Production of phenolic compounds from spirulina maxima microalgae and its protective effects in vitro toward hepatotoxicity model

This study illustrates the process of enhancing phenolics synthesis in Spirulina maxima grown in Zarrouk's medium supplemented with sodium nitrate (NaNO3) and or phenylalanine (L-PA); attaining highest production obtained in medium containing 3.77 g.L-1 NaNO3 and 100 mgL-1 L-PA. HPLC profile showed the presence of phenolic acids and flavonoids predominantly with gallate; chlorogenate; cinnamate; pinostrobate and p-OH-benzoates. The protective action of Spirulina phenolic compounds (SPC) against CCl4-induced in vitro hepato-toxicity symptoms like microsomal lipid peroxidation and hydroxyl radical formation was studied. SPC exhibited antioxidant effects on DPPH radical scavenging with IC50 values ranging from 23.22 to 35.62 ?gmL-1 and inhibit CCl4 induced lipid peroxidation in hepato-microsoms model; in dose-depended manner. Their protective potential was comparable to that of standard phenolic antioxidants such as BHT; BHA and a -tocopherol (IC50 values ranged from 13.22 to 23.62? ?gmL-1)

Safety evaluation of olive phenolic compounds as natural antioxidants.

Free and total polyphenolic compounds were extracted from the fruits and leaves of the Picual cultivar. The safety limits of these compounds were recognized by measuring the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the levels of high-density lipoprotein (HDL) cholesterol and total lipids of rat serum. The free and total phenolic compounds (400, 800, and 1600 ppm) and butylated hydroxy toluene (BHT) (200 ppm) were daily ingested for 7 weeks. The administration of olive total and free phenolic compounds at 400 and 800 ppm did not cause any significant changes on ALT and AST activities and serum total lipids. These compounds at 1600 ppm caused significant increase in ALT and AST activities and the content of total lipids. Both olive phenolic compounds were superior to that of BHT in increasing HDL-cholesterol level. Nutritional experiments demonstrated that BHT at 200 ppm caused an enlargement in the kidney and liver of the rat compared with the administration of total and free olive phenolic compounds at 1200 and 1600 ppm. Microscopical examination of kidney and liver tissues of rats administered free and total phenolic compounds at 1200 ppm had the same histological character as that of control rats, while the administration of BHT (200 ppm) and phenolic compounds (1600 ppm) induced severe damage to the tissues of the rat kidney and liver.

Comparative Study on the Deterioration of Oils by Microwave and Conventional Heating.

Refined cottonseed oil and hydrogenated palm oil were heated by two methods, conventionally by gas-cooker (deep fat frying) and by microwave energy. Quality assurance methods such as refractive index, color, diene content, acid value, peroxide value, thiobarbituric acid value, iodine value, petroleum ether insoluble oxidized fatty acid content, and degree of polymerization were determined. Exposing the oil samples to various heating times and microwave oven power levels caused some hydrolysis to free fatty acids and accelerated the formation of hydroperoxides and secondary oxidation products. The value from each test increased with both the power settings of the microwave oven and the time of heating. In general, the development of rancidity for refined cottonseed oil heated by microwaves was twice as fast as that produced by conventional heating. Also, the chemical values indicating deterioration for refined cottonseed oil were much higher for refined cottonseed oil than for hydrogenated palm oil in all cases. Gas-liquid chromatographic analysis of fatty acids obtained from the heated oils indicates the occurrence of oxidative degradation and production of short-chain acids.

Antimicrobial Activity of Some Egyptian Spice Essential Oils.

Six spice essential oils (sage, rosemary, caraway, cumin, clove, and thyme) and their basic ingredients were tested for their inhibitory effect against 3 strains of Gram-negative bacteria, 4 strains of Gram-positive bacteria, one acid fast bacterium, and one yeast. Preliminary screening of antimicrobial activity of the essential oils was done using the filter paper disc agar diffusion method. The minimum inhibitory concentration for each essential oil against various micro-organisms was also measured. Very low concentrations (0.25 - 12 mg/ml) of the various essential oils were sufficient to prevent microbial growth. The data show that Gram-positive bacteria were more sensitive to the antimicrobial compounds in spices than Gram-negative. The inhibition zones of different microbial growth produced by various essential oils were similar to those produced by their basic compounds. Thyme and cumin oils possessed very strong antimicrobial activity compared with the other essential oils. There was a relationship between the chemical structures of the most abundant compounds in the essential oils under investigation and the antimicrobial activity.