Pharmacological Properties of Bioactive Extracts from the Rhizome of Aristolochia longa L

Abstract

Aristolochia longa is a medicinal plant well known in Moroccan folk medicine for its activity against constipation, intestinal infections and skin diseases. The present study was performed to evaluate in vitro and in vivo immunomodulatory and cytotoxic activities of aqueous and protein extracts of A. longa. The in vitro immunomodulatory results showed that aqueous extract at 0.1 mg/mL enhanced T-lymphocyte cells proliferation in the presence of ConA. While, in the presence of ConA and PMA, the protein extract at 0.1 mg/mL induced a significant decrease of T-lymphocytes and splenocytes proliferation. Both extracts were found to exhibit a significant diminution in phagocytic capacity and macrophage cells proliferation. They also induced a significant decline in the non-specific and specific humoral immune response. The protein chromatography separation was used to isolate two major fractions (F1: 75KDa and F2: 5 KDa) which showed an inhibitory effect on all studied immune cells. The in vivo immunomodulatory response of aqueous and protein extracts have equally evoked a significant dose dependent suppressor effect on total leukocyte count including the lymphocytes, monocytes and granulocytes, whereas the LD50 was 1.26 g/kg by intraperitoneal route. A. longa extracts also demonstrated apoptotic effects by about 9 to 11% against normal immune cells which confirmed the cytotoxic effects of both extracts. In conclusion, Aristolochia longa extracts exerts immunosuppression activities in vitro and in vivo, have cytotoxic effects in vivo explained by the apoptotic properties of aqueous and protein extracts against normal immune.