Inhibition of Monilinia fructicola sporulation and pathogenicity through eucalyptol-mediated targeting of MfCat2 by Streptomyces lincolnensis strain JCP1-7.

Peach brown rot, attributed to Monilinia fructicola, presents a significant threat to postharvest peach cultivation, causing losses of up to 80%. With an increasing number of countries, spearheaded by the European Union, imposing bans on chemical agents in fruit production, there is a growing interest in mining highly active antibacterial compounds from biological control strains for postharvest disease management. In this study, we highlight the unique ability of Streptomyces lincolnensis strain JCP1-7 to inhibit M. fructicola sporulation, despite its limited antimicrobial efficacy. Through GC-MS analysis, eucalyptol was identified as the key compound. Fumigation of diseased fruits with eucalyptol at a concentration of 0.0335 µg cm-3 demonstrated an in vivo inhibition rate against M. fructicola of 93.13%, completely suppressing spore formation. Transcriptome analysis revealed the impact of eucalyptol on multiple pathogenesis-related pathways, particularly through the inhibition of catalase 2 (Cat2) expression. Experiments with a MfCat2 knockout strain (ΔMfCat2) showed reduced pathogenicity and sensitivity to JCP1-7 and eucalyptol, suggesting MfCat2 as a potential target of JCP1-7 and eucalyptol against M. fructicola. Our findings elucidate that eucalyptol produced by S. lincolnensis JCP1-7 inhibits M. fructicola sporulation by regulating MfCat2, thereby effectively reducing postharvest peach brown rot occurrence. The use of fumigation of eucalyptol offers insights into peach brown rot management on a large scale, thus making a significant contribution to agricultural research.

Determination of in vitro synergy and antibiofilm activities of antimicrobials and essential oil components.

Using existing adrentimicrobials with essential oil components to prevent antimicrobial resistance is an alternative strategy. This study aimed to evaluate the resistance status, synergistic combinations, and in vitro biofilm formation activities of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), Stenotrophomonas maltophilia and Candida albicans against antimicrobial agents and cinnamaldehyde, carvacrol, eugenol, limonene and eucalyptol. Antimicrobial activities were evaluated by microdilution, cytotoxicity by XTT, synergy by checkerboard and time-kill, and biofilm inhibition by microplate methods. Cinnamaldehyde and carvacrol showed strong antimicrobial activity. Synergistic effects were observed when using all essential oils with antimicrobials. Only two C. albicans isolates showed antagonism with cinnamaldehyde and fluconazole. The constituents showed cytotoxic effects in the L929 cell line (except limonene). A time-kill analysis revealed a bacteriostatic effect on S. maltophilia and MRSA isolates and a fungicidal effect on C. albicans isolates. These results are important for further research to improve antimicrobial efficacy or to develop new agents.

Eucalyptol Ameliorates Retinal Microvascular Defects through Modulating ER Stress and Angiopoietin-Tie Signaling in Diabetic Eyes.

Loss of the inner blood-retinal barrier (BRB) integrity is a main feature of ocular diseases such as diabetic macular edema. However, there is a lack of clarity on how inner BRB function is modulated within the diabetic retina. The current study examined whether eucalyptol inhibited inner BRB destruction and aberrant retinal angiogenesis in 33 mM glucose-exposed human retinal microvascular endothelial (RVE) cells and db/db mice. This study further examined the molecular mechanisms underlying endothelial dysfunction including retinal endoplasmic reticulum (ER) stress and angiopoietin (Ang)/Tie axis in conjunction with vascular endothelial growth factor (VEGF). Eucalyptol is a naturally occurring monoterpenoid and an achiral aromatic component of many plants including eucalyptus leaves. Nontoxic eucalyptol reduced the production of amyloid-ß (Aß) protein in glucose-loaded RVE cells and in diabetic mice. This natural compound blocked apoptosis of Aß-exposed RVE cells in diabetic mouse eyes by targeting ER stress via the inhibition of PERK-eIF2α-ATF4-CHOP signaling. Eucalyptol promoted activation of the Ang-1/Tie-2 pathway and dual inhibition of Ang-2/VEGF in Aß-exposed RVE cells and in diabetic eyes. Supply of eucalyptol reversed the induction of junction proteins in glucose/Aß-exposed RVE cells within the retina and reduced permeability. In addition, oral administration of eucalyptol reduced vascular leaks in diabetic retinal vessels. Taken together, these findings clearly show that eucalyptol inhibits glucose-induced Aß-mediated ER stress and manipulates Ang signaling in diabetic retinal vessels, which ultimately blocks abnormal angiogenesis and loss of inner BRB integrity. Therefore, eucalyptol provides new treatment strategies for diabetes-associated RVE defects through modulating diverse therapeutic targets including ER stress, Ang-1/Tie-2 signaling, and Ang-2/VEGF.

