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.

Prediction Mechanism of Nevadensin as Antibacterial Agent against S. sanguinis: In vitro and In silico Studies.

BACKGROUND: Streptococcus sanguinis can contribute to tooth demineralization, which can lead to dental caries. Antibiotics used indefinitely to treat dental caries can lead to bacterial resistance. Discovering new antibacterial agents from natural products, like Ocimum basilicum, will help combat antibiotic resistance. In silico analysis (molecular docking) can help determine the lead compound by studying the molecular interaction between the drug and the target receptor (MurA enzyme and DNA gyrase). It is a potential candidate for antibacterial drug development. OBJECTIVES: The research objective is to isolate the secondary metabolite of O. basilicum extract that exhibits activity against S. sanguinis through in vitro and in silico analysis. METHODS: n-Hexane extract of O. basilicum was purified by combining column chromatography with bioactivity-guided fractionation. The in vitro antibacterial activity against S. sanguinis was determined using the disc diffusion and microdilution method, while molecular docking simulation of nevadensin (1) with MurA enzyme and DNA gyrase was performed by using PyRx 0.8 program. RESULTS: Nevadensin from O. basilicum was successfully isolated and characterized by spectroscopic methods. This compound showed antibacterial activity against S. sanguinis with MIC and MBC values of 3750 and 15000 µg/mL, respectively. In silico analysis showed that the binding affinity to MurA was -8.5 Kcal/mol, and the binding affinity to DNA gyrase was -6.7 Kcal/mol. The binding of nevadensin-MurA is greater than fosfomycin-MurA. Otherwise, Nevadensin-DNA gyrase has a weaker binding affinity than fluoroquinolone-DNA gyrase and chlorhexidine-DNA gyrase. CONCLUSION: Nevadensin showed potential as a new natural antibacterial agent by inhibiting the MurA enzyme rather than DNA gyrase.

Potential Fatty Acid as Antibacterial Agent Against Oral Bacteria of Streptococcus mutans and Streptococcus sanguinis from Basil (Ocimum americanum): In vitro and In silico Studies.

BACKGROUND: Streptococcus mutans and Streptococcus sanguinis are Gram-positive bacteria that cause dental caries. MurA enzyme acts as a catalyst in the formation of peptidoglycan in bacterial cell walls, making it ideal as an antibacterial target. Basil (Ocimum americanum) is an edible plant that is diverse and has been used as a herbal medicine for a long time. It has been reported that basil has a pharmacological effect as well as antibacterial activity. The purpose of this study was to identify antibacterial compounds in O. americanum and analyze their inhibition activity on MurA enzyme. METHODS: Fresh leaves from O. americanum were extracted with n-hexane and purified by a combination of column chromatography on normal and reverse phases together with in vitro bioactivity assay against S. mutans ATCC 25175 and S. sanguinis ATCC 10556, respectively, while in silico molecular docking simulation of lauric acid (1) was conducted using PyRx 0.8. RESULTS: The structure determination of antibacterial compound by spectroscopic methods resulted in an active compound lauric acid (1). The in vitro evaluation of antibacterial activity in compound 1 showed Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values of 78.13 and 156.3 ppm and 1250 and 2500 ppm against S. sanguinis and S. mutans, respectively. Further analysis and in silico evaluation determined lauric acid (1) as MurA Enzyme inhibitor. Lauric acid (1) showed a binding affinity of -5.2 Kcal/mol, which was higher than fosfomycin. CONCLUSION: Lauric acid showed the potential as a new natural antibacterial agent through MurA inhibition in bacterial cell wall biosynthesis.