Lentinula edodes (Shiitake) mushroom extract protects against hydrogen peroxide induced cytotoxicty in peripheral blood mononuclear cells.

Lentinula edodes (Berk) Pegler, commonly known as Shiitake mushroom has been used as medicinal food in Asian countries, especially in China and Japan and is believed to possess strong immunomodulatory property. In the present study, the methanolic extract of the fruit bodies of L. edodes was investigated for cytoprotective effect against H2O2-induced cytotoxicity in human peripheral blood mononuclear cells (PBMCs) by measuring the activities of xanthine oxidase (XO) and glutathione peroxidase (GPx) . H2O2 at a concentration of 5 μM caused 50% inhibition of PBMCs viability. The extract improved the PBMC viability and exerted a dose-dependent protection against H2O2-induced cytotoxicity. At 100 μg/ml of extract concentration, the cell viability increased by 60% compared with the PBMCs incubated with H2O2 alone. The extract also inhibited XO activity in PBMC, while showing moderate stimulatory effect on GPx. However, in the presence of H2O2 alone, both the enzyme activities were increased significantly. The GPx activity increased, possibly in response to the increased availability of H2O2 in the cell. When the cells were pretreated with the extract and washed (to remove the extract) prior to the addition of H2O2, the GPx and XO activities as well as the cell viability were comparable to those when incubated with the extract alone. Thus, it is suggested that one of the possible mechanisms via which L. edodes methanolic extract confers protection against H2O2-induced oxidative stress in PBMC is by inhibiting the superoxide-producing XO and increasing GPx activity which could rapidly inactivate H2O2.

Protective effect of Carica papaya L leaf extract against alcohol induced acute gastric damage and blood oxidative stress in rats / Efecto protectivo del extracto de la hoja de Carica papaya L contra el daño gástrico agudo inducido por alcohol y el estrés oxidativo en ratas

The effects of Carica papaya leaf (CPL) aqueous extract on alcohol induced acute gastric damage and the immediate blood oxidative stress level were studied in rats. The results showed that gastric ulcer index was significantly reduced in rats pretreated with CPL extract as compared with alcohol treated controls. The in vitro studies using 2,2-Diphenyl-1-Picryl-Hydrazyl (DPPH) assay showed strong antioxidant nature of CPL extract. Biochemical analysis indicated that the acute alcohol induced damage is reflected in the alterations of blood oxidative indices and CPL extract offered some protection with reduction in plasma lipid peroxidation level and increased erythrocyte glutathione peroxidase activity. Carica papaya leaf may potentially serve as a good therapeutic agent for protection against gastric ulcer and oxidative stress.

Los efectos de; extracto acuoso de la hoja de Carica papaya (CPL) en el daño gástrico agudo inducido por alcohol y el nivel de estrés oxidativo inmediato en la sangre, fueron estudiados en ratas. Los resultados mostraron que el índice de úlcera gástrica se reducía significativamente en ratas pre-tratadas con extracto de CPL, en comparación con los controles tratados con alcohol. Los estudios in vitro mediante el ensayo con 2,2-difenil-1-picrihidrazilo) mostraron la fuerte naturaleza antioxidante de extracto de CPL. El análisis bioquímico indicó que el daño agudo inducido por alcohol se refleja en las alteraciones de los índices oxidativos de la sangre y el extracto de CPL ofreció cierta protección con la reducción del nivel de peroxidación lipídica del plasma y el aumento de la actividad de la glutatión peroxidasa de los eritrocitos. La hoja de la Carica papaya puede servir potencialmente como un buen agente terapéutico para la protección contra la úlcera gástrica y el estrés oxidativo.