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.

Obtención de extractos secos a partir de extractos acuosos de Justicia pectoralis (tilo) / Obtention of dry extract from aqueous extracts of Justicia pectoralis Jacq (tilo)

Introducción: Justicia pectoralis Jacq. (Acanthaceae) es una especie medicinal nativa de la América tropical. En Cuba es usada en la medicina tradicional en el tratamiento de afecciones nerviosas. La industria farmacéutica cubana trabaja en el desarrollo de procesos tecnológicos para la obtención de materias primas de calidad farmacéutica a partir de productos naturales. Objetivo: desarrollar un proceso tecnológico para la obtención de extractos secos a partir de extractos acuosos de Justicia pectoralis. Métodos: se desarrolló un proceso para la obtención de extracto seco por spray drying a partir de extracto acuoso de Justicia pectoralis. La influencia que sobre el contenido de cumarina tenían la relación sólido-líquido y el tiempo de extracción fue estudiada aplicando un diseño superficie respuesta. Se estudió el proceso de secado y la posterior evaluación farmacológica del polvo seco. Resultados: estos mostraron que la relación sólido-líquido tenía una fuerte influencia estadísticamente significativa sobre la extracción de la cumarina en las condiciones de trabajo experimentadas. El tiempo de extracción y la interacción entre ambos factores no fueron significativos para el modelo de regresión estudiado. Por otro lado, la evaluación de la influencia de aditivos inertes en el proceso de secado mostró que los mejores rendimientos se alcanzaban cuando se empleaba almidón soluble 30 por ciento, y no se afectaba la actividad sedante del producto. Conclusiones: una relación sólido-líquido de 1:20 y un tiempo de extracción de 15 min resultaron las condiciones óptimas para la extracción de cumarina

Introduction: Justicia pectoralis Jacq. (Acanthaceae), is a medicinal species native to the American tropics. In Cuba it is used in folk medicine in the treatment of nervous disorders. The Cuban Pharmaceutical Industry is working on the development of technological processes for the obtention of pharmaceutical quality raw materials from natural products.Objectives: develop a technological process to obtain dry extract from aqueous extracts of J. pectoralis.Methods: a process to obtain dry extract by spray drying from aqueous extract of J. pectoralis was developed. The influence of solid-liquid r ratio and extraction time on coumarin content was evaluated by applying a response surface methodology (RSM). The drying process and later pharmacological evaluation of the dry powder were studied. Results: results show that solid-liquid ratio was the statistically significant main effect, having a strong positive influence on coumarin extraction in our working conditions. Extraction time and interaction between both factors were not significant for regression models. On the other hand, evaluation of the influence of inert additives on drying s showed that the best results were obtained with the use of 30 percent soluble starch, which did not affect sedative activity. Conclusions: a solid-liquid ratio of 1:20 and an extraction time of 15 minutes were suggested as optimum parameters for coumarin extraction