Potential of 24-Propylcholestrol as Immunity Inducer against Infection of COVID-19 Virus: In Silico Study Immunomodulatory Drugs.

BACKGROUND: COVID-19 (Coronavirus Disease 2019) caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) has infected millions of people and caused hundreds of thousands of deaths worldwide. However, until now no specific drug for SARS-CoV-2 infection has been found. This prompted many researchers to explore compounds as anti-SARS-CoV-2 candidates. One of the efforts to deal with the spread of the COVID-19 virus is to increase the body's immune system (immune). Medicinal plants are known to have the ability as immune-modulators, one of which is Betel leaf (Piper betle L.) which has good activity as antibacterial, antioxidant, and anti-viral with other pharmacological effects. An in silico approach in drug development was used to search for potential antiviral compounds as inhibitors of SARS-CoV-2 Mpro Protein, RBD, and Non-structural Protein (NSP15). OBJECTIVE: This study aimed to determine the potential of Betel leaf compounds as immunemodulators and good inhibitory pathways against COVID-19. METHODS: In this study, a potential screening of steroid class compounds, namely 24- propilcholesterol was carried out as an anti-SARS-CoV-2 candidate, using an in silico approach with molecular docking simulations for three receptors that play an important role in COVID-19, namely Mpro SARS-CoV-2, RBD SARS-CoV-2 and a non-structural protein (NSP15) and were compared with Azithromycin, Favipiravir and Ritonavir as positive controls. RESULTS: Based on the results of molecular docking simulations, compound from Betel leaf, 24- Propylcholesterol, showed high binding affinity values for spike glycoprotein RBD and nonstructural protein 15 (NSP15), namely -7.5 and -7.8 kcal/mol. Meanwhile, a native ligand of Mpro, inhibitor N3, has a higher binding affinity value than 24-propylcholesterol -7.4 kcal/mol. CONCLUSION: 24-Propylcholesterol compound predicted to have potential as an anti-SARS-CoV-2 compound. However, it is necessary to carry out in vitro and in vivo studies to determine the effectiveness of the compound as an anti-SARS-CoV-2.

The Potential of 24-Propylcholestrol as Antibacterial Oral Bacteria of Enterococcus faecalis ATCC 29212 and Inhibitor Biofilms Formation: in vitro and in silico Study.

Introduction: Uncontrolled biofilm can cause several diseases such as dental caries, gingivitis, and periodontitis. Dental caries is a disease caused by the accumulation of plaque-containing pathogenic bacteria, including Enterococcus faecalis. These bacteria infect the root canals of teeth and colonize to form biofilms. Biofilm inhibition is carried out by interfering with cell wall formation metabolism. MurA enzyme has a role in peptidoglycan biosynthesis of cell walls. Enterococcal surface protein (Esp) is the main contributor of E. faecalis to form biofilms. In addition, inhibition of biofilms by interfering with the quorum sensing (QS) system, suppressing gelatinase virulence factors by blocking autoinducers gelatinase biosynthesis-activating pheromone (GBAP). Purpose: Knowing the potential of Piper betel Linn. compounds as antibacterial in vitro and antibiofilm agents against E. faecalis in silico. Patients and Methods: The compounds were purified by a bioactivity-guided chromatographic method. Antibacterial activity was tested by disc diffusion method, in vitro studies. In silico study, compound P. betel L. was used as the test ligand and compared with positive control fosfomycin, ambuic acid, quercetin, and taxifolin. The proteins used MurA, Esp, GBAP, and gelatinase were docking with the Autodock Vina PyRx 0.8 followed by the PYMOL program and visualized with the Discovery Studio 2020 program. Results: An antibacterial compound was identified 24-propylcholesterol which can inhibit the activity of E. faecalis ATCC 29212 with MIC value of 78.1 µg/mL and MBC value of 156.3 µg/mL. Molecular docking results showed the binding affinity of 24-propylcholesterol with MurA, ESP, GBAP, and gelatinase enzymes was -7.6, -8.7, -5.3, and -7.9 kcal/mol. Conclusion: 24-propylcholesterol has potential as an antibacterial against E. faecalis and as an antibiofilm through in silico inhibition of QS. However, further research is needed in vitro and in vivo to determine the effectiveness of these compounds as antibacterial and antibiofilm.

Potential Allylpyrocatechol Derivatives as Antibacterial Agent Against Oral Pathogen of S. sanguinis ATCC 10,556 and as Inhibitor of MurA Enzymes: in vitro and in silico Study.

BACKGROUND: Streptococcus sanguinis is Gram-positive bacteria that contribute to caries. Many antibacterial agents are resistant against bacteria so that the discovery of new antibacterial agents is a crucial issue. Mechanism of antibacterial agents by disrupting cell wall bacteria is a promising target to be developed. One of the enzymes contributing to the cell wall is MurA enzyme. MurA is an enzyme catalyzing the first step of peptidoglycan biosynthesis in the cell wall formation. Inhibiting MurA is an effective and efficient way to kill the bacteria. Source of bioactive compounds including the antibacterial agent can be found in natural product such as herbal plant. Piper betle L. was reported to contain active antibacterial compounds. However, there is no more information on the antibacterial activity and molecular mechanism of P. betle's compound against S. sanguinis. PURPOSE: The study aims to identify antibacterial constituents of P. betle L. and evaluate their activities through two different methods including in vitro and in silico analysis. MATERIALS AND METHODS: The antibacterial agent was purified by bioactivity-guided isolation with combination chromatography methods and the chemical structure was determined by spectroscopic methods. The in vitro antibacterial activity was evaluated by disc diffusion and dilution methods while the in silico study of a compound binds on the MurA was determined using PyRx program. RESULTS: The antibacterial compound identified as allylpyrocatechol showed inhibitory activity against S. sanguinis with an inhibition zone of 11.85 mm at 1%, together with MIC and MBC values of 39.1 and 78.1 µg/mL, respectively. Prediction for molecular inhibition mechanism of allylpyrocatechols against the MurA presented two allylpyrocatechol derivatives showing binding activity of -5.4, stronger than fosfomycin as a reference with the binding activity of -4.6. CONCLUSION: Two allylpyrocatechol derivatives were predicted to have a good potency as a novel natural antibacterial agent against S. sanguinis through blocking MurA activity that causes disruption of bacterial cell wall.