New Synergistic Combination Therapy of Mupirocin and α-Pinene Against Multidrug-Resistant Clinical Strains of Methicillin-Resistant Staphylococcus aureus.

OBJECTIVE: Increased mupirocin use leads to mupirocin resistance and is associated with persistence of methicillin-resistant Staphylococcus aureus (MRSA) carriers, prolonged hospitalization, and significant economic burdens for health systems. The study aimed to investigate the antimicrobial activity of compounds of Salvia rosmarinus L. ("rosemary", formerly Rosmarinus officinalis), alone or in combination with mupirocin, against multidrug resistant MRSA using isolates obtained from pediatric patients. METHODS: The in vitro antibacterial activity of the monoterpene α-pinene (α-Pi), a rosemary essential oil constituent, alone and in combination with mupirocin, was evaluated by determining the minimum inhibitory concentrations and minimum bactericidal concentrations (MBCs) and the fractional inhibitory concentration indices (FICIs) and fractional bactericidal concentration indices against multidrug-resistant clinical MRSA strains. The in vivo efficacy of α-Pi, alone and in combination with mupirocin, to eradicate MRSA infection was determined using an optimized mouse model of MRSA-infected wounds. Mouse skin samples (obtained via biopsy) were assessed for toxicity, and rabbit skin samples for irritation. RESULTS: Both in vitro and in vivo, α-Pi was active against MRSA strains and acted synergistically with mupirocin against MRSA strains. Mupirocin-monoterpene combinations exhibited FICI values of 0.2 to 0.4, reducing the MBC of topical mupirocin 33-fold. A topical formulation containing α-Pi and mupirocin enhanced the efficacy of mupirocin in an in vivo MRSA-infected mouse skin model without significantly harming the skin of mice and rabbits. CONCLUSIONS: A topical formulation combining mupirocin and α-Pi may aid in the development of innovative agents for treating MRSA infections.

3-carene supresses inflammatory cytokine interleukin-4, interleukin-5 and interleukin-13 in a murine model of asthma.

Asthma is a common airway disease associated with allergic inflammation. Environmental factors, such as pollens, pollution, insect-borne antigens, or commercial chemicals, cause this disease. The common symptoms of this airway allergic reaction are increasing mucus, narrowing of the airway wall, coughing, and chest tightness. Medications, such as steroids, alleviate the disease but with severe side effects. Several studies have reported the anti-inflammatory effects of tree-based essential oil components, particularly 3-carene. Therefore, this study used 3-carene to determine if it alleviates asthmatic symptoms in the murine model. First, BALB/c mice were sensitized to an ovalbumin and aluminium hydroxide mixture on day 7th and 14th. From days 21st to 23rd, the mice were challenged with 3-carene and budesonide. The lung trachea, plasma, and bronchiolar lavage fluid (BAL fluid) were collected on day 24. The 3-carene treatment suppressed the cytokine gene expression, such as interleukin-4 (IL-4), IL-5, and IL-13, reducing the lung epithelial cell thickness in the asthmatic model. These results suggest that essential oil 3-carene has an anti-asthmatic effect.

Promising Antileishmanial Activity of Micromeria nervosa Essential Oil: In Vitro and In Silico Studies.

