Lauric acid and myristic acid from Allium sativum inhibit the growth of Mycobacterium tuberculosis H37Ra: in silico analysis reveals possible binding to protein kinase B

Physiological and Transcriptomic Analyses of the Effects of Exogenous Lauric Acid on Drought Resistance in Peach (Prunus persica (L.) Batsch)

Peach (Prunus persica (L.) Batsch) is a fruit tree of economic and nutritional importance, but it is very sensitive to drought stress, which affects its growth to a great extent. Lauric acid (LA) is a fatty acid produced in plants and associated with the response to abiotic stress, but the underlying mechanism remains unclear. In this study, physiological analysis showed that 50 ppm LA pretreatment under drought stress could alleviate the growth of peach seedlings. LA inhibits the degradation of photosynthetic pigments and the closing of pores under drought stress, increasing the photosynthetic rate. LA also reduces the content of O₂^-, H₂O₂, and MDA under drought stress; our results were confirmed by Evans Blue, nitroblue tetrazolium (NBT), and DAB(3,3-diaminobenzidine) staining experiments. It may be that, by directly removing reactive oxygen species (ROS) and improving enzyme activity, i.e., catalase (CAT) activity, peroxidase (POD) activity, superoxide dismutase (SOD) activity, and ascorbate peroxidase (APX) activity, the damage caused by reactive oxygen species to peach seedlings is reduced. Peach seedlings treated with LA showed a significant increase in osmoregulatory substances compared with those subjected to drought stress, thereby regulating osmoregulatory balance and reducing damage. RNA-Seq analysis identified 1876 DEGs (differentially expressed genes) in untreated and LA-pretreated plants under drought stress. In-depth analysis of these DEGs showed that, under drought stress, LA regulates the expression of genes related to plant-pathogen interaction, phenylpropanoid biosynthesis, the MAPK signaling pathway, cyanoamino acid metabolism, and sesquiterpenoid and triterpenoid biosynthesis. In addition, LA may activate the Ca²⁺ signaling pathway by increasing the expressions of CNGC, CAM/CML, and CPDK family genes, thereby improving the drought resistance of peaches. In summary, via physiological and transcriptome analyses, the mechanism of action of LA in drought resistance has been revealed. Our research results provide new insights into the molecular regulatory mechanism of the LA-mediated drought resistance of peach trees.

Appraisal of the Possible Role of PPARγ Upregulation by CLA of Probiotic Pediococcus pentosaceus GS4 in Colon Cancer Mitigation

The prevalence of colon cancer (CC) is increasing at the endemic scale, which is accompanied by subsequent morbidity and mortality. Although there have been noteworthy achievements in the therapeutic strategies in recent years, the treatment of patients with CC remains a formidable task. The current study focused on to study role of biohydrogenation-derived conjugated linoleic acid (CLA) of probiotic Pediococcus pentosaceus GS4 (CLA_GS4) against CC, which induced peroxisome proliferator-activated receptor gamma (PPARγ) expression in human CC HCT-116 cells. Pre-treatment with PPARγ antagonist bisphenol A diglycidyl ether has significantly reduced the inhibitory efficacy of enhanced cell viability of HCT-116 cells, suggesting the PPARγ-dependent cell death. The cancer cells treated with CLA/CLA_GS4 demonstrated the reduced level of Prostaglandin E2 PGE₂ in association with reduced COX-2 and 5-LOX expressions. Moreover, these consequences were found to be associated with PPARγ-dependent. Furthermore, delineation of mitochondrial dependent apoptosis with the help of molecular docking LigPlot analysis showed that CLA can bind with hexokinase-II (hHK-II) (highly expressed in cancer cells) and that this association underlies voltage dependent anionic channel to open, thereby causing mitochondrial membrane depolarization, a condition that initiates intrinsic apoptotic events. Apoptosis was further confirmed by annexin V staining and elevation of caspase 1p10 expression. Taken all together, it is deduced that, mechanistically, the upregulation of PPARγ by CLA_GS4 of P. pentosaceus GS4 can alter cancer cell metabolism in association with triggering apoptosis in CC.

Ingestional Toxicity of Radiation-Dependent Metabolites of the Host Plant for the Pale Grass Blue Butterfly: A Mechanism of Field Effects of Radioactive Pollution in Fukushima

Biological effects of the Fukushima nuclear accident have been reported in various organisms, including the pale grass blue butterfly Zizeeria maha and its host plant Oxalis corniculata. This plant upregulates various secondary metabolites in response to low-dose radiation exposure, which may contribute to the high mortality and abnormality rates of the butterfly in Fukushima. However, this field effect hypothesis has not been experimentally tested. Here, using an artificial diet for larvae, we examined the ingestional toxicity of three radiation-dependent plant metabolites annotated in a previous metabolomic study: lauric acid (a saturated fatty acid), alfuzosin (an adrenergic receptor antagonist), and ikarugamycin (an antibiotic likely from endophytic bacteria). Ingestion of lauric acid or alfuzosin caused a significant decrease in the pupation, eclosion (survival), and normality rates, indicating toxicity of these compounds. Lauric acid made the egg-larval days significantly longer, indicating larval growth retardation. In contrast, ikarugamycin caused a significant increase in the pupation and eclosion rates, probably due to the protection of the diet from fungi and bacteria. These results suggest that at least some of the radiation-dependent plant metabolites, such as lauric acid, contribute to the deleterious effects of radioactive pollution on the butterfly in Fukushima, providing experimental evidence for the field effect hypothesis.

