Abstract:Withania somnifera is an important medicinal plant, which is used in traditional medicine to cure many diseases. Flavonoids were determined in the extracts of W. somnifera root (WSREt) and leaf (WSLEt). The amounts of total flavonoids found in WSREt and WSLEt were 530 and 520 mg/100 g dry weight (DW), respectively. Hypoglycaemic and hypolipidaemic effects of WSREt and WSLEt were also investigated in alloxan-induced diabetic rats. WSREt and WSLEt and the standard drug glibenclamide were orally administered daily to diabetic rats for eight weeks. After the treatment period, urine sugar, blood glucose, haemoglobin (Hb), glycosylated haemoglobin (HbA1C), liver glycogen, serum and tissues lipids, serum and tissues proteins, liver glucose-6-phosphatase (G6P) and serum enzymes like aspartate transaminase (AST), alanine transaminase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) levels were determined. The levels of urine sugar, blood glucose, HbA1C, G6P, AST, ALT, ACP, ALP, serum lipids except high density lipoprotein-bound cholesterol (HDL-c) and tissues like liver, kidney and heart lipids were significantly (p < 0.05) increased, however Hb, total protein, OPEN ACCESSInt. J. Mol. Sci. 2009, 10 2368 albumin, albumin:globulin (A:G) ratio, tissues protein and glycogen were significantly (p < 0.05) decreased in alloxan-induced diabetic rats. Treatment of the diabetic rats with WSREt, WSLEt and glibenclamide restored the changes of the above parameters to their normal level after eight weeks of treatment, indicating that WSREt and WSLEt possess hypoglycaemic and hypolipidaemic activities in alloxan-induced diabetes mellitus (DM) rats.

The phenolic compounds and flavonoids were determined from the extracts of Withania somnifera root (WSREt) and leaf (WSLEt). The WSREt has 28.26 mg/g total phenolic compounds and 17.32 mg/g flavonoids, whereas WSLEt has 5.4 mg/g total phenolic compounds and 5.1 mg/g flavonoids. The WSREt, WSLEt and glibenclamide were orally administered daily to diabetic rats for 8 weeks. After the treatment, the levels of urine sugar, blood glucose, liver glycogen, and antioxidants like vitamin C and E in plasma and superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in liver, kidney and heart were determined. Diabetic rats showed a significant (p<0.05) elevation in glucose and TBARS and a significant (p<0.05) reduction in glycogen, vitamin C and E, SOD, CAT, GPx, GST, and GSH levels when compared to normal control rats. Administration of WSREt, WSLEt and glibenclamide to diabetic rats restored the levels to normal. In the light of aforesaid facts, it is suggested that the presence of phenolic compounds including flavonoids in W. somnifera root and leaf extracts and their antioxidant activity may play a vital role in reduction of blood glucose level in alloxan-induced diabetic rats.

An efficient and reproducible Agrobacterium-mediated in planta transformation was developed in Jatropha curcas. The various factors affecting J. curcas in planta transformation were optimized, including decapitation, Agrobacterium strain, pin-pricking, vacuum infiltration duration and vacuum pressure. Simple vegetative in vivo cleft grafting method was adopted in the multiplication of transformants without the aid of tissue culture. Among the various parameters evaluated, decapitated plants on pin-pricking and vacuum infiltrated at 250 mmHg for 3 min with the Agrobacterium strain EHA 105 harbouring the binary vector pGA 492 was proved to be efficient in all terms with a transformation efficiency of 62.66%. Transgene integration was evinced by the GUS histochemical analysis, and the GUS positive plants were subjected to grafting. Putatively transformed J. curcas served as "Scion" and the wild type J. curcas plant severed as "Stock". There was no occurrence of graft rejection and the plants were then confirmed by GUS histochemical analysis, polymerase chain reaction (PCR) and Southern hybridization. Genetic stability of the grafted plants was evaluated by using randomly amplified polymorphic DNA (RAPD), marker which showed 100% genetic stability between mother and grafted plants. Thus, an efficient in planta transformation and grafting based multiplication of J. curcas was established.

Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. So, this study was aimed to evaluate the in vitro antioxidant capacity of one of the phenolic compounds phloretin. Phloretin was used at four different concentrations like 20, 40, 60 and 80 µg/ml to determine the antioxidant activity by different methods such as total antioxidant capacity, reducing power, DPPH radical scavenging, superoxide anion radical scavenging and metal chelating assays. In addition to that the ascorbic acid was used as reference compound. The results showed that the phloretin displayed potent in vitro antioxidant capacity. It was able to scavenge different in vitro free radicals in all tested concentrations. Among the different concentrations, 80 µg of phloretin has maximum activity when compared to other concentrations in all in vitro antioxidant assays. High antioxidant property and maximum protective effect of phloretin were observed in a concentration dependent manner. The results were expressed as IC50 value. The lowest IC50 value indicates the highest scavenging activity. The reducing power of the phloretin was also found in concentration dependent. According to the results of this study, we concluded that the phloretin possesses antioxidant property. Therefore, phloretin is a powerful antioxidant phytocompound which can protect biological systems against the oxidative stress. From this study, we suggest that the phloretin may be used as a dietary natural antioxidant supplement for preventing free radical related diseases.

The present study was aimed to screen the phytochemicals and quantification of alkaloids, phenolic compounds and flavonoids and to evaluate the nematicidal activity of ethanolic leaf extracts of Datura metel, Datura innoxia and Brugmansia suaveolens against Meloidogyne incognita. Phytochemical screening of leaf extracts of D. metel, D. innoxia and B. suaveolens was carried out by qualitative analysis and the results revealed that the presence of bioactive compounds like alkaloids, steroids, flavonoids, terpenoids, phenolic compounds, tannins, anthroquinone glycosides,