Antioxidative and radioprotective activities of semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1

Two Potential Probiotic Bacillus with Proteolytic Activity to Dietary Protein from Adult Feces

　Two Bacillus strains were screened and identified using 16S rRNA gene sequencing the phenotypic tests, and then characterized in vitro for the probiotic characteristics. They were able to tolerate pH 2.5 for 2.5 h, following 0.3% bile salts and 0.1% pancreatin treatment for 5 h. They exhibited good ability to attach to intestinal epithelial cells and were susceptible to most of the antibiotics and being killed by several. Further and more important, they showed good proteolytic activity to food protein as gelatin and milk, with even higher activity than the reference strain. Thus, these two Bacillus strains are considered as potential proteolytic probiotic strains to food proteins.

In vitro stimulatory effect of N-acetyl tryptophan-glucopyranoside against gamma radiation induced immunosuppression

Radiation-induced manifestations like free radical burst, oxidative damage and apoptosis leading to cell death. In present study, N-acetyl tryptophan glucopyranoside (NATG) was assessed for its immune-radioprotective activities using J774A.1 cells. Clonogenic cell survival, cell cycle progression and cytokines i.e. IFN-γ, TNF-α, IL-2, IL-10, IL-12, IL-13 and IL-17A expression were evaluated in irradiated and NATG pretreated cells using clonogenic formation ability, flow cytometry and ELISA assay. Results indicated that 0.25μg/ml NATG exhibited maximum radioprotection against gamma-radiation (2Gy) without intervening in cell cycle progression. NATG pretreated (-2 h) plus irradiated cells showed significant elevation in IFN-γ (∼38.2%), IL-17A (∼53.7%) and IL-12 (∼58.8%) expression as compared to only irradiated cells. Conversely, significant decrease in TNF-α (∼21.6%), IL-10 (∼31.2%), IL-2 (∼23.7%) and IL-13 expression (∼17.8%) were observed in NATG pretreated plus irradiated cells as compared to irradiated cells. Conclusively, NATG pretreatment to irradiated J774A.1 cells, stimulate Th₁ while diminish Th₂ cytokines that contributes to radioprotection.

Appraisal of biochemical classes of radioprotectors: evidence, current status and guidelines for future development

The search for efficient radioprotective agents to protect from radiation-induced toxicity, due to planned or accidental radiation exposure, is still ongoing worldwide. Despite decades of research and development of widely different biochemical classes of natural and derivative compounds, a safe and effective radioprotector is largely unmet. In this comprehensive review, we evaluated the evidence for the radioprotective performance of classical thiols, vitamins, minerals, dietary antioxidants, phytochemicals, botanical and bacterial preparations, DNA-binding agents, cytokines, and chelators including adaptogens. Where radioprotection was demonstrated, the compounds have shown moderate dose modifying factors ranging from 1.1 to 2.7. To date, only few compounds found way to clinic with limited margin of dose prescription due to side effects. Most of these compounds (amifostine, filgratism, pegfilgrastim, sargramostim, palifermin, recombinant salmonella flagellin, Prussian blue, potassium iodide) act primarily via scavenging of free radicals, modulation of oxidative stress, signal transduction, cell proliferation or enhance radionuclide elimination. However, the gain in radioprotection remains hampered with low margin of tolerance. Future development of more effective radioprotectors requires an appropriate nontoxic compound, a model system and biomarkers of radiation exposure. These are important to test the effectiveness of radioprotection on physiological tissues during radiotherapy and field application in cases of nuclear eventualities.

Semiquinone glucoside derivative provides protection against γ-radiation by modulation of immune response in murine model

Present study was undertaken to evaluate radioprotective and immunomodulatory activities of a novel semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1 in C57 BL/6 mice. Whole body survival study was performed to evaluate in vivo radioprotective efficacy of SQGD. To observe effect of SQGD on immunostimulation, Circulatory cytokine (i.e., interleukin-2 (IL-2), IFN-γ, IL-10, granulocyte colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating factor (GM-CSF), and macrophage colony stimulating factor (M-CSF) expression was analyzed in serum of irradiated and SQGD treated mice at different time intervals using ELISA assay. Results of the present investigation indicated that SQGD pre-treatment (-2 h) to lethally irradiated mice provide ∼ 83% whole body survival compared with irradiated mice where no survival was observed at 30(th) post irradiation day. Significant (p < 0.05) induction in IL-2 and IFN-γ expression was observed at all tested time intervals with SQGD pre-treated irradiated mice as compared with irradiated mice alone. However, sharp increase in IL-10 expression was observed in irradiated mice which were found to be subsidized in irradiated mice pre-treated with SQGD. Similarly, significant (p < 0.05%) induction in G-CSF, M-CSF and GM-CSF expression was observed in irradiated mice treated with SQGD as compared with irradiated control mice at tested time intervals. In conclusion, SQGD pre-treatment to irradiated mice enhanced expression of IL-12 and IFN-γ while down-regulated IL-10 expression and thus modulates cytoprotective pro-inflammatory TH1 type immune response in irradiated mice. Further, SQGD pre-treatment to irradiated mice accelerate G-CSF, GM-CSF and M-CSF expression suggesting improved haematopoiesis and enhanced cellular immune response in immuno-compromised irradiated mice that may contribute to in vivo radiation protection.

