No abstract

In the presented study, Bacillus subtilis strain AG4 isolated from marine was identified based on morphological, physiological, phylogenetic characteristics and an examination of 16S rRNA sequences. Novel exopolysaccharide (EPSR4) was extracted and isolated from the Bacillus subtilis strain as a major fraction of exopolysaccharide (EPS). The analysis of structural characterization indicated that EPSR4 is a β-glycosidic sulphated heteropolysaccharide (48.2%) with a molecular weight (Mw) of 1.48 × 104 g/mole and has no uronic acid. Analysis of monosaccharide content revealed that EPSR4 consists of glucose, rhamnose and arabinose monosaccharide in a molar ratio of 5:1:3, respectively. Morphological analysis revealed that EPSR4 possess a high crystallinity degree with a significant degree of porosity, and its aggregation and conformation in the lipid phase might have a significant impact on the bioactivity of EPSR4. The biological activity of EPSR4 was screened and evaluated by investigating its antioxidant, cytotoxicity, anti-inflammatory, and anti-Alzheimer activities. The antioxidant activity results showed that EPSR4 has 97.6% scavenging activity toward DPPH free radicals at 1500 µg/mL, with an IC50 value of 300 µg/mL, and 64.8% at 1500 µg/mL toward hydrogen peroxide free radicals (IC50 = 1500 µg/mL, 30 min). Furthermore, EPSR4 exhibited considerable inhibitory activity towards the proliferation of T-24 (bladder carcinoma), A-549 (lung cancer) and HepG-2 (hepatocellular carcinoma) cancer cell lines with IC50 of 244 µg/mL, 148 µg/mL and 123 µg/mL, respectively. An evaluation of anti-inflammatory activity revealed that EPSR4 has potent lipoxygenase (LOX) inhibitory activity (IC50 of 54.3 µg/mL) and a considerable effect on membrane stabilization (IC50 = 112.2 ± 1.2 µg/mL), while it showed cyclooxygenase (COX2) inhibitory activity up to 125 µg/mL. Finally, EPSR4 showed considerable inhibitory activity towards acetylcholine esterase activity. Taken together, this study reveals that Bacillus subtilis strain AG4 could be considered as a potential natural source of novel EPS with potent biological activities that would be useful for the healthcare system.

Colocasia esculenta (Taro) is an edible tuberous plant; however, corms are its most worldwide consumed part while the corm powder is widely used in food industries. In this work, a sulphated polysaccharide extract of C. esculenta corm (SCE) was prepared and its cancer chemopreventive properties were explored. The amending of carcinogen metabolism and radical scavenging affinity revealed that SCE is a strong tumor anti-initiation agent via suppressing cytochrome P450-1A and enhancing glutathione and the carcinogen detoxification enzyme; glutathione S-transferase. SCE exhibited a strong scavenging affinity towards critical radicals (hydroxyl and peroxyl). It induced lymphocyte growth and modulated the macrophage functions into an anti-inflammatory profile, via elevating macrophage proliferation and its binding affinity of fluorescein isothiocyanate-lipopolysaccharide (FITC-LPS) and inhibiting nitric oxide and tumor necrosis factor-α generation. Furthermore, SCE showed a potent cytotoxicity against human breast MCF-7 carcinoma cells (IC 50 27.73 µg/mL), whereas SCE treatment inhibited the activity of histone deacetylase (HDAC IC 50 37.70 µg/mL) and disturbed the pattern of cell cycle phases. An arrest in both S-and G2/M-phases was linked with shifted cell populations towards late apoptosis and necrosis, as detected by flow cytometry. SCE is a promising cancer chemopreventive agent to be used in healthy food industries and for the high breast cancer-risk population.

Gold nanorods (GNRs) are now under extensive investigation for biomedical applications. The in vivo genotoxic profile GNRs are not elucidated yet, therefore we investigated it in comparison with one of the most effective chemotherapeutic agents, cyclophosphamide (CP), in a mice model. PEGylatedGNRs (50 nm) were injected to Balb/C mice triple times, while CP-treated mice were treated once and the bone marrow cells (BMCs) were collected after 21 days. Chromosome aberrations, mitotic index, sister chromatid exchanges (SCEs), replicative index, micronucleus (MN) and DNA damage using comet assay were investigated. GNRs induced chromosome aberrations including-and excluding-gaps significantly at p < 0.001 and p < 0.01, respectively, however CP resulted in a higher significant increase in both types with p < 0.001. The percentage of SCEs/cell was not affected by GNRs treatment, while it was extremely significant with CP. Both mitotic activity and proliferative index were reduced dramatically with both of GNRs and CP. The recorded MN were lower in GNRsthan CP-treated mice. The percentage DNA damage, tail length and tail moment were higher in CP than GNRs. In conclusion, CP induced extreme genotoxicity more than GNRs. Both of GNRs and CP induced DNA damage. The study indicated the advantage of lower GNRs genotoxicity than that of CP. After 21 days, one injection of CP led to extreme persistent genotoxic effect more than that of multiple injections of GNRs.

No abstract