Investigation on structural, spectroscopic, DFT, biological activity and molecular docking simulation of essential oil Gamma-Terpinene

(-)-Epicatechin metabolites as a GPER ligands: a theoretical perspective

Diet habits and nutrition quality significantly impact health and disease. Here is delve into the intricate relationship between diet habits, nutrition quality, and their direct impact on health and homeostasis. Focusing on (-)-Epicatechin, a natural flavanol found in various foods like green tea and cocoa, known for its positive effects on cardiovascular health and diabetes prevention. The investigation encompasses the absorption, metabolism, and distribution of (-)-Epicatechin in the human body, revealing a diverse array of metabolites in the circulatory system. Notably, (-)-Epicatechin demonstrates an ability to activate nitric oxide synthase (eNOS) through the G protein-coupled estrogen receptor (GPER). While the precise role of GPER and its interaction with classical estrogen receptors (ERs) remains under scrutiny, the study employs computational methods, including density functional theory, molecular docking, and molecular dynamics simulations, to assess the physicochemical properties and binding affinities of key (-)-Epicatechin metabolites with GPER. DFT analysis revealed distinct physicochemical properties among metabolites, influencing their reactivity and stability. Rigid and flexible molecular docking demonstrated varying binding affinities, with some metabolites surpassing (-)-Epicatechin. Molecular dynamics simulations highlighted potential binding pose variations, while MMGBSA analysis provided insights into the energetics of GPER-metabolite interactions. The outcomes elucidate distinct interactions, providing insights into potential molecular mechanisms underlying the effects of (-)-Epicatechin across varied biological contexts.

Synergistic interaction between Chlorella vulgaris extract and Origanum elongatum essential oil against methicillin-resistant Staphylococcus aureus

The massive emergence of antimicrobial resistance in recent decades has rendered the use of a single-agent strategy ineffective. Consequently, the combination of different therapeutic agents has emerged as a promising new approach. The aim of the present study was to investigate the combined effect of Chlorella vulgaris methanol extract (CVME) and Origanum elongatum essential oil (OEEO) on methicillin-resistant Staphylococcus aureus (MRSA). Thus, the antibacterial activity of OEEO and CVME on Escherichia coli, Staphylococcus aureus, and MRSA was evaluated using the agar well diffusion and broth microdilution methods. The killing activity of CVME and OEEO, individually and in combination, on MRSA ATCC 43300 was tested using the time-kill assay. The synergistic effect was examined by determining the fractional inhibitory concentration index (FICI) using the checkerboard test. The results showed very significant antibacterial activity against all the bacteria tested, for both OEEO and CVME, with minimum inhibitory concentrations (MICs) ranging from 0.125 to 0.25% (v/v) for OEEO and from 3.12 to 6.25 mg mL-1 for CVME. Minimum bactericidal concentration (MBC) values for OEEO and CVME were in the range 0.125-0.5% (v/v) and 6.25-12.5 mg mL-1, respectively. The inhibition zones associated with OEEO were distinctly greater than those associated with CVME for all the bacteria examined. When used individually, the time-kill curves of OEEO and CVME revealed a dose-dependent effect on MRSA proliferation. Compared with controls, both agents were able to prolong the latent phase of growth curves and decelerate bacterial growth. The killing effect of OEEO on MRSA was considerably higher than that observed with CVME. OEEO prevented MRSA proliferation at only 1/2 of its MIC, while the CVME did so at 2 times its MIC. The combination of OEEO with CVME demonstrated a synergistic effect against MRSA, with a FIC index value of 0.49. The findings therefore suggest that the combination of C. vulgaris methanol extract and O. elongatum essential oil at very low doses may be promising anti-MRSA candidates. A search of the published literature revealed that, to our knowledge, no studies have yet been carried out on the antibacterial potential of combining essential oils and microalgae extracts in the fight against MRSA.

Insight into the inhibitory activity of mangiferin and Silybin against HER2 and EGFR using theoretical and experimental approaches

Despite the advances made in diagnosing and treating breast cancer, it continues to pose a significant threat to women's health. High-risk mutations can lead to high resistance to current treatments and poor prognosis. Therefore, new treatment strategies are needed. Mangiferin and silybin, two natural substances obtained from plants, have demonstrated encouraging results as anticancer drugs. This study investigated the activity of these compounds against two therapeutic targets, human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR). We assessed the binding affinity and stability of these compounds with the active sites of wild-type and mutated HER2 and EGFR by using computational screening techniques, namely molecular docking, density functional theory, and molecular dynamics (MD) simulations with the MMGBSA method. We used molecular docking, triplicate MD simulations summing 300 ns each, and density functional theory analysis to estimate the binding mechanism of mangiferin and silybin inside the wild-type and mutated EGFR and HER2 active regions. Moreover, an in vitro experiment showed that mangiferin and silybin inhibited the growth of two HER2-positive breast cancer cell lines, BT-474 and SK-BR-3, at micromolar concentrations. These findings suggest the potential for developing novel anticancer therapies that specifically target EGFR and HER2.