Semiquinone fraction isolated from Bacillus sp. INM-1 protects hepatic tissues against γ-radiation induced toxicity

Present study was focused on evaluation of a semiquinone glucoside derivative (SQGD) isolated from radioresistant bacterium Bacillus sp. INM-1 for its ability against γ radiation induced oxidative stress in irradiated mice. Animals were divided into four group, i.e., (i) untreated control mice; (ii) SQGD treated (50 mg/kg b. wt. i.p.) mice; (iii) irradiated (10 Gy) mice; and (iv) irradiated mice which were pre-treated (-2 h) with SQGD (50 mg/kg b. wt. i.p.). Following treatment, liver homogenates of the treated mice were subjected to endogenous antioxidant enzymes estimation. Result indicated that SQGD pre-treatment, significantly (P < 0.05) induced superoxide dismutase (SOD) (19.84 ± 2.18% at 72 h), catalase (CAT) (26.47 ± 3.11% at 12 h), glutathione (33.81 ± 1.99% at 24 h), and glutathione-S-transferase (24.40 ± 2.65% at 6 h) activities in the liver of mice as compared with untreated control. Significant (P < 0.05) induction in SOD (50.04 ± 5.59% at 12 h), CAT (62.22 ± 7.50 at 72 h), glutathione (42.92 ± 2.28% at 24 h), and glutathione-S-transferase (46.65 ± 3.25 at 12 h) was observed in irradiated mice which were pre-treated with SQGD compared with only irradiated mice. Further, significant induction in ABTS(+) radicals (directly proportional to decrease mM Trolox equivalent) was observed in liver homogenate of H2 O2 treated mice which were found to be significantly inhibited in H2 O2 treated mice pre-treated with SQGD. Thus, it can be concluded that SQGD treatment neutralizes oxidative stress caused by irradiation not only by enhancing endogenous antioxidant enzymes but also by improving total antioxidant status of cellular system and thus cumulative effect of the phenomenon may contributes to radioprotection.

A semiquinone glucoside derivative provides protection to male reproductive system of the mice against gamma radiation toxicity

Present investigation was carried out to evaluate the radioprotective efficacy of a novel Semiquinone glucoside derivative (SQGD), isolated from Bacillus sp. INM-1, in the male reproductive system of BALB/c mice. Animals were administered 50 mg/kg b.wt. (i.p.) SQGD 2 h before whole body γ-irradiation (10 Gy). Radiation-induced cellular toxicity and its modulation by SQGD pretreatment was evaluated in the mice testes by quantitative histological and protein expression analysis. SQGD pretreatment protects irradiated mice from radiation-induced testicular atrophy and germ cells degeneration, which may lead to emptiness of seminiferous tubules. Significant decrease in P53 and P21((Cip/WAF-1)) expression was observed in the irradiated mice pretreated (2 h) by SQGD at 6 h compared with only irradiated mice. However, contrary to P53, expressions of P21 at latter time, that is, 24-72 h was found to be increased significantly in the irradiated mice pretreated by SQGD. Significant increase in the intact PARP-1 protein expression were observed in the testes of the mice pretreated by SQGD 2 h before irradiation at 24-72 h compared with the only irradiated mice, whereas significant increase in PARP-1 cleaved fragment was noticed at 24 h. Similarly, significant increase in NF-kB and BCL-2/BAX expressions ratio was noticed in SQGD-treated mice (± irradiation) compared with irradiated mice, suggested a role of SQGD in the activation of prosurvival signaling in the testicular germinal cells population of the irradiated mice and thus contributed to protection against lethal γ-irradiation.

Semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1 protects against gamma radiation-induced oxidative stress

In the present study, radioprotective potential of Semiquinone glucoside derivative (SQGD) isolated from radioresistant bacterium Bacillus sp. INM-1 was evaluated. γ-Radiation induced protein carbonylation, plasmid DNA damage, enzyme functional impairment, lipid peroxidation, HO radicals generation and their protection by SQGD was assessed. As a result of SQGD treatment, significant inhibition (p<0.05) in protein carbonylation was observed with BSA. SQGD treatment was found to restore supercoiled (~70±3.21%) form of irradiated plasmid DNA against γ-irradiation. SQGD protects enzymes (EcoR1 and BamH1) against radiation-induced dysfunctioning. SQGD significantly inhibited (p<0.05) lipid peroxidation in liposomes, brain and liver homogenate. Higher HO(•) radicals-averting activity of SQGD was observed in the serum and liver homogenate of C57BL/6 mice against H2O2-induced oxidative stress. In conclusion, SQGD demonstrates excellent radical-scavenging activity towards bio-macromolecules in irradiated environment and can be developed as an ideal radioprotector against radiation-induced oxidative stress in future.

