Constituents Of Oil Research Articles

Investigation on chemical composition and insecticidal activity against Anopheles gambiae of essential oil obtained by co-distillation of Cymbopogon citratus and Hyptis suaveolens from Western Burkina Faso.

Essential oils of Cymbopogon citratus and Hyptis suaveolens are known for their insecticidal properties, but remain ineffective against mosquitoes resistant to synthetic insecticides. In order to improve insecticidal properties of these plants, this study aimed to investigate the chemical composition and insecticidal activity against Anopheles gambiae mosquitoes of essential oil obtained by co-distillation of dry leaves of C. citratus and H. suaveolens. Essential oils were extracted by hydrodistillation from dry leaves of C. citratus and H. suaveolens, separately, then from the mixture of the dry leaves of the two plants in mass ratio 50/50. Each pure essential oil and the mixture obtained either by co-distillation or by combining pure essential oils in volume ratio 50/50 were then analysed by GC/MS. All essential oils and Deltamethrin 0.05% (positive control) were tested on two species of mosquitoes of the genus Anopheles gambiae according to the World Health Organization standard methods. Essential oil obtained by co-distillation mainly contained piperitone (40.80%), 1,8-cineole (24.64%), p-menth-4(8)-ene (13.20%), limonene (6.09%) and α-pinene (4.73%). However, the mixture of pure essential oils of these two plants mostly contained geranial (20.74%), neral (16.42%), 1,8-cineole (19.79%), sabinene (6.03%) and β-pinene (3.87%). The essential oil of C. citratus mainly contained geranial (41.49%), neral (32.83%), β-myrcene (13.66%) and geraniol (3.49%) while the major constituents of essential oil of H. suaveolens were 1,8-cineole (39.58%), sabinene (12.06%), β-pinene (7.73%), α-terpinolene (6.72%) and (E)-caryophyllene (7.49%). At the dose of 1%, all essential oils, except that of H. suaveolens, induced about 100% of mortality on the sensitive species of An. gambiae. However, on the resistant species at the same dose, the essential oil obtained by co-distillation induced the highest mortality (53.44%). The essential oils of C. citratus, H. suaveolens and the mixture of the two pure essential oils caused respectively 2.47, 15.28 and 18.33% of mortality. The synthetic insecticide caused 100 and 14.84% of mortality respectively on the sensitive and resistant species of An. gambiae. Essential oil obtained by co-distillation showed good insecticidal efficacy against a resistant species of An. gambiae and might constitute a new solution to fight against mosquitoes resistant to synthetic insecticides.

Pioneering technologies over time to rehabilitate crude oil-contaminated ecosystems: a review.

The unremitting pollution of our environment induced by crude oil spillage and drilling site accidents has jeopardized every living species in the biological ecosystem. Removing heavy crude oil constituents with the help of traditional and mainstream oil sorbents because of their ingrained raised viscosities is a strenuous venture. Lighter distillates of crude oil, like condensate, do not aggregate with tremulous shine on the aquatic surface nor settle at the bottom sediment of the water bodies like the heavier components do with time. Fabricating optimally designed materials capable of capturing, degrading, or removing toxic chemical constituents of this fossil fuel is critical in this modern era. This review comprehensively discusses the evolution of scientific technologies developed to separate these constituents from land and aquatic bodies. We provide an overview of the latest physical and chemical strategies and prevalent biological remediation schemes for removing these pollutants from soils and water for environmental protection. The article highlights the urgency of preventing oil spill accidents, whose anticipation is challenging to harness. A spectrum of advanced functional methodologies is also discussed to adequately treat discharged hydrocarbon contaminants, establish public safety, and pave the path to enhancing the circular economy metrics linked with oil industries.

