Bio-evaluation of crustacean and fungal nano-chitosan for applying as food ingredient

Chitosan, bio-polyaminosacharide, is derived from chitin. Two sources (shrimp wastes and fungus biomass) were used to produce chitosan. And then the chitosan was produced in the nano-form followed by characterization by transmission electron microscopy. The images obtained clearly showed that the size of nano-chitosan ranged between 7 and 13 and 3–6 nm with spherical shape for shrimp and fungal sources, respectively. The antimicrobial activities of the tested concentrations of chitosan and nano-chitosan were examined and found to have high activity against the tested pathogens. The evaluation of the toxicity of the tested concentrations of the produced chitosan and its nano-size were performed using brine shrimp and rat bioassay. Toxicity examination of chitosan and their nano derivatives is an essential procedure to assess the possibility of using these concentrations as food ingredient. Nine groups of rats were treated with either chitosan or nano-chitosan of both sources at 100 and 200 mg kg−1 bw. Adding chitosan in the diet of all groups showed no significant changes in both the blood biochemical and oxidative stress parameters when compared with control group. The histopathology of liver, kidney and stomach confirmed the results of the previous parameters. No signs of inflammation, fibrosis or cirrhosis were found in examined organs. It is concluded that chitosan and nano-chitosan of shrimp and Rhizopus stolonifer had high antimicrobial activity and are not toxic in the same time and it can be used as food ingredients. Keywords: Chitosan, Nanochitosan, Antimicrobial activity, Toxicity evaluatio

Antimicrobial and anticancer activities of Scenedesmus obliquus metabolites

This study was conducted to evaluate the antimicrobial activities and cytotoxicity of both crude extracts of Scenedesmus obliquus and their fractions. In vitro cytotoxicity assay against human hepatocellular carcinoma (HepG2), colon cancer (HCT116) and breast cancer (MCF7) cell line was monitored. The highest inhibition was observed using diethyl ether crude extract (DEE) recording between 12.5 and 19.5 mm inhibition zone against all tested bacteria and between 8.7 and 18.3 mm against tested fungi. The highest anticancer effect of DEE was observed at IC50 against HCT116 and HepG2 cell lines using just 24.6 and 42.8 μg ml−1, respectively. While, high concentration, 93.8 μg ml−1, was required to exhibit its effect against MCF7. Column chromatography technique was used to separate DEE crude extract to its main components using 7 different mobile phases. Fractions F1 and F7 were the highest fractions that had antimicrobial activity against tested bacteria and fungi. High IC50 > 80 μg ml−1 were required to exhibit anticancer activity at IC50 against the tested cancer cell lines. The main compounds responsible for the bioactivity were identified using GC-MS, nonadecane and butylated hydroxytoluene in F1 and 9-octadecadienoic acid and quercetin 7,3′,4′-trimethoxy in F7 were identified. The current study highlights the potential use of S. Obliquus extract and their fractions as a source of antimicrobial and anticancer compounds

Synergistic Effect of Mandarin Peels and Hesperidin with Sodium Nitrite against Some Food Pathogen Microbes

Food preservatives such as NaNO2, which are widely used in human food products, undoubtedly affect, to some extent, human organs and health. For this reason, there is a need to reduce the hazards of these chemical preservatives, by replacing them with safe natural bio-preservatives, or adding them to synthetic ones, which provides synergistic and additive effects. The Citrus genus provides a rich source of such bio-preservatives, in addition to the availability of the genus and the low price of citrus fruit crops. In this study, we identify the most abundant flavonoids in citrus fruits (hesperidin) from the polar extract of mandarin peels (agro-waste) by using spectroscopic techniques, as well as limonene from the non-polar portion using GC techniques. Then, we explore the synergistic and additive effects of hesperidin from total mandarin extract with widely used NaNO2 to create a chemical preservative in food products. The results are promising and show a significant synergistic and additive activity. The combination of mandarin peel extract with NaNO2 had synergistic antibacterial activity against B. cereus, Staph. aureus, E. coli, and P. aeruginosa, while hesperidin showed a synergistic effect against B. cereus and P. aeruginosa and an additive effect against Staph. aureus and E. coli. These results refer to the ability of reducing the concentration of NaNO2 and replacing it with a safe natural bio-preservative such as hesperidin from total mandarin extract. Moreover, this led to gaining benefits from their biological and nutritive values

Phenolic Profiling and In-Vitro Bioactivities of Corn (Zea mays L.) Tassel Extracts by Combining Enzyme-Assisted Extraction

