Sanaullah Iqbal

Characterization of a heterodimeric GH2 β-galactosidase from Lactobacillus sakei Lb790 and formation of prebiotic galacto-oligosaccharides.

The lacLM genes from Lactobacillus sakei Lb790, encoding a heterodimeric β-galactosidase that belongs to glycoside hydrolase family GH2, were cloned and heterologously expressed in Escherichia coli . Subsequently, the recombinant β-galactosidase LacLM was purified to apparent homogeneity and characterized. The enzyme is a β-galactosidase with narrow substrate specificity because o-nitrophenyl-β-D-galactopyranoside (oNPG) was efficiently hydrolyzed, whereas various structurally related oNP analogues were not. The K(m) and k(cat) values for oNPG and lactose were 0.6 mM and 180 s(-1) and 20 mM and 43 s(-1), respectively. The enzyme is inhibited competitively by its two end-products D-galactose and D-glucose (K(i) values of 180 and 475 mM, respectively). As judged by the ratio of the inhibition constant to the Michaelis constant, K(i)/K(m), this inhibition is only very moderate and much less pronounced than for other microbial β-galactosidases. β-Galactosidase from L. sakei possesses high transgalactosylation activity and was used for the synthesis of galacto-oligosaccharides (GalOS), employing lactose at a concentration of 215 g/L. The maximum GalOS yield was 41% (w/w) of total sugars at 77% lactose conversion and contained mainly non-lactose disaccharides, trisaccharides, and tetrasaccharides with approximately 38, 57, and 5% of total GalOS formed, respectively. The enzyme showed a strong preference for the formation of β-(1→6)-linked transgalactosylation products, whereas β-(1→3)-linked compounds were formed to a lesser extent and β-(1→4)-linked reaction products could not be detected.

Novel Combination of Prebiotics Galacto-Oligosaccharides and Inulin-Inhibited Aberrant Crypt Foci Formation and Biomarkers of Colon Cancer in Wistar Rats.

The selectivity and beneficial effects of prebiotics are mainly dependent on composition and glycosidic linkage among monosaccharide units. This is the first study to use prebiotic galacto-oligosaccharides (GOS) that contains β-1,6 and β-1,3 glycosidic linkages and the novel combination of GOS and inulin in cancer prevention. The objective of the present study is to explore the role of novel GOS and inulin against various biomarkers of colorectal cancer (CRC) and the incidence of aberrant crypt foci (ACF) in a 1,2-dimethyl hydrazine dihydrochloride (DMH)-induced rodent model. Prebiotic treatments of combined GOS and inulin (57 mg each), as well as individual doses (GOS: 76–151 mg; inulin 114 mg), were given to DMH-treated animals for 16 weeks. Our data reveal the significant preventive effect of the GOS and inulin combination against the development of CRC. It was observed that inhibition of ACF formation (55.8%) was significantly (p ≤ 0.05) higher using the GOS and inulin combination than GOS (41.4%) and inulin (51.2%) treatments alone. This combination also rendered better results on short-chain fatty acids (SCFA) and bacterial enzymatic activities. Dose-dependent effects of prebiotic treatments were also observed on cecum and fecal bacterial enzymes and on SCFA. Thus, this study demonstrated that novel combination of GOS and inulin exhibited stronger preventive activity than their individual treatments alone, and can be a promising strategy for CRC chemoprevention.

Impact of Novel Prebiotic Galacto-Oligosaccharides on Various Biomarkers of Colorectal Cancer in Wister Rats

Colorectal cancer (CRC) is one of the leading causes of cancer deaths around the globe. Bioactive food ingredients such as prebiotics have protective potential in colon cancer. Data on galacto-oligosaccharides (GalOS) against CRC are very limited and GalOS used in this study have β-1,6 and β-1,3 as major glycosidic linkages and, to our best knowledge, were never used before against any cancer treatment. This study aims to investigate the protective role of novel GalOS against various biomarkers of CRC including aberrant crypt foci (ACF), bacterial enzymes and short chain fatty acids (SCFA) in a rodent model induced with 1,2-dimethylhydrazine dihydrochloride (DMH). Inulin group was taken as positive control in present study to compare novel GalOS protective effects. GalOS doses of 76–151 mg and inulin doses of 114 mg were given to different groups treated with DMH. Results showed that ACF formation was significantly (p ≤ 0.05) less in high dose GalOS group (27.3%). GalOS also had protective effects against DMH-induced body weight loss and showed higher level of cecal and fecal SCFA (acetate, propionate and butyrate). High doses of GalOS also resulted in significant (p ≤ 0.05) reduction of bacterial enzymatic activities. Increased populations of beneficial bacteria (bifidobacteria and lactobacilli) and decreased concentrations of harmful bacteria were observed in all prebiotics treatment groups. It can be concluded that novel GalOS exhibit robust protective activity against ACF formation in vivo.

