NaCl pretreatment alleviates salt stress by enhancement of antioxidant defense system and osmolyte accumulation in mungbean (Vigna radiata L. Wilczek).

Enhancement of salt (NaCl) tolerance by pretreatment with sublethal dose (50 mM) of NaCl was investigated in V. radiata seedlings. NaCl stress caused drastic effects on roots compared to shoots. Accompanying reductions in length, number of root hairs and branches, roots became stout, brittle and brown in color. Salt stress caused gradual reduction in chlorophyll, carotenoid pigment contents and chlorophyll fluorescence intensity also. Superoxide dismutase and catechol peroxidase activities increased under stress in both roots and leaves. But catalase activity showed an increase in roots and decrease in leaves. In these seedlings, the oxidative stress has been observed under salinity stress and the level of proline, H2O2 and malondialdehyde content were increased. But pretreatment with sublethal dose of NaCl was able to overcome the adverse effects of stress imposed by NaCl to variable extents by increasing growth and photosynthetic pigments of the seedlings, modifying the activities of antioxidant enzymes, reducing malondialdehyde and H2O2 content and increasing accumulation of osmolytes like proline. Thus, mungbean plants can acclimate to lethal level of salinity by pretreatment with sublethal level of NaCl, improving their health and production under saline condition.

Quadruple therapy for initial eradication of Helicobacter pylori in peptic ulcer: comparison with triple therapy.

BACKGROUND: Quadruple therapy appears to be more effective than standard triple therapy in the management of patients with Helicobacter pylori infection who harbor drug-resistant organisms. No data are available on the relative efficacies of triple and quadruple drug regimens from India. METHODS: Consecutive patients with peptic ulcer and H. pylori infection were randomized to receive lansoprazole 30 mg twice daily along with either amoxycillin (500 mg four times daily) and clarithromycin (500 mg twice a day) (Group A), or tri-potassium dicitrato bismuthate (120 mg four times daily), metronidazole (400 mg thrice daily) and tetracycline (500 mg 4 times daily) (Group B) for 10 days. Presence of H. pylori infection was looked for using an in-house urease test and histology before starting treatment, and 30 days after completion of treatment. RESULTS: Twenty-nine of 35 patients in Group A and 24 of 33 in Group B had eradication of infection (82.8% and 72.7% by intention-to-treat analysis, and 87.9% and 85.7% by per protocol analysis, respectively; p = ns). Side-effects occurred in 4 (12%) and 5 (18%) patients in Groups A and B, respectively (p = ns); discontinuation of drugs was required in two patients in group B. CONCLUSIONS: Quadruple therapy for initial treatment of H. pylori infection does not offer any advantage over standard triple therapy in Indian patients.