1,8-cineole ameliorates experimental diabetic angiopathy by inhibiting NLRP3 inflammasome-mediated pyroptosis in HUVECs via SIRT2.

Accumulating evidence strongly support the key role of NLRP3-mediated pyroptosis in the pathogenesis and progression of vascular endothelial dysfunction associated with diabetes mellitus. Various studies have demonstrated that the activation or upregulation of Silent Information Regulation 2 homolog 2 (SIRT2) exerts inhibitory effect on the expression of NLRP3. Although 1,8-cineole has been found to protect against endothelial dysfunction and cardiovascular diseases, its role and mechanism in diabetic angiopathy remain unknown. Therefore, the aim of this study was to investigate the ameliorative effect of 1,8-cineole through SIRT2 on pyroptosis associated with diabetic angiopathy in human umbilical vein endothelial cells (HUVECs) and to elucidate the underlying mechanism. The findings revealed that 1,8-cineole exhibited a protective effect against vascular injury and ameliorated pathological alterations in the thoracic aorta of diabetic mice. Moreover, it effectively mitigated pyroptosis induced by palmitic acid-high glucose (PA-HG) in HUVECs. Treatment with 1,8-cineole effectively restored the reduced levels of SIRT2 and suppressed the elevated expression of pyroptosis-associated proteins. Additionally, our findings demonstrated the occurrence of NLRP3 deacetylation and the physical interaction between NLRP3 and SIRT2. The SIRT2 inhibitor AGK2 and siRNA-SIRT2 effectively attenuated the effect of 1,8-cineole on NLRP3 deacetylation in HUVECs and compromised its inhibitory effect against pyroptosis in HUVECs. However, overexpression of SIRT2 inhibited PA-HG-induced pyroptosis in HUVECs. 1,8-Cineole inhibited the deacetylation of NLRP3 by regulating SIRT2, thereby reducing pyroptosis in HUVECs. In conclusion, our findings suggest that PA-HG-induced pyroptosis in HUVECs plays a crucial role in the development of diabetic angiopathy, which can be mitigated by 1,8-cineole.

Preparation and Application of Volatilized Wormwood Essence Derived Naturally into Green Insecticide.

Naturally occurring substances and their derivatives function as vital resources for pesticides that can be used in fields, such as insecticide production and fungicide development. As a botanical entity displaying multifaceted biological functions, wormwood has received thorough scrutiny across multiple sectors. The insect repellency potency combined with antibacterial and antifungal activities of wormwood position it as a potential candidate for prospective development into eco-friendly chemical pesticides. In this research, Wormwood essential oil was procured via ethanol water under ultrasonic scenarios and subsequently diluted with PEG 400 to formulate green chemical pesticides. The defensive efficacy of this green pesticide on plants was validated through 2 weeks of clustered plant growth experiments. Active constituents that exerted their effects were scrutinized by GC-MS. Furthermore, this green pesticide also displays efficacious effects on the prevention and management of aphids, exhibiting a dose-dependent relationship. 4-terpenol, eucalyptol, carvacrol, and L-borneol were identified by GC-MS as the predominant active constituents in this green chemical pesticide. Wormwood can be leveraged to develop green chemical pesticides, which can protect plants without contaminating the environment.

Antioxidant and anti-Alzheimer's disease activities of 1,8-cineole and its cyclodextrin inclusion complex.

1,8-Cineole is a bicyclic monoterpene widely distributed in the essential oils of various medicinal plants, and it exhibits significant anti-inflammatory and antioxidant activities. We aimed to investigate the therapeutic effect of 1,8-cineole on anti-Alzheimer's disease by using transgenic Caenorhabditis elegans models. Our studies demonstrated that 1,8-cineole significantly relieved Aß1-42-induced paralysis and exhibited remarkable antioxidant and anti-Aß1-42 aggregation activities in transgenic nematodes CL4176, CL2006 and CL2355. We developed a 1,8-cineole/cyclodextrin inclusion complex, displaying enhanced anti-paralysis, anti-Aß aggregation and antioxidant activities compared to 1,8-cineole. In addition, we found 1,8-cineole treatment activated the SKN-1/Nrf-2 pathway and induced autophagy in nematodes. Our results demonstrated the antioxidant and anti-Alzheimer's disease activities of 1,8-cineole, which provide a potential therapeutic approach for Alzheimer's disease.

