[Progress of studies on anti-breast tumor mechanism of alkaloids].

Breast tumor has become one of the malignant tumors with the highest incidence, and is a serious threat to human health, especially to women. Chemotherapy is an important anti-breast tumor therapy, which can be used in almost every stage of breast tumor therapy alone or in the combination with surgery and radiation therapy. Alkaloids are a kind of ubiquitous natural products, and important active components of various medicinal plants. A large number of studies have shown that alkaloids could exert an anti-breast tumor effect by inhibiting proliferation, metastasis and angiogenesis, resisting mitosis, promoting apoptosis and autophagy, and triggering cell cycle arrest. The extensive anti-breast tumor effect makes alkaloids an important candidate drug source. This paper reviews the anti-breast tumor mechanism of natural products of alkaloids.

Immunization with recombinant actin from Trypanosoma evansi induces protective immunity against T. evansi, T. equiperdum and T. b. brucei infection.

Actin gene of Trypanosoma evansi (STIB 806) was cloned and expressed in Escherichia coli. The predicted amino acid sequence of T. evansi actin shows 100%, 98.7%, and 93.1%, homology with Trypanosoma equiperdum, Trypanosoma brucei brucei, and Trypanosoma cruzi. Recombinant actin was expressed as inclusion bodies in E. coli. It was purified and renatured for immunological studies. Mice immunized with the renatured recombinant actin were protected from lethal challenge with T. evansi STIB 806, T. equiperdum STIB 818, and T. b. brucei STIB 940, showing 63.3%, 56.7%, and 53.3% protection, respectively. Serum collected from the rabbit immunized with recombinant actin inhibited the growth of T. evansi, T. equiperdum, and T. b. brucei in vitro cultivation. Serum from mice and rabbits immunized with recombinant actin only recognized T. evansi actin but not mouse actin. The results of this study suggest that the recombinant T. evansi actin induces protective immunity against T. evansi, T. equiperdum, and T. b. brucei infection and may be useful in the development of a vaccine with other cytoskeletal proteins to prevent animal trypanosomiasis caused by these three trypanosome species.