The present study aimed to evaluate the leishmanicidal potential of the essential oil (EO) of Micromeria (M.) nervosa and to investigate its molecular mechanism of action by qPCR. Furthermore, in silicointeraction study of the major M. nervosa EO compounds with the enzyme cytochrome P450 sterol 14α-demethylase (CYP51) was also performed. M. nervosa EO was analyzed by gas chromatography-mass spectrometry (GC-MS). Results showed that α-pinene (26.44%), t-cadinol (26.27%), caryophyllene Oxide (7.73 ± 1.04%), and α-Cadinene (3.79 ± 0.12%) are the major compounds of M. nervosa EO. However, limited antioxidant activity was observed, as this EO was ineffective in neutralizing DPPH free radicals and in inhibiting ß-carotene bleaching. Interestingly, it displayed effective leishmanicidal potential against promastigote (IC50 of 6.79 and 5.25 µg/mL) and amastigote (IC50 of 8.04 and 7.32 µg/mL) forms of leishmania (L.) infantum and L. major, respectively. Molecular mechanism investigation showed that M. nervosa EO displayed potent inhibition on the thiol regulatory pathway. Furthermore, a docking study of the main components of the EO with cytochrome P450 sterol 14α-demethylase (CYP51) enzyme revealed that t-cadinol exhibited the best binding energy values (-7.5 kcal/mol), followed by α-cadinene (-7.3 kcal/mol) and caryophyllene oxide (-7 kcal/mol). These values were notably higher than that of the conventional drug fluconazole showing weaker binding energy (-6.9 kcal/mol). These results suggest that M. nervosa EO could serve as a potent and promising candidate for the development of alternative antileishmanial agent in the treatment of leishmaniasis.

Antenna-Biased Odorant Receptor PstrOR17 Mediates Attraction of Phyllotreta striolata to (S)-Cis-Verbenol and (-)-Verbenone.

Phyllotreta striolata, the striped flea beetle, is one of the most destructive pests in Brassicaceae plants worldwide. Given the drawbacks associated with long-term use of chemical insecticides, green strategies based on chemical ecology are an effective alternative for beetle control. However, the lack of information on beetle ecology has hindered the development of effective biocontrol strategies. In this report, we identified two odorants, (S)-cis-verbenol and (-)-verbenone, which displayed significant attraction for P. striolata (p < 0.05), indicating their great potential for P. striolata management. Using the Drosophila "empty neuron" system, an antenna-biased odorant receptor, PstrOR17, was identified as responsible for the detection of (-)-verbenone and (S)-cis-verbenol. Furthermore, the interactions between PstrOR17 and (-)-verbenone or (S)-cis-verbenol were predicted via modeling and molecular docking. Finally, we used RNAi to confirm that PstrOR17 is essential for the detection of (-)-verbenone and (S)-cis-verbenol to elicit an attraction effect. Our results not only lay a foundation for the development of new and effective nonchemical insecticide strategies based on (S)-cis-verbenol and (-)-verbenone, but also provide new insight into the molecular basis of odorant recognition in P. striolata.

Eucalyptus Oils Phytochemical Composition in Correlation with Their Newly Explored Anti-SARS-CoV-2 Potential: in Vitro and in Silico Approaches.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the latest arisen contagious respiratory pathogen related to the global outbreak of atypical pneumonia pandemic (COVID-19). The essential oils (EOs) of Eucalyptus camaldulensis, E. ficifolia F. Muell., E. citriodora Hook, E. globulus Labill, E. sideroxylon Cunn. ex Woolls, and E. torquata Luehm. were investigated for its antiviral activity against SARS-CoV-2. The EOs phytochemical composition was determined using GC/MS analysis. Correlation with the explored antiviral activity was also studied using multi-variate data analysis and Pearson's correlation. The antiviral MTT and cytopathic effect inhibition assays revealed very potent and promising anti SARS-CoV-2 potential for E. citriodora EO (IC50 = 0.00019 µg/mL and SI = 26.27). The multivariate analysis revealed α-pinene, α-terpinyl acetate, globulol, γ -terpinene, and pinocarvone were the main biomarkers for E. citriodora oil. Pearson's correlation revealed that globulol is the top positively correlated compound in E. citriodora oil to its newly explored potent anti SARS-CoV-2 potential. A molecular simulation was performed on globulol via docking in the main active sites of both SARS-CoV-2 viral main protease (Mpro) and spike protein (S). In silico predictive ADMET study was also developed to investigate the pharmacokinetic profile and predict globulol toxicity. The obtained in silico, in vitro and Pearson's correlation results were aligned showing promising SARS-CoV-2 inhibitory activity of E. citriodora and globulol. This study is a first record for E. citriodora EO as a novel lead exhibiting potent in vitro, and in silico anti SARS-CoV-2 potential and suggesting its component globulol as a promising candidate for further extensive in silico, in vitro and in vivo anti-COVID studies.