Comparative analysis of antioxidant and antibacterial activities of leaf and zest essential oils from "Citrus limon”

This work is part of the study of the antibacterial and antioxidant activity of Algerian aromatic and medicinal plants. We conducted a study on a plant widely used by the local population, Citrus limon, an aromatic plant from the Ghardaïa region. Essential oils were extracted from Citrus limon (zest and leaves) using hydrodistillation, yielding 1.12% for the zest and 0.71% for the leaves. The essential oils were analyzed using GC/MS, identifying 35 constituents in the leaf oils, with 19.41% L-Limonene and 15.02% Nerol acetate, and 25 constituents in the zest oils, with 45.62% L-Limonene, 9.40 Beta-Pinene and 8.3% 3-Carene as major compounds. The antioxidant activity of the essential oils was evaluated using three methods. The first method was the DPPH free radical scavenging test, where the zest showed an IC50 of 135.678 mg/mL, higher than that of the leaf essential oil (IC50 of 34.238 mg/mL). The second method, potassium ferricyanide reduction (FRAP), showed that the essential oils of the leaves had an antioxidant activity of EC50 = 63.3773 mg/mL, and the zest showed EC50 = 200.875 mg/mL. The third method, ammonium phosphomolybdate, based on molybdate reduction (TAC), gave antioxidant activities for the leaves and zest, respectively, of EC50 = 1.5722 mg/mL and EC50 = 1.9604 mg/mL. The antibacterial activity was tested against six reference bacterial strains, with Klebsiella pneumoniae being the most sensitive to both essential oils, showing inhibition zones of 48 mm for the leaf oil and 40 mm for the zest oil. According to the obtained results, the essential oils appear to exhibit excellent antioxidant and antibacterial activity.

Essential Oils of The Leaves of Syzygium hemilamprum (F. Muell.) Craven & Biffin.: Chemical Analysis, Antimicrobial, Mosquito Larvicidal, Molecular Docking, and ADMET Studies.

The chemical composition of the essential oil and n-hexane extract from Syzygium hemilamprum leaves was first performed. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the essential oil was predominantly composed of monoterpene hydrocarbons (71.5 %) and oxygenated derivatives (20.2 %), with β-pinene (31.5 %), limonene (19.4 %), α-pinene (12.3 %), and α-terpineol (7.4 %) being the principal constituents. The n-hexane extract contained monoterpene hydrocarbons (42.2 %) and non-terpenic compounds (34.0 %), with β-pinene (32.8 %) and n-hexadecane (10.2 %) as the major components. Antimicrobial and mosquito larvicidal assays demonstrated that both samples exhibited antimicrobial activity against Staphylococcus aureus (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Saccharomyces cerevisiae (yeast), with a minimum inhibitory concentration (MIC) of 128 μg/mL for all tested organisms. Both samples also showed significant mosquito larvicidal activity against Aedes aegypti and Culex quinquefasciatus, with LC50 and LC90 values below 20 μg/mL at 24 and 48 hours post-treatment. Molecular docking studies suggested that limonene and α-terpineol could serve as potent inhibitors of mosquito odorant binding proteins. Additionally, an in silico analysis was performed to evaluate the physicochemical and ADMET (absorption, distribution, metabolism, and toxicity) properties of the major constituents of the essential oil.

Whole UVCB Tests Can Yield Biotic and Abiotic Degradation Kinetics of Known and Unknown Constituents for an Enhanced UVCB Degradation Profile

The green transition and move towards safe and sustainable-by-design chemicals entail the need for new methods to study the biodegradability of UVCBs (substances of Unknown or Variable composition, Complex reaction products and Biological materials). Standard simulation biodegradation tests have been developed for single substances and are generally not applicable for UVCBs. The aims of this study were (1) to combine a whole UVCB biodegradation test with a sensitive constituent specific analytical technique, (2) to measure biotic and abiotic degradation of known and unknown UVCB constituents and (3) to determine the impact of a WWTP discharge on the constituent specific biodegradation in stream water. Lavender oil and black pepper oil are of significance in the perfume and cosmetics industries and served as model UVCBs. Stream water sampled upstream and downstream of a wastewater treatment plant (WWTP) discharge point was used as inoculum (i.e., naturally and wastewater adapted bacterial consortia). Tests were conducted in gastight headspace vials and automated Arrow Solid Phase Microextraction GC-MS-scan was applied on unopened vials. Peak area ratios between biotic test systems and abiotic controls were used to determine primary biodegradation kinetics, and freshly spiked analytical references to separate biotic from abiotic degradation. Biodegradation half-times were below 20 days for all known (8-12) and unknown constituents (>78) in the essential oils. Dual column GC-MS analysis produced a level 2 identification of 16 unknown lavender constituents. Biodegradation kinetics were similar in inoculum taken before and after the WWTP outlet, confirming that native stream microorganisms were competent degraders.