Exploring the therapeutic potential of Rhododendron anthopogon D.Don essential oil constituents against lung cancer: A network pharmacology-based analysis with molecular docking and experimental studies

Rhododendron anthopogon D.Don is an evergreen shrub used by Himalayan healers to treat many ailments most notably lung problems. However, the mechanism by which R. anthopogon essential oil fights lung cancer has not been well studied. Here, in the present study, we used network pharmacology in combination with chemical profiling, molecular docking, and in-vitro experimental studies to uncover the mechanism of R. anthopogon essential oil constituents against lung cancer. By employing network pharmacology-based analysis, a total of 266 potential target genes obtained for 12 active components of R. anthopogon interacted with 260 common targets and 17,731 disease targets associated with lung cancer were retrieved. Using protein-protein interaction network (PPI), search tool for the retrieval of interacting genes/proteins (STRING) and database for annotation, visualization, and integrated discovery (DAVID) databases, we predicted that the main signaling pathways involved in the association of lung cancer with R. anthopogon essential oil constituents are the cancer signaling pathway and vascular endothelial growth factor and its receptor (VEGFR) cancer signalling pathway. Using TIMER 2.0 analysis and University of Alabama Cancer Database (UALCAN) findings, the expression pattern of EGFR was investigated across all TCGA (The cancer genome atlas) datasets. The study revealed that EGFR expression was elevated in various cancers especially in lung adenocarcinoma. Molecular docking analysis revealed that linalool, α-bisabolol, and guaiol possessed strong binding affinity with TNF-α, MAPK3, and EGFR protein drug targets. Our results predicted that TNF-α, MAPK3, and EGFR may be potential molecular targets of R. anthopogon essential oil constituents for the treatment of lung cancer. Furthermore, our study verified that R. anthopogon essential oil constituents inhibit proliferation, and induces apoptosis in lung cancer cell lines. Therefore, the present study highlights anti-lung cancer activity of the constituents of R. anthopogon essential oil and its potential involvement in comprehending therapeutic mechanism that may be applied in the lung cancer therapy.

Exploring the role of pomalidomide in androgen-dependent prostate cancer: a computational analysis

Prostate cancer (PC) is among the most prevalent cancers in males. It is the leading cause of death in men, in around 48 out of 185 countries. Increased androgen receptor (AR) activity is the key factor contributing to the development or progression of newly diagnosed cases of prostate cancer. Over time, numerous compounds targeting AR have been identified, presenting encouraging avenues for suppressing its hyperactivity. In our investigation, we used the GEPIA tool to study the importance of AR in the context of prostate cancer. This tool integrates the data from TCGA and GTEx in the gene expression pattern analysis and their clinical relevance. This analysis evaluates overall survival, disease-free survival, and transcripts per million (TPM) analysis of AR in PC. We performed docking and simulation for FDA-approved anticancer drugs to assess their potential interactions with the AR. We also conducted a comprehensive analysis of drugs using a quantum calculation (DFT) which provides electronic properties, chemical reactivity, and stability using the HOMO-LUMO energy gap. This study suggests that repurposed synthetic anticancer drugs could be better options for treating prostate cancer by inhibiting AR. In this work, we have shown the potential of pomalidomide, a synthetic anticancer drug, as a potential candidate for androgen-dependent PC treatment.

Schinus molle Resin Essential Oil as Potent Bioinsecticide Against Tribolium castaneum: Chemical Profile, In Vitro Acetylcholinesterase Inhibition, DFT Calculation and Molecular Docking Analysis

