A Computational Study of Carbazole Alkaloids from Murraya koenigii as Potential SARS-CoV-2 Main Protease Inhibitors.

Despite COVID-19 vaccination, immune escape of new SARS-CoV-2 variants has created an urgent priority to identify additional antiviral drugs. Targeting main protease (Mpro) expressed by SARS-CoV-2 is a therapeutic strategy for drug development due to its prominent role in viral replication cycle. Leaves of Murraya koenigii are used in various traditional medicinal applications and this plant is known as a rich source of carbazole alkaloids. Thus, this computational study was designed to investigate the inhibitory potential of carbazole alkaloids from Murraya koenigii against Mpro. Molecular docking was initially used to determine the binding affinity and molecular interactions of carbazole alkaloids and the reference inhibitor (3WL) in the active site of SARS-CoV-2 Mpro (PDB ID: 6M2N).The top scoring compounds were further assessed for protein structure flexibility, physicochemical properties and drug-likeness, pharmacokinetic and toxicity (ADME/T) properties, antiviral activity, and pharmacophore modeling. Five carbazole alkaloids (koenigicine, mukonicine, o-methylmurrayamine A, koenine, and girinimbine) displayed a unique binding mechanism that shielded the catalytic dyad of Mpro with stronger binding affinities and molecular interactions than 3WL. Furthermore, the compounds with high affinity displayed favorable physicochemical and ADME/T properties that satisfied the criteria for oral bioavailability and druggability. The pharmacophore modeling study shows shared pharmacophoric features of those compounds for their biological interaction with Mpro. During the molecular dynamics simulation, the top docking complexes demonstrated precise stability except koenigicine. Therefore, mukonicine, o-methylmurrayamine A, koenine, and girinimbine may have the potential to restrict SARS-CoV-2 replication by inactivating the Mpro catalytic activity.

Soybean oil and coconut oil enhance the absorption of chlorogenic acid in humans.

The effect of a mainly polyunsaturated oil (soybean oil) and a mainly medium chain triglyceride oil (coconut oil) on the absorption of the phenolic antioxidant chlorogenic acid (5-caffeoylquinic acid) was investigated using 90 healthy volunteers. Serum concentrations and the absorbed percentages of chlorogenic acid of volunteers who received chlorogenic acid without oils (0.006 ± 0.001 mg/ml, 5.7 ± 0.2%), chlorogenic acid with soybean oil (0.012 ± 0.001 mg/ml, 11.8 ± 1.3%), and chlorogenic acid with coconut oil (0.067 ± 0.014 mg/ml, 65.6 ± 18.1%) were significantly different from each other (p < .05). There was a strong positive correlation between the increase in serum and plasma antioxidant capacity and the absorption of chlorogenic acid. The major fatty acid of each of soybean oil and coconut oil also improved the permeability of chlorogenic acid in Caco-2 cell monolayers. The results suggest that the tested edible oils may improve the nutritional value of chlorogenic acid-containing foods by improving the absorption of chlorogenic acid. PRACTICAL APPLICATIONS: Small polar antioxidants such as phenolic acids and flavonoids are poorly absorbed through the intestinal epithelium. Chlorogenic acid was used in the present study as a model for small polar phenolic antioxidants. According to the present study, soybean oil with mainly polyunsaturated fatty acids and coconut oil with mainly medium chain fatty acids improve the absorption of these antioxidants. These findings suggest that proper planning of diets or food supplements containing phenolic antioxidants with medium chain or polyunsaturated fatty acid-rich edible oils may enhance the nutritional benefits expected from phenolic antioxidants.

Expression of Nitric Oxide Synthase and Nitric Oxide Levels in Peripheral Blood Cells and Oxidized Low-Density Lipoprotein Levels in Saliva as Early Markers of Severe Dengue.

