Bostrycin

Background:Bostrycin is a natural pigment product with anthraquinone skeleton, which has excellent inhibitory effect on a variety cancer cells. However, its suppression on tongue squamous cell carcinoma has not been reported.Methods:We studied the effects of bostrycin on the cell growth and apoptosis of tongue squamous cell carcinomain vitro, and explored its mechanism.Results:Bostrycin could inhibit the proliferation and migration of tongue squamous cell carcinoma by arresting cell cycle at G2/M phase, and inducing cell apoptosis with mitochondrial membrane potential changes. West-blotting analysis also showed that bostrycin could inhibit the growth of tongue squamous cell carcinoma cells by activating the apoptosis-related signal proteins especially in mitochondrial apoptotic pathway.Conclusions:Bostrycin can be used as a new anti-tumor candidate drug for further research. Our study provides reference for the potential application of bostrycin in the treatment of the tongue squamous cell carcinoma.

Tuberculosis (TB) is caused by bacterial pathogen Mycobacterium tuberculosis (Mtb) and remains a major health problem worldwide. The increasing prevalence of drug-resistant Mtb strains and the extended duration of anti-TB regimens have created an urgent need for new anti-tuberculosis antibiotics with novel targets or inhibitory strategies. Anthracenedione compound bostrycin has been shown to inhibit the growth of Mtb in vitro and inhibit the activity of the effector protein tyrosine phosphatase (MptpB) secreted by Mtb. In this study, we characterized the proteomic profile of the Mtb strain H37Ra exposed to 1 mg/L and 25 mg/L of bostrycin for 24 h. Bioinformatic analysis of the differential abundant proteins indicated that bostrycin treatment may induce oxidative stress and interfere with essential processes such as synthesis of NAD(+) and the tricarboxylic acid cycle in mycobacteria. Then, the molecular docking of bostrycin and 15 candidates of targeted proteins showed that Rv3684 and Rv1908c got higher scores compared to MptpB, suggesting the direct interaction of bostrycin and these two proteins. Further docking of potential targeted proteins with the functional group-removal derivatives of bostrycin revealed possible key functional groups of bostrycin and provides direction for the modification of bostrycin in future. BIOLOGICAL SIGNIFICANCE: It is a challenging work to determine the potential target(s) of an antibiotic accurately and quickly. In this study, we conducted a proteomic analysis of Mtb responding to the treatment of bostrycin, and provided insight into the inhibiting mechanism of this anti-Mtb compound. The proper interaction of bostrycin and targeted proteins, as well as the interacting residues of targets, and functional groups of bostrycin were also identified within the docking surface, providing a direction for further modification of bostrycin. Our study also suggests a reference for the interaction analysis between mycobacteria and antibiotics, and provides potential targets information for other active anthraquinones.

Bostrycin, a red antibacterial agent produced byNigrosporasp. no. 407, is considered for meat processing. To optimize production, the culture conditions of submerged fermentation (SmF) and solid-state fermentation (SSF) were investigated. The optimal SmF conditions were a medium containing 1.0% cane molasses and incubation at 30 °C and 150 rpm for 6 days. In SSF, other than bostrycin, less pigment was produced and the optimal ratio of bagasse to water was 1:2 for 10 days. The production and recovery rate of bostrycin by SmF were 120 mg/L and 40%, respectively. Bostrycin exhibited thermostable, pH-dependent color change and dose-dependent antibacterial activity againstClostridium botulinum. Bostrycin-modified meat turned strong red for at least 24 h and could not be removed by washing; bostrycin maintained its antibacterial activity with a bacteriostasis rate of 91% onStaphylcoccus aureus. This is an easy and inexpensive means of acquiring bostrycin from molasses and sugarcane.