Plants offer a bountiful source of natural pest control solutions through their essential oils. This research introduces and analyzes an eco-friendly natural essential oil for red flour beetle control. Therefore, the current study was included to show the chemical profile and the insecticidal efficacy of resin essential oil (REO) and its fractions (F1-3), resulting from chromatographic separation, from the plant Schinus molle against Tribolium castaneum adults. The trunk bark resin essential oil and its fractions' composition were analyzed by GC-MS. Overall, 33 constituents with 98.3% of the total EO composition were identified. REO and F1-3 displayed impressive repellent properties at a concentration of 0.12 µL/cm2. After 120 min of exposure, repellency ranged from 73.3% to a remarkable 96.7%. They also exhibited noteworthy fumigant properties, with median lethal doses of LD50 = 120.6-160.8 μL/L. The fractions F1 and F3 showed the most notable topical toxicity at a concentration of 10%, with LD50 values of 8.6% and 5.6%, respectively. Fractions F3 and F2 demonstrated the most effective inhibition of acetylcholinesterase (AChE) activity, providing insight into their insecticidal mechanisms. The in silico molecular docking and DFT studies corroborate the results of in vitro tests performed to identify new insecticide products derived from natural sources.

Network analysis and molecular modeling studies of pinocembrin a bioactive phytochemical of Dodonaea viscosa against Parkinson's disease

Parkinson's disease, a neurodegenerative disorder, is quickly progressing and accounts for 15% of dementia cases. Parkinson's disease is the second most frequent form of neuronal degeneration after Alzheimer's, with an average age of 55 years for individuals exhibiting neuropsychiatric and physiological symptoms. Due to the effectiveness, low toxicity, and low side effects, bioactive compounds from plants have received increased attention recently as therapeutic drugs. In the current study, effective anti-neurodegenerative phytochemicals from Dodonaea viscosa were screened using in silico methods and have been proposed to be further investigated for the treatment of Parkinson's disease. The structures of twenty bioactive chemicals were screened and graph theoretical network analysis revealed alpha-synuclein as a potent therapeutic target. Based on docking scores, an effective bioactive molecule was selected, and its energy values, electrostatic potential surface and drug-like qualities were examined using molecular orbitals, pharmacokinetics and toxicity studies. Pinocembrin was found as a superior binder based on molecular docking as it demonstrated stronger binding with - 10.2 kcal/mol. An investigation using Ramachandran plot validated the protein-ligand complex secondary structure's stability. Pinocembrin, a bioactive phytochemical from Dodonaea viscosa, may be a viable lead molecule that may be developed as a candidate medicine for anti-neurodegenerative therapy against Parkinson's disease.

Evaluation of phytochemicals from Thymus serpyllum as potential drug candidates to manage oxidative stress in transition dairy cows

Dairy cows undergo immense stress and experience autoimmune reactions during the transition period, majorly due to the generation of ROS in the body. So, pharmacological approaches are needed to manage oxidative stress in the transition cows. Recently, the use of phytochemicals as feed additives in cows' nutrition has gained interest in managing various disease conditions. In the current study, we have evaluated the potential effects of phytochemicals derived from methanolic extract of Thymus serpyllum against oxidative stress and autoimmunity via inhibition of bovine nuclear factor kappa B (NF-κB). The free radical scavenging activity of Thymus serpyllum seed and leaf extracts was 71.8 and 75.6%, respectively at 100 µg/mL concentration. Similarly, both extracts displayed radicals reducing power and inhibition of lipid-peroxidation maximally at 100 µg/mL. A total of 52 bioactive compounds were identified when the plant extract was characterized by the GC-MS analysis, and five (Thymol, Luteolin 7-o-glucuronide, Rosmarinic acid, Apigenin 6,8-di-c-glucoside, Kaempferol) had binding free energy values of -11.6433, -10.002, -8.2615, -7.1714, -6.4870, respectively, in complexes with bovine NF-κB. Through computational analysis, the screened compounds showed good pharmacokinetic parameters, including non-toxicity, non-carcinogenic, high gastrointestinal absorption and thus can serve as potential drug candidates. MD simulation studies predicted the stability of complexes and the complex of Kaempferol was most stable based on RSMD value and MM/GBSA binding energy. The biochemical assays and computational studies indicated that Thymus serpyllum could be used as a promising feed additive in dairy cows to manage oxidative stress during the transition period.Communicated by Ramaswamy H. Sarma.

