A computational biology approach for the identification of potential SARS-CoV-2 main protease inhibitors from natural essential oil compounds.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has fomented a climate of fear worldwide due to its rapidly spreading nature, and high mortality rate. The World Health Organization (WHO) declared it as a global pandemic on 11th March, 2020. Many endeavors have been made to find appropriate medications to restrain the SARS CoV-2 infection from spreading but there is no specific antiviral therapy to date. However, a computer-aided drug design approach can be an alternative to identify probable drug candidates within a short time. SARS-CoV-2 main protease is a proven drug target, and it plays a pivotal role in viral replication and transcription. Methods: In this study, we identified a total of 114 essential oil compounds as a feasible anti-SARS-CoV-2 agent from several online reservoirs. These compounds were screened by incorporating ADMET profiling, molecular docking, and 50 ns of molecular dynamics simulation to identify potential drug candidates against the SARS-CoV-2 main protease. The crystallized SARS-CoV-2 main protease structure was collected from the RCSB PDB database (PDB ID 6LU7). Results: According to the results of the ADMET study, none of the compounds have any side effects that could reduce their druglikeness or pharmacokinetic properties. Out of 114 compounds, we selected bisabololoxide B, eremanthin, and leptospermone as our top drug candidates based on their higher binding affinity scores, and strong interaction with the Cys 145-His 41 catalytic dyad. Finally, the molecular dynamics simulation was implemented to evaluate the structural stability of the ligand-receptor complex. MD simulations disclosed that all the hits showed conformational stability compared to the positive control α-ketoamide. Conclusions: Our study showed that the top three hits might work as potential anti-SARS-CoV-2 agents, which can pave the way for discovering new drugs, but for experimental validation, they will require more in vivo trials.

Astrodaucus persicus (Boiss.) Drude: A Mini-Review on Phytochemistry and Pharmacological Effects

Astrodaucus persicus (Boiss) Drude is an annual flowering plant of the Apiaceae family. A. persicus is mainly native to Asia and grows mostly in Iran, Turkey, Syria, and Iraq. In Iran, it grows mainly in Mazandaran, Golestan, Semnan, Tehran, Qazvin, and Kurdistan provinces. In Iran and Turkey, the plant's aerial parts and young roots are traditionally used as food additives. Various studies have been performed on essential oils and plant extracts. Essential oil compounds and some plant extract compounds have been identified. Different pharmacological effects of plant extracts and essential oils have also been reported. Monoterpenes are the main constituents in the essential oils of various parts of A. persicus. Plant extract (especially plant roots extract) effectively treats breast and colorectal cancers, which seems to be due to the presence of benzodioxole compounds or the antioxidant effects in the roots. The ripe fruits of the plant have potent larvicidal effects. Also, the fruits and roots of the plant significantly inhibit Plasmodium berghei, which can be effective in treating malaria.

Antiviral and Virucidal Properties of Essential Oils and Isolated Compounds – A Scientific Approach

Essential oils and isolated essential oil compounds are known to exert various pharmacological effects, such as antibacterial, antifungal, antiviral, anti-inflammatory, anti-immunomodulatory, antioxidant, and wound healing effects. Based on selected articles, this review deals with the potential antiviral and virucidal activities of essential oils and essential oil compounds together with their mechanism of action as well as in silico studies involving viral and host cell-specific target molecules that are indispensable for virus cell adsorption, penetration, and replication. The reported in vitro and in vivo studies highlight the baseline data about the latest findings of essential oils and essential oil compounds antiviral and virucidal effects on enveloped and non-enveloped viruses, taking into account available biochemical and molecular biological tests. The results of many in vitro studies revealed that several essential oils and essential oil compounds from different medicinal and aromatic plants are potent antiviral and virucidal agents that inhibit viral progeny by blocking different steps of the viral infection/replication cycle of DNA and RNA viruses in various host cell lines. Studies in mice infected with viruses causing respiratory diseases showed that different essential oils and essential oil compounds were able to prolong the life of infected animals, reduce virus titers in brain and lung tissues, and significantly inhibit the synthesis of proinflammatory cytokines and chemokines. In addition, some in vitro studies on hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds exhibited a promising way to improve the chemical stability and enhance the water solubility, bioavailabilty, and antiviral efficacy of essential oils and essential oil compounds.