1.8-cineole prevents platelet activation and aggregation by activating the cAMP pathway via the adenosine A2A receptor.

AIMS: Dysregulated platelet aggregation is a fatal condition in many bacterial- and virus-induced diseases. However, classical antithrombotics cannot completely prevent immunothrombosis, due to the unaddressed mechanisms towards inflammation. Thus, targeting platelet hyperactivation together with inflammation might provide new treatment options in diseases, characterized by immunothrombosis, such as COVID-19 and sepsis. The aim of this study was to investigate the antiaggregatory effect and mode of action of 1.8-cineole, a monoterpene derived from the essential oil of eucalyptus leaves, known for its anti-inflammatory proprieties. MAIN METHODS: Platelet activity was monitored by measuring the expression and release of platelet activation markers, i.e., P-selectin, CD63 and CCL5, as well as platelet aggregation, upon treatment with 1.8-cineole and stimulation with several classical stimuli and bacteria. A kinase activity assay was used to elucidate the mode of action, followed by a detailed analysis of the involvement of the adenylyl-cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway by Western blot and ELISA. KEY FINDINGS: 1.8-cineole prevented the expression and release of platelet activation markers, as well as platelet aggregation, upon induction of aggregation with classical stimuli and immunological agonists. Mechanistically, 1.8- cineole influences the activation of the AC-cAMP-PKA pathway, leading to higher cAMP levels and vasodilator-stimulated phosphoprotein (VASP) phosphorylation. Finally, blocking the adenosine A2A receptor reversed the antithrombotic effect of 1.8-cineole. SIGNIFICANCE: Given the recognized anti-inflammatory attributes of 1.8-cineole, coupled with our findings, 1.8-cineole might emerge as a promising candidate for treating conditions marked by platelet activation and abnormal inflammation.

Synergistic interactions of essential oil components with antibiotics against multidrug-resistant Corynebacterium striatum.

AIM: In this study, it was aimed to examine the antibacterial activity of the essential oil components (EOCs), carvacrol (CAR), cinnamaldehyde (CIN), thymol (TH), alpha pinene (α-PN), eucalyptol (EU), limonene (LIM), and the antibiotics, linezolid (LZD), vancomycin (VAN), gentamicin (GEN), ciprofloxacin (CIP), clindamycin (CLN), and penicillin (PEN) against 50 multidrug resistant Corynebacterium striatum strains, and the synergistic interactions of CAR and CIN with the antibiotics against 10 randomly selected Coryne. striatum strains to explore synergistic interactions to determine if their combined use could enhance antibiotic activity and potentially reduce resistance. METHODS AND RESULTS: The activity of the EOCs and the antibiotics against Coryne. striatum strains isolated from clinical specimens, was examined by broth microdilution method. The synergistic interactions of the EOCs with the antibiotics against 10 randomly selected Coryne. striatum strains were determined by checkerboard method. EOCs, CIN, and CAR and antibiotics, LZD, VAN, GEN, CIP, and CLN were detected to have antibacterial activity against Coryne. striatum strains alone and either synergistic interactions were observed in combinations of the antibiotics with EOCs. CONCLUSIONS: All Coryne. striatum strains were determined to be susceptible to VAN and LZD and resistant to GEN, PEN, CIP, and CLN. Synergistic interactions were observed in all combinations of antibiotics tested with CAR and CIN.

Effectiveness and chemical insights: Exploring interactions between nanomicelles and monoterpenoids for head lice treatment.