Crithmum maritimum L.-Study on the Histochemical Localization of Essential Oil

Crithmum maritimum L. is a perennial halophyte plant that is a medicinal herb known by people from different cultures since ancient times. However, the therapeutic potential of this halophyte has not been completely investigated, and the scientific data on it are limited. The purpose of the present study was to estimate the chemical composition of the essential oil (EO) obtained from the aerial parts of Crithmum maritimum L. growing wild in Bulgaria, as well as the histolocalization of secretory structures for the synthesis and accumulation of volatile oils. The results obtained on the EO composition of Bulgarian Crithmum maritimum L. provide an opportunity to reveal potential future applications in various fields, such as medicine, pharmacy, agriculture, food, and the cosmetic industry. Gas chromatography with mass spectrometry was performed to assess the chemical profile of the isolated EO. The phenylpropanoid dillapiole was identified as the major compound in the EO, accounting for 34.09% of the total EO. Monoterpene hydrocarbons represented 62.07% of the total oil composition. γ-Terpinene, D-limonene, and β-pinene were the most abundant monoterpene hydrocarbons in the composition of the EO. In addition, histochemical localization of EO in the stem and leaves of Crithmum maritimum L. was carried out. The secretory structures were located in the cortical region of the stem and in the mesophyll tissues of the leaves in the form of secretory ducts. The performed histochemical analysis confirmed the lipophilic nature of the secretion from the duct cells. This is the first report related to the histolocalization and chemical composition of the EO from Bulgarian Crithmum maritimum L. Furthermore, our data indicate some potential possibilities for the evaluation of the therapeutic activity of the EO obtained from this plant species and outline its future applications as a therapeutic agent. Also, the EO from the studied halophyte plant has prominent potential to be used as a biopesticide, which is an environmentally friendly option compared to standard pesticides.

Cytotoxic Effect Induced by Sicilian Oregano Essential Oil in Human Breast Cancer Cells

Origanum vulgare L. is an aromatic plant that exerts antibacterial, antioxidant, anti-inflammatory, and antitumor activities, mainly due to its essential oil (EO) content. In this study, we investigated the possible mechanism underlying the in vitro antitumor activity of EO extracted by hydrodistillation of dried flowers and leaves of Origanum vulgare L. grown in Sicily (Italy) in MDA-MB-231 and MCF-7 breast cancer cell lines. Gas chromatography-mass spectrometry analysis of Oregano essential oil (OEO) composition highlighted the presence of twenty-six major phytocompounds, such as p-cymene, γ-terpinene, and thymoquinone p-acetanisole. OEO possesses strong antioxidant capacity, as demonstrated by the DPPH test. Our studies provided evidence that OEO reduces the viability of both MCF-7 and MDA-MB-231 cells. The cytotoxic effect of OEO on breast cancer cells was partially counteracted by the addition of z-VAD-fmk, a general caspase inhibitor. Caspases and mitochondrial dysfunction appeared to be involved in the OEO-induced death mechanism. Western blotting analysis showed that OEO-induced activation of pro-caspases-9 and -3 and fragmentation of PARP decreased the levels of Bcl-2 and Bcl-xL while increasing those of Bax and VDAC. In addition, fluorescence microscopy and cytofluorimetric analysis showed that OEO induces a loss of mitochondrial membrane potential in both cell lines. Furthermore, we tested the effects of p-cymene, γ-terpinene, thymoquinone, and p-acetanisole, which are the main components of OEO. Our findings highlighted that the effect of OEO on MDA-MB-231 and MCF-7 cells appears to be mainly due to the combination of different constituents of OEO, providing evidence of the potential use of OEO for breast cancer treatment.

Lupenone, a wonder chemical obtained from Euphorbia segetalis to boost affinity for the transcriptional factor escalating drought-tolerance in Solanum Lycopersicum: A cutting-edge computational biology approach

Drought is the single greatest abiotic factor influencing crop yield worldwide. Plants remain in one area for extended periods, making them vulnerable to natural and man-made influences. Understanding plant drought responses will help us develop strategies for breeding drought-resistant crops. Large proteome analysis revealed that leaf and root tissue proteins respond to drought differently depending on the plant's genotype. Commonly known as tomatoes, Solanum Lycopersicum is a globally important vegetable crop. However, drought stress is one of the most significant obstacles to tomato production, making the development of cultivars adapted to dry conditions an essential goal of agricultural biotechnology. Breeders have put quite a lot of time and effort into the tomato to increase its productivity, adaptability, and resistance to biotic and abiotic challenges. However, conventional tomato breeding has only improved drought resistance due to the complexity of drought traits. The resilience of tomatoes under drought stress has been the subject of extensive study. Using contemporary sequencing approaches like genomics, transcriptomics, proteomics, and metabolomics has dramatically aided in discovering drought-responsive genes. One of the most prominent families of plant transcription factors, WRKY genes, plays a crucial role in plant growth and development in response to natural and abiotic stimuli. To develop plants that can withstand both biotic and abiotic stress, understanding the relationships between WRKY-proteins (transcription factors) and other proteins and ligands in plant cells is essential. This is despite the fact that tomatoes have a long history of domestication. This research aims to utilize Lupenone, a hormone produced in plant roots in response to stress, to increase drought resistance in plants. Lupenone exhibits a strong affinity for the WRKY protein at -9.64 kcal/mol. Molecular docking and modeling studies show that these polyphenols have a significant role in making Solanum Lycopersicum drought-resistant and improving the quality of its fruit. As a result of climate change, droughts are occurring more frequently and persisting for more extended periods, making it necessary to breed crops resistant to drought. While considerable variability for tolerance exists in wild cousins, little is known about the processes and essential genes influencing drought tolerance in cultivated tomato species.

