An efficient in vitro shoot regeneration from leaf petiolar explants and ex vitro rooting of Bixa orellana L.- A dye yielding plant.

Bixa orellana L. (Bixaceae) is a multipurpose tree grown for the production of commercially important dyes. In the present study, an efficient, reproducible protocol was developed for direct plant regeneration from in vitro derived petiole explants of Bixa orellana L. Murashige and Skoog medium (MS) supplemented with 2-isopentenyl adenine (9.8 µM) and naphthalene acetic acid (10.7 µM) was found to be optimum for production of high frequency of shoot organogenesis. Subculturing of the shoots onto the fresh MS medium containing similar concentrations of 2-iP (9.8 µM) and NAA (10.7 µM) produced elongated shoots. Elongated shoots when placed onto MS medium supplemented with 1.7 µM indole-3-acetic acid and 14.7 µM 2-iP produced optimal rooting. Rooted plantlets were acclimatized and transplanted to the field successfully. Histological investigation revealed the origin of shoot primordia, from sub-epidermal cells of petiole explants. The regeneration protocol developed in this study can be useful for mass in vitro propagation and effective genetic transformation of commercially important edible dye yielding tree species.

Methyl angolensate, a natural tetranortriterpenoid induces intrinsic apoptotic pathway in leukemic cells.

Methyl angolensate (MA), a natural tetranortriterpenoid, purified from Soymida febrifuga is examined for the first time for its anticancer properties. We find that MA inhibits growth of T-cell leukemia and chronic myelogenous leukemia cells in a time- and dose-dependent manner. Accumulation of cells in the subG1 peak, annexin V binding and DNA fragmentation suggested induction of apoptosis. Besides, upregulation of BAD (proapoptotic) and downregulation of BCL2 (antiapoptotic) gene products further supported induction of apoptosis. Loss of mitochondrial membrane potential, activation of caspase 9, caspase 3, cleavage of PARP, downregulation of Ku70/80 and phosphorylation of MAP kinases suggested that MA could induce intrinsic pathway of apoptosis in leukemic cells.

In Vitro Production of Echioidinin, 7-O-Methywogonin from Callus Cultures of Andrographis lineata and Their Cytotoxicity on Cancer Cells.

Andrographis lineata is an herbal medicinal plant used in traditional medicine as a substitute for Andrographis paniculata. Here, using mature leaf explants of A. lineata we demonstrate for the first time the callus induction established on MS medium containing 1.0 mg l-1 IAA. Dried callus was subjected to solvent extraction with acetone. Further the acetone residue was separated by silica gel column chromatography, crystallized and characterized on the basis of nuclear magnetic resonance (proton and c13) and liquid chromatographic mass spectroscopy. This analysis revealed the occurrence of two known flavones namely, 7-O-methylwogonin (MW) and Echioidinin (ED). Furthermore, these compounds were tested for their cytotoxicity against leukemic cell line, CEM. We identify that ED and MW induced cytotoxicity in a time- and concentration-dependent manner. Further increase in the LDH release upon treatment with ED and MW further confirmed our cytotoxicity results against leukemic cell line. Strikingly, MW was more potent than ED when compared by trypan blue and MTT assays. Our results recapitulate the utility of callus cultures for the production of plant specific bioactive secondary metabolites instead of using wild plants. Together, our in vitro studies provide new insights of A. lineata callus cultures serving as a source for cancer chemotherapeutic agents.

Phytochemicals and antimicrobial potentials of mahogany family

Drug resistance to human infectious diseases caused by pathogens lead to premature deaths through out the world. Plants are sources for wide variety of drugs used for treating various diseases. Systematic screening of medicinal plants for the search of new antimicrobial drug candidates that can inhibit the growth of pathogens or kill with no toxicity to host is being continued by many laboratories. Here we review the phytochemical investigations and biological activities of Meliaceae. The mahogany (Meliaceae) is family of timber trees with rich source for limonoids. So far, amongst the different members of Meliaceae, Azadirachta indica and Melia dubia have been identified as the potential plant systems possessing a vast array of biologically active compounds which are chemically diverse and structurally complex. Despite biological activities on different taxa of Meliaceae have been carried out, the information of antibacterial and antifungal activity is a meager with exception to Azadirachta indica. Together we provide new insights of Meliaceae members demonstrating as a potential source as antimicrobial agents using in vitro studies.

Phytochemical and Antimicrobial Studies of Methyl Angolensate and Luteolin-7-O-glucoside Isolated from Callus Cultures of Soymida febrifuga.

Soymida febrifuga (Roxb.) A. Juss. is an indigenous lofty deciduous medicinal tree, monotypic genus endemic to India. Hexane, ethyl acetate and methanol extracts of Soymida febrifuga root callus were tested for their phytochemical constituents and antimicrobial activity. Among them, ethyl acetate extract was found to be most effective, which on subjection to silica gel column chromatography led to the separation and isolation of methyl angolensate and luteolin-7-O-glucoside. Structures were determined by Nuclear Magnetic Resonance and Liquid Chromatographic Mass Spectroscopic methods. Further studies indicated that methyl angolensate and luteolin-7-O-glucoside had an anti-bacterial effect against Bacillus subtilis and Salmonella typhimurium, respectively. In addition to that methyl angolensate had an anti-fungal activity against Aspergillus niger while luteolin-7-O-glucoside inhibited Alternaria alternata.