Chemical Composition, In vitro and In silico Evaluation of Essential Oil Extracted from Mentha Piperita L. for Lung Cancer

Background: Mentha piperita, a naturally occurring herb, is utilized in medicinal formulations. It possesses abundant bioactive elements, including flavonoids and phenolic acid compounds,that exhibit various properties such as antioxidants, anti-inflammatory and anti-cancer. Objective: In the present study, chemical constituents of essential oil extracted from Mentha piperita were analyzed and identified through GC-MS. In vitro antiproliferative activity was performed on A549 lung cancer cell line lines. In silico study was conducted by Schrodinger’s Maestro’s software to identify chemical constituents in the plant as potential EGFR (Epidermal Growth Factor Receptors) inhibitors Methods: Hydro-distilled essential oil was analyzed by GC-MS to identify chemical components based on the retention index and mass fragmentation pattern, which was then tested for its antiproliferative activity by MTT assay against human lung cancer cell lines. All the identified constituents were investigated in silico for their affinity towards EGFR (Epidermal Growth Factor Receptors). Results: A total of thirty constituents were identified where D-carvone (56.69%), L-limonene (12.36%), squalene (3.36%), cis-carveol (2.93%), and α-amorphene (2.36%) were observed as major constituents of the essential oil. The essential mentha oil also exhibited antiproliferative activity against lung cancer cell lines with an IC50 value of 86.05 µg/ml. Furthermore, from the in silico study, five constituents were identified to have a better affinity for EGFR (Epidermal Growth Factor Receptors) than that of the standard drug Osimertinib. Conclusion: In the present study, the aerial part of the plant Mentha piperita was hydrodistilled.Thirty phytoconstituents were identified through GC-MS data. An in-silico study was performed using Schrodinger software, and a further in vitro study was performed in which essential oil showedgood antiproliferative activity against the A549 cancer cell line.

Diversity and morpho-chemo correlations of Cinnamon (Cinnamomum verum J. Presl) bark oil from Sri Lanka

The wide natural variation of Cinnamomum verum morphology in Sri Lanka suggests the chemo-diversity, which must be revealed for efficient utilization in a vast scope of industries. This study was carried out to determine the variation of essential oil constituents of cinnamon bark from major growing areas of Sri Lanka, morphological markers for oil constituents and genetic relationships for the correlations among major chemical constituents. E-Cinnamaldehyde (CM), (E)-Cinnamyl acetate (CA), Eugenol (EU), Benzyl benzoate (BB), linalool (LN) and β-caryophyllene (CR) were the highest abundant six out of 188 constituents reported through GC-MS analysis of bark essential oil. The mean values and 95% confidence intervals of CM, CA, EU, BB, LN and CR were 65.10±2.4 (60.15, 70.05), 15.93 ±2.14 (11.51, 20.34), 4.07±0.42 (3.19, 4.95), 3.21±0.52 (2.15, 4.28), 1.44 ± 0.16 (1.09,1.79) and 1.31±0.10 (1.11,1.53) respectively. CM was the highest abundant in 29/30 accessions, while CA was the highest abundant only in 1/30. CM varied with growing district. CM was negatively correlated with CA, (r=0.81) at the 0.01% level of significance irrespective of the growing district. The correlation between EU and BB was significant (r=0.49) at 0.01% level of significance. Chemical constituents were linked with the morphological characters: The leaf width (LW) was correlated with EU, (r=0.37) at 0.05% level of significance and the bark thickness (BT) was in a correlation with CR, (r=0.54) at 0.01% level of significance. Gene network model analysis identifying two pathways for CM, CA and BB biosynthesis, and two pathways for EU biosynthesis explained the correlations between major constituents.

