Effect of Neem (Azadirachta indica) oil on the progressive growth of a spontaneous T cell lymphoma

The present study was undertaken to investigate the effect of in vivo administration of neem oil intra-peritoneally (i.p.) to mice bearing a progressively growing transplantable T cell lymphoma of spontaneous origin, designated as Daltons lymphoma (DL), on the tumor growth. Mice were administered various doses of neem oil mixed in groundnut oil, which was used as a diluting vehicle or for administration to control DL-bearing mice. Administration of neem oil resulted in an acceleration of tumor growth along with a reduction in the survival time of the tumor-bearing host. Neem oil administered DL-bearing mice showed an augmented apoptosis in splenocytes, bone marrow cells and thymocytes along with an inhibition in the anti-tumor functions of tumor-associated macrophages. Thus this study gives an altogether a novel information that neem oil instead of the popular belief of being anti-tumor and immunoaugmentary may in some tumor-bearing conditions, behave in an opposite way leading to an accelarated tumor progression along with a collapse of the host's anti-tumor machinery. These observations will thus have long lasting clinical significance, suggesting caution in use of neem oil for treatment of cancer.