Inhibition of SARS-CoV2 viral infection with natural antiviral plants constituents: An in-silico approach

Background and Objective

In 2019, a novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) was declared pandemic. Advancement in computational technology has provided rapid and cost-effective techniques to test the efficacy of newer therapeutic agents. This study evaluated some of the potent phytochemicals obtained from AYUSH (Ayurveda, Yoga, Naturopathy, Unani, Siddha, Sowa-Rigpa, and Homeopathy)-listed medicinal plants against SARS-CoV-2 proteins using computational techniques.

Materials and methods

The potential SARS-CoV-2 protein targets were utilized to study the ligand-protein binding characteristics. The bioactive agents were obtained from ashwagandha, liquorice, amla, neem, tinospora, pepper, and stevia. Ivermectin was utilized as a reference agent to compare its efficacy with phytochemicals.

Results

The computational analysis suggested that all the bioactive components from the selected plants possessed negative docking scores (ranging from -6.24 to -10.53). The phytoconstituents were well absorbed, distributed in the body except for the CNS, metabolized by liver enzymes, well cleared from the body, and well tolerated. The data suggest that AYUSH-recommended plants demonstrated therapeutic efficacy against SARS CoV-2 virus infection with significantly reduced toxicity.

Conclusion

The phytoconstituents were found to hinder the early stages of infection, such as absorption and penetration, while ivermectin prevented the passage of genetic material from the cytoplasm to the nucleus. Additional research involving living tissues and clinical trials are suggested to corroborate the computational findings.

Synthesis and characterization of SnO2/rGO nanocomposite for an efficient photocatalytic degradation of pharmaceutical pollutant: Kinetics, mechanism and recyclability

The SnO₂ and SnO₂/rGO nanostructures were successfully synthesized using the facile hydrothermal synthesis technique. The prepared nanostructures were well studied using different techniques such as XRD, XPS, UV-DRS, FT-IR, EDX, SEM and HR-TEM analysis. The crystalline nature of SnO₂ and SnO₂/rGO was confirmed by the XRD technique. The formation of highly pure SnO₂ and SnO₂/rGO nanostructures was confirmed by EDX analysis. The morphological results show the good agglomeration of several spherical nanoparticles. The optical properties were studied through the UV-DRS technique and the bandgap energies of SnO₂ and SnO₂/rGO are estimated to be 3.12 eV and 2.71 eV, respectively. The photocatalytic degradation percentage in presence of SnO₂ and SnO₂/rGO against RhB was found to be 96% and 98%, respectively. The degradation of TTC molecules was estimated as 90% and 88% with SnO₂/rGO and SnO₂, respectively. The degradation of both RhB and TTC molecules was well suited with the pseudo-first-order kinetics. The results of successive experiments clearly show the enhancement in the photocatalytic properties in the SnO₂/rGO nanostructures.

Development of a floating drug delivery system with superior buoyancy in gastric fluid using hot-melt extrusion coupled with pressurized CO₂

The present study aimed to develop a continuous single-step manufacturing platform to prepare a porous, low-density, and floating multi-particulate system (mini-tablet, 4 mm size). This process involves injecting inert, non-toxic pressurized CO₂gas (P-CO₂) in zone 4 of a 16-mm hot-melt extruder (HME) to continuously generate pores throughout the carrier matrix. Unlike conventional methods for preparing floating drug delivery systems, additional chemical excipients and additives are not needed in this approach to create minute openings on the surface of the matrices. The buoyancy efficiency of the prepared floating system (injection of P-CO₂) in terms of lag time (0 s) significantly improved (P < 0.05), compared to the formulation prepared by adding the excipient sodium bicarbonate (lag time 120 s). The main advantages of this novel manufacturing technique include: (i) no additional chemical excipients need to be incorporated in the formulation, (ii) few manufacturing steps are required, (iii) high buoyancy efficiency is attained, and (iv) the extrudate is free of toxic solvent residues. Floating mini-tablets containing acetaminophen (APAP) as a model drug within the matrix-forming carrier (Eudragit® RL PO) have been successfully processed via this combined technique (P-CO₂/HME). Desired controlled release profile of APAP from the polymer Eudragit® RL PO is attained in the optimized formulation, which remains buoyant on the surface of gastric fluids prior to gastric emptying time (average each 4 h).