Antihyperglycemic potential of the Lavandula stoechas aqueous extract via inhibition of digestive enzymes and reduction of intestinal glucose absorption

Overview of Ethnobotanical-Pharmacological Studies Carried Out on Medicinal Plants from the Serra da Estrela Natural Park: Focus on Their Antidiabetic Potential

The Serra da Estrela Natural Park (NPSE) in Portugal stands out as a well-preserved region abundant in medicinal plants, particularly known for their pharmaceutical applications in diabetes prevention and treatment. This comprehensive review explores these plants' botanical diversity, traditional uses, pharmacological applications, and chemical composition. The NPSE boast a rich diversity with 138 medicinal plants across 55 families identified as traditionally and pharmacologically used against diabetes globally. Notably, the Asteraceae and Lamiaceae families are prevalent in antidiabetic applications. In vitro studies have revealed their significant inhibition of carbohydrate-metabolizing enzymes, and certain plant co-products regulate genes involved in carbohydrate metabolism and insulin secretion. In vivo trials have demonstrated antidiabetic effects, including glycaemia regulation, insulin secretion, antioxidant activity, and lipid profile modulation. Medicinal plants in NPSE exhibit various activities beyond antidiabetic, such as antioxidant, anti-inflammatory, antibacterial, anti-cancer, and more. Chemical analyses have identified over fifty compounds like phenolic acids, flavonoids, terpenoids, and polysaccharides responsible for their efficacy against diabetes. These findings underscore the potential of NPSE medicinal plants as antidiabetic candidates, urging further research to develop effective plant-based antidiabetic drugs, beverages, and supplements.

Chemical Analysis of the Antihyperglycemic, and Pancreatic α-Amylase, Lipase, and Intestinal α-Glucosidase Inhibitory Activities of Cannabis sativa L. Seed Extracts

Cannabis is considered (Cannabis sativa L.) a sacred herb in many countries and is vastly employed in traditional medicine to remedy numerous diseases, such as diabetes. This research investigates the chemical composition of the aqueous extracts from Cannabis sativa L. seeds. Furthermore, the impact of these extracts on pancreatic α-amylase and lipase, and intestinal α-glucosidase enzymes is evaluated, as well as their antihyperglycemic effect. Analysis of the chemical composition of the aqueous extract was conducted using high-performance liquid chromatography with a photodiode array detector (HPLC-DAD). In contrast, the ethanol, hexanic, dichloromethane, and aqueous extract compositions have been established. Additionally, the inhibitory effects of ethanolic, dichloromethane, and aqueous extracts on pancreatic α-amylase and lipase, and intestinal α-glucosidase activities were evaluated in vitro and in vivo. The results of HPLC analysis indicate that the most abundant phenolic compound in the aqueous cannabis seed extract is 3-hydroxycinnamic acid, followed by 4-hydroxybenzoic acid and rutin acid. Moreover, administration of ethanolic and aqueous extracts at a dose of 150 mg/Kg significantly suppressed postprandial hyperglycemia compared to the control group; the ethanolic, dichloromethane, and aqueous extracts significantly inhibit pancreatic α-amylase and lipase, and intestinal α-glucosidase in vitro. The pancreatic α-amylase test exhibited an inhibition with IC50 values of 16.36 ± 1.24 µg/mL, 19.33 ± 1.40 µg/mL, 23.53 ± 1.70 µg/mL, and 17.06 ± 9.91 µg/mL for EAq, EDm, EET, and EHx, respectively. EET has the highest inhibitory capacity for intestinal α-glucosidase activity, with an IC50 of 32.23 ± 3.26 µg/mL. The extracts inhibit porcine pancreatic lipase activity, demonstrating their potential as lipase inhibitors. Specifically, at a concentration of 1 mg/mL, the highest inhibition rate (77%) was observed for EDm. To confirm these results, the inhibitory effect of these extracts on enzymes was tested in vivo. The oral intake of aqueous extract markedly reduced starch- and sucrose-induced hyperglycemia in healthy rats. Administration of the ethanolic extract at a specific dose of 150 mg/kg significantly reduced postprandial glycemia compared with the control group. It is, therefore, undeniable that cannabis extracts represent a promising option as a potentially effective treatment for type 2 diabetes.