Antidiabetic Effect of Passiflora ligularis Leaves in High Fat-Diet/Streptozotocin-Induced Diabetic Mice.

Type 2 diabetes mellitus (T2DM) is a major global public health concern, prompting the ongoing search for new treatment options. Medicinal plants have emerged as one such alternative. Our objective was to evaluate the antidiabetic effect of an extract from the leaves of Passiflora ligularis (P. ligularis). For this purpose, T2DM was first induced in mice using a high-fat diet and low doses of streptozotocin. Subsequently, an aqueous extract or an ethanolic extract of P. ligularis leaves was administered for 21 days. The following relevant results were found: fasting blood glucose levels were reduced by up to 41%, and by 29% after an oral glucose overload. The homeostasis model assessment of insulin resistance (HOMA-IR) was reduced by 59%. Histopathologically, better preservation of pancreatic tissue was observed. Regarding oxidative stress parameters, there was an increase of up to 48% in superoxide dismutase (SOD), an increase in catalase (CAT) activity by 35% to 80%, and a decrease in lipid peroxidation (MDA) by 35% to 80% in the liver, kidney, or pancreas. Lastly, regarding the lipid profile, triglycerides (TG) were reduced by up to 30%, total cholesterol (TC) by 35%, and low-density lipoproteins (LDL) by up to 32%, while treatments increased high-density lipoproteins (HDL) by up to 35%. With all the above, we can conclude that P. ligularis leaves showed antihyperglycemic, hypolipidemic, and antioxidant effects, making this species promising for the treatment of T2DM.

Optimization of flavonoid extraction from Passiflora quadrangularis leaves with sedative activity and evaluation of its stability under stress conditions

Abstract Passiflora species have been widely used in folk medicine as tranquilizers, and previous pharmacological studies have reported sedative activity for P. quadrangularis L., Passifloraceae, leaf extracts. The aim of this work was to contribute to the standardization of P. quadrangularis leaf extract with sedative activity. For this purpose, the extraction of total flavonoids was optimized, evaluating variables such as drug-solvent ratio, extraction solvents and extraction time, using Response Surface Methodology. The stability of total and individual flavonoids on the optimized extract of P. quadrangularis leaves under stress conditions was also evaluated. Sedative activity was verified by the ethyl ether-induced hypnosis test in Swiss ICR mice. Based on the results, the highest concentration of total flavonoids was obtained at a drug-solvent ratio of 1:15 (w:v), extraction solvent EtOH:H2O (1:1, v/v) and percolation time of 48 h. Regarding stability under stress conditions, it was found that the flavonoids from the optimized extract are photostable, and practically stable under neutral hydrolysis and oxidation, but labile by acid and basic hydrolysis, with the main degradation products being identified. Finally, it was demonstrated that the optimized extract improves the sedative effect when compared to previously evaluated extract in the ethyl ether-induced hypnosis test.