Category: Readings

Acid labile linkers have been used widely for various biomedical applications with preferential applications in drug delivery. In this report, we have synthesized, glycerol based b-thiopropionate esters having an acid-labile β-thiopropionate linker with Michael addition reaction between hydrophobic thiol and hydrophilic tri-glycerol diacrylate. The solvent free reaction and purification by simply solvent extraction instead of any sophisticated chromatographic techniques provide an upper edge for their application in biomedical or other fields. These β-thiopropionate esters can potentially be used for the delivery and release of hydrophobic drugs at acidic sites particularly in cancer cells.

Justicia adhatoda L. is an Indian medicinal plant traditionally used to treat respiratory ailments in Ayurvedic and Unani medicines.  It is widespread in the Indian subcontinent. The plant leaves are known to have broad range of pharmacological activities including analgesic, anti-inflammatory, antispasmodic and antibacterial properties. Some studies have highlighted the antimicrobial effects of its major bioactive components like vasicine and vasicinone However, not much work has been done to explore the enormous benefits that the bioactive components might hold. Hence, in the present study, we explored the plant for its potential as an effective anti- mycobacterial agent. We aim to investigate the antimycobacterial effect of J. adhatoda L. plant leaf extracts on Mycobacterium smegmatis and Mycobacterium bovis (BCG) and identify, and isolate th bioactive component(s) for the plant leaf extract. The isolated components were also analyzed further for their antimycobacterial activity in synergy with Isoniazid. The leaves of J. adhatoda L. were powdered and extracted with ethanol, water, ethyl acetate, and hexane and antimycobacterial activity was assessed by MABA. The ethanol extract showed >96% and 98% reduction in colony-forming units (CFU) at 100µg/ml on Mycobacterium smegmatis and Mycobacterium bovis (BCG) respectively. Active phytoconstituent from ethanol extract was isolated and further fractionated via Prep-TLC. They were bioassayed against M. smegmatis and M. bovis (BCG) to study cytotoxicity, synergy, and external damage on the bacteria. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were carried out on treated bacilli to observe the external and internal cellular damage. The isolated fractions showed strong anti-mycobacterial activity, with low cytotoxicity and synergism when used with isoniazid. When subjected to electron microscopy, the fractions were found to adversely affect the cell wall and membrane of BCG, causing cytoplasmic leakage. Our study demonstrated that the active fractions isolated from J. adhatoda L. could be evaluated further for potentially effective anti-mycobacterial agents.

One of the first-line therapy of diabetes mellitus is alpha-glucosidase inhibitors. Due to side effects caused by synthetic drugs and limited sources, various studies have been conducted on herbal plants and macroalgae consisting of bioactive compounds with alpha-glucosidase inhibitory activity. This study examines the alpha-glucosidase inhibitory activity and phytochemical compounds in ethyl acetate and ethanol extract of Bornetella oligospora, an abundant green alga in eastern Indonesia. The result showed that ethanol and ethyl acetate extract of Bornetella oligospora contained phytochemical components such as flavonoid, glycoside, triterpenoid, and steroid. The thin layer chromatography test showed ethanol extract have five spots with Rf 0.545, 0.527, 0.5, 0.473, and 0.154, while the ethyl acetate extract has two spots with Rf 0.58 and 0.64. The alpha-glucosidase inhibition assay showed IC50 values of the ethanol extract was 11.702 ug/mL and ethyl acetate extract was 95.384 ug/mL. In conclusion, Bornetella oligospora extract has the potential as an antidiabetic agent.

Effect of astaxanthin from Haematococcus pluvialis on lipid peroxidation and oxidative stress induced by ambient air exposure was studied. Wistar albino rats were exposed to ambient air was administered with astaxanthin in doses varying between 0.5 to 2% of food intake. Various biological parameters like ALT, AST, ALP, malondialdehyde, hydrogen peroxide, superoxide dismutase, catalase and glutathione reductase, were estimated biochemically and the expression of Nrf2 and glutathione peroxidase genes were estimated by reverse transcriptase PCR. Plasma ALT, AST, ALP, MDA and the activity of antioxidant enzymes; SOD, GRd, catalase were found increased significantly in ambient air exposed rats. Ambient air exposure decreased the levels of glutathione, non protein thiols and GPx expression whereas total thiols and expression of Nrf2 increased. However the concurrent administration of astaxanthin was found to reverse these changes in a dose dependent manner. The results of this study revealed the ability of astaxanthin to alleviate liver toxicity and oxidative stress induced by ambient air exposure and points to the possibility of developing astaxanthin as a dietary supplement that reduce the ill effect of toxic chemicals from ambient air.