Odorant-binding protein 19 in Monochamus alternatus involved in the recognition of a volatile strongly emitted from ovipositing host pines.

Monochamus alternatus is the primary carrier of pine wood nematodes, which pose a serious threat to Pinus spp. in many countries. Newly emerging M. alternatus adults feed on heathy host pines, while matured adults transfer to stressed host pines for mating and oviposition. Several odorant-binding proteins (OBPs) of M. alternatus have been proved to aid in the complex process of host location. To clarify the corresponding relations between OBPs and pine volatiles, more OBPs need to be studied. In this research, MaltOBP19 showed a specific expression in the antennae and mouthparts of M. alternatus, and it was marked in 4 types of antenna sensilla by immunolocalization. Fluorescence binding assays demonstrated the high binding affinity of MaltOBP19 with camphene and myrcene in vitro. In Y-tube olfactory experiments, M. alternatus adults were attracted by camphene and RNAi of OBP19 via microinjection significantly decreased their attraction index. Myrcene induced phobotaxis, but RNAi had no significant effect on this behavior. Further, we found that ingesting dsOBP19 produced by a bacteria-expressed system with a newly constructed vector could lead to the knockdown of MaltOBP19. These results suggest that MaltOBP19 may play a role in the process of host conversion via the recognition of camphene, which has been identified to be strongly released in stressed host pines. In addition, it is proved that knockdown of OBP can be achieved by oral administration of bacteria-expressed double-stranded RNA in M. alternatus adults, providing a new perspective in the control of M. alternatus.

Myrtenol Inhalation Mitigates Asthma-Induced Cognitive Impairments: an Electrophysiological, Behavioral, Histological, and Molecular Study.

Asthma is an inflammatory disorder with significant health problems. It generally affects the lungs but can also impact brain performance via several mechanisms. Some investigations have proposed that asthma impairs cognition. This study assessed the impacts of myrtenol as a monoterpene on cognitive disorders following asthma at behavioral, molecular, and synaptic levels. Asthma was induced by injection and inhalation of ovalbumin (OVA). Male Wistar rats were allocated to five groups: control, asthma, asthma/vehicle, asthma/myrtenol, and asthma/budesonide. Myrtenol (8 mg/kg) or budesonide (160 µg/kg) was administered through inhalation once a day for 1 week, and at the end of the inhalation period, behavioral tests (MWM and Open Field), field potential recording, hippocampal brain-derived neurotrophic factor (BDNF), IL1ß (ELISA), and NFκB measurement (Western blot) were performed to evaluate cognitive performance. Moreover, H&E (hematoxylin and eosin) staining was used for hippocampus histological evaluation. Myrtenol improved spatial learning, memory, LTP (long-term potentiation) impairments, and anxiety-like behaviors following asthma. Myrtenol inhalation increased the BDNF level and decreased the IL1ß level and NFκB expression in the hippocampus of the asthmatic rats. The neuronal damage in the hippocampus following allergic asthma was alleviated via myrtenol administration. Myrtenol, as an herbal extract, protects the hippocampus from asthma consequences. Our observations revealed that myrtenol can improve spatial learning, memory, synaptic plasticity impairments, and anxiety-like behaviors following asthma. We believe that these ameliorating effects of myrtenol can be attributed to inflammation suppression and increased BDNF in the hippocampus.

Sialagogic Effects Through Olfactory Stimulation with Mastic Resin and α-pinene Volatiles in vivo.