This study evaluates the pediculicidal activity of nanoformulations containing different binary essential oil component mixtures (eugenol:linalool, 1,8 -cineole:linalool, and eugenol:thymol) using immersion bioassays. These have allowed us to evaluate the knockdown time affecting 50% of the individuals (KT50). In addition, the type of interaction between the components in each mixture was established in terms of the combination index (IC). The KT50 values were 6.07; 8.83; 7.17 and 27.23 h for linalool, 1,8 -cineole, eugenol, and thymol, respectively. For the eugenol:linalool mixtures, the efficacy was lower or equal to that obtained for the nanoformulations of the pure compounds, with values of KT50 about 13.33, 8.16 and 6.71 h for mixtures with ratios 3:1, 1:1 and 1:3, respectively. These mixtures present IC > 1, evidencing antagonistic interaction, which is enhanced with eugenol content. In the case of the binary mixtures of 1,8 -cineole: linalool, KT50 values were similar to those obtained for eugenol:linalool mixtures with similar ratios. In this case, IC assumes values close to unity, suggesting additive interactions independently of the mixture composition. On the other side, mixtures of eugenol:thymol with 1:1 and 1:3 ratios showed values of 9.40 and 32.93 h, while the mixture with a 3:1 ratio showed the greatest effectiveness (KT50 of 4.42 h). Eugenol:thymol mixtures show synergistic interaction (IC < 1) for combinations 3:1 and 1:1, while no interaction was observed for 1:3 combination. This indicates that eugenol enhances thymol activity. These results must be considered an important step forward to the development of effective pediculicidal nanoformulations based on botanical compounds.

Molecular insights of Eucalyptol (1,8-Cineole) as an anti-arthritic agent: in vivo and in silico analysis of IL-17, IL-10, NF-κB, 5-LOX and COX-2.

The monoterpene oxide, Eucalyptol (1,8-Cineole), a primary component of eucalyptus oil, has been evaluated pharmacologically for anti-inflammatory and analgesic activity. Current research aimed to evaluate Eucalyptol's anti-arthritic potential in a Complete Freund's adjuvant induced arthritis that resembles human rheumatoid arthritis. Polyarthritis developed after 0.1 mL CFA injection into the left hind footpad in rats. Oral administration of Eucalyptol at various doses (100, 200 and 400 mg/kg) significantly reduced paw edema, body weight loss, 5-LOX, PGE2 and Anti-CCP levels. Real-time PCR investigation showed significant downregulation of COX-2, TNF-α, NF-κB, IL-17, IL-6, IL-1ß and upregulation of IL-4 and IL-10 in Eucalyptol treated groups. Hemoglobin and RBCs counts significantly increased post-treatment with Eucalyptol while ESR, CRP, WBCs and platelets count significantly decreased. Eucalyptol significantly increased Superoxide Dismutase, Catalase and Glutathione levels compared to CFA-induced arthritic control however, MDA significantly decreased post-treatment. Further, radiographic and histopathological examination of the ankle joints of rodents administered Eucalyptol revealed an improvement in the structure of the joints. Piroxicam was taken as standard. Furthermore, molecular docking findings supported the anti-arthritic efficacy of Eucalyptol exhibited high binding interaction against IL-17, TNF-α, IL-4, IL-10, iNOS NF-κB, 5-LOX, and COX-2. Eucalyptol has reduced the severity of CFA induced arthritis by promoting anti-inflammatory cytokines for example IL-4, IL-10 and by inhibiting pro-inflammatory cytokines such as 5-LOX, COX-2, IL-17, NF-κB, TNF-α, IL-6 and IL-1ß. Therefore, Eucalyptol might be as a potential therapeutic agent because of its pronounced anti-oxidant and anti-arthritic activity.

Eucalyptol ameliorates chlorpyrifos-induced necroptosis in grass carp liver cells by down-regulating ROS/NF-κB pathway.

Chlorpyrifos (Diethoxy-sulfanylidene-(3,5,6-trichloropyridin-2-yl) oxy-λ5-phosphane, CPF) was extensively used organophosphorus pesticide, extensively deteriorating public problem with the enrichment in the water bodies. Eucalyptol (1,3,3-Trimethyl-2-oxabicyclo[2.2.2] octane, EUC), a colorless cyclic monoterpene oxide, has shown anti-inflammatory and anti-oxidation properties. To explore the effect of EUC on CPF-induced necroptosis in the grass carp liver cells (L8824 cells), we treated L8824 cells with 60 mM CPF and 5 µM EUC for 24 h. The results showed that CPF exposed lead to excessive accumulation of reactive oxygen species (ROS) and oxidative stress, activating the NF-κB and RIPK1 pathway, increasing the level of cell necroptosis. However, EUC treatment attenuated the toxic effects of CPF treatment on L8824 cells. In summary, the study demonstrated that CPF induced necroptosis and inflammation, and EUC treatment could decrease CPF-caused cell injury.

