PurposeTo obtain protein hydrolysates from fresh water green algae Scenedesmus obliquus by three different enzymes and evaluate its antioxidant and antiviral activity.MethodsEnzymatic hydrolysates of green algae Scenedesmus obliquus protein were prepared by treatment with: 1.2% solution of pepsin, trypsin or papain. Protein was extracted from S. obliquus by three different extraction methods. Protein extracts and hydrolysates were assessed from stained gels following SDS–PAGE of samples. Antioxidant activity of protein hydrolysates was investigated.ResultsS. obliquus cells and protein extracts were rich in Arg, Lys, Asp, Ala, and His. Protein hydrolyzed by papain (Sd1pa) and protein hydrolyzed by trypsin (Sd2Try) induced highest antioxidant activity based on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging (41.41% and 40.62%) respectively, and on 2,2′-azinobis 3-ethyl-benzothiazoline-6-sulphonate (ABTS) radical (87.03% and 45.12%) respectively, at 150 µg/ml. The inhibitory effect and mode of action of protein hydrolysates were evaluated against Coxsackie B3 virus (CVB3). Protein hydrolyzed by papain (Sd2pa) and protein hydrolyzed by pepsin (Sd1pep) at 100 µg/ml exhibited antiviral activity (66.2% and 57.6%, respectively), against (CVB3) from all protein hydrolysates.ConclusionS. obliquus protein hydrolysates have a potential as antioxidative neutraceutical ingredients and a potential therapeutic agent against CVB3.

This research addresses studying the lipid content of Hydroclathrus clathraus brown algae from the Red Sea, Egypt Region and their assess acute oral LD 50 of sterol fraction in albino mice and anticancer activity against different cancer cell lines including; colon cancer cell line (Caco-2) and liver cancer cell line (Huh-7) using MMT, apoptosis analysis, EGFR and genes' expression. Total lipids, glycolipid, sulfolipid, and phospholipid of Hydroclathrus clathraus content were 1mg/g, 0.08 mg/g, 0.25±0.01 mg/g and 0.57±0.04 mg/g respectively. The LD 50 of Hydroclathrus clathraus sterols was greater than 3g/kg in the mice. The major fatty acid is palmitic acid (67.04%). Polyunsaturated fatty acids content was arachidonic (8.05%), α-Linolenic acid (4.36%) and Linoleic acid (1.69%). The major sterols fractions were Hexacosane (18.54%), Octacosane (14.96%) and Nonadecane (13.31%). Cholesterol (8.32%), β-Sitosterol (2.08%) and Campesterol (1.36%) were presented as minor sterols. However, algal sterol showed the best potential antitumor activity with IC 50 of 0.22 µg/ml and 3.09µg/ml against CaCo2 and HuH7. These sterols fraction reduced tumor genesis by three mechanisms that firstly, the cells' apoptosis which may reduce the regulatory suppressive activity of the epidermal growth factor receptor (EGFR) enzyme, secondly, gene expression of bcl2 was downregulated and thirdly, it induced cell cycle arrest at the G1/S. Thus, algal sterols can be used as medicine to treat disorders liver and colon cancers

Imidacloprid (IMI), the main component of neonicotinoid insecticides, promotes oxidative stress and genotoxicity in mammals. The aim of this experiment is to assess oxidative stress in liver cells and genotoxicity of erythrocytes for rats exposed to sub-lethal doses of IMI and the protective effects for Rhodophyta as antioxidant material versus imidacloprid. A total of 30 adult male albino rats (average body weight, 190-200 g) were divided into six groups (n=5) as follows: group 1 served as the control, group 2 received 200 mg/kg red algae, group 3 received 45 mg/kg IMI (high-dose group), group 4 received 22.5 mg/kg IMI (low-dose group), group 5 received 200 mg/kg red algae +45 mg/kg IMI, and group 6 received 200 mg/kg red algae +22.5 mg/kg IMI. After 28 d of treatment, the antioxidant activity of the crude extract of red algae was assessed in terms of free radical scavenging activity and found to be higher in TCA (75.57%) followed by DPPH (50.08%) at concentration 100 μg extract and a significant increase in lipid peroxidation and reductions in glutathione were observed in liver cells were intoxicated with high and low doses of IMI. Moreover decreases in catalase and glutathione peroxidase parameters in same previous groups which indicated oxidative stress. In addition significant increases in micronucleus frequency (MN) in the bone marrow of the rats as a genotoxicity marker which indicated DNA damage in erythrocytes cells with alterations in the histopathology of liver cells were also noted such as necrosis, inflammatory cells, infiltration, and necrobiotic changes. Whereas Rhodophyta succeeded in alleviation the oxidative damage and genotoxicity induced by the insecticide. In conclusion, IMI demonstrates hazardous effects, such as alterations in antioxidant status and mutagenicity of erythrocytes and polysaccharides from Rhodophyta has good antioxidant activity in vivo model systems against imidacloprid.

We investigated the effects of fucoxanthin isolated from the edible macroalga Dilophys fasciola on pathogenic microbes and probiotics in vitro and the antioxidant activity of fucoxanthin. The yield concentration of the obtained crude was 50.5% fucoxanthin. We found strong inhibition against Grampositive Staphylococcus aureus and Listeria monocytogenes, and lower inhibition against Gram-negative bacteria and fungi. The probiotic strains progressed between 1.2 and 1.67 log cycles at a concentration of 30 μg/mL. The antioxidant activity ranged between 54.76% and 88.36% at a concentration of 40 μg/mL. The 50% lethal dose of algal fucoxanthin was shown to be more than 2511.88 mg/kg. The production of stirred yoghurt incorporated with 20 mg and 30 mg of fucoxanthin per kilogram of milk was evaluated through chemical, microbiological, and sensory analyses during storage for 21 days and compared with control samples. The maximum growth for probiotics (Bifidobacterium bifidum and Lacticaseibacillus casei) was found on day 14, but more viability counts were detected in the treatment with 30 mg/kg. All treatments were free from mould and yeast counts up to 7 days, and the small numbers of mould, yeast, and psychrotrophic counts appeared first in control samples. Also, the highest dry matter content was observed for treatments with 30 mg/kg. Moreover, the protein, fat, and ash content of all treatments increased with a progressive cold storage period. Greater reductions in the pH were found in treatments than in the control, and were consistent with the development of acidity. During storage, the amount of crude fucoxanthin had no significant impact on the flavour, colour, or appearance scores.

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