BACKGROUND: Xerostomia, often associated with decreased saliva quality, poses challenges due to limited treatment efficacy. This study aimed to investigate alternative approaches to enhance saliva secretion through olfactory volatile stimulation with mastic resin and its main compound α-pinene, known for inhibiting acetylcholinesterase in vitro. METHODS: The inhibitory effects of freshly prepared mastic resin extract oil and α-pinene oil on acetylcholinesterase (AChE) activity were measured in vitro. Eighty healthy participants were recruited and divided into two groups: exposed to mastic resin volatiles (n = 40) or α-pinene volatiles (n = 40). Saliva samples were collected pre, during and post exposure to analyze saliva flow rate, spinnbarkeit, ion composition and MUC5B levels. RESULTS: Mastic resin extract oil and α-pinene oil inhibited AChE activity by 207 % and 22 %, respectively. Olfactory stimulation with these volatiles significantly increased saliva secretion rate without altering spinnbarkeit and ion composition. Salivary MUC5B concentration rose after exposure to mastic resin volatiles. CONCLUSIONS: Olfactory stimulation with mastic resin and α-pinene volatiles demonstrated a bona fide in vivo effect on saliva secretion, confirming their sialagogic capability, potentially as a result of local glandular AChE inhibition. These findings highlight the therapeutic potential of both volatile compounds in treating patients with xerostomia and hyposalivation through olfactory exposure.

Insecticidal and Detoxification Enzyme Inhibition Activities of Essential Oils for the Control of Pulse Beetle, Callosobruchus maculatus (F.) and Callosobruchus chinensis (L.) (Coleoptera: Bruchidae).

Pulse beetle is the most harmful pest attacking stored grains and affecting quality and marketability. Continuous use of chemical-based pesticides against pulse beetle led to the development of insecticidal resistance; essential oils (EOs) can be an effective natural alternative against this pest. The main objective was to study the chemical composition of seven EOs viz., Acorus calamus, Hedychium spicatum, Lavandula angustifolia, Juniperus recurva, Juniperus communis, Cedrus deodara and Pinus wallichiana, their insecticidal and enzyme inhibition activities against pulse beetle. The primary compounds present in these EOs were cis-asarone, 1,8-cineole, linalyl isobutyrate, 2-ß-pinene, camphene, α-dehydro-ar-himachalene and camphene. A. calamus oil showed promising fumigant toxicity to Callosobruchus maculatus and C. chinensis (LC50 = 1357.86 and 1379.54 µL/L, respectively). A combination of A. calamus + L. angustifolia was effective against C. maculatus and C. chinensis (LC50 = 108.58 and 92.18 µL/L, respectively). All the combinations of EOs showed synergistic activity. In the repellency study, A. calamus showed more repellence to C. maculatus and C. chinensis (RC50 = 53.98 and 118.91 µL/L, respectively). A. calamus and L. angustifolia oil at 2500, 5000 and 10,000 µL/L significantly inhibited the AChE and GST enzymes in C. maculatus and C. chinensis after 24 and 48 h.

α-Pinene inhibits the growth of cervical cancer cells through its proapoptotic activity by regulating the miR-34a-5p/Bcl-2 signaling axis.

Among gynecological tumors, cervical cancer (CC) has the second-highest prevalence and mortality rate. α-Pinene is a bicyclic monoterpenoid compound extracted from pine needles that carried promising anticancer properties. Nevertheless, its effect on CC and the underlying mechanism has not yet been elucidated. Therefore, we investigated the effect of α-Pinene on apoptosis in CC via in vitro assays of flow cytometry (FCW), terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot. Following that, we detected the proapoptotic function of α-Pinene on HeLa cells in vivo by TUNEL assay and immunofluorescence staining. Our results displayed that the α-Pinene inhibited the growth of HeLa cells and stalled the cells in the G0/G1 phase. Interestingly, we also detected that α-Pinene induced HeLa cells to apoptosis. The results investigated that α-Pinene induced HeLa cells apoptosis along with up-regulating the expression of Bax, Bid, caspase-9, caspase-3, miR-34a-5p, and down-regulating the expression of Bcl-2 in vitro. At the same time, the expression levels of target genes in vivo were consistent with those in vitro. Our experiment proved that α-Pinene promoted apoptosis, which will be used to hopefully maximize the therapeutic strategies in clinical studies in CC.

Neuroprotective effect of alpha-pinene is mediated by suppression of the TNF-α/NF-κB pathway in Alzheimer's disease rat model.