Inhaled Litsea glaucescens K. (Lauraceae) leaves' essential oil has anxiolytic and antidepressant-like activity in mice by BDNF pathway activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Litsea glaucescens K. (Lauraceae) is a small tree from the Mexican and Central American temperate forests, named as "Laurel". Its aromatic leaves are ordinarily consumed as condiments, but also are important in Mexican Traditional Medicine, and among the most important non wood forest products in this area. The leaves are currently used in a decoction for the relief of sadness by the Mazahua ethnic group. Interestingly, "Laurel" has a long history. It was named as "Ehecapahtli" (wind medicine) in pre-Columbian times and applied to heal maladies correlated to the Central Nervous System, among them depression, according to botanical texts written in the American Continent almost five centuries ago. AIM OF THE STUDY: Depression is the first cause of incapacity in the world, and society demands alternative treatments, including aromatherapy. We have previously demonstrated the antidepressant-like activity of L. glaucescens leaves' essential oil (LEO), as well as their monoterpenes linalool, and beta-pinene by intraperitoneal route in a mice behavioral model. Here we now examined if LEO and linalool exhibit this property and anxiolytic activity when administered to mice by inhalation. We also investigated if these effects occur by BDNF pathway activation in the brain. MATERIALS AND METHODS: The LEO was prepared by distillation with water steam and analyzed by gas chromatography-mass spectrometry (GC-MS). The monoterpenes linalool, eucalyptol and ß-pinene were identified and quantified. Antidepressant type properties were determined with the Forced Swim Test (FST) on mice previously exposed to LEO or linalool in an inhalation chamber. The spontaneous locomotor activity and the sedative effect were assessed with the Open Field Test (OFT), and the Exploratory Cylinder (EC), respectively. The anxiolytic properties were investigated with the Elevated Plus Maze Apparatus (EPM) and the Hole Board Test (HBT). All experiments were video documented. The mice were subjected to euthanasia, and the brain hippocampus and prefrontal cortex were dissected. RESULTS: The L. glaucescens essential oil (LEO) contains 31 compounds according to GC/MS, including eucalyptol, linalool and beta-pinene. The LEO has anxiolytic effect by inhalation in mice, as well as linalool, and ß-pinene, as indicated by OFT and EC tests. The LEO and imipramine have antidepressant like activity in mice as revealed by the FST; however, linalool and ketamine treatments didn't modify the time of immobility. The BDNF was increased in FST in mice treated with LEO in both areas of the brain as revealed by Western blot; but did not decrease the level of corticosterone in plasma. The OFT indicated that LEO and imipramine didn't reduce the spontaneous motor activity, while linalool and ketamine caused a significant decrease. CONCLUSION: Here we report by the first time that L. glaucescens leaves essential oil has anxiolytic effect by inhalation in mice, as well as linalool, and ß-pinene. This oil also maintains its antidepressant-like activity by this administration way, similarly to the previously determined intraperitoneally. Since inhalation is a common administration route for humans, our results suggest L. glaucescens essential oil deserve future investigation due to its potential application in aromatherapy.

Identification of algicidal monoterpenoids from four chemotypes of Cinnamomum camphora and their algicidal mechanisms on Microcystis aeruginosa.

Cyanobacterial blooms cause serious environmental issues, and plant secondary metabolites are considered as new algaecide for controlling them. Cinnamomum camphora produces a wide spectrum of terpenoids and has 4 main chemotypes, including linalool, camphor, eucalyptol and borneol chemotype. To develop the new cyanobacterial algaecide by using suitable chemotype of Cinnamomum camphora and the main terpenoids, we analyzed the terpenoid composition in the 4 chemotype extracts, evaluated the algicidal effects of the extracts and their typical monoterpenoids on Microcystis aeruginosa, and investigated the algicidal mechanism of the stronger algicidal agents. Among the 4 chemotypes, eucalyptol and borneol chemotype extracts exhibited stronger algicidal effects. In the 4 chemotype extracts, monoterpenoids were the main compounds, of which linalool, camphor, eucalyptol and borneol were the typical components. Among the 4 typical monoterpenoids, eucalyptol and borneol showed stronger algicidal effects, which killed 78.8% and 100% M. aeruginosa cells, respectively, at 1.2 mM after 48 h. In 1.2 mM eucalyptol and borneol treatments, the reactive oxygen species levels markedly increased, and the caspase-3-like activity also raised. With prolonging the treatment time, M. aeruginosa cells gradually shrank and wrinkled, and the cell TUNEL fluorescence intensity and DNA degradation gradually enhanced, indicating that the lethal mechanism is causing apoptosis-like programmed cell death (PCD). Therefore, eucalyptol and borneol chemotype extracts and their typical monoterpenoids have the potential for developing as algaecides to control cyanobacteria through triggering apoptosis-like PCD.

