A Histopathological Analyses of in vivo Anti-tumor Effect of an Aqueous Extract of Aristolochia longa Used in Cancer Treatment in Traditional Medicine in Morocco

In Morocco, Aristolochia longa L. (AL) is commonly used in cancer treatment. The in vivo anti-tumour effect of this plant has never been investigated before. We therefore developed an experimental gingival hyperplasia model in immune-competent rats to study the in vivo action of an aqueous extract of AL on the evolution of the hyperplasia during the initiation and post-initiation phases of 4NQO-induced gingival tumorigenesis. We also aimed to understand its toxicological potential and to characterize the cellular inflammatory infiltrate present around these hyperplasic areas.The hyperplasia was amplified by the AL treatment compared to controls. The data demonstrated that the gingival topical application of AL at saturation limit dose (10%), induced significant pro-inflammatory reactions not limited to the tissue treated, but extended to different tissues of the oral cavity (lips, tongue) and to lungs tissues where we noted an intense peribronchiolar hyperplasic lymphoid follicles with a high number of eosinophils. When given for a long period (3 weeks), the high inflammatory potential of AL was responsible of severe toxic effects with irreversible tissue lesions, particularly in lungs which limits the utilization of this plant as an anti-tumour product and must be forbidden to use in folk medicine.