A semiquinone glucoside derivative isolated from Bacillus sp. INM-1 provides protection against 5-fluorouracil-induced immunotoxicity

5-Fluorouracil (5-FU) is a widely used anti-cancer agent; however, it induces immunosuppression in patients undergoing a chemotherapy regime. The mode of action by which 5-FU induces immunosuppression is primarily via inhibition of hematopoietic growth factors. In the present study, immunoprotective effects of a semiquinone glucoside derivative (SQGD), a bacterial metabolite isolated from Bacillus sp. INM-1, were evaluated in a model of 5-FU-induced immunotoxicity in C57Bl/6 male mice. The evaluation was done by analyzing G-CSF, GM-CSF, and M-CSF expression in the serum, spleen, and bone marrow cells of the mice at different timepoints after 5-FU treatment. Mice received a single intraperitoneal injection of either 5-FU (75 mg/kg) alone, SQGD (50 mg/kg) alone, or SQGD 2 h prior to the 5-FU treatment. Control mice received saline vehicle only. The results demonstrated that 5-FU treatment significantly inhibited G-CSF, GM-CSF, and M-CSF expression in all three sites at all timepoints from 6-72 h post 5-FU. In SQGD treated mice, up-regulation of factor expression was observed in each compartment, and significantly so most often after 12 h. SQGD treatment prior to 5-FU administration to the mice significantly increased in all sites evaluated - relative to values in both control mice and 5-FU only-treated mice - G-CSF, M-CSF, and GM-CSF expression at almost every timepoint. The present findings suggest that SQGD provides protection against 5-FU-induced immunotoxicity in mice and could protect bone marrow progenitor cells against the effects of cytotoxic drugs used for treatment of cancer. The findings also suggested to us that SQGD is a potential immunomodulator and could protect hematopoiesis against toxic assault caused by anti-cancer drugs in the clinical setting.

Antioxidant and anticancer activity of 3,5-dihydroxy-4-isopropylstilbene produced by Bacillus sp. N strain isolated from entomopathogenic nematode

3,5-Dihydroxy-4-isopropylstilbene is a natural phytoalexin and was first identified as bacterial secondary metabolites. The aim of this study is to investigate in vitro antioxidant and anticancer activity of 3,5-dihydroxy-4-isopropystilbene purified from the cell free culture filtrate of Bacillus sp. N strain associated with rhabditid entomopathogenic nematode. Antioxidant activity was evaluated by five separate methods: free radical scavenging, reducing power assay, chelating effects on ferrous ions, NBT superoxide radical scavenging assay and hydroxyl radical scavenging activity. The stilbene recorded powerful antioxidant activity at various antioxidant systems in vitro. The superoxide radical scavenging (92.1 %) and hydroxyl radical scavenging (83.4 %) activities of the stilbenes at 100 μg/ml were higher than the butylated hydroxyanisole, the known antioxidant agent. Anticancer activity of stilbene was tested against breast cancer (MDAM B-231), cervical cancer (HeLa), lung cancer (A 549), colon cancer (HTL 116) cell lines using MTT method. The induction of apoptosis was studied by morphological analysis, apoptotic cell staining, caspase 3 activation assay and cell cycle analysis using flow cytometry. Stilbene induced significant morphological changes and DNA fragmentation associated with apoptosis in HeLa cells. Acridine orange/ethidium bromide stained cells indicated apoptosis induction by stilbene. Up-regulation of caspase 3 activity was also found in cells treated with stilbene. Flow cytometry analysis showed an increase in the percentage of apoptotic cells in sub G0 phase (2.4 % in control plates to 11.4 % in 25 μg/ml of stilbene) confirming the stilbene induced apoptosis. The results of the present study showed that stilbene demonstrated a strong antioxidant and anticancer effects. These suggest that stilbene may be used as possible natural antioxidant and anticancer agents to control various human diseases.

Semiquinone derivative isolated from Bacillus sp. INM-1 protects cellular antioxidant enzymes from γ-radiation-induced renal toxicity

This study was focused to evaluate protection of indigenous antioxidant system of mice against gamma radiation-induced oxidative stress using a semiquinone (SQGD)-rich fraction isolated from Bacillus sp. INM-1. Male C57bl/6 mice were administered SQGD (50 mg/kgb.w.i.p.) 2 h before irradiation (10 Gy) and modulation in antioxidant enzymes activities was estimated at different time intervals and compared with irradiated mice which were not pretreated by SQGD. Compared to untreated controls, SQGD pretreatment significantly (p < 0.05) accelerates superoxide dismutase, catalase, GSH, and glutathione-S-transferase activities. Similarly, significant (p < 0.05) increase in the expression of superoxide dismutase, catalase, GSH, and glutathione-S-transferase was observed in irradiated mice pretreated by SQGD, compared to only irradiated groups. Total antioxidant status equivalent to trolox was estimated in renal tissue of the mice after SQGD administration. Significant ABTS(+) radical formation was observed in H2O2-treated kidney homogenate, due to oxidative stress in the tissue. However, significant decrease in the levels of ABTS(+) radical was observed in kidney homogenate of the mice pretreated with SQGD. Therefore, it can be concluded that SQGD neutralizes oxidative stress by induction of antioxidant enzymes activities and thus improved total antioxidant status in cellular system and hence contributes to radioprotection.