (roselle) is a plant that grows wild in a tropical climate. It has been used in folk medicine for thousands of years. Thanks to the numerous active compounds, including polyphenols, polysaccharides, organic acids, or pectins, it is reported to exhibit hypoglycemic, antioxidant, hypotensive, and anti-lipidemic activities and numerous indirect effects that are related to them. The aim of this review was to update the knowledge about the therapeutic effects of roselle in diabetes and its comorbidities based on in vitro, animal, and human studies. After a careful analysis of the scientific literature, it can be stated that roselle is a promising product that can be used either on its own or as an addition to the conventional treatment regimens to prevent or treat diabetes and its accompanying diseases.

Optimization of extraction flavonoids from Exocarpium Citri Grandis and evaluation its hypoglycemic and hypolipidemic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Exocarpium Citri Grandis (ECG; Huajuhong in Chinese) is a precious traditional Chinese medicine with a history of hundreds of years in China. It has been demonstrated to possess numerous pharmacological properties, including antitussive, expectorant, anti-inflammatory, hypoglycemic, and hypolipidemic. However, no in-depth report exists on the hypoglycemic and hypolipidemic properties of ECG.

AIM OF THE STUDY

This study aimed to evaluate the hypoglycemic and hypolipidemic properties of ECG flavonoids extract in vitro and in vivo so as to lay the foundation for further researches in this field.

MATERIALS AND METHODS

Total flavonoids (TF) and naringin were separately extracted from ECG, and the components of TF were identified by HPLC-MS. The antioxidant capacities of TF and naringin were determined by 2,2,1-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging tests, and digestive enzymes activity inhibition assays in vitro in order to evaluate their hypoglycemic properties. Furthermore, diabetic mice experiments were performed to assess the hypoglycemic and hypolipidemic properties of TF and naringin in vivo.

RESULTS

Five compounds were identified from TF, including naringin, rhoifolin, poncirin, bergaptol, and naringenin. The half maximal inhibitory concentration (IC₅₀) of TF and naringin to DPPH-free radicals were 0.269 and 1.946 mg/mL, respectively. TF and naringin demonstrated a certain inhibitory effect on α-glucosidase and a weaker inhibitory effect on α-amylase. The results of animal experiments showed that TF and naringin had no significant effect on the blood glucose levels, but they could lead to significant (p < 0.05 or p < 0.01) increase in the serum insulin level and high-density lipoprotein cholesterol (HDL-C) levels with concomitant reduction in the total cholesterol (TC), total triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels in diabetic mice. In addition, TF and naringin could reduce the liver index of diabetic mice (p < 0.01) and reduce the kidney index at low doses (p < 0.05).

CONCLUSIONS

Our study revealed that the hypoglycemic and hypolipidemic activities of TF is mainly derived from naringin, and other active ingredients in TF also have the effects of alleviating oxidative stress, inhibiting digestive enzyme activity and reducing blood lipids. Our results thus provide a scientific basis for the application of ECG in antidiabetic treatment.

Protein-Bound Anthocyanin Compounds of Purple Sweet Potato Ameliorate Hyperglycemia by Regulating Hepatic Glucose Metabolism in High-Fat Diet/Streptozotocin-Induced Diabetic Mice

Purple sweet potato is known as a rich source of protein and anthocyanins. Anthocyanins can form complexes with protein present in food products through non-covalent forces or covalent bonds during processing, transportation, and storage as their protein affinity. We evaluated the hypoglycemic effects of protein-bound anthocyanin compounds of purple sweet potato (p-BAC-PSP) and free anthocyanin compounds of purple sweet potato (FAC-PSP) in high-fat diet/streptozotocin-induced diabetic mice. The results showed that administration of both p-BAC-PSP and FAC-PSP improved diabetic condition, as evidenced by the improvement of glucose tolerance and lipid metabolism, and the decrease of oxidative stress and liver damage. For the mechanism study, we have found that p-BAC-PSP and FAC-PSP induced the expression of AMP-activated protein kinase in liver. With p-BAC-PSP or FAC-PSP treatment, glucose transporter type 2, the protein levels of glucokinase, and insulin receptor α were found to be improved significantly (p < 0.05). Glycolysis key genes, phosphofructokinase and pyruvate kinase, were upregulated in two treatment groups, while gluconeogenic genes, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, were downregulated. Our findings suggested that p-BAC-PSP has great potential as a dietary supplement with hypoglycemic activity for general, pre-diabetic, and diabetic population.

Antidiabetic activity-guided isolation of gallic and protocatechuic acids from Hibiscus sabdariffa calyxes

We isolated and identified gallic and protocatechuic acids as the antidiabetic principles in Hibiscus sabdariffa using solvent extraction, column chromatographic fractionation, and nuclear magnetic resonance (NMR) spectroscopy. Ethylacetate fraction of the aqueous extract of H. sabdariffa inhibited α-amylase and α-glucosidase with IC₅₀ of 411.73 and 433.93 μg/ml, respectively. Furthermore, fractions I and II obtained from column chromatography inhibited α-amylase with IC₅₀ of 27.03 and 20.12 μg/ml, and α-glucosidase with IC₅₀ of 24.30 and 22.29 μg/ml, respectively. In addition, the principles reduced the serum glucose and lipid peroxide levels of diabetic rats and with an improvement in the rat lipid profiles and antioxidant defenses. Fractions I and II were identified as protocatechuic acid and gallic acid, respectively, using ¹ H and ¹³ C NMR. Protein-ligand docking showed that these compounds form multiple favorable interactions with the active-site residues of the two glycosidases. Overall, protocatechuic and gallic acids emerge as natural antidiabetic agents. PRACTICAL APPLICATIONS: Hibiscus sabdariffa (Zoborodo) is a refreshment drink for ceremonial gatherings in Nigeria. Also, its pharmacological use includes diabetes, hypertension, hyperlipidemia, metabolic syndrome, and hepatoprotection. The consumption of this food drink could improve diabetes, hypertension, dyslipidemia, metabolic syndrome, and liver disease. Furthermore, the inhibition of α-amylase and α-glucosidase could prevent diabetic complications associated with postprandial glucose. Developing the extract of H. sabdariffa calyx as food supplement could be used in managing diabetes and its associated complications such as dyslipidemia, hypertension, and metabolic syndrome.