Background & Aim: Glycyrrhiza L. (Fabaceae) consists of perennial herbs grow in sandy soils with hard lightness. Three species of the genus grow in Iran, among them G. glabra L. has the widest distribution. It is well known in English as Licorice and the root extract includes flavonoids and glycyrrhizin are used widely in medicine, food industry, tobacco products and other industries. Liquiritin and glabridin are the major constituents of flavonoids in its extract, which have quasi estrogenic, ant oxidative, anti-helicobacter, anti-nephritic activities and ROS scavenging.Experimental: In this research, the interactive effects of salicylic acid (SA) with cold stress on some antioxidant enzymes such as peroxidase (PRX) and polyphenol oxidase (PPO) were studied by spectrophotometric method in a factorial experiment of completely randomized design with three replications. SA pretreatments were included 10, 50, 100 and 500 µM and three levels of cold stress, 5, 10 and 20h in 4 oC were applied.Results & Discussion: The results showed that cold stress did not affect PPO activity, while SA decreased it. In addition, PRX activity was decreased with increasing cold stress and SA resulted in similar response at this condition. It seems that SA can considerably alleviate oxidative damage that occurred under cold stress condition with direct scavenging of reactive oxygen species. Thus it resulted in decrease activity of antioxidant enzymes. تفاصيل المقالة

Background & Aim: Free radicals play a crucial role in the development of tissue damage in various human diseases such as cancer, aging, neurodegenerative disease, malaria and arteriosclerosis, and pathological events in living organisms. Antioxidants may have an important role in the prevention of these diseases. The aim of this study is to evaluate potency of scavenging of DPPH free radicals in the circulatory system of rats by the methanolic extracts of Salvia aethiopis. This species belongs to the genus Salvia of the family Lamiaceae, many species of which are valuable in food and medicine. Further studies will indicate whether this plant can be as a suitable candidate for pharmacological and industrial applications. Experimental: Ten female rats (200-250 g) were randomly selected and then divided in three groups. The rats were injected intraperitoneally with 0.5 ml of 1, 1-diphenyl-2-picryl hydrazyl (DPPH) free radical in methanol (3×10-4 M), 1 ml of methanolic extract of S. aethiopis (1 mg/ml) along with 0.5 ml of methanolic solution of DPPH and 1 ml of ascorbic acid along with 0.5 ml of methanolic solution of DPPH as positive control, respectively. The absorbance of DPPH solution in the blood serum of rats was measured by spectrophotometric method in 517 nm. Results & discussion: Decrease in absorbance of DPPH free radical (1.85 nm) in circulatory system of the rats in presence of ascorbic acid as positive control (1.07 nm) and S. aethiopis extract (0.78 nm) as sample. It can be concluded that the potency of free radical scavenging by the metabolic extract of S. aethiopis in circulatory system of the rats is more than that of ascorbic acid. Industrial and practical recommendations: The Results from present investigation showed that S. aethiopis extract can be used as a natural compound with a high antioxidant activity in future studies. تفاصيل المقالة