Sikha Dutta

Study of Antioxidant Activity and Immune Stimulating Potency of the Ethnomedicinal Plant, Cassia alata (L.) Roxb.

Today there is renewed awareness of the value of natural resources, and this realization has led to carrying out tests for an increased utilization of wild plants as food and drug sources [1-4]. Cassia alata (L.) Roxb. (Leguminosae family) is a medicinal plant, whose English names are Ringworm bush and Candelabra bush. It is a native plant of South America and can found widely in tropical region. Fresh or dried leaflet of Cassia alata has been used as folk medicines in many countries for treatment of constipation, stomach pain, and ringworm and skin disease [5]. In present study, an attempt has been made to investigate the antioxidant potency and the immune stimulating property of this ethno medicinally important plant Cassia alata. Methanolic extract of the leaves of C. alata was assayed for determining the antioxidant compounds present in this plant. Estimation of total phenols, Vitamin-C, Vitamin-A, flavonoids, carotenoids and anthra quinones was done. DPPH radical scavenging activity of the methanolic extract of leaves was also tested against a synthetic antioxidant, Butylated hydroxytoluene (BHT). It is evident from the results that the plant Cassia alata possesses strong antioxidant activity, as it contains good quantity of antioxidant compounds like phenols, Vitamin-C, Vitamin- A, flavonoids, carotenoids and anthraquinone. In addition, it has very high DPPH radical scavenging activity in contrast to the synthetic antioxidant compound, BHT. The plant Cassia alata has strong immune-modulating or immune-stimulating potency, as evidenced by a steep rise in the total count of leucocytes with concomitant increasing in granulocyte: a granulocyte ratio as well as remarkable increase in the total number of peritoneal macrophages in the rabbits treated with the aqueous extract of leaves of C. alata. Thus, the plant Cassia alata may extensively be used in therapeutic medicines as a resource of natural antioxidants and immune stimulating agent.

Synergism of VAM and Rhizobium on production and metabolism of IAA in roots and root nodules of Vigna mungo.

Mature and healthy root nodules of Vigna mungo appeared to contain higher amount of indole-acetic acid (IAA) than non-nodulated roots. Dual effect of VAM fungus, Glomus fasciculatum and the nitrogen-fixing bacteria, Rhizobium sp. on the nodulation of roots of V. mungo was studied. It was recorded that the roots which were inoculated simultaneously with both the symbionts i.e., G. fasciculatum and Rhizobium exhibited greater amount of IAA production than the non-inoculated roots. A tryptophan pool present in the mature nodules and young leaves might serve as a precursor for IAA production in the roots and in the nodules. Activity of IAA-metabolizing enzymes, such as IAA oxidase, peroxidase, and polyphenol oxidase was investigated which indicates the active metabolism of IAA in roots and nodules. The Rhizobium symbiont isolated from fresh nodules of V.mungo produced significant amount of IAA under in vitro condition when tryptophan was added to the medium as precursor. Present study represents some beneficial effects of Rhizobium and G. fasciculatum on the production and metabolism of IAA in roots and nodules of V. mungo. The important physiological implication of the study on IAA production and its metabolism in Rhizobium–Legume–VAM tripartite symbiosis is certainly representing a new approach to satisfy the hormonal balance in the host plant.

Phytoaccumulation of iron by callus tissue of Clerodendrum indicum (L)

Clerodendrum indicum (L.) is one of the important medicinal plants, originating in India. The plant is used as medicine for bronchitis, asthma and different immunological disease. Micro-propagation is a quick method, producing a huge number of plants. Apical leaf of Clerodendrum indicum (L.) was used as an explant for callogenesis. The combinations of different plant growth regulators (2,4-D, NAA, KN) in MS (Murashige and Skoog) medium produced two types of calli: one was friable and loose and the other was green, embryogenic and compact. Heavy metals cause pollution and health hazards. The plant absorbs heavy metals, which is very useful for controlling environmental pollution. Iron is a major nutrient for both plants and animals, but hyper accumulation of iron is injurious to health. Calli were used to study the optimum conditions of iron uptake in presence of different chemical environments. The different environments were created by using different chemical reagents such as (HCL, HNO3, H3PO4 and KNO3). Iron (III) was spiked with radioactive Fe-59 and dynamics of uptake was followed by measuring radioactivity by gamma-ray spectrometer. The best condition of iron uptake corresponded to 1 mol L−1 KNO3 after 4 hour of equilibration.