Résumé
Scientists of agriculture and plant pathology are on the lookout for potential biological control agents to control the plant pathogenic organisms in order to avoid soil contamination. Rhizospheric bacteria are excellent agents to control soil-borne plant pathogens. In this study an attempt has been made to evaluate the antagonistic activity of a bacterial strain Bacillus circulans against Curvularia lunata, Alternaria alternata and Cladosporium sp., which are important seed and soil borne pathogens distributed throughout the world. These infections cause grain mold and leaf spot diseases, resulting in significant economic loss to the crops. A soil bacterium Bacillus circulans isolated from the rhizospheric soil of Vigna unguiculata, showed high antagonistic activity against Curvularia lunata, Alternaria alternata and Cladosporium sp. on dual plate assay. Bacillus circulans showed a distinct inhibition zone in the dual plate assay and also produced a clear inhibition zone in chitin amended agar medium containing 0.5% colloidal chitin, indicating that it secretes chitinase.
Résumé
Oxalis corniculata is well known for its medicinal properties like anti-inflammatory, digestive, diuretic, antibacterial, antiseptic etc. The present study focuses on the ability of O. corniculata to alleviate liver damage caused by over dose of paracetamol. Antioxidant activity of O. corniculata was evaluated using the free radical scavenging activity of 1, 1-diphenyl-2- picrylhydrazyl radicals, total anti oxidant capacity by phosphomolybdenum method and total phenolic content was also evaluated. The ethanolic extract of whole plant of O. corniculata (OC, 500 µg/mL, po) significantly reduced 1, 1-diphenyl-2- picrylhydrazyl radicals. This dose also caused significant reduction (62.67%) in malondialdehyde levels of murine hepatic tissues. The antioxidant capacity of OC was comparable to that of standard ascorbic acid and showed 53.5 µg of phenol/mg OC. Rats pre-treated with OC for 4 days showed significant reduction in the serum enzymes such as glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, alkaline phosphatase, serum bilirubin and showed almost normal histological liver architecture of the treated groups compared to paracetamol induced hepatic damage group, indicating its hepatoprotective and antioxidant potential.
Résumé
Cassia occidentalis Linn. mast cell degranulation at a dose of 250 mg/kg, showed dose dependent stabilizing activity towards human RBC, with is widely used in traditional medicine of India to treat a number of clinical conditions including allergy and inflammatory manifestations. In the present study anti-allergic, anti-inflammatory and anti-oxidant properties of C. occidentalis whole plant ethanolic extract (CO) was investigated. Effects of CO on rat mast cell degranulation inhibition and human red blood cell (HRBC) membrane stabilization were studied in vitro following standard methods. The anti lipidperoxidant effects of CO were also studied in vitro. Effect of CO on carrageenan-induced mouse paw oedema inhibition was also assessed. CO significantly decreased maximum protection of 80.8% at 15 μg/ml. The extract also caused significant reduction in malondialdehyde (MDA) levels of murine hepatic microsomes at 100 μg/ml (56%) and significantly reduced carrageenan induced inflammation in mice at a dose of 250 mg/kg. Results of the present study indicated that CO inhibited mast cell degranulation, stabilized HRBC membrane thereby alleviating immediate hypersensitivity besides showing anti oxidant activity.
Résumé
Hibiscus hispidissimus Griff. is used in tribal medicine of Kerala, the southern most state of India, to treat liver diseases. In the present study, the effect of the ethanolic extract of Hibiscus hispidissimus whole plant on paracetamol (PCM)-induced and carbon tetrachloride (CCl4)-induced liver damage in healthy Wistar albino rats was studied. The results showed that significant hepatoprotective effects were obtained against liver damage induced by PCM and CCl4 as evidenced by decreased levels of serum enzymes, glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase (SAKP), serum bilirubin (SB) and an almost normal histological architecture of the liver of the treated groups compared to the toxin controls. The extract also showed significant antilipid peroxidant effects in vitro, besides exhibiting significant activity in quenching 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical, indicating its potent antioxidant effects.