The Fate of 1,8-cineole as a Chemical Penetrant: A Review.

The stratum corneum continues to pose the biggest obstacle to transdermal drug delivery. Chemical penetrant, the first generation of transdermal drug delivery system, offers a lot of potential. In order to fully examine the permeation mechanism of 1,8-cineole, a natural monoterpene, this review summarizes the effects of permeation-enhancing medications on drugs that are lipophilic and hydrophilic as well as the toxicity of this substance on the skin and other tissues. For lower lipophilic drugs, 1,8-cineole appears to have a stronger osmotic-enhancing impact. An efficient and secure tactic would be to combine enhancers and dose forms. 1,8-cineole is anticipated to be further developed in the transdermal drug delivery system and even become a candidate drug for brain transport due to its permeability and low toxicity.

Eucalyptol regulates Nrf2 and NF-kB signaling and alleviates gentamicin-induced kidney injury in rats by downregulating oxidative stress, oxidative DNA damage, inflammation, and apoptosis.

Gentamicin, an aminoglycoside antibiotic, is nowadays widely used in the treatment of gram-negative microorganisms. The antimicrobial, anti-inflammatory, and antioxidant activities of eucalyptol, a type of saturated monoterpene, have been reported in many studies. The aim of this study was to examine the possible effects of eucalyptol on gentamicin-induced renal toxicity. A total of 32 rats were divided into 4 groups; Control (C), Eucalyptol (EUC), Gentamicin (GEN), and Gentamicin + Eucalyptol (GEN + EUC). In order to induce renal toxicity, 100 mg/kg gentamicin was administered intraperitoneally (i.p.) for 10 consecutive days in the GEN and GEN + EUC groups. EUC and GEN + EUC groups were given 100 mg/kg orally of eucalyptol for 10 consecutive days. Afterwards, rats were euthanized and samples were taken and subjected to histopathological, biochemical, immunohistochemical, and real-time PCR examinations. The blood urea nitrogen (BUN) and creatinine (CRE) levels were significantly decreased in the GEN + EUC group (0.76 and 0.69-fold, respectively) compared to the GEN group. The glutathione peroxidase (GPx) and catalase (CAT) activities were significantly increased in the GEN + EUC group (1.35 and 2.67-fold, respectively) compared to the GEN group. In GEN group, Nuclear factor kappa B (NF-kB), Interleukin 1-beta (IL-1ß), Inducible nitric oxide synthase (iNOS), Tumor necrosis factor-α (TNF-α), Caspase-3, 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and Nuclear factor erythroid 2-related factor (Nrf2) expression levels were found to be quite irregular. GEN + EUC group decreased the expressions of NF-kB, IL-1ß, iNOS, TNF-α, Caspase-3, and 8-OHdG (0.55, 0.67, 0.54, 0.54, 0.63 and 0.67-fold, respectively), while it caused increased expression of Nrf2 (3.1 fold). In addition, eucalyptol treatment ameliorated the histopathological changes that occurred with gentamicin. The results of our study show that eucalyptol has anti-inflammatory, antioxidative, antiapoptotic, nephroprotective, and curative effects on gentamicin-induced nephrotoxicity.

Attenuation of quorum sensing regulated virulence functions and biofilm of pathogenic bacteria by medicinal plant Artemisia annua and its phytoconstituent 1, 8-cineole.