Seasonal variation of fatty and essential oil in terebinth (Pistacia terebinthus L.) fruit

A member of Anacardiaceae family, terebinth (Pistacia terebinthus L.) is a perennial tree that is evergreen. Terebinth is spread on a very wide area in Turkey, from the Mediterranean costs to South-Eastern Anatolia. In the present study, to determine seasonal variation of fatty oil and essential oil in terebinth fruits, harvests were made when the fruit colour was Green (GF), Red (RF), Red-Black (RBF) and Black (BF). Upon ripening, fatty oil rate in the fruit raised from 13.40% to 37.08%, while essential oil rate reduced from 0.116% to 0.082%. In all growth periods, oleic, linoleic and palmitic acids made-up the main composition of the oil, and through growth there was increase in the amounts of oleic and palmitic oil acids while a decrease was reported in linoleic acid rate. In terms of essential oil compounds, α- pinene, limonene, p-cymen-8-ol and p-anisaldehyde composed the main compounds, the highest α- pinene rate was observed during BF period as 37.23%, the highest limonene rate was observed during RBF period as 22.01%, while the highest p-cymen-8-ol and panisaldehyde rates have been observed during the GF harvest period by 11.29% and 7.25%, respectively. In conclusion is that the fruit should be harvested during the black fruit colour, when the fruit is fully ripened, in order to get a good quality fruit and aroma and people picking the fruit from nature should be trained about this.

Prospects of Ocimum Gratissimum Linn. (Lamiaceae) to Control Exorista SorbillansWiedemann (Diptera: Tachinidae) Menace of Silkworm in Seriecosystem

Tachinid parasitoids are in focus mostly as biocontrol agents to be released against lepidopteran pest. But surprisingly certain tachinid parasitoids attack economically beneficial insects like silkworm and demands control measures against them. The uzi fly Exoristasorbillans (Diptera: Tachinidae) infests all commercially important silkworm species including Antheraeaassamensis where it causes upto 80 percent crop loss. The control of such parasitoids is a difficult task as the larval stage is endoparasitic and chemical insecticides do not reach the targeted parasitoid without exposing the silkworm host.In the present study,we evaluated adulticidal activity of different solvent extracts and essential oil of Ocimumgratissimum. We found higher efficacy of essential oil in comparison to other solvent extracts. The effective fraction of oil was found to contain thymol or its isomer carvacrol as the major compound in GC-MS studies. Finally, O. gratissimum oil-based combination (MI) and carvacrol based combination of essential oil compounds (MII) were prepared, tested and found to be effective against the fly. In silico positive interaction of essential oil compounds with acetylcholinesterase enzyme model of the fly revealed that the said enzyme is one of the target proteins for these oil compounds to interrupt its function and subsequent lethal action.

Acaricidal activity of essential oils of Cinnamomum zeylanicum and Eremanthus erythropappus, major compounds and cinnamyl acetate in Rhipicephalus microplus

This study aimed to chemically characterize the essential oils (EOs) of Cinnamomum zeylanicum (cinnamon) and Eremanthus erythropappus (candeia) and evaluate their acaricidal activity, together with that of their major compounds and cinnamyl acetate derivative, against Rhipicephalus microplus. Essential oil compounds were identified through gas chromatography. The larval packet test (LPT) at concentrations ranging from 0.31 to 10.0 mg/mL and the adult immersion test (AIT) at concentrations between 2.5 and 60.0 mg/mL were performed. (E)-cinnamaldehyde and α-bisabolol were the major compounds in cinnamon (86.93%) and candeia (78.41%) EOs, respectively. In the LPT, the EOs of cinnamon and candeia and the compounds (E)-cinnamaldehyde, α-bisabolol and cinnamyl acetate resulted in 100% mortality at concentrations of 2.5, 2.5, 5.0, 10.0 and 10.0 mg/mL respectively. In the AIT, percentage control values > 95% were observed for cinnamon and candeia EOs, (E)-cinnamaldehyde and α-bisabolol at the concentrations of 5.0, 60.0, 20.0, and 20.0 mg/mL, respectively, whereas cinnamyl acetate showed low activity. We conclude that EOs and their compounds showed high acaricidal activity, whereas the acetylated derivative of (E)-cinnamaldehyde presented less acaricidal activity on R. microplus engorged females.