In this work, enzyme-assisted extraction (EAE) of phenolic compounds from corn tassel using cellulase, protease, and their combination (1:1) was developed and optimized by central composite response surface methodology. The phenolic profile of obtained corn tassel extracts (CTE) was elucidated by high-performance liquid chromatography–diode array detection (HPLC–DAD) analysis, and their antioxidative, antimicrobial, and cytotoxic properties were evaluated in vitro. The results showed that CTE by EAE with combined enzymes had the highest total phenolic content (TPC). Under optimum enzymatic conditions, the experimental TPC values were 9.78, 8.45, and 10.70 mg/g, respectively, which were significantly higher than that of the non-enzymatic control (6.75 mg/g) (p < 0.05). Fourteen more phenolic compounds (13.80–1694.36 µg/g) were identified in CTE by EAE with the combined enzymes, and thus the antioxidant activity of that extract, determined by DPPH and ABTS radical scavenging method, was demonstrated to be stronger than that of the extracts by EAE with the single and ethanol extraction. Furthermore, this extract also showed remarkably better antimicrobial properties against all tested food-borne pathogenic bacteria and mycotoxigenic fungi than CTE by other extraction methods. CTE by EAE were nontoxic to normal lung fibroblast cell line (Wi-38) but cytotoxic to human colorectal and lung cancer cell lines (Caco-2 and A549), with IC50 values of 392.62–461.98 and 210.66–359.56 µg/mL, respectively, which indicated its potential anticancer properties. In conclusion, CTE by EAE, especially with the combined use of cellulase and protease, seems to hold promising potential for multifunctional application in food and pharma fields

Characterization and Isolation of the Major Biologically Active Metabolites Isolated from Ficus retusa and Their Synergistic Effect with Tetracycline against Certain Pathogenic-Resistant Bacteria

Globally, pathogenic microbes have reached a worrisome level of antibiotic resistance. Our work aims to identify and isolate the active components from the bioactive Ficus retusa bark extract and assess the potential synergistic activity of the most major compounds’ constituents with the antibiotic tetracycline against certain pathogenic bacterial strains. The phytochemical screening of an acetone extract of F. retusa bark using column chromatography led to the identification of 10 phenolic components. The synergistic interaction of catechin and chlorogenic acid as the most major compounds with tetracycline was evaluated by checkerboard assay followed by time-kill assay, against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, and Salmonella typhi with fraction inhibitory concentration index values (FICI) of 0.38, 0.43, 0.38, 0.38, 0.38, and 0.75 for catechin and 0.38, 0.65, 0.38, 0.63, 0.38, and 0.75 for chlorogenic acid. The combination of catechin and chlorogenic acid with tetracycline significantly enhanced antibacterial action against gram-positive and gram-negative microorganisms; therefore, catechin and chlorogenic acid combinations with tetracycline could be employed as innovative and safe antibiotics to combat microbial resistance

Hypoglycemic, hypolipidemic and antioxidant effects of green sprouts juice and functional dairy micronutrients against streptozotocin-induced oxidative stress and diabetes in rats

Hyperglycemia, the mark normal for diabetes and associated disorders are the main goals of natural diabetes therapies. In this context, the present research was designed to study the effects of fenugreek sprouts juice (FS), barley sprouts juice (BS), cell-free probiotic extract (cell-free PE), whey protein hydrolysate (WPH) and their mixture on diabetic rats. Free radical scavenging activity, total phenolic contents (TPC) and total flavonoid contents (TFC) of each item mentioned were determined. Diabetes was induced through the injection of male rats with a single intraperitoneal dose (45 mg/kg) of streptozotocin. After the development of diabetes, diabetic rats were orally administered daily with 1ml of with fenugreek sprouts juice, barley sprouts juice, cell-free probiotic extract, whey protein hydrolysate or their mixture until the end of the study period (45 day). Oral administration of fenugreek sprouts juice, barley sprouts juice, cell-free probiotic extract, whey protein hydrolysate and their mixture to diabetic rats significantly reduced fasting blood glucose levels and improved the lipid profile. All the studied items limit the reductions of haemoglobin concentrations and plasma α-amylase activities. Also all the studied items suppressed the elevation of malondialdehyde values and the reduction of catalase activities. Histopathological investigation of pancreas, liver and kidneys of the diabetic rats showed histological alterations. On the other hand, supplementations with the tested materials lead to relieving these injuries. Results revealed that fenugreek sprouts juice, barley sprouts juice, cell-free probiotic extract, whey protein hydrolysate and their mixture had promising effects towards hyperglycemia and associated disorders