Medicinal bismuth: Bismuth-organic frameworks as pharmaceutically privileged compounds

Historically organometallic compounds have been used to cure certain diseases with limited applications. Although bismuth belongs to the category of heavy metals, many of its derivatives have found applications in modern drug discovery research, mainly because of its low toxicity and higher bioavailability. Being an eco-friendly mild Lewis acid, compounds having bismuth as a central atom are capable of binding several proteins in humans and other species. Bismuth complexes demonstrated antibacterial potential in syphilis, diarrhea, gastritis, and colitis. Apart from antibacterial activities, bismuth compounds exhibited anticancer, antileishmanial, and some extent of antifungal and other medicinal properties. This article discusses major synthetic methods and pharmacological potentials of bismuth complexes exhibiting in vitro activity to significant clinical performance in a systematic and timely manner.Copyright © 2022 Elsevier Ltd

A highly sensitive switch-on spectrofluorometric method for determination of ascorbic acid using a selective eco-friendly approach.

Ascorbic acid has recently been extensively used due to its role in the management of COVID-19 infections by stimulating the immune system and triggering phagocytosis of the corona virus. The currently used spectrofluorometric methods for determination of ascorbic acid require using derivatizing agents or fluorescent probes and suffer from a number of limitations, including slow reaction rates, low yield, limited sensitivity, long reaction times and high temperatures. In this work, we present a highly sensitive spectrofluorometric method for determination of ascorbic acid by switching-on the fluorescence of salicylate in presence of iron (III) due to a reduction of the cation to iron (II). The addition of ascorbic acid resulted in a corresponding enhancement in the fluorescence intensity of iron (III)-salicylate complex at emission wavelength = 411 nm. The method was found linear in the range of 1-8 µg/mL with a correlation coefficient of 0.9997. The limits of detection and quantitation were 0.035 µg/mL and 0.106 µg/mL, respectively. The developed method was applied for the determination of ascorbic acid in the commercially available dosage form; Ruta C60® tablets. The obtained results were compared with those obtained by a reported liquid chromatographic method at 95% confidence interval, no statistically significant differences were found between the developed and the reported methods. Yet, the developed spectrofluorometric method was found markedly greener than the reference method, based on the analytical Eco-scale and the green analytical procedure index. This work presents a simple, rapid and sensitive method that can possibly be applied for determination of ascorbic acid in pharmaceuticals, biological fluids and food samples.

Botanical drugs and supplements affecting the immune response in the time of COVID-19: Implications for research and clinical practice.

In times of health crisis, including the current COVID-19 pandemic, the potential benefit of botanical drugs and supplements emerges as a focus of attention, although controversial efficacy claims are rightly a concern. Phytotherapy has an established role in everyday self-care and health care, but, since botanical preparations contain many chemical constituents rather than single compounds, challenges arise in demonstrating efficacy and safety. However, there is ample traditional, empirical, and clinical evidence that botanicals can offer some protection and alleviation of disease symptoms as well as promoting general well-being. Newly emerging viral infections, specifically COVID-19, represent a unique challenge in their novelty and absence of established antiviral treatment or immunization. We discuss here the roles and limitations of phytotherapy in helping to prevent and address viral infections, especially regarding their effects on immune response. Botanicals with a documented immunomodulatory, immunostimulatory, and antiinflammatory effects include adaptogens, Boswellia spp., Curcuma longa, Echinacea spp., Glycyrrhiza spp., medicinal fungi, Pelargonium sidoides, salicylate-yielding herbs, and Sambucus spp. We further provide a clinical perspective on applications and safety of these herbs in prevention, onset, progression, and convalescence from respiratory viral infections.