BACKGROUND: Severe dengue (SD), experienced by only a fraction of dengue patients, can be lethal. Due to the lack of early markers that can predict the evolution of SD, all dengue patients have to be monitored under hospital care. We discovered early oxidative stress markers of SD to identify patients who can benefit from early intervention before the symptoms appear. METHODS: The expression of inducible nitric oxide synthase (iNOS) in peripheral blood cells (PBC), nitric oxide (NO), and oxidized low-density lipoprotein (oxLDL) levels in plasma and saliva collected at early stages of dengue infection from 20 nonsevere dengue fever (DF) patients and 20 patients who later developed SD were analyzed in a retrospective nested case-control study. RESULTS: The expression of iNOS is significantly (P < 0.05) lower in patients who developed SD than in DF patients at admission within 4 days from fever onset. Median plasma NO concentration within 4 days from fever onset is also significantly (P < 0.05) lower in patients who developed SD (17.9 ± 1.6 µmol/L) than DF (23.0 ± 2.1 µmol/L). Median oxLDL levels in plasma within 3 days from fever onset is significantly (P < 0.05) lower in patients who developed SD (509.4 ± 224.1 ng/mL) than DF (740.0 ± 300.0 ng/mL). Median salivary oxLDL levels are also significantly (P < 0.05) lower in patients who developed SD (0.8 ± 0.5 ng/mL) than DF (3.6 ± 2.6 ng/mL) within 4 days from fever onset. CONCLUSIONS: These findings suggest that the expression of iNOS (73% sensitivity, 86% specificity) and plasma NO (96% sensitivity, 61% specificity at 22.3 µmol/L; P < 0.05) may serve as early markers of SD within 3 days from fever onset. Salivary oxLDL levels may serve as early noninvasive markers of SD with a sensitivity and specificity, respectively, of 57% and 91% at 0.9 ng/mL; 76% and 55% at 2.3 ng/mL; and 100% and 50% at 4.6 ng/mL (P < 0.05) within 4 days from fever onset.

Effect of chain length and saturation of the fatty acids in dietary triglycerides on lipid metabolism in Wistar rats.

We investigated the effect of the chain length and the degree of saturation of fatty acids in dietary triglycerides on serum lipid profiles and hepatic lipid metabolism in Wistar rats. Fat component of the basal diet (soybean oil) was replaced with fats with fatty acids of different chain lengths and saturation and the serum lipids were monitored for 150 days. Principal component (PC) analysis of serum lipid components was related to chain length and saturation. The combined effect of chain length and saturation on PC 1 scores was evaluated by multiple regression analysis. The results indicated that average chain length of the fatty acids of triglycerides has a higher influence on the quality of serum lipid parameters than the average degree of saturation. Expression of selected genes responsible for lipid metabolism showed similar trends in medium chain saturated and long chain polyunsaturated diet groups. PRACTICAL APPLICATIONS: Dietary lipids contain a wide range of saturated and unsaturated fatty acids with different chain lengths. Overall contribution of these different fatty acids decides the health effects of the lipids in the diet. Present study shows that the fats with medium chains and higher degree of saturation and fats with long chains and higher degree of unsaturation (lower degree of saturation) affect serum lipid parameters and expression of hepatic genes involved in the lipid metabolism in a similar manner. Such information is important for physicians to plan dietary schemes to improve the nutritional health and manage the noncommunicable diseases.

Antioxidant and Nutritional Properties of Domestic and Commercial Coconut Milk Preparations.

The aqueous extract of scraped coconut kernel is known as coconut milk. Coconut milk preparations are also commercially available in the form of desiccated powders or liquids. While these various coconut milk preparations are heavily used in cooking in the Asian countries as a major source of dietary fat, limited studies have been conducted on their chemical and nutritional composition. In this study, we have determined the chemical composition and nutritional effects of both domestic preparations of coconut milk and the commercially available counterparts. The results indicate that the phenolic compounds of all coconut milk preparations provide protection against oxidative damage on lipids and inhibit oxidative damage of both proteins and DNA. The lipid profiles are not significantly affected by the consumption of the three coconut milk preparations despite their different fat contents.