Traditional Chinese Herbal Medicine: Therapeutic Potential in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow obstruction and manifested by symptoms such as chronic cough, sputum, and dyspnea. Traditional Chinese medicine (TCM) has long been used to treat COPD. This article summarizes potential Chinese herbal medicines (CHM) for COPD treatment through a literature review and collation. The findings highlight 14 kinds of effective CHM for COPD, including Scutellaria radix, Salvia miltiorrhiza radix et rhizoma, Hippophae fructus, Ginseng radix et rhizoma, and Astragali radix. Flavonoids, terpenoids, alkaloids, and volatile oil constituents are the main bioactive components for the treatment of COPD. They mainly inhibit the tumor necrosis factor alpha/nuclear factor kappa B (TNF-α/NF-κB) signaling pathway by reducing the production and release of inflammatory factors such as interleukin 1 beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), TNF-α, and NF-κB, thereby reducing inflammation in lungs of rats with COPD and protect the lung tissues. Some active ingredients can inhibit toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase-protein kinase B (PI3K-Akt), Janus kinase-signal transducer and activator of transcription (JAK-STAT), and transforming growth factor beta (TGF-β) signaling pathways to express anti-inflammatory activity. This work establishes a foundation for using CHM in COPD treatment and offers new insights and approaches for developing novel anti-COPD drugs.

Impact of altitudinal gradients on chemical profiling and pesticidal activities of Hedychium spicatum Sm

Hedychium spicatum Sm. is an endangered herb which grows preferably in humid tropics and subtropics known for its distinct camphoraceous flavour and medicinal properties. The essential oils of H. spicatum rhizomes from six different natural habitats at different altitudes in Uttarakhand, India were analyzed. Twenty compounds were identified, accounting for 87.4–98.5% of the essential oils, with 1,8-cineole (33.4–41.9%), α-terpinene (39.6%), camphor (31.4%), and linalool (29.9%), being the prevalent major constituents of all accessions. HS-ALM (H. spicatum rhizomes Almora essential oil), HS-DDN (H. spicatum rhizomes Dehradun essential oil), HS-PAU (H. spicatum rhizomes Pauri essential oil), HS-TEH (H. spicatum rhizomes Tehri essential oil), and HS-USN (H. spicatum rhizomes Udham Singh Nagar essential oil) were dominated by oxygenated monoterpenes with 43.1–74.0%, respectively. In contrast, in HS-PIT (H. spicatum rhizomes Pithoragarh essential oil), hydrogenated monoterpenes dominated 57.8% of the total oil constituents. All accessions were assessed for significant nematicidal potential against Meloidogyne incognita and insecticidal potential against Spodoptera litura. The proteins/enzymes used for validation using docking studies were acetylcholinesterase (PBD ID: IC2O) and carboxylesterase (PDB ID: 1CI8). The study produced significant outcomes, showing the binding energy estimation of tested oil components to active sites supported the structure-activity relationship with bioinformatics tools.

Oil biomarkers: main types, value and applications fields

Recent advances in modern chemistry provide environmental scientists with the ability to identify and track spilled oil residues in various environments. The compounds commonly used to identify the source of spilled oil are called biomarkers, they are universal in crude oil and petroleum products and are generally more stable to atmospheric environmental influences than most other oil constituents. The distribution of biomarker compounds is unique to each oil. Fingerprint indices calculated from oil fingerprints provide a stable and useful tool for determining the correspondence or non-correspondence of various oil residues present in some environmental samples. This paper highlights the main biomarkers of oil, their role in the study of oil and its deposits, and also shows the results of the authors’ own research.

Chemical analysis and bioactivity evaluation of Citrus limon leaves volatile oil from Palestine: investigating phytochemical, anti-inflammatory, antimicrobial, and cytotoxic properties

IntroductionScientists consider repurposing discarded waste into valuable resources for the pharmaceutical, cosmetic, and food flavoring manufacturing industries a challenge to generate new revenue streams, lower production costs, and reduce waste. Therefore, the current study aimed to identify Citrus limon leaf volatile oil (VO) constituents from Palestine and assess its in vitro antimicrobial, anti-inflammatory, and cytotoxic properties. MethodsThe components of the VO were analyzed using Gas Chromatography/Mass Spectrometry (GC/MS). The antimicrobial activity of VO was assessed using a microdilution technique. The cyclooxygenases (COX-1 and COX-2) assay was utilized to assess the anti-inflammatory effect. An aqueous one solution cell proliferation (MTS) assay was employed to determine the cytotoxic effect of the VO. ResultsThirty-six molecules were identified in the oil, and geranial, neral, and limonene are the most abundant molecules, comprising 31.06%, 23.98%, and 14.32%, respectively. The antimicrobial results showed that the VO has notable inhibition against Proteus vulgaris, Methicillin-resistant Staphylococcus aureus, and Candida albicans. The COX IC50 calculations revealed that it has high potency against COX-2 IC50=9.32±0.88µg/ml. The most potent cytotoxic effect of C. limon VO was noticed against MCF-7, with an IC50 dose of 162.90±1.85 mg/ml. ConclusionThe GC-MS analyses revealed that geranial, neral, and limonene are the predominant compounds in the VO of C. limon leaves from Palestine. The biological test results demonstrated that the VO has potential inhibitory actions against some cancer cells, bacterial and fungal species, and COX-2 enzyme, suggesting it may be a viable choice for treating or preventing microbial infections, cancer, and inflammatory illnesses.