Monoterpene alpha-pinene possesses antioxidant, cardioprotective, and neuroprotective properties. We evaluated the effect of alpha-pinene on oxidative/nitrosative stress, neuroinflammation, and molecular and behavioral changes induced by beta-amyloid (Aß)1-42 in rats and investigated the possible mechanisms of these outcomes. Male Wistar rats received alpha-pinene (50 mg/kg intraperitoneally) for 14 consecutive days after intrahippocampal injection of Aß1-42 . Alpha-pinene decreased malondialdehyde and nitric oxide levels, increased glutathione content, and enhanced catalase activity in Aß-injected rats. Also, messenger RNA expression of tumor necrosis factor-α, interleukin-1ß, interleukin-6, nuclear factor κB, and N-methyl- d-aspartate receptor subunits 2A and 2B reduced in the hippocampus of these animals. Besides this, alpha-pinene repressed the Aß1-42 -induced reduction of nicotinic acetylcholine receptor α7 subunit and brain-derived neurotrophic factor expression. Treatment with alpha-pinene caused Aß-receiving rats to spend more time in the target quadrant in the Morris water maze test and led to an increase in percentages of open arm entrance and time spent in the open arm in the elevated plus-maze test. We concluded that alpha-pinene strengthens the antioxidant system and prevents neuroinflammation in the hippocampus of rats receiving Aß. It improves spatial learning and memory and reduces anxiety-like behavior in these animals. Consequently, alpha-pinene alleviates Aß-induced oxidative/nitrosative stress, neuroinflammation, and behavioral deficits. It is probably a suitable candidate for the treatment of neurodegenerative diseases.

The Effects of ß-Pinene, a Pine Needle Oil Monoterpene, on Adenovirus Type 3.

The mechanisms of the inhibitory action of ß-pinene, a pine needle oil monoterpene, on human adenovirus type 3 were studied using cytopathic inhibition test, MTT test, atomic force and laser confocal microscopy. ß-Pinene inhibited the viruses stronger that the reference antiviral medication ribavirin (p<0.05). Inhibition of viral cytopathic effect (CPE) increased with increasing the concentration of ß-pinene, which attested to direct elimination of adenovirus type 3. During viral reproduction phase, ß-pinene significantly inhibited proliferation of adenovirus type 3. Typical signs of adenoviral CPE as cell swelling and rounding were less pronounced in comparison with the control (ribavirin treatment). In addition, elevation of ß-pinene concentration significantly increased the cell survival rate (p<0.05). Laser confocal microscopy showed that fluorescence intensity in the ß-pinene group was significantly lower than in the control group (p<0.01), which was consistent with the results of MTT test, thereby providing additional arguments that ß-pinene affects the virus during the absorption phase. Thus, ß-pinene directly inactivates adenovirus type 3 and impedes its invasion into the cells, but produces no protective effects on cells. Understanding the mode of action of such monoterpenes as ß-pinene is of great importance for the development of new antiviral drugs.

Bioactive Molecules of Mandarin Seed Oils Diminish Mycotoxin and the Existence of Fungi.

Mandarin is a favorite fruit of the citrus family. Mandarin seeds are considered a source of nontraditional oil obtained from byproduct materials. This investigation aimed to assess the biomolecules of mandarin seeds and evaluated their antimycotic and antimycotoxigenic impact on fungi. Moreover, it evaluated the protective role of mandarin oil against aflatoxin toxicity in cell lines. The two types of extracted oil (fixed and volatile) were ecofriendly. The fatty acid composition, tocopherol, sterols, and carotenoids were determined in the fixed oil, whereas volatiles and phenolics were estimated in the essential oil. A mixture of the two oils was prepared and evaluated for its antimicrobial impact. The reduction effect of this mixture was also investigated to reduce mycotoxin secretion using a simulated experiment. The protective effect of the oil was evaluated using healthy strains of cell lines. Fixed oil was distinguished by the omega fatty acid content (76.24%), lutein was the major carotenoid (504.3 mg/100 g) and it had a high ß-sitosterol content (294.6 mg/100 g). Essential oil contained limonene (66.05%), α-pinene (6.82%), ß-pinene (4.32%), and γ-terpinene (12.31%) in significant amounts, while gallic acid and catechol were recorded as the dominant phenolics. Evaluation of the oil mix for antimicrobial potency reflected a considerable impact against pathogenic bacteria and toxigenic fungi. By its application to the fungal media, this oil mix possessed a capacity for reducing mycotoxin secretion. The oil mix was also shown to have a low cytotoxic effect against healthy strains of cell lines and had potency in reducing the mortality impact of aflatoxin B1 applied to cell lines. These results recommend further study to involve this oil in food safety applications.

