The Role of Intestinal Flora in Anti-Tumor Antibiotic Therapy.

Anti-tumor antibiotics are chemical substances produced by micro-organisms to control cancer development. Some of the currently used cancer treatment regimens are anti-tumor antibiotics. However, many studies have demonstrated that anti-tumor antibiotics may have adverse effects on normal cells. This calls for development of strategies to alleviate these negative effects and improve cancer treatment. Recent studies have suggested that the efficacy of anti-tumor antibiotics may be affected by intestinal microbiota. For instance, intestinal microbiota can alleviate the negative effects of antibiotic treatment and regulate the tumor immune micro-environment. In this way, anti-tumor antibiotics can improve tumor control. However, the specific mechanisms need to be further explored. This review discusses the effect of intestinal flora on anti-tumor antibiotic therapy and summarizes the specific mechanisms by which antibiotics inhibit harmful intestinal micro-organisms and promote efficacy of probiotics, which may improve the control of neoplasm development and growth.

An "olivomycin A" derivative from a sponge-associated Streptomyces sp. strain SP 85.

We isolated an actinobacterium, Streptomyces sp. strain SP 85 from the marine sponge Dysidea avara. Polyphasic identification of the microorganism showed that the strain SP 85 had high 16S rRNA gene similarity (99%) with Streptomyces olivaceus strain NBRC 12805, while some physiological and biochemical differences were observed. A cytotoxic compound, SP 85 was isolated from the active culture extract of the strain SP 85 by bioassay-guided purification over silica gel column chromatography, preparative TLC, and HPLC. The structure elucidation based on the spectroscopic analysis, including UV, ESI-MS, and 13C NMR data revealed that SP 85 compound is an analog of anti-tumor drug, "olivomycin A". The SP 85 compound showed high cytotoxic activity against three human cancer cell lines, including SW480, HepG2, and MCF7 with IC50 values of 16, 93, and 78 nM, respectively. SP 85 exhibited significantly (2-10 times) higher cytotoxicity against the tumor cell lines in comparison with HUVECs as the normal cell line, which also induced apoptosis in the tested cancerous cell line. This is the first report on the production of an "olivomycin A" derivative by a sponge-associated Streptomyces, showing the great potential of sponge-associated actinobacteria in producing cytotoxic natural products.

Recent advances in the drug formulations of anti-tumor antibiotics / 药学学报

Anti-tumor antibiotics exhibit great application potential in the anti-tumor therapy. Some drugs have become the first-line medication clinically. However, there are always various problems associated with anti-tumor antibiotics, such as poor solubility and instability as well as severe systemic side effects. It is important to choose suitable delivery carriers for a reasonable delivery system for a good targeting ability, enhanced anti-tumor efficacy and reduced adverse effects of the anti-tumor antibiotics, especially in the smart delivery systems. This review summarizes the carriers and the advances in the delivery systems of anti-tumor antibiotics, including anti-tumor antibiotic drugs currently on the market, in the clinical research stage and in the basic research stage.

Interaction Between Anthracene Quinone Type Anti-tumor Antibiotics and DNA / 中华医院感染学杂志

OBJECTIVE To study the interaction of anthracene quinone type anti-tumor antibiotics and DNA as well as the experiment method.METHODS Spectrophotometry was developed including absorption spectrum,fluorescence spectrum,electrochemical method and so on.RESULTS The union of inlay and insertion observed in ultraviolet and visible spectrophotometry usually caused hypochromic effect and red shift.Under the certain concentrations of bovin serum albumin(BSA),the endogene fluorescence intensity of BSA orderly reduced with the increase in concentration of doxorubicin(adriamycin) hydrochloride(?em 344 and the peak shape were invariable);?ex and ?em at the biggest wave length of doxorubicin were 478 and 596 nm.The fluorescence intensity was maximal of the excitation and emission spectrum when pH was 3.0.CONCLUSIONS The interaction of doxorubicin and DNA is the strongest according to the experiment and is the most widely used at present in clinics.