Chemical profiling and bioactivity analysis of shoots and roots essential oil of Indian Blumea mollis D. Don (Merr.)

Aromatic plants contain essential oils, potent extracts renowned for therapeutic benefits. Essential oils are commonly utilized due to their diverse range of phytochemicals that possess therapeutic properties. The present study analyses the chemical composition of the essential oil obtained from shoots and roots of Blumea mollis (Family: Asteraceae), using GC-FID and GC-MS techniques. A total of 49 and 46 compounds were identified from shoots and roots accounting for 95.6 % and 88.4 % respectively. β-caryophyllene is reported as major compound 36.2 ± 0.50 % in essential oil of the shoots and 33.8 ± 0.55 % in essential oil of the roots. Both essential oils of shoots and roots were dominated by sesquiterpene hydrocarbons (59.2–76.4%), followed by oxygenated sesquiterpene (14.9–20.3%). The in vitro antioxidant activity was determined using DPPH radical scavenging activity, H2O2 radical scavenging activity, and Iron(II) complexing activity. The highest antioxidant activity was observed in root essential oil of B. mollis. The oils also inhibited the activity of α-amylase with IC50 of 3.53 ± 0.04 μg/ml (shoot), 3.45 ± 0.04 μg/ml (root). Root oil also showed good activity for protein denaturation with IC50 of 3.02 ± 0.03 g/ml as compared to shoot essential oil. This is first time that essential oil constituent and biological activity of B. mollis roots and shoots have been characterized from India.

Artemisia pallens Wall. ex. DC: A comprehensive review

Davana (Artemisia pallens Wall. ex DC) is a well-known and precious essential oil-bearing plant under the family Compositae (Asteraceae). It is an erectly grown herbaceous plant exclusively cultivated as a short-term crop in south India during winter. It is distributed in the northern hemisphere in subtropical Africa, South Africa, West America, and South America; however, it is indigenous to southern India. The yearly productivity of davana oil typically falls between 8 to 10 tones. Davana oil is mainly used to flavor pastries, cakes, tobacco, and some beverages. It consists of diverse phyto-molecules and is an important and unique commodity in the fragrance, flavor, and liquor industries. It has excellent biological potential and contains volatile and nonvolatile constituents such as terpenoids, flavonoids, and alkaloids, which have high pharmacological values. Several investigations have focused on validating the importance of chemical constituents and the biological efficacy of essential oils and various extracts in multiple industries. The review focuses on the complete agronomic practices, botany, breeding, biotechnology, and chemistry of davana essential oil (DEO), viz, volatile and nonvolatile constituents, phytomedicinal and pharmacological properties, which may help researchers achieve their future goals for approaching its industrial or commercial viability as a natural product ingredient.

Deterrent Effects of Clary Sage Oil and Two Major Constituents against Drosophila suzukii (Diptera: Drosophilidae).

Drosophila suzukii (Diptera: Drosophilidae), spotted-wing drosophila, poses a significant threat to soft-skinned fruit crops in the Americas, Europe, Africa, and Oceania, as well as in Asia. The application of chemical insecticides is the primary control strategy for D. suzukii; however, resistance has developed with the indiscriminate use of chemical insecticides. Essential oils, considered potential alternatives to pesticidal strategies, exhibit potent toxic and sublethal behavioral effects against numerous pests, including D. suzukii. Clary sage oil repels a variety of agricultural and household pests; however, whether it has a repellent effect against D. suzukii remains unknown. Here, we found that clary sage oil exhibited dose-dependent repellency against D. suzukii adults in a T-maze assay, a two-choice assay and a two-choice attraction assay. Also, clary sage oil showed a significant repellent effect against D. suzukii larvae. Next, we explored the chemical constituents of clary sage oil by GC-MS and identified two major constituents, linalyl acetate (40.03%) and linalool (23.02%). Furthermore, the behavioral assays of linalyl acetate and linalool showed that both compounds conferred comparable repellency against D. suzukii adults and larvae. Finally, we found clary sage oil, linalyl acetate, and linalool elicited EAG responses in D. suzukii, especially clary sage oil, suggesting the repellency was mediated by the olfactory system. These findings indicate that D. suzukii shows olfactory-based behavioral avoidance of clary sage oil, linalyl acetate, and linalool. Clary sage oil and its major constituents may be possible alternatives in the management of D. suzukii.