The terpenes camphene and alpha-bisabolol inhibit inflammatory and neuropathic pain via Cav3.2 T-type calcium channels.

T-type calcium channels are known molecular targets of certain phytocannabinoids and endocannabinoids. Here we explored the modulation of Cav3.2 T-type calcium channels by terpenes derived from cannabis plants. A screen of eight commercially available terpenes revealed that camphene and alpha-bisabolol mediated partial, but significant inhibition of Cav3.2 channels expressed in tsA-201 cells, as well as native T-type channels in mouse dorsal root ganglion neurons. Both compounds inhibited peak current amplitude with IC50s in the low micromolar range, and mediated an additional small hyperpolarizing shift in half-inactivation voltage. When delivered intrathecally, both terpenes inhibited nocifensive responses in mice that had received an intraplantar injection of formalin, with alpha-bisabolol showing greater efficacy. Both terpenes reduced thermal hyperalgesia in mice injected with Complete Freund's adjuvant. This effect was independent of sex, and absent in Cav3.2 null mice, indicating that these compounds mediate their analgesic properties by acting on Cav3.2 channels. Both compounds also inhibited mechanical hypersensitivity in a mouse model of neuropathic pain. Hence, camphene and alpha-bisabolol have a wide spectrum of analgesic action by virtue of inhibiting Cav3.2 T-type calcium channels.

Chemical Composition and Biological Activities of Essential Oils from the Leaves, Stems, and Roots of Kadsura coccinea.

The chemical composition and biological activities of the essential oils from the leaves, stems, and roots of Kadsura coccinea (K. coccinea) were investigated. The essential oils were extracted by hydro distillation and analyzed by gas chromatography mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Antioxidant activities of the essential oils were examined with DPPH radical scavenging assay, ABTS cation radical scavenging assay, and ferric reducing antioxidant power assay. Antimicrobial activities were evaluated by determining minimum inhibitory concentrations (MIC) and minimum microbiocidal concentrations (MMC). Acetylcholinesterase and butyrylcholinesterase inhibitory activity of the essential oils were also tested. A total of 46, 44, and 47 components were identified in the leaf, stem, and root oils, representing 95.66%, 97.35%, and 92.72% of total composition, respectively. The major compounds of three essential oils were α-pinene (16.60-42.02%), ß-pinene (10.03-18.82%), camphene (1.56-10.95%), borneol (0.50-7.71%), δ-cadinene (1.52-7.06%), and ß-elemene (1.86-4.45%). The essential oils were found to have weak antioxidant activities and cholinesterase inhibition activities. The essential oils showed more inhibitory effects against Staphylococcus aureus (S. aureus) than those of other strains. The highest antimicrobial activity was observed in the root oil against S. aureus, with MIC of 0.78 mg/mL. Therefore, K. coccinea essential oils might be considered as a natural antibacterial agent against S. aureus with potential application in food and pharmaceutical industries.

Myrtenal and ß-caryophyllene oxide screened from Liquidambaris Fructus suppress NLRP3 inflammasome components in rheumatoid arthritis.

