Adaptogenic and in vitro antioxidant activity of flavanoids and other fractions of Argyreia speciosa (Burm.f) Boj. in acute and chronic stress paradigms in rodents.

Argyreia speciosa (sweet) (Burm.f.) Boj. is an Ayurvedic rasayana plant used as an adaptogen. The present study reports the investigations done on the adaptogenic property of ethanol (EtAS; 100 and 200 mg/kg; po), ethyl acetate (EAAS; 100 and 200 mg/kg; po) fraction and flavanoids such as quercetin and kaempferol (25 mg/kg; po) of the root. Immobilization induced acute stress (AS; 3 days) and chronic stress (CS; 7 days) and swimming induced stress models were used to screen the anti-stress effect of the plant fractions and isolated flavanoids. The tested doses of EtAS and isolated flavanoids were able to produce significant effects in normalizing altered serum biochemical parameters and the severity of ulcer in both AS and CS models. Higher dose of EtAS, quercetin and kaempferol (25 mg/kg; po) were found to be significant in restoring the hypertrophy of adrenal gland and atrophy of spleen and thymus gland only in CS model. Greater swimming time was noted in the mice pretreated with tested doses of flavanoids and EtAS. In addition, levels of adrenal ascorbic acid and cortisol were restored compared to stress control group. EtAS exhibited significant scavenging effect of DPPH, hydroxyl radical and LPO. Thus, EtAS, quercetin and kaempferol are capable of increasing the capacity to tolerate non-specific stress in experimental animals, as evident from restoration of large number of parameters in the stress models studied. Bioactivity of EtAS may be due to the synergetic action of isolated flavanoids. Improvement in stress markers may be due its prolong effect of resistance to stress and partly due to free radical scavenging activity.

Antimicrobial activity of flavanoid sulphates and other fractions of Argyreia speciosa (Burm.f) Boj.

Antimicrobial activity of flavanoid sulphates and different fractions of A. speciosa root was studied against bacteria, fungi and Mycobacterium tuberculosis H37 Rv sensitive strain by in vitro and in vivo assays. Flavanoid sulphates such as quercetin 3'7 di-O methyl 3- sulphate and kaempferol 7-O methyl 3-sulphate were isolated from the n-butanol fraction of 80% methanolic extract of the plant. The structures of the isolated flavanoids were confirmed by spectral studies. Ethyl acetate (EAAS) fraction and flavanoid sulphates inhibited the growth of M. tuberculosis Rv sensitive strain at MIC values 50 and 25 microg/ml, respectively. Ethanolic fraction (EtAS) showed significant inhibition of gram positive organism with a MIC of 31.25 microg/ml. More inhibition was observed with a less MIC (2 microg/ml) for flavanoid sulphates against Klebsiella pneumoniae, a gram negative organism and it is almost comparable with the standards. Interestingly, chloroform fraction alone exhibited significant antifungal activity with a MIC of 100 microg/ml. A synergistic effect between flavanoids sulphates and commercially available antitubercular drugs was observed with FIC index of 0.443 +/- 0.245, 0.487 +/- 0.247 for isoniazid and 0.468 +/- 0.333, 0.417 +/- 0.345 for rifampicin, whereas EAAS fraction showed partial synergistic effect. A synergistic effect was observed for EAAS fraction and flavanoids sulphates with FIC index < 0.5 with antibiotics. Hemolysis assay on RBCs suggested that EAAS and flavanoids sulphates exhibited least cellular toxicity to erythrocytes as compared to chloramphenicol. In vivo studies in mice infected with K. pneumoniae demonstrated that on day 10 post treatment of different fractions and isolated compounds of A. speciosa, about 60% of the animals treated with EAAS, 70% of animals treated with flavanoids sulphates and 40% of animals treated with EtAS were survived.

Hepatoprotective and antioxidant effects of Argyreia speciosa in rats.

The present study has been designed to evaluate the liver protective and in-vivo antioxidant role of Ethanolic extract (EtAS) and Ethyl acetate extract (EAAS) of roots of Argyreia speciosa, an important 'rasayana' herb in Indian System of medicine, in CCl(4)-induced hepatotoxicity and oxidative stress in rats. Animals were treated with EtAS and EAAS at doses of 200 mg and 400 mg/kg body weight p.o. along with CCl(4) (0.7 ml/kg in olive oil, 1:1 v/v i.p. on every alternate days) for seven days. Serum biochemical parameters such as SGOT, SGPT, ALP, cholesterol, total and direct bilirubin were determined. Antioxidant status in liver was determined by measuring the activities of Super oxide dismutase (SOD), catalase and peroxidase. Histopathological study of isolated liver specimens was also carried out to know the protection offered by the extracts. There was a significant rise in the levels of serum GOT, GPT, and ALP and other biochemical parameters, decrease in the levels of SOD, catalase and peroxidase after administration of CCl(4). Suspensions of EtAS and EAAS (200 and 400 mg/kg) successfully prevented the alterations of these effects in rats (p< 0.001). Histopathological examination demonstrated that CCl(4) treated group induces ballooning degeneration and centrilobular necrosis. Groups treated with EtAS and EAAS showed recovery on ballooning degeneration and centrolobular bridging necrosis was occasionally present. Data also showed that these extracts possessed strong antioxidant activity, and were comparable to Silymarin, a well known liver protecting herbal formulation.