New therapeutic agents from selected medicinal plants against disease

Djebbar Atmani

Abstract

Reactive oxygen species (ROS) are byproducts of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. However, their accumulation in cells, as in oxidative stress, may cause damage to biological molecules and cell membranes, ultimately leading to cell death. The present study was designed to investigate the anti-inflammatory, antidiabetic and anticancer potential of Pistacialentiscus (Anacardiaceae) and Fraxinus angustifolia (Oleaceae) extracts, as well as identification of active compounds, usingappropriate methodology. Evaluation of antioxidant activity was undertaken to support the anti-inflammatory effects. The results indicated that P. lentiscus and F. angustifolia extracts, exhibited a promising anti-diabetic activity in streptozotocin (STZ)-induced diabetic rats, by a significant reduction (55%) of blood glucose level, a result confirmed by the inhibition of alpha-amylase activity (65%). The results of the anti-inflammatory activity of P. lentiscus and F. angustifolia showed significant reduction of the paw edema induced by carrageenan. Furtheremore, P. lentiscus extracts showed a significant reduction of pro-inflammatory cytokines (IL-1β) in activated macrophages. Moreover, the extracts of F. angustifolia, significantly inhibited ear edema induced by single and multiple doses of 12-O-tetradecanoylphorbol 13-acetate (TPA) and suppressed the cellular infiltration. In vivo, the vesicles loaded with the crude extract of F. angustifolia and especially penetration enhancer-containing vesicles (PEV) inhibited oxidative stress in human keratinocytes against H2O2 and attenuated edema and leukocyte infiltration by stimulating the repair of TPA-induced skin damage. Chromatographic and spectroscopic analyses allowed the identification of known and new phenolic compounds, some of which are endowed with highly interesting biological activities. Finally, the different extracts of leaf and fruit exhibited strong and promising antioxidant activity.