BACKGROUND: Liquidambaris Fructus (LF) is the infructescence of Liquidambar formosana. In Traditional Chinese Medicine, LF has been used to treat joint pain, a common symptom of arthritis and rheumatism; however, a lack of pharmacological evidence has limited its applications in modern clinics. Therefore, this study aims to explore the protective effect of LF on rheumatoid arthritis (RA) and to identify its active ingredients. METHODS: Rats with adjuvant-induced arthritis (AIA) were divided into 4 groups and administered petroleum ether extract of LF (PEL), ethyl acetate extract of LF (EEL), water extract of LF (WEL), or piroxicam (PIR) respectively for 3 weeks. Two additional groups were used as normal control (NC) and model control (MC) and administered distilled water as a placebo. The clinical scores for arthritis, bone surface, synovial inflammation and cartilage erosion were used to evaluate the therapeutic efficacy of each treatment. The serum IL-1ß and TNF-α level and the expression of NLRP3, IL-1ß and caspase-1 p20 in the synovial tissue of AIA rats were evaluated by ELISA and Western blot. The active ingredients of LF were investigated using network pharmacology and molecular docking methods, and their inhibition of NLRP3 inflammasome activation was verified in the human rheumatoid arthritis fibroblast-like synovial cells (RA-FLS) model. RESULTS: PEL could alleviate paw swelling, bone and joint destruction, synovial inflammation and cartilage erosion in the AIA rats, with significantly superior efficacy to that of EEL and WEL. PEL reduced IL-1ß and TNF-α serum levels, and attenuated the upregulation of NLRP3, IL-1ß and caspase-1 p20 expression in the synovial tissue of AIA rats. Network pharmacology and molecular docking results indicated that myrtenal and ß-caryophyllene oxide were the main two active ingredients of PEL, and these two compounds showed significant inhibition on TNF-α, NLRP3, IL-1ß and caspase-1 p20 expression in RA-FLS. CONCLUSIONS: Myrtenal and ß-caryophyllene oxide screened from PEL could suppress the activation of NLRP3 inflammasome, thereby alleviating RA symptoms.

Myrtenol alleviates oxidative stress and inflammation in diabetic pregnant rats via TLR4/MyD88/NF-κB signaling pathway.

Gestational diabetes mellitus (GDM) is a special kind of diabetes that arises only during pregnancy. A woman with GDM has a higher risk of developing type-2 diabetes and other metabolic diseases. In this exploration, we intended to scrutinize the therapeutic actions of Myrtenol against the streptozotocin (STZ)-provoked GDM in rats. GDM was provoked in the pregnant rats via injecting the 1% of STZ (25 mg/kg) and then treated with the 50 mg/kg of myrtenol. The glucose level and bodyweight of animals were noted. The lipid profile, that is, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) was determined by respective kits. The lipid peroxidation and antioxidants status were examined using assay kits. The status of proinflammatory markers was investigated by assay kits. The messenger RNA (mRNA) expressions of TLR4/MyD88/NF-κB signaling proteins were studied by reverse transcription polymerase chain reaction analysis. The hepatic and pancreatic tissues were examined microscopically. Myrtenol treatment notably decreased the status of blood glucose and lipid profile and improved the HDL in the GDM rats. The status of lipid peroxidation and inflammatory markers were substantially reduced by the myrtenol and it enhanced the antioxidants status of GDM animals. Myrtenol treatment remarkably downregulated the mRNA expressions of TLR4/MyD88/NF-κB signaling proteins. The histological findings also proved the therapeutic actions of myrtenol. Altogether, the findings of this investigation unveiled the therapeutic actions of the myrtenol against the STZ-provoked GDM in rats. Myrtenol could be a promising therapeutic agent to treat GDM in the future.

Identification and Behavioral Assays of Alarm Pheromone in the Vetch Aphid Megoura viciae.

