RESUMEN
The purpose of this study is to evaluate the probiotic characteristics of 15 yeast strains isolated from nectar of toddy palm. Initially, the collected samples were inoculated on yeast extract peptone dextrose agar plates and the colonies so obtained were culturally and morphologically characterized. Commercial probiotic yeast, Saccharomyces boulardii served as the control in these experiments. Of the 15 yeast strains, the isolates that were resistant to antibiotics and worked synergistically with other cultures were considered for further evaluation. Selected isolates were evaluated in vitro for tolerance to simulated gastrointestinal conditions such as temperature, pH, bile and gastric juice. Further the yeast isolates were evaluated for their pathogenicity and adherence to intestinal epithelial cells. The 2 yeast isolates with efficient probiotic properties were finally characterized by sequencing their 5.8 S rRNA and partial sequences of internal transcribed spacer 1 and 2. The sequences were BLAST searched in the National Center for Biotechnology Information, nucleic acid database for sequence similarity of organisms and phylogenetic evolutionary analysis was carried out. Based on maximum similarity of basic local alignment search tool results, organisms were characterized as Pichia kudriavzevii OBS1 (100%) and Saccharomyces cerevisiae OBS2 (96%) and sequences were finally deposited in the GenBank data library. Among these two isolates, S. cerevisiae OBS2 displayed slight/moderate antioxidant and anticancer property. Hence, strain OBS2 can be utilized and explored as a potential probiotic for therapeutic applications.
RESUMEN
Microtubules form crucial dynamic structural cellular components of the cell and are composed of the alpha beta tubulin heterodimers. Microtubules are involved in a wide variety of functions in the cell such as attribution to cell shape, motility, intracellular trafficking and mitotic spindle formation. Owing to these reasons, tubulin and microtubules have gained significant interest as important targets for cancer therapy. A review of the existing microtubule targeting drugs specifies that these agents can be categorised into two of the major categories: Microtubule stabilizing agents such as paclitaxel, docetaxel, epothilones, and discodermolide which bind to the tubulin polymer and stabilize the microtubules, microtubule destabilizing agents such as vinca alkaloids, colchicine and combretastatins which bind to tubulin dimers and cause destabilization. These agents ultimately alter the equilibrium between tubulin and microtubule resulting in disruption of mitotic spindle, thereby effecting a critical transition in the cell cycle, leading to cell death. Further, clinical studies of these agents are limited by toxicity effects and emergence of drug resistance. The hybrid drugs are a combination of two or more drugs wherein pharmacophores are incorporated into a single molecule to interact with multiple targets and enhance the cytotoxic action with minimal side effects. Such hybrid regimens can improve therapeutic efficacy and reduce drug toxicity. Therefore, studies on new hybrids with such biological properties form important part in chemistry. In this review, we present an overview of various recent hybrids of colchicines, combretastatin, phodophyllotoxin, etc generated by combination among themselves through linkers or with other pharmacophores and their properties like tubulin stabilization and tubulin destabilization. We also attempted to provide chemistry, toxicity, resistance, side effects of these molecular hybrids acting as microtubule targeting drugs.