Production, characterization and biological activities of acidic exopolysaccharide from marine Bacillus amyloliquefaciens 3MS 2017.

OBJECTIVE: To evaluate in-vitro antioxidant, anti-inflammatory and antitumor abilities against human breast adenocarcinoma (MCF7) and human prostate cancer (PC3) as well as the suppressor effect of bacterial exopolysaccharide (BAEPS) on Ehrlich ascites carcinoma (EAC).

METHODS: In-vitro antioxidants characters of BAEPS were determined using various methods, while anti-inflammatory activity was estimated against cyclooxygenase (COX-1 and COX-2). In-vitro study, anticancer against MCF7 and PC3 were assessed by the mitochondrial dependent reduction of yellow MTT. In in-vivo study against EAC progression, mice were inoculated with EAC cells and then were orally administered BAEPS at 200 mg/kg after 24 h (equals to 0.10 of determined LD50 )/10 d.

RESULTS: BAEPS was acidic exopolysaccharide contained uronic acid (12.3%) and sulfate (22.8%) with constitution of glucose, galactose and glucuronic acid in a molar ratio 1.6:1.0:0.9, respectively, with a molecular mass of 3.76 × 104  g/mol. BAEPS appeared potent antioxidant characters as free radical scavenging, oxygen reactive species scavenging and metal chelation, while its reducing power was low. BAEPS showed selective anti-inflammatory activity against COX-2 than COX-1, COX-2 selective. BAEPS exhibited potent and selective effect to breast cell cancer MCF7, the death percentage was 65.20% with IC50  = 70 μg/mL and IC90  = 127.40 μg/mL. BAEPS decreased counted viable EAC cells and induced non-viable cells. BAEPS improved all assessed hematological parameters. These improvements were reflected in the increasing median survival time and significant increment (P < 0.05) in life span.

CONCLUSIONS: BAEPS has anti-tumor activity with a good margin of safety. The anti-tumor activity of BAEPS may be due to its content from sulfated groups and uronic acids and they have antioxidant and anti-inflammatory properties.