Growth inhibitory, immunosuppressive, cytotoxic, and genotoxic effects of γ-terpinene on Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

γ-Terpinene, a monoterpene widely present in essential oils of many medicinal and aromatic plants with numerous biological properties, was evaluated for its insecticidal activity against melon fruit fly, Zeugodacus cucurbitae (Coquillett). Different concentrations (5, 25, 125, 625, and 3125 ppm) of γ-terpinene along with control were fed to larvae of melon fly. The number of pupae formed and adults emerged declined significantly after treatment. Morphologically deformed adults and pupae were also observed. The developmental duration too prolonged in treated larvae. Food assimilated, mean relative growth rate, larval weight gain, and pupal weight also declined. In the larvae treated with LC30 and LC50 concentrations, there was a decline in the titers of phenoloxidase and total hemocyte count, and variations were observed in the differential hemocyte count, suggesting an immunosuppressive effect of γ-terpinene on melon fly. Both concentrations also led to an increase in the apoptotic and necrotic cells as well as decrease in the viable hemocytes in the circulating hemolymph of treated larvae. Comet parameters (tail length, % tail DNA, tail moment, and olive tail moment) of γ-terpinene fed larvae increased significantly. Given the observed effects of γ-terpinene on normal developmental and nutritional physiology, its immunosuppressive properties, and its potential for genome damage, it can be considered for incorporation into integrated pest management strategies for controlling Z. cucurbitae.

Active Compounds with Medicinal Potential Found in Maxillariinae Benth. (Orchidaceae Juss.) Representatives-A Review

Orchids are widely used in traditional medicine for the treatment of a whole range of different health conditions, and representatives of the Neotropical subtribe Maxillariinae are not an exception. They are utilized, for instance, for their spasmolytic and anti-inflammatory activities. In this work, we analyze the literature concerning the chemical composition of the plant extracts and secretions of this subtribe's representatives published between 1991 and 2022. Maxillariinae is one of the biggest taxa within the orchid family; however, to date, only 19 species have been investigated in this regard and, as we report, they produce 62 semiochemicals of medical potential. The presented review is the first summary of biologically active compounds found in Maxillariinae.

Docking simulation and ADMET prediction based investigation on the phytochemical constituents of Noni (Morinda citrifolia) fruit as a potential anticancer drug

Morinda citrifolia is a traditional plant used in Asian and African countries for its wide nutraceutical and therapeutic effects for the treatment of various ailments. The fruit of M. citrifolia has various biological properties such as anti-bacterial, anti-oxidant, anti-cancer. Using the molecular docking based investigation; we explored around twenty three bioactive phytochemicals in M. citrifolia fruit against human cancer. MAPK6 (mitogen-activated protein kinase 6) was selected as target protein and these twenty three phytochemicals along with a known MAPK6 inhibitor were docked against the target protein. The docking scores of the bioactive phytochemicals against MAPK6 protein range between - 4.5 kcal/mol to - 7.9 kcal/mol and the docking score of the standard drug (CID: 447077) was - 7.3 kcal/mol. Based on the binding affinity five phytochemicals asperuloside (- 6.7 kcal/mol), asperulosidic acid (- 7.2 kcal/mol), deacetylasperulosidic acid (- 7.0 kcal/mol), eugenol (- 6.8 kcal/mol) and rutin (- 7.9 kcal/mol) were chosen for further evaluation. These five compounds were further investigated through RC plot analysis, density function theory and ADMET properties. Stable linkage of protein-ligand interaction was observed through RC plot, density function theory showed the structural stability and reactivity of bioactive compounds through the energy gap between HOMO and LUMO and the ADMET (adsorption, distribution, metabolism, excretion and toxicity) studies showed the safety profile of the bioactive compounds. These in silico results support the utilization of M. citrifolia fruit in the traditional medication and the initiation for the development of new drug against human cancer through in vivo and in vitro evaluation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-022-00130-4.