Aphids are destructive pests, and alarm pheromones play a key role in their chemical ecology. Here, we conducted a detailed analysis of terpenoids in the vetch aphid, Megoura viciae, and its host plant Pisum sativum using gas chromatography/mass spectrometry. Four major components, (-)-ß-pinene (49.74%), (E)-ß-farnesene (32.64%), (-)-α-pinene (9.42%) and ( +)-limonene (5.24%), along with trace amounts of ( +)-sabinene, camphene and α-terpineol) (3.14%) were found in the aphid. In contrast, few terpenoids were found in the host plant, consisting mainly of squalene (66.13%) and its analog 2,3-epoxysqualene (31.59%). Quantitative analysis of the four major terpenes in different developmental stages of the aphid showed that amounts of the monoterpenes increased with increasing stage, while the sesquiterpene amount peaked in the 3rd instar. (-)-ß-Pinene was the most abundant terpene at all developmental stages. Behavioral assays using a three-compartment olfactometer revealed that the repellency of single compounds varied in a concentration-dependent manner, but two mixtures [(-)-α-pinene: (-)-ß-pinene: (E)-ß-farnesene: ( +)-limonene = 1:44.4:6.5:2.2 or 1:18.4:1.3:0.8], were repellent at all concentrations tested. Our results suggest that (-)-α-pinene and (-)-ß-pinene are the major active components of the alarm pheromone of M. viciae, but that mixtures play a key role in the alarm response. Our study contributes to the understanding of the chemical ecology of aphids and may help design new control strategies against this aphid pest.

Neuroprotective effect of α-pinene self-emulsifying nanoformulation against 6-OHDA induced neurotoxicity on human SH-SY5Y cells and its in vivo validation for anti-Parkinson's effect.

Oxidative stress (OS) is involved in the multifaceted pathogenic paradigm of neurodegenerative diseases like Parkinson's disease (PD). Monoterpenes like α-pinene (ALP) is considered to be a therapeutically potent antioxidant agent able to attenuate and scavenge various reactive oxygen species and reactive nitrogen species. The present study aimed to evaluate the in vitro and in vivo neuroprotective effect of α-pinene self-emulsifying nanoformulation (ALP-SENF) for PD. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was done to evaluate the neurotoxic dose of the ALP-SENF; however, the neuroprotective effect was assessed by 6-hydroxydopamine (6-OHDA) induced neurotoxicity model on SH-SY5Y taking NAC (N-acetyl-l-cysteine) as standard. The in vivo anti-Parkinson's activity of the ALP-SENF was compared with that of the plain ALP suspension by using reserpine antagonism and haloperidol-induced Parkinsonism model in rats. Various behavioral tests and biochemical antioxidant enzymes were estimated. The in vitro results revealed that treatment with ALP-SENF at a concentration of 100 and 200 µM was found to show significant neuronal SH-SY5Y cell viability against 50 µM 6-OHDA. ALP-SENF treated animals have seen significant neurobehavioral improvement. Furthermore, the levels of antioxidative enzymes in biochemical test reveals a marked enhancement in the expression of antioxidant enzymes that significantly attenuated the OS induced neurodegeneration. Due to the mechanisms of their antioxidant action, it was probably due to the scavenging of free radicals and the expression of antioxidant enzymes. It also improved neurobehavioral changes induced by reserpine and haloperidol.

The Mode of Action of Cyclic Monoterpenes (-)-Limoneneand (+)-α-Pinene on Bacterial Cells.

A broad spectrum of volatile organic compounds' (VOCs') biological activities has attracted significant scientific interest, but their mechanisms of action remain little understood. The mechanism of action of two VOCs-the cyclic monoterpenes (-)-limonene and (+)-α-pinene-on bacteria was studied in this work. We used genetically engineered Escherichia coli bioluminescent strains harboring stress-responsive promoters (responsive to oxidative stress, DNA damage, SOS response, protein damage, heatshock, membrane damage) fused to the luxCDABE genes of Photorhabdus luminescens. We showed that (-)-limonene induces the PkatG and PsoxS promoters due to the formation of reactive oxygen species and, as a result, causes damage to DNA (SOSresponse), proteins (heat shock), and membrane (increases its permeability). The experimental data indicate that the action of (-)-limonene at high concentrations and prolonged incubation time makes degrading processes in cells irreversible. The effect of (+)-α-pinene is much weaker: it induces only heat shock in the bacteria. Moreover, we showed for the first time that (-)-limonene completely inhibits the DnaKJE-ClpB bichaperone-dependent refolding of heat-inactivated bacterial luciferase in both E. coli wild type and mutant ΔibpB strains. (+)-α-Pinene partially inhibits refolding only in ΔibpB mutant strain.