Extraction and chemical constituents of the essential oils from Rosmarinus officinalis L. and Corymbia citriodora

The essential oils of Rosmarinus officinalis L. and Corymbia citriodora (Hook.) K.D.Hill & L.A.S.Johnson leaves have chemical constituents with fungicide potential. The objective of this work was to determine the yield and the main chemical compounds of the essential oils of these species. Plants of the two species were georeferenced and collected in municipalities of Rio Grande do Sul, and identified in the Botany Laboratory of UNIJUÍ. The essential oils were extracted by hydrodistillation and the yield was based on fresh vegetable mass. The analyses of the chemical constituents were determined by CG-MS. A yield of 0.49% was obtained for R. officinalis and of 1.54% for C. citriodora. Similar to other studies, the major constituents of rosemary essential oil were camphor, 1,8-cineol, canfene and α-pineno, and the ones of eucalyptus essential oil were citronelal, isopulegol and citronelol. It is concluded that the chemical constituents are similar to those reported in the literature and the essential oil yield of the species is low and dependent on external conditions.

Parentucellia viscosa (growing in Türkiye): Essential Oil, Phenolic Composition, Antimicrobial and Lipase Inhibition

The essential oil (EO) and phenolic constituents of Parentucellia viscosa L. were analyzed by GC-FID-MS and HPLC, respectively. A total of 20 volatile compounds were identified accounting for 99.97% in hydrodistillation. Monoterpenes (50.57%, 5 compounds) were the primary chemical class in the essential oil of P. viscosa. Limonene (44.02%) and 1-octen-3-ol (25.23%) were the major components in the essential oil of P. viscosa. The phenolic constituent analysis for the methanol extract of P. viscosa gave benzoic acid (0.97 mg/g) as the major compound. The antimicrobial activities of the EO and crude solvent (n-hexane, acetonitrile, methanol, and water) extracts of P. viscosa were screened in vitro against ten microorganisms. n-Hexane and the acetonitrile extracts of P. viscosa resulted in the best activity against Mycobacterium smegmatis with IC50 values of 19.2 µg/mL and 53.8 µg/mL, respectively. The highest lipase enzyme inhibition activity was detected in the n-hexane extract with 44.22±1.1628 µg/mL IC50 value.

Turmeric Essential Oil Constituents as Potential Drug Candidates: A Comprehensive Overview of Their Individual Bioactivities.

The therapeutic properties of turmeric essential oil have been extensively documented in both preclinical and clinical studies. Research indicates that its primary active compounds are promising candidates for addressing a wide range of pathologies, exhibiting anticancer, anti-inflammation, antioxidant, cardiovascular, hypoglycemic, dermatological, hepatoprotective, neurological, antiparasitic, antiviral, insecticidal, antifungal, and antivenom activities. While numerous compounds possess similar potential applications, the isolated active constituents of turmeric essential oil stand out due to their unique pharmacological profiles and absence of toxicity. This literature review meticulously compiles and analyzes the bioactivities of these constituents, emphasizing their molecular mechanisms of action, reported pharmacological effects, and potential therapeutic applications. The aim of this review is to provide a comprehensive synthesis of currently available clinical and preclinical findings related to individual turmeric essential oil compounds, while also identifying critical knowledge gaps. By summarizing these findings, this work encourages further research into the isolated compounds from turmeric oil as viable drug candidates, ultimately contributing to the development of innovative therapeutic strategies.

Investigating the Antimicrobial Properties of Essential Oil Constituents and Their Mode of Action.