The emergence of multidrug resistance (MDR) in bacterial pathogens is a serious public health concern. A significant therapeutic target for MDR infections is the quorum sensing-regulated bacterial pathogenicity. Determining the anti-quorum sensing abilities of certain medicinal plants against bacterial pathogens as well as the in-silico interactions of particular bioactive phytocompounds with QS and biofilm-associated proteins were the objectives of the present study. In this study, 6 medicinal plants were selected based on their ethnopharmacological usage, screened for Anti-QS activity and Artemisia annua leaf extract (AALE) demonstrated pigment inhibitory activity against Chromobacterium violaceum CV12472. Further, the methanol active fraction significantly inhibited the virulence factors (pyocyanin, pyoverdine, rhamnolipid and swarming motility) of Pseudomonas aeruginosa PAO1 and Serratia marcescens MTCC 97 at respective sub-MICs. The inhibition of biofilm was determined using a microtiter plate test and scanning electron microscopy. Biofilm formation was impaired by 70%, 72% and 74% in P. aeruginosa, C. violaceum and S. marcescens, respectively at 0.5xMIC of the extract. The phytochemical content of the extract was studied using GC-MS and 1, 8-cineole was identified as major bioactive compound. Furthermore, 1, 8-cineole was docked with quorum sensing (QS) proteins (LasI, LasR, CviR, and rhlR) and biofilm proteins (PilY1 and PilT). In silico docking and dynamics simulations studies suggested interactions with QS-receptors CviR', LasI, LasR, and biofilm proteins PilY1, PilT for anti-QS activity. Further, 1, 8-cineole demonstrated 66% and 51% reduction in violacein production and biofilm formation, respectively to validate the findings of computational analysis. Findings of the present investigation suggests that 1, 8-cineole plays a crucial role in the QS and biofilm inhibitory activity demonstrated by Artemisia annua extract. RESEARCH HIGHLIGHTS: Artemisia annua leaf extract (AALE) methanol fraction demonstrated broad-spectrum QS and biofilm inhibition Scanning electron microscopy (SEM) confirmed biofilm inhibition Molecular docking and simulation studies suggested positive interactions of 1,8-cineol with QS-receptors and biofilm proteins.

Eucalyptol alleviates avermectin exposure-induced apoptosis and necroptosis of grass carp hepatocytes by regulating ROS/NLRP3 axis.

The wide application of Avermectin (AVM) has caused pollution of surface water and damage to non-target organisms. A growing body of evidence supports the most prominent role of Eucalyptol (EUC) is antioxidation. To the purpose of explore the injury mechanism of Avermectin on grass carp hepatocytes and the antagonistic effect of Eucalyptol, 5.7 µM AVM and/or 20 µM EUC were used to treat grass carp hepatocytes for 24 h to establish hepatocyte exposure model. The results showed that Avermectin exposure significantly increased the contents of reactive oxygen species (ROS) and malondialdehyde (MDA) in cells, reduced the activities of superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC). Also, the expressions of NLRP3 inflammasome-related genes including NLRP3, ASC, and Caspase-1, the necroptosis-related genes including RIPK1, RIPK3, and MLKL and apoptotic genes including Bax, Caspase-3, and Caspase-9 were all up-regulated. Meanwhile, the expressions of Caspase-8 and Bcl-2 were significantly decreased upon exposure to Avermectin. However, the toxicity was significantly alleviated with the treatment of EUC or N-acetyl-l-cysteine (NAC). The above results indicated that eucalyptol alleviated AVM exposure-induced apoptosis and necroptosis of grass carp hepatocytes by regulating the ROS/NLRP3 signaling pathway.

Comparative Transcriptomic Analyses Propose the Molecular Regulatory Mechanisms Underlying 1,8-Cineole from Cinnamomum kanehirae Hay and Promote the Asexual Sporulation of Antrodia cinnamomea in Submerged Fermentation.

Antrodia cinnamomea is a valuable edible and medicinal mushroom with antitumor, hepatoprotective, and antiviral effects that play a role in intestinal flora regulation. Spore-inoculation submerged fermentation has become the most efficient and well-known artificial culture process for A. cinnamomea. In this study, a specific low-molecular compound named 1,8-cineole (cineole) from Cinnamomum kanehirae Hay was first reported to have remarkably promoted the asexual sporulation of A. cinnamomea in submerged fermentation (AcSmF). Then, RNA sequencing, real-time quantitative PCR, and a literature review were performed to predict the molecular regulatory mechanisms underlying the cineole-promoted sporulation of AcSmF. The available evidence supports the hypothesis that after receiving the signal of cineole through cell receptors Wsc1 and Mid2, Pkc1 promoted the expression levels of rlm1 and wetA and facilitated their transfer to the cell wall integrity (CWI) signal pathway, and wetA in turn promoted the sporulation of AcSmF. Moreover, cineole changed the membrane functional state of the A. cinnamomea cell and thus activated the heat stress response by the CWI pathway. Then, heat shock protein 90 and its chaperone Cdc37 promoted the expression of stuA and brlA, thus promoting sporulation of AcSmF. In addition, cineole promoted the expression of areA, flbA, and flbD through the transcription factor NCP1 and inhibited the expression of pkaA through the ammonium permease of MEP, finally promoting the sporulation of AcSmF. This study may improve the efficiency of the inoculum (spores) preparation of AcSmF and thereby enhance the production benefits of A. cinnamomea.

