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Ayapana triplinervis (M.Vahl) R.M.King & H.Rob. (Asteraceae), popularly known as japana, is a tropical, aromatic subshrub widely used as tea to combat some diseases. The essential oil was obtained from the leaves by hydrodistillation (3 h), and the chemical composition was analyzed by gas chromatography coupled to mass spectrometry. For in vivo assays, Mus musculus/Swiss mice were used to evaluate oral acute toxicological (at dose of 2000 mg/kg); peripheral and central analgesic for abdominal contortion (doses of 6.25, 12.5, 25, 50 and 100 mg/kg), hot plate test (12.5, 25, 50, and 100 mg/kg) and formalin (25, 50 and 100 mg/kg); open field test (100 mg/kg); and anti-inflammatory by ear swelling induced by xylene (6.25,12.5, 25, 50, and 100 mg/kg). The yield of A. triplinervis essential oil (AtEO) was 4.6%, and the oxygenated monoterpene 2,5-dimethoxy-p-cymene was the major compound in this study (63.6%). AtEO at a dose of 2,000 mg/kg orally did not change the behavior patterns or mortality of the animals; liver and kidney biochemical levels were similar to the control group, indicating no liver and kidney toxicity. Moreover, AtEO, at doses of 6.25, 12.5, 25, 50, and 100 mg/kg, reduced abdominal contortions by 21%, 54%, 91%, 58%, and 55%, respectively. In the hot plate test, AtEO showed a significant increase in latency time in the 60-min interval at doses of 25 mg/kg (11.3 ± 3.3 s) and 100 mg/kg (11.9 ± 0.9 s). In the first phase of the formalin test, AtEO decreased paw licking time at doses of 25, 50, and 100 mg/kg, with inhibition of 22%, 38%, and 83%; in the second phase, the same doses, decreased licking time with inhibition of 24%, 34%, and 76%. AtEO did not present a significant change in the spontaneous locomotor activity of the animals. Doses of 6.25, 12.5, 25, 50, and 100 mg/kg significantly reduced ear edema induced by topical application of xylene with percentages of 40%, 39%, 54%, 45%, and 45%, respectively. So, AtEO demonstrated low acute oral toxicity and exhibited significant antinociceptive and anti-inflammatory actions, consistent with the use of A. triplinervis in traditional medicine.

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Introduction: Essential oils (EOs) from the Hyptis genus have been reported as bactericides and fungicides. However, the properties of these oils can be affected by climatic factors, as well as the collection period, which promotes changes in the chemical composition of the oil. In this context, this study aimed to evaluate the climatological influences on the chemical composition of the essential oil from the leaves of Hyptis crenata. Methods: The leaves were collected in Marajó island (Brazil) monthly for a year. The EOs were obtained by hydrodistillation and analyzed by Gas Chromatography coupled to Mass Spectrometry (GC-MS). Pearson's correlation was used to evaluate the relationship between climatic parameters, content, and chemical composition of essential oil; multivariate analysis was used to evaluate the interrelationship between samples and their chemical constituents. Results and Discussion: The constituents with the highest contents (>2.0%) in essential oils during the studied period were 1,8-cineole (28.48% ± 4.32%), α-pinene (19.58% ± 2.29%), camphor (11.98% ± 2.54%), ß-pinene (9.19% ± 1.47%), limonene (6.12% ± 3.15%), α-terpineol (2.42% ± 0.25%) and borneol (2.34% ± 0.48%). ß-Pinene significantly correlated (p < 0.05) with precipitation and humidity. According to the chemometric tools, two groups were formed: chemical profile I, marked by 1,8 cineole, α-pinene, ß-pinene, borneol, α-terpineol, and limonene, while group II (July) presented a chemical type characterized by camphor. It is understood that the species in question can be a reliable source of biologically active components during different climatic periods in the Amazon. The chemical variability could have significant implications for the pharmaceutical industry and traditional medicine.

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Gamma-terpinene (γ-TPN) is a cyclohexane monoterpene isolated from plant essential oils, such as tea tree (Melaleuca alternifolia), oregano (Origanum vulgare), rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris Marchand), and eucalyptus (Eucalyptus sp.). Terpenes are widely studied molecules pharmacologically active on the cardiovascular system, hemostasis, and antioxidant actions. Herein, it was investigated the cytotoxic and antiplatelet activity of γ-TPN using different non-clinical laboratory models. For in silico evaluation, the PreADMET, SwissADME, and SwissTargetPrediction softwares were used. Molecular docking was performed using the AutoDockVina and BIOVIA Discovery Studio databases. The cytotoxicity of γ-TPN was analyzed by the MTT assay upon normal murine endothelial SVEC4-10 and fibroblast L-929 cells. Platelet aggregation was evaluated with platelet-rich (PRP) and platelet-poor (PPP) plasma from spontaneously hypertensive rats (SHR), in addition to SVEC4-10 cells pre-incubated with γ-TPN (50, 100, and 200 µM) for 24 h. SHR animals were pre-treated by gavage with γ-TPN for 7 days and divided into four groups (negative control, 25, 50, and 100 mg/kg). Blood samples were collected to measure nitrite using the Griess reagent. Gamma-TPN proved to be quite lipid-soluble (Log P = +4.50), with a qualified profile of similarity to the drug, good bioavailability, and adequate pharmacokinetics. It exhibited affinity mainly for the P2Y12 receptor (6.450 ± 0.232 Kcal/mol), moderate cytotoxicity for L-929 (CC50 = 333.3 µM) and SVEC 4-10 (CC50 = 366.7 µM) cells. The presence of γ-TPN in SVEC 4-10 cells was also able to reduce platelet aggregation by 51.57 and 44.20% at lower concentrations (50 and 100 µM, respectively). Then, γ-TPN has good affinity with purinergic receptors and an effect on the reversal of platelet aggregation and oxidative stress, being promising and safe for therapeutic targets and subsequent studies on the control of thromboembolic diseases.

