The study was planned to screen the marine actinobacterial extract for the protease inhibitor activity and its anti- Pf activity under in vitro and in vivo conditions. Out of 100 isolates, only 3 isolates exhibited moderate to high protease inhibitor activities on trypsin, chymotrypsin and proteinase K. Based on protease inhibitor activity 3 isolates were chosen for further studies. The potential isolate was characterized by polyphasic approach and identified as Streptomyces sp LK3 (JF710608). The lead compound was identified as peptide from Streptomyces sp LK3. The double-reciprocal plot displayed inhibition mode is non-competitive and it confirms the irreversible nature of protease inhibitor. The peptide from Streptomyces sp LK3 extract showed significant anti plasmodial activity (IC50: 25.78 µg/ml). In in vivo model, the highest level of parasitemia suppression (≈45%) was observed in 600 mg/kg of the peptide. These analyses revealed no significant changes were observed in the spleen and liver tissue during 8 dpi. The results confirmed up-regulation of TGF-β and down regulation of TNF-α in tissue and serum level in PbA infected peptide treated mice compared to PbA infection. The results obtained infer that the peptide possesses anti- Pf activity activity. It suggests that the extracts have novel metabolites and could be considered as a potential source for drug development.

Embryogenic cells of bananan cv. Rasthali (AAB) have been transformed with the 's' gene of hepatitis B surface antigen (HBsAg) using Agrobacterium mediated transformation. Four different expression cassettes (pHBS, pHER, pEFEHBS and pEFEHER) were utilized to optimize the expression of HBsAg in banana. The transgenic nature of the plants and expression of the antigen was confirmed by PCR, Southern hybridization and reverse transcription (RT)-PCR. The expression levels of the antigen in the plants grown under in vitro conditions as well as the green house hardened plants were estimated by ELISA for all the four constructs. Maximum expression level of 38 ng/g F.W. of leaves was noted in plants transformed with pEFEHBS grown under in vitro conditions, whereas pHER transformed plants grown in the green house showed the maximum expression level of 19.92 ng/g F.W. of leaves. Higher monoclonal antibody binding of 67.87% of the antigen was observed when it was expressed with a C-terminal ER retention signal. The buoyant density in CsCl of HBsAg derived from transgenic banana leaves was determined and found to be 1.146 g/ml. HBsAg obtained from transgenic banana plants is similar to human serum derived one in buoyant density properties. The transgenic plants were grown up to maturity in the green house and the expression of HBsAg in the fruits was confirmed by RT-PCR. These transgenic plants were multiplied under in vitro using floral apex cultures. Attempts were also made to enhance the expression of HBsAg in the leaves of transgenic banana plants by wounding and/or treatment with plant growth regulators. This is the first report on the expression of HBsAg in transgenic banana fruits.

In the present study, the marine actinobacteria mediated biosynthesis of silver nanoparticles (AgNps) was achieved using Streptomyces sp LK3. The synthesized AgNps showed the characteristic absorption spectra in UV-vis at 420 nm, which confirmed the presence of nanoparticles. XRD analysis showed intense peaks at 2θ values of 27.51°, 31.87°, 45.57°, 56.56°, 66.26°, and 75.25° corresponding to (210), (113), (124), (240), (226), and (300) Bragg's reflection based on the fcc structure of AgNps. The FTIR spectra exhibited prominent peaks at 3,417 cm(-1) (OH stretching due to alcoholic group) and 1,578 cm(-1) (C=C ring stretching). TEM micrograph showed that the synthesized AgNps were spherical in shape with an average size of 5 nm. Surface morphology and topographical structure of the synthesized AgNps were dignified by AFM. The synthesized AgNps showed significant acaricidal activity against Rhipicephalus microplus and Haemaphysalis bispinosa with LC50 values of 16.10 and 16.45 mg/L, respectively. Our results clearly indicate that AgNps could provide a safer alternative to conventional acaricidal agents in the form of a topical antiparasitic formulation. The present study aimed to develop a novel, cost-effective, eco-friendly actinobacteria mediated synthesis of AgNps and its antiparasitic activity.

This study describes a novel biological route for the biosynthesis of silver oxide nanoparticles utilising the aqueous extract of Callistemon lanceolatus D.C. leaves. Formation of silver oxide nanoparticles was confirmed by UVÀvisible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopeÀenergy dispersive X-ray spectroscopy and X-ray diffraction spectroscopy analysis. The biologically synthesised silver oxide nanoparticles were found to be 3À30 nm in size with spherical and hexagonal shape by high-resolution transmission electron microscope analysis. Furthermore, the biogenic silver oxide nanoparticles demonstrated significant (p < 0.05) dose-dependent antioxidant activity in various in vitro antioxidant methods. These particles also exhibited significant (p < 0.05) dosedependent and time-dependent cytotoxic activity towards brine shrimp nauplii. Moreover, the reported method is a simple, cost-effective and eco-friendly approach for the synthesis of silver oxide nanoparticles with useful pharmacological properties.

The aim of this study was to investigate the antioxidant and DNA damage inhibition potential of methanolic extract of Carissa carandas leaves. Extract was found to exhibit significant (p<0.05) dose dependent DPPH radical scavenging activity (IC 50 value= 73.12µg/ml), total antioxidant activity, H 2 O 2 scavenging activity (IC 50 value 84.03µg/ml), reducing power activity. In addition, extract was found to exhibit complete protection of pBR322 plasmid DNA from free radicals mediated oxidative stress during DNA damage inhibition assay. Antioxidant and DNA damage inhibition properties of C. carandas could be attributed to the presence of high amount of phenolic compounds (84.00 mg GAE/gm dry weight of the extract) in the extract which was estimated by Folin-Ciocalteau assay. These observations emphasize the high antioxidant and DNA damage inhibition potential of the C. carandas which can be further used to develop natural antioxidant compounds for therapeutic applications.