Essential oils (EOs) and plant extracts, rich in beneficial chemical compounds, have diverse applications in medicine, food, cosmetics, and agriculture. This study investigates the antibacterial activity of nine essential oil constituents (EOCs) against Escherichia coli, focusing on the effects of treatment pH and biosynthetic requirements. The impact of EOCs on bacterial inactivation in E. coli strains was examined using both nonselective and selective culture media. Computer-assisted drug design (CADD) methods were employed to identify critical binding sites and predict the main binding modes of ligands to proteins. The EOCs, including citral, α-terpinyl acetate, α-terpineol, and linalool, demonstrated significant bacterial inactivation, particularly under acidic conditions. This study revealed that EOCs have an effect on the presence of sublethal damage to both the cytoplasmic membrane and the outer membrane in Gram-negative bacteria. Adding penicillin G to the repair medium prevents the recovery of sublethal injuries in E. coli treated with α-terpinyl acetate, α-terpineol, linalool, and citral, indicating that peptidoglycan synthesis is essential for recovering from these injuries. However, penicillin G did not hinder the recovery process of most sublethally injured cells treated with the other assessed EOCs. Molecular docking studies revealed the favorable binding interactions of α-terpinyl acetate, α-terpineol, linalool, and citral with the β-lactamase enzyme Toho-1, indicating their potential as effective antibacterial agents. The findings suggest that EOCs could serve as viable alternatives to synthetic preservatives, offering new strategies for combating antibiotic-resistant bacteria.

Bioassay-guided isolation of dehydrocostus lactone from Echinops kebericho as a leishmanicidal drug

Several strains of Leishmania parasite are involved in the occurrence of leishmaniasis infections, which makes its prevention and treatment very challenging. Currently, all forms of leishmaniasis are being treated with chemical drugs, which have limitations and adverse effects. Discovering antileishmanial agents from natural sources can lead to novel drugs against this dreadful disease. The essential oils and nonpolar solvent extracts of the roots of E. kebericho exhibit antileishmanial activity. Thus, the isolation of the leishmanicidal compounds from the roots of E. kebericho through a bioassay-guided technique was carried out in this study. The present finding showed that the essential oil and hexane fraction of crude extract from the roots of E. kebericho possessed significant leishmanicidal activity against L. major and L. tropica. Dehydrocostus lactone (1), one of the major constituents of the essential oil and hexane fraction, was more active than the standard drug miltefosine against L. major and L. tropica promastigotes. The presence of α-methylene, γ-lactone is the responsible moiety of dehydrocostus lactone towards the leishmanicidal activity against the tested Leishmania species. The MTT assay of dehydrocostus lactone showed inactive toxicity against the human cervical carcinoma HeLa cells. In addition, dehydrocostus lactone exhibits a broad spectrum of antibiotic activities. Based on this interesting finding, dehydrocostus lactone was identified as a potential lead for treating infections caused by Leishmania.

Linalool may have a therapeutic effect on cadmium-induced nephrotoxicity by regulating NF-κB/TNF and GRP78/CHOP signaling pathways

Cadmium (Cd) is an environmental pollutant heavy metal with nephrotoxic effect. One of the primary constituents of essential oils is Linalool (Lin), a monoterpene having a variety of pharmacological properties including antimicrobial, anti-inflammatory, and antioxidant effects. The purpose of this study was to ascertain how Lin affected endoplasmic reticulum stress (ERS) and pro-inflammatory mediators in Cd-induced nephrotoxicity. In the experiment, 28 male rats were randomly divided into four equal groups as control (no application), Cd (Cd at a dose of 3 mg/kg for the first 7 days), Cd+Lin (Cd at a dose of 3 mg/kg for the first 7 days and 100 mg/kg/day Lin) and Lin (100 mg/kg/day Lin) (n=7). The experiment was completed on the 15th day after all treatments were performed. Blood serum and kidney tissue samples were used for analyses. Cd-induced histopathological changes, inflammation, oxidative stress, and apoptosis were determined to increase in kidney tissue. However, it was observed that Cd-induced adverse effects in kidney tissue were mainly eliminated by Lin treatment. In conclusion, Lin demonstrated anti-inflammatory, anti-oxidant and anti-apoptotic effects in Cd-induced nephrotoxicity. Therefore, we believe that Lin may represent a high potential therapeutic strategy against renal tissue damage.