Structural characteristics and functional properties of a fucose containing prebiotic exopolysaccharide from Bifidobacterium breve NCIM 5671.

AIM: To evaluate the structure and functions of capsular exopolysaccharide (CPS) from Bifidobacterium breve NCIM 5671. METHODS AND RESULTS: A CPS produced by the probiotic bacteria B. breve NCIM 5671 was isolated and subjected to characterization through GC analysis, which indicated the presence of rhamnose, fucose, galactose, and glucose in a molar ratio of 3:1:5:3. The average molecular weight of the CPS was determined to be ∼8.5 × 105 Da. Further, NMR analysis revealed the probable CPS structure to be composed of major branched tetra- and penta-saccharide units alternately repeating and having both α- and ß-configuration sugar residues. CPS displayed an encouraging prebiotic score for some of the studied probiotic bacteria. Compared to standard inulin, CPS showed better resistance to digestibility against human GI tract in vitro. DPPH, total antioxidant, and ferric reducing assays carried out for CPS displayed decent antioxidant activity too. CONCLUSION: This study indicates that the CPS from B. breve NCIM 5671 has the potential to be utilized as a prebiotic food supplement. It is a high-molecular-weight (∼8.5 × 105 Da) capsular heteropolysaccharide containing rhamnose, fucose, galactose, and glucose.

Rotenone mediated developmental toxicity in Drosophila melanogaster.

Rotenone (ROT) is a widely used natural pesticide, and its effect on growth and developmental toxicity remain unclear. In the present study, the effects of ROT exposure on the reproductive structure and function of the female Drosophila melanogaster and third instar larvae were investigated. ROT exposure on female Drosophila melanogaster resulted in developmental inhibition and ovarian abnormality, which were evident from the disruptive growth of border cells as well as morphological changes in the orientation of nurse cells during the 9th-10th stage of developing egg chamber of in the Drosophila ovary. Other abnormalities, such as, altered developmental gene expression (Osk, Grk, Nos, Bic-d), inhibition in the kinesin motor protein level (KIF-5B), increased caspases activities (Caspase 3, 8, & 9) and apoptosis were also observed. Subsequently, ROT treated larvae exhibited behavioral deficits and delay in developmental time. The above findings demonstrate that the exposure of ROT causes developmental toxicity in Drosophila melanogaster.

Low Molecular Weight Chitosan (∼20 kDa) protects acrylamide induced oxidative stress in D. melanogaster by restoring dopamine and KIF5B levels.

Acrylamide (AA) presence and formation are predominant in fried, baked and heat-processed foods. Using Drosophila model, we have investigated the dietary AA-arbitrate oxidative stress induced neurotoxicity and the effect of soluble Low Molecular Weight Chitosan (LMWC) supplementation. We assessed the neurodegenerative and behavioural effect of AA (0-10 mM) exposure in Drosophila (adult males). As a result, the exposed flies showed distinctive locomotor impairments and incident of mortality [51% in 5 mM AA (sub-toxic level) for 7 days] and higher mortality with increased concentration of acrylamide. Further, exposure of AA toxicity was also correlated with changing levels of oxidative markers, ETC complexes and cholinergic function of flies. Decreased dopamine (25 µg/mg) and kinesin motor protein levels were confirmed by HPLC and Immunoblotting studies, respectively. Interestingly, the co-exposure of LMWC alongside AA ameliorates respective biochemical changes with restoring dopamine (30 µg/mg, control groups 32 µg/mg) and kinesin motor protein (KIF5B) levels. These results indicated that supplementation of biocompatible LMWC may be promising candidate for complete protection against AA induced oxidative stress.