Diethylaminoethyl-dextran and monocyte cell membrane coated 1,8-cineole delivery system for intracellular delivery and synergistic treatment of atherosclerosis.

We have developed a biomimetic delivery system termed the Monocyte Cell Membrane-Coated 1,8-Cineole Biomimetic Delivery System (MM-CIN-BDS or BDS), which integrates diethylaminoethyl-dextran (DEAE) and monocyte cell membrane (MM). This innovative approach enhances the cellular uptake efficiency of 1,8-cineole (CIN) and facilitates targeted therapy for atherosclerosis. Our findings demonstrate the successful modification of the drug carrier with DEAE and MM, as validated by measurements of particle size, zeta potential, microscopic morphology, and western blotting analyses. Notably, cellular uptake experiments unveil a significant enhancement in cellular uptake efficiency due to DEAE modification. However, the introduction of monocyte cell membranes diminishes this effect in normal human umbilical vein endothelial cells (HUVECs), although this efficiency is notably restored in HUVECs activated with lipopolysaccharide (LPS). Through in vivo imaging investigations, we observe that the MM coating augments distribution in the spleen, brain, and atherosclerotic plaques, while concurrently diminishing distribution in the heart and kidneys. Animal studies corroborate these findings, illustrating that MM-CIN-BDS treatment curtails lipid parameters, dampens the expression of inflammatory factors and proteins, mitigates vascular tissue damage, and ultimately reduces the extent of atherosclerotic lesion areas. To encapsulate, DEAE emerges as an especially adept agent for modifying drug carriers with suboptimal cellular uptake efficiency in the realm of cardiovascular diseases. The potential therapeutic promise of MM-CIN-BDS for atherosclerosis treatment is evident from our research.

1,8-Cineole Alleviates OGD/R-Induced Oxidative Damage and Restores Mitochondrial Function by Promoting the Nrf2 Pathway.

This study examined the effects of 1,8-cineole on reducing oxidative stress injury and restoring mitochondrial function in oxygen-glucose deprivation and reoxygenation (OGD/R) HT22 cells via the nuclear factor erythrocyte 2 related factor 2 (Nrf2) pathway. The optimal concentration of 1,8-cineole to reduce OGD/R injury was screened via cell morphology, cell survival rate, and lactate dehydrogenase (LDH) leakage rate. Oxidative damage was observed by measuring superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) activities, and reactive oxygen species (ROS), glutathione (GSH), protein carbonyl, malondialdehyde (MDA), lipid peroxidation (LPO) content, and 8-hydroxy-2 deoxyguanosine (8-OHDG) expression. Mitochondrial function was observed by mitochondrial membrane potential (MMP) and ATPase activity. Nrf2 pathways were observed by the expression levels of total Nrf2, nucleus Nrf2, reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H): quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1), the mRNA levels of HO-1 and NQO1. Among different concentrations of 1,8-cineole for promoting HT22 cell proliferation and attenuated OGD/R injury, 10 µmol/L 1,8-cineole was the best. After 1,8-cineole treatment, SOD, GSH-PX, and CAT activities and GSH content increased, while ROS, MDA, LPO, protein carbonyl, and 8-OHDG levels decreased. 1,8-Cineole could restore MMP and increase mitochondrial enzyme activity. It could also increase the total Nrf2, nucleus Nrf2, NQO1, and HO-1, and Nrf2 inhibitor brusatol reduced the effect of 1,8-cineole. Immunofluorescence assay showed that 1,8-cineole could facilitate the transfer of Nrf2 into the nucleus. 1,8-cineole increased the mRNA levels of NQO1 and HO-1. The above results showed that 1,8-cineole could alleviate OGD/R-induced oxidative damage and restores mitochondrial function by activating the Nrf2 signal pathway.