Differential expression of microRNA, miR-150 and enhancer of zeste homolog 2 (EZH2) in peripheral blood cells as early prognostic markers of severe forms of dengue.

BACKGROUND: Dengue presents a wide clinical spectrum. Most patients recover following a self-limiting non-severe clinical course. A small proportion of patients progress to severe disease, mostly characterized by plasma leakage with or without hemorrhage. Early symptoms of severe dengue (SD) are similar to those of non-severe dengue fever (DF). Severe symptoms manifest after 3-5 days of fever, which can be life threatening due to lack of proper medications and inability to distinguish severe cases during the early stages. Early prediction of SD in patients with no warning signs who may later develop severe infection is very important for proper disease management to alleviate related complications and mortality. microRNA are small non-coding RNA molecules that regulate post-transcriptional gene expression. Due to the remarkable stability and the role of microRNA in gene expression, altered expression of microRNA was evaluated to explore clinically relevant prognostic markers of severe dengue. METHODS: The relative expression of microRNA hsa-let-7e (let-7e), hsa-miR-30b-5p (miR-30b), hsa-miR-30e-3p (miR-30e), hsa-miR-33a (miR-33a), and hsa-miR-150-5p (miR-150) and several putative target genes in peripheral blood cells (PBC) collected from 20 DF and 20 SD positive patients within 4 days from fever onset was evaluated by quantitative reverse transcription PCR (qRT-PCR). RESULTS: miR-150 showed significant (P < 0.01) up regulation in PBC of SD patients compared to DF patients during the acute phase of infection. Expression of enhancer of zeste homolog 2 (EZH2) was significantly (P < 0.01) down regulated indicating that genes involved in epigenetic regulation are also differentially expressed in SD patients during the early stage of infection. CONCLUSIONS: Differential expression of microRNA miR-150 and the putative target gene EZH2 may serve as reliable biomarkers of disease severity during early stages of dengue infection.

Effect of three edible oils on the intestinal absorption of caffeic acid: An in vivo and in vitro study.

Polyphenolic antioxidants are mainly absorbed through passive paracellular permeation regulated by tight junctions. Some fatty acids are known to modulate tight junctions. Fatty acids resulting from the digestion of edible oils may improve the absorption of polyphenolic antioxidants. Therefore, we explored the effect of three edible oils on the intestinal absorption of caffeic acid. Rats were fed with soybean oil and caffeic acid dissolved in distilled water. Caffeic acid contents in the plasma collected up to 1 hr were quantified. The experiment was repeated with coconut oil and olive oil. Component fatty acids of the oils were individually tested in vitro for their effect on permeability of caffeic acid using Caco-2 cell monolayers. Highest absorption of caffeic acid was observed in animals fed with coconut oil. In vitro transport percentages of caffeic acid in 2.5 mmol/L solutions of fatty acids were 22.01±0.12 (lauric), 15.30 ± 0.25 (myristic acid), 13.59 ± 0.35 (linoleic acid), 3.70 ± 0.09 (oleic acid) and 0.10-2.0 (all other fatty acids). Lauric acid and myristic acid are the two major fatty acids present in coconut oil. Therefore, these fatty acids may contribute to the higher absorption of caffeic acid in the presence of coconut oil.

Imine hydrolysis and role of a rhodium(I)-imine-amine complex in homogeneous H2-hydrogenation of the imine and a rare example of inequivalent NH2 protons.

A Rh-catalyzed, homogeneous hydrogenation of the imine, PhCH(2)N=CHPh, is shown to involve a Rh-imine-amine species that subsequently activates H(2), the amine (benzylamine) being formed via a Rh-catalyzed hydrolysis of the imine by adventitious water. The imine-amine complex, cis-(Rh[P(p-tolyl)(3)](2)(PhCH(2)N=CHPh)(NH(2)CH(2)Ph))PF(6) (2b), is structurally characterized, and the solution (1)H NMR data reveal inequivalent NH(2) protons.