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.

Obtenção de extratos de própolis sob diferentes condições e avaliação de sua atividade antifúngica / Antifungal activity evaluation of different propolis extracts

A própolis é uma resina coletada das árvores pelas abelhas Apis mellifera L., que contém inúmeras substâncias, dentre elas os flavonóides. Devido a grande variedade de sua composição química, apresenta várias ações farmacológicas, destacando-se as ações antiinflamatória, cicatrizante, antitumoral e antimicrobiana, principalmente a antifúngica. Esta ação foi testada frente a leveduras isoladas de onicomicoses, que são infecções de difícil e longo tratamento que causam efeitos indesejáveis ao paciente. A própolis surge como uma eficiente opção de tratamento, pois é de baixa toxicidade e pode ser de uso tópico. Este trabalho objetivou avaliar a otimização do processo extrativo da própolis através de parâmetros físico-químicos e demonstração da atividade antifúngica.

Propolis is a resin collected by the bees Apis mellifera L., which contains several substances including the flavonoids. Due to a diversified chemical composition propolis presents some pharmacological actions, being distinguished the anti-inflammatory, healing, antitumoral and antimicrobial properties and, in particular, its antifungal action. This action has been tested against yeasts obtained from onychomycosis, which are infections of difficult and long treatment and they can manifest intolerable effects on the patient. The propolis appears as an efficient therapy option, as it has low toxicity and should be of dermal use. The aim of the present study was to evaluate the optimization of the propolis extractive process through physiochemical parameters and antifungal activity demonstration.

Optimization of Technique Conditions for Decolorization and Extract of Exopolysaccharide by Cordyceps jiangxiensis / 微生物学通报

The technique conditions of decolonization of fermentation broth were successively optimized using single factor assay and orthogonal layout method in Cordyceps jiangxiensis. The optimal condition of decolorization was investigated to be 3g/100mL active carbon, 5 min absorption time, pH5 of fermented broth and 25℃absorption temperature. Under the optimal condition, the maximum decolorization rate of fermented broth reached 89. 6% , simultaneously 10. 7% consuming rate of exopolysaccahride was minimum. Subsequently, the extract condition of exopolysaccharide of C. jiangxiensis was further optimized by orthogonal layout design. The maximum exopolysaccharide production was 0. 38 g/L under the optimal condition, i. e. firstly fermented filtrate decolorized and deproteined was concentrated to 1/7 of its total volume, secondly concentration broth was mixed with four times its volume of absolute ethanol and stirred vigorously, lastly precipitation of exopolysaccharide proceeded at 4℃for 16 hrs and the exopolysaccharide collected by centrifugal ion and dryness.