Traditional Medicinal Plants as a Source of Antituberculosis Drugs: A System Review

Medicinal plants are the chief components in the different oriental formulations in different traditional medical systems worldwide. As a thriving source of medicine, the medicinal plants with antituberculosis (TB) properties inspire the pharmacists to develop new drugs based on their active components or semimetabolites. In the present review, the anti-TB medicinal plants were screened from the scientific literatures, based on the botanical classification and the anti-TB activity. The obtained anti-TB medicinal plants were categorized into three different categories, viz., 159 plants critically examined with a total 335 isolated compounds, 131 plants with their crude extracts showing anti-TB activity, and 27 plants in literature with the prescribed formula by the traditional healers. Our systemic analysis on the medicinal plants can assist the discovery of novel and more efficacious anti-TB drugs.

In Silico Approach for Phytocompound-Based Drug Designing to Fight Efflux Pump-Mediated Multidrug-Resistant Mycobacterium tuberculosis

Tuberculosis (TB), caused by the bacteria Mycobacterium tuberculosis, is one of the principal causes of death in the world despite the existence of a significant number of antibiotics aimed against it. This is mainly due to the drug resistance mechanisms present in the bacterium, which leads to multidrug-resistant tuberculosis (MDR-TB). Additionally, the development of new antibiotics has become limited over the years. Although there are various drug resistance mechanisms present, efflux pumps are of utmost importance because they extrude out several dissimilar antitubercular drugs out of the cell. There are many efflux pump proteins present in Mycobacterium tuberculosis. Therefore, blocking these efflux pumps by inhibitors can raise the efficacy of the existing antibiotics and may also pave the path for the discovery and synthesis of new drugs. Plant compounds can act as a resource for the development of efflux pump inhibitors (EPIs), which may eventually replace or augment the current therapeutic options. This is mainly because plants have been traditionally used for ages for food or treatment and are considered safe with little or no side effects. Various computational tools are available which are used for the virtual screening of a large number of phytocompounds within a short span of time. This review aims to highlight the mechanism and appearance of drug resistance in Mycobacterium tuberculosis with emphasis on efflux pumps along with the significance of phytochemicals as inhibitors of these pumps and their screening strategy by computational approaches.

In silico identification of compounds from Nigella sativa seed oil as potential inhibitors of SARS-CoV-2 targets

BACKGROUND

The growing number of cases, severity and fatality of the COVID-19 pandemic, coupled with the fact that no cure has been found has made infected individuals especially in Africa, to resort to the consumption of different natural products to alleviate their condition. One of such plant materials that have been consumed to remedy the severity of this viral infection is the oil of Nigella sativa seed commonly called black seed oil. In this study, we extracted and characterized the oil from this seed using gas chromatography coupled to a mass selective detector to identify the component phytochemicals. Site-directed multiligand docking of the identified compounds was performed on SARS-CoV-2 molecular targets- Replicase polyprotein 1a, RNA binding protein of NSP9, ADP ribose phosphatase of NSP3, 3-chymotrypsin-like protease 3CLpro, and RNA-dependent RNA polymerase RDRP, and ACE2-angiotensin-converting enzyme from the Homo sapiens.

RESULTS

The binding affinity of caryophyllene oxide was the highest on 3CLpro (- 6.0 kcal/mol), NSP3 (- 6.3 kcal/mol), NSP9 (- 6.3 kcal/mol), and RDRP (- 6.9 kcal/mol) targets, while α-bergamotene gave the best binding affinity on RPIA (5.7 kcal/mol) target. The binding affinity of β-bisabolene on the ACE2 target (- 8.0 kcal/mol) was almost the same as Remdesivir (- 8.1 kcal/mol). The ADMET properties of these three phytochemicals showed that they are good drug leads for these SARS-CoV-2 receptors.

CONCLUSION

The findings from this study strongly indicate that the reported recovery from COVID-19 infection claimed by patients who consumed black seed oil could be linked to the presence of caryophyllene oxide, α-bergamotene, and β-bisabolene in this natural product.

