In silico Molecular Docking Analysis of Three Molecules Isolated from Litsea guatemalensis Mez on Anti-inflammatory Receptors

BACKGROUND

The Litsea genus has four native species from Mesoamerica. Litsea guatemalensis Mez. is a native tree, traditionally used as a condiment and herbal medicine in the region. It has demonstrated antimicrobial, aromatic, anti-inflammatory and antioxidant activity. Bioactive fractionation attributed the anti-inflammatory and anti-hyperalgesic activities to pinocembrin, scopoletin, and 5,7,3´4´-tetrahydroxy-isoflavone. In silico analysis, these molecules were analyzed on receptors involved in the anti-inflammatory process to determine which pathways they interact.

OBJECTIVE

To analyze and evaluate 5,7,3',4'-tetrahydroxyisoflavone, pinocembrin, and scopoletin using the in silico analysis against selected receptors involved in the inflammatory pathway.

METHODS

Known receptors involved in the anti-inflammatory process found as protein-ligand complex in the Protein Data Bank (PDB) were used as references for each receptor and compared with the molecules of interest. The GOLD-ChemScore function, provided by the software, was used to rank the complexes and visually inspect the overlap between the reference ligand and the poses of the studied metabolites.

RESULTS

53 proteins were evaluated, each one in five conformations minimized by molecular dynamics. The scores obtained for dihydroorotate dehydrogenase were greater than 80 for the three molecules of interest, scores for cyclooxygenase 1 and glucocorticoid receptor were greater than 50, and identified residues with interaction in binding sites overlap with the reference ligands in these receptors.

CONCLUSION

The three molecules involved in the anti-inflammatory process of L. guatemalensis show in silico high affinity to the enzyme dihydroorotate dehydrogenase, glucocorticoid receptors and cyclooxygenase-1.

Antimicrobial Air Filter Coating with Plant Extracts Against Airborne Microbes

Antimicrobial air filters are required to protect humans from the risk of secondary bioaerosol pollution as well as airborne particles. Three plant extracts (tea-tree oil, rosemary, and garlic) were selected to replace antimicrobial chemicals in air filters. The antimicrobial activity of plant extracts was investigated using Micrococcus luteus and Escherichia coli. Phytochemicals present in the three plant extracts were identified using a gas chromatograph coupled with a mass spectrometer. The extracts were spray-coated on polyethylene terephthalate filter surfaces using silicate polymeric coating and evaluated via X-ray photoelectron spectroscopy and a scanning electron microscope with energy dispersive spectroscopy. After coating, an increase of 9.1% in the pressure drop was observed. The strain Micrococcus luteus was used to evaluate the antimicrobial activity of the air filter. After bioaerosol exposure, the tea-tree oil-coated filters immediately induced M. luteus cell inactivation (40–55%), whereas the rosemary and garlic coated filters did not. However, 48 h after exposure, a significant M. luteus inactivation of 99.99%, 99.0%, and 99.9% was recorded for concentrations of 2.89, 6.73, and 11.51 mg/cm2 for the tea-tree, rosemary, and garlic extracts, respectively. The coated filters exhibited high antimicrobial activity, thereby indicating significant potential for application as self-cleaning air filters.