The effects of Maillard reaction products (MRPs) on apple and potato polyphenol oxidase (PPO) were estimated spectrophotometrically. Model systems of glucose and amino acids [lysine (lys), tyrosine (tyr), proline (pro), cysteine (cys), glumatic acid (glu), aspartic acid (asp), and histidine (his)] were heated at 90°C for 3 h. The MRPs showed inhibitory effects on PPO extracted from apple and potato. These effects depend on the type of MRP and origin of PPO. The antioxidant activity of MRPs was evaluated. It was found that MRPs exhibit different free radical scavenging activity and these effects were significant. The colour intensity of MRPs was estimated. Browning was not directly related to the antioxidant activity.

No abstract

Different plant seeds extracts of Citrus sinensis, Hordeum sativum, Triticum sativum, Canna indica, Citrullus vulgaris and Capsicum annuum were evaluated for their antioxidant activity by the following methods: 2,2-diphenyl-1-pycril-hydrazyl (DPPH) radical scavenging, reducing power, RBCs hemolysis and linoleic acid oxidation, a long with the determination of total phenolic and flavonoids contents. All the methanolic extracts showed high antioxidant activity and have high contents of phenolic and flavonoid. The Canna indica extract exhibited strong antioxidant as a reducing power and as DPPH radical-scavenging (3.61 absorbance, 87.12%, respectively), while the Hordeum sativum extract exhibited highest inhibitory effect on RBCs hemolysis (59.55%) and the Capsicum annuum extract has highest inhibitory effect on linoleic acid peroxidation (65.06%).

Cumin (Cuminum cyminum L.) and caraway (Carum carvi L.) are aromatic plants within the Apiaceae family. They have a variety of purposes and demonstrate antioxidant and antimicrobial properties. Methanolic and acetonic seed extracts of both plants were able to neutralize free radicals and carried antioxidant properties. Both seed extracts were able to protect erythrocytes from hemolysis. The methanolic cumin extract showed a higher percentage of protection than both extracts of caraway. Seed extracts of cumin showed slightly higher neutralization ability than caraway seed extracts (57.0 and 52.4% vs. 44.7 and 39.5%, respectively). Antioxidant properties of both seed plants may be useful in pharmacologic preparations.

No abstract

β-galactosidase (EC 3.2.1.23) is important in the formation of a medicinal plant Artemisia judaica (al-ba'atharan) aroma. The crude plant extracts of Artemisia judaica were used to characterize the enzyme in the term of pH, temperature, enzyme kinetic and effects of some heavy metals on its activity. The enzyme activity was measured by its ability to hydrolyze the substrate 2-nitrophenyl β-D-galactopyranoside (ONPG). The enzyme activity was reached maximum at 50°C and at pH 6.0. The K m and V max values of the enzyme were 3.6 mM and 1.67 µmol/min, respectively. Uncompetitive inhibition was observed in presence of Hg +2 , Fe +3 and Zn +2 for the enzyme β-galactosidase in the crude extract through the decrease in the K m and V max values. Pb +2 and Cu +2 were found to act as a noncompetitive inhibitors on the enzyme β-galactosidase in the crude extract due to increase in the K m values and decrease in V max values. The study showed that Hg +2 was the most potent inhibitor while Cu +2 exhibited the least inhibition degree on β-galactosidase activity in the Artemisia judaica. These finding indicated that the enzyme β-galactosidase in the crude leaves extract of Artemisia judaica can be used in industrial and medical applications.

No abstract

The effect of the alcoholic extract of Arbutus andrachne on certain biochemical parameters and the histology of the visceral organs in nonpregnant adult female rats was studied. The lethal dose 50% (LD) 50 was estimated, and three different doses (1/10th , 1/15th and 1/20th ) of the LD 50 extracts were injected intra-peritoneally for 14 consecutive days into three groups of animals (n ¼ 5 in each group), with one group used as a control and injected with distilled water through the same route. Blood was collected after sacrificing the animals and the following biochemical parameters were detected: glutamate pyruvate transaminase (GPT), glutamate oxaloacetate transaminase, alkaline phosphatase, cholesterol, glucose, triglycerides, creatinine and bilirubin. In addition, the total white blood (WBC) and red blood cells (RBC) were estimated in the blood of all groups. The gross and microscopic findings were reported after the collection of specimens from the animals, and processed routinely for standard histological procedures. The results showed an increase in the number of WBC, which indicated a defence response; while the RBC were decreased because of damage in tissues or organs. The gross and the microscopic changes seemed to be dosedependent, as very little or no effects were noticed in the lowest treated group, and more obvious changes were detected in the highest-dose group of animals. In addition, changes were observed in almost all biochemical parameters under investigation, with the exception of creatinine and GPT, which reflect the general effect of the material used on the animal health.