Nutraceutical, Anti-Inflammatory, and Immune Modulatory Effects of β-Glucan Isolated from Yeast

β-Glucan is a dietary fibre, found in many natural sources, and controls chronic metabolic diseases effectively. However, β-glucan from the yeast has rarely been investigated. Objectively, conditions were optimized to isolate β-glucan from the yeast (max. 66% yield); those optimized conditions included 1.0 M NaOH, pH 7.0, and 90°C. The purity and identity of the isolated β-glucan were characterized through FT-IR, SEM, DSC, and physicofunctional properties. The obtained results from DSC revealed highly stable β-glucan (m.p., 125°C) with antioxidant activity (TAC value 0.240 ± 0.0021 µg/mg, H2O2 scavenging 38%), which has promising bile acid binding 40.463% and glucose control (in vitro). In line with these results, we evaluated the in vivo anti-inflammatory potential, that is, myeloperoxidase activity and reduction in MDA and NO; protective effect on proteins and keeping viscosity within normal range exhibited improvement. Also, the in vivo cholesterol binding and reduction in the skin thickness by β-glucan were highly encouraging. Finally, our results confirmed that yeast β-glucan is effective against some of the inflammatory and oxidative stress markers studied in this investigation. In general, the effect of 4%  β-glucan was more noticeable versus 2%  β-glucan. Therefore, our results support the utilization of β-glucan as a novel, economically cheap, and functional food ingredient.

White Sesame Seed Oil Mitigates Blood Glucose Level, Reduces Oxidative Stress, and Improves Biomarkers of Hepatic and Renal Function in Participants with Type 2 Diabetes Mellitus

Abstract Objectives: The study was designed to investigate the impact of white sesame seed oil (WSSO) consumption on fasting blood glucose (GLU), insulin (INS), glycosylated hemoglobin (HbA1c), and hepatic antioxidant enzymes. A secondary aim was to check the influence on serum biochemistry, hepatic, cardiac, and renal functions. Methods: Forty-six participants with type 2 diabetes were recruited and randomly divided into two equal groups: diabetic control (DCON) and diabetic sesame oil (DSO). At baseline and 30, 60, and 90 days, blood samples were drawn and analyzed. Two-way repeated-measures analysis of variance was used to evaluate the difference between groups and across time. Results: In both groups, GLU, INS, and HbA1c were not significantly different at baseline (mean 187.07 ± 5.63 mg/dl, mean 12.12 ± 1.03 μU/ml, and mean 7.55 ± 0.37%, respectively). At 90 days, GLU was significantly (p < 0.05) decreased in DSO (137.83 ± 3.16 mg/dl) when compared with DCON (218.13 ± 5.92 mg/dl), while INS was significantly increased in DSO (23.13 ± 1.15 μU/ml) as compared to DCON (7.93 ± 0.38 μU/ml). At 90 days, HbA1c was significantly lower (p < 0.05) in DSO as compared to DCON. Thiobarbituric acid reactive substances were significantly lower (p < 0.05) in DSO (1.08 ± 0.05 [MDA] nmol/ml) as compared to DCON (2.26 ± 0.07 [MDA] nmol/ml). In DSO, activities of hepatic antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) increased while in DCON these activities decreased significantly (p < 0.05) across the time period. Biomarkers of liver, cardiac, and renal functions improved significantly in DSO as compared to DCON. Conclusion: WSSO as a functional food may play an important role in GLU regulation and against deleterious effects of diabetes in humans with type 2 diabetes.

Influence of Yeast β-Glucan on Cookies Sensory Characteristics and Bioactivities

β-Glucan is biologically active polysaccharide, ubiquitously found in many grains, bacteria, and fungi and much yeast. The aim of this study was to determine the effect of substituting wheat flour by 1, 2, and 4% yeast isolated β-glucan in cookies on the sensory acceptance, antioxidants, oxidative stability, and quality evaluation which were investigated. According to the results, cookies supplemented at 2% yeast β-glucan were proved satisfactory on sensory quality perspective. During the storage study it was found that cookies made with 2 and 4% β-glucan have effectively ( ) kept the peroxide value (PV) within acceptable range, demonstrating the promising role of β-glucan in deterring oxidative. It is further noted that 2 or 4% β-glucan incorporated cookies assimilated highest absorption spectra, suggesting the retardation in freshness losses, with having minimum microbial loads, showing microbiological safety. β-Glucan fortification in foods is technologically and economically feasible, suggesting that a significant prospect of β-glucan as low-cost food ingredient in formulating cookies at 2% offers exciting new use of β-glucan of yeast origin.

Effect of hydrogenated fat replacement with white sesame seed oil on physical, chemical and nutritional properties of cookies

Sesame seed oil has known antioxidant properties that may improve both nutritional importance and shelf-life of the product. Three aims of the study were to: a) examine nutritional value and physicochemical properties of white sesame seed oil (WSSO) and hydrogenated vegetable fat (HVF) cookies, b) compare the antioxidant potential of the cookies and c) determine the effects of storage and treatment conditions on palatability of the cookies. Results showed that energy and fat% were significantly higher (P < 0.05) in WSSO than HVF cookies. At 60th day, mean moisture, peroxide value, and acidity were higher (P < 0.05) in HVF cookies. Over time, protein and fiber% decreased significantly (p < 0.05) in both cookies but remained higher (P < 0.05) in WSSO at 60 days. WSSO cookies had longer shelf life, greater palatability, improved physical properties and greater antioxidant potential.