M. tuberculosis curli pili (MTP) is associated with alterations in carbon, fatty acid and amino acid metabolism in a THP-1 macrophage infection model

The initial host-pathogen interaction is crucial for the establishment of infection. An improved understanding of the pathophysiology of Mycobacterium tuberculosis (M. tuberculosis) during macrophage infection can aid the development of intervention therapeutics against tuberculosis. M. tuberculosis curli pili (MTP) is a surface located adhesin, involved in the first point-of-contact between pathogen and host. This study aimed to better understand the role of MTP in modulating the intertwined metabolic pathways of M. tuberculosis and its THP-1 macrophage host. Metabolites were extracted from pelleted wet cell mass of THP-1 macrophages infected with M. tuberculosis wild-type V9124 (WT), Δmtp-deletion mutant and the mtp-complemented strains, respectively, via a whole metabolome extraction method using a 1:3:1 ratio of chloroform:methanol:water. Metabolites were detected by two-dimensional gas chromatography time-of-flight mass spectrometry. Significant metabolites were determined through univariate and multivariate statistical tests and online pathway databases. Relative to the WT, a total of nine and ten metabolites were significantly different in the Δmtp and complement strains, respectively. All nine significant metabolites were found in elevated levels in the Δmtp relative to the WT. Additionally, of the ten significant metabolites, eight were detected in lower levels and two were detected in higher levels in the complement relative to the WT. The absence of the MTP adhesin resulted in reduced virulence of M. tuberculosis leading to alterations in metabolites involved in carbon, fatty acid and amino acid metabolism during macrophage infection, suggesting that MTP plays an important role in the modulation of host metabolic activity. These findings support the prominent role of the MTP adhesin as a virulence factor as well as a promising biomarker for possible diagnostic and therapeutic intervention.

Novel fatty acid-thiadiazole derivatives as potential antimycobacterial agents

The discovery of antibiotics around the middle twentieth century led to a decrease in the interest in antimycobacterial fatty acids. In order to re-establish the importance of naturally abundant fatty acid, a series of fatty acid-thiadiazole derivatives were designed and synthesized based on molecular hybridization approach. In vitro antimycobacterial potential was established by a screening of synthesized compounds against Mycobacterium tuberculosis H37Rv strain. Among them, compounds 5a, 5d, 5h, and 5j were the most active, with compound 5j exhibiting minimum inhibitory concentration of 2.34 μg/ml against M.tb H37Rv. Additionally, the compounds were docked to determine the probable binding interactions and understand the mechanism of action of most active molecules on enoyl-acyl carrier protein reductases (InhA), which is involved in the mycobacterium fatty acid biosynthetic pathway.

Therapeutic Role of Deep Eutectic Solvents Based on Menthol and Saturated Fatty Acids on Wound Healing

The breakthroughs achieved in green solvents promote the emergence of therapeutic deep eutectic solvents (THEDES), which possess intriguing possible applications in the biomedical field. Herein, the main aim was to unravel the biomedical potential of hydrophobic THEDES based in menthol and saturated fatty acids with different chain lengths (e.g., stearic acid (SA), myristic acid (MA), and lauric acid (LA)). Our comprehensive strategy resulted in the thermophysical characterization of different formulations, which allow one to identify the most suitable molar ratio, as well as the intermolecular interactions behind the successful formation of THEDES. The evaluation of their biological performance was also performed toward bacteria and HaCaT cells. Among the different formulations of THEDES, the one based on menthol and SA establishes stronger hydrogen bonding interactions, being also the most promising formulation because it did not elicit any relevant cytotoxicity, and potentiated wound healing, while presenting antibacterial properties against Staphylococcus epidermis and Staphylococcus aureus strains, some of which were methicillin resistant. This work provides clues on the future use of THEDES based on menthol:SA in wound dressings.

In vitro inhibition potential of mono-n-octyl phthalate on Mycobacterium tuberculosis H37Ra: Possibility of binding to mycobacterial PknB-An in silico approach

Fatty acids of specific chain lengths have been shown to inhibit the growth of Mycobacterium tuberculosis. In the present study, specific synthetic aromatic derivatives of n-octyl esters were investigated for their property to inhibit the growth of M. tuberculosis H37Ra. Agar well diffusion assay indicated that the crude synthetic derivatives obtained by the esterification of phthalic acid (PA) and n-octanol exhibited antimycobacterial activity. Further, the activity was authenticated with the Miroplate Alamar Blue Assay (MABA). Subsequently, the active component was purified by bioactivity guided chromatographic fractionation. The structure of the synthetic derivative was deduced by UV-Vis, FT-IR, LC-MS, GC-mass spectrometry, and NMR spectroscopy. Molecular docking and molecular dynamic simulation (MDS) were performed with Autodock 4.0 and GROMACS 5.1.2 softwares, respectively. It was found that mono-n-octyl phthalate (MOP) exhibited antimycobacterial activity with a MIC of 20 μg/mL, and not by any other related compounds, including di-n-octyl phthalate, PA, phthalic anhydride, and n-octanol. Binding of MOP with protein kinase B can participate in the binding cavity region, which was previously reported. Subsequently, we authenticate the stability with MDS. This is first report on the inhibition of M. tuberculosis growth by MOP.