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Background: The scope of the study was to analyze original preclinical studies on the antimicrobial effects of carvacrol and derivatives on the Mycobacterium genus. Materials & methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, four databases (PubMed, Web of Science, SCOPUS and EMBASE) were searched. Results: The search retrieved 392 records, of which 11 papers were selected. Heterogeneity in the techniques and mycobacterial targets was observed. Carvacrol demonstrated synergistic antimycobacterial activity with rifampicin against multidrug-resistant Mycobacterium tuberculosis on membranes and biofilms. In silico approaches showed specific targets in mycobacteria, by inhibition and molecular docking assays, on the enzyme chorismate mutase and the heat shock protein 16.3. Conclusion: Carvacrol has been shown to be a scaffold candidate for future molecules with activity against mycobacteria.

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Essential oils (EOs) produced by aromatic plants belonging to different families, such as Asteraceae, Lamiaceae, Lauraceae, Myrtaceae, and Piperaceae, are generally suggested as potential sources of new molecules with insecticidal activity. The EOs are constituted bioactive molecules that may have to control Drosophila suzukii (Matsumura), a serious economic invasive pest of small fruits worldwide. Currently, the control strategy against D. suzukii depends especially on treatment with synthetic insecticides. Due to impacts to human health and the environment, efforts have been made to seek efficient insecticides in chemical pest control. Thus, sixty-five oils extracted from plants were selected to find new alternative types of insecticides active against D. suzukii. The monoterpenes, such as limonene, α-pinene, 1,8-cineole, linalool, menthol, geranial, and neral, were the most representative, which stand out for their insecticidal efficiency. The OEs demonstrated to be used in the management of D. suzukii, thus being an effective strategy to control this pest, ensuring crop protection and agricultural sustainability. Therefore, the substitution by natural products or eco-friendly pesticides instead of synthetic pesticides represents a notable option to mitigate harmful effects on human health and the environment.

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The chemical constituents and antimic robial activity of the essential oil isolated from the rhizomes of Alpinia menghaiensis S.Q. Tong & Y.M. Xia in S.Q. Tong from Vietnam was studied and reported. The techniques of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) were used to characterize the chemical constituents of the essential oil while the microdilution assay was used to evaluate the antimicrobial activity. The main compounds identified in the rhizome essential oil consist of ß - pinene (46.5%), ß - phellandrene (25.7%) and α - pinene (8.5%). The studied essential oil inhibited the growth of Pseudomonas aeruginosa ATCC27853 with minimum inhibitory concentrations (MIC) value of 15.32 µg/mL ± 0. 01, and median inhibitory concentration (IC50) value of 32.0 ± 0.01 µg/mL. The essential oil also displayed activity against Staphylococcus aureus ATCC25923 (MIC 31.57 ± 0.01 µg/mL) and Bacillus cereus ATCC14579 (MIC, 34.21 µg/mL ± 0.01 µg/mL), and IC 50 va lue of 64.0 ± 0.01 µg/mL. This is the first report on the rhizome oil composition, as well as the antimicrobial of essential oils from A. menghaiensis . The paper discusses further the comparative analysis of essential oils from A. menghaiensis .

Se investigaron los componentes químicos y la actividad antimicrobiana del aceite escencial aislado de los rizomas de Alpinia menghaiensis S.Q. Ton g & Y. M. Xia en S.Q. Tong de Vietnam. Se usaron las técnicas de cromatografía de gases (GC) y cromatografía de gases con espectrometría de masas (GC/MS) para caracterizar los componentes químicos del aceite escencial, mientras que se utilizó un ensayo de microdilución para evaluar la actividad antimicrobial. Se identificaron los componentes principales en el aceite escencial del rizoma, compuesto de ß - pineno (46.5%), ß - fellandreno (25.7%) y α - pineno (8.5%). El aceite escencial estudiado inhibió el crecimie nto de Pseudomonas aeruginosa ATCC27853 con concentraciones de actividad mínima inhibitoria (MIC) de 15.32 µg/mL ± 0.01, y una m ediana de concentración inhibitoria (IC 50 ) de 32.0 ± 0.01 µg/mL. El aceite escencial también mostró actividad contra Staphylococ cus aureus ATCC25923 (MIC 31.57 ± 0.01 µg/mL) y Bacillus cereus ATCC14579 (MIC, 34.21 µg/mL ± 0.01 µg/mL), y valor IC 50 de 64.0 ± 0.01 µg/mL. Este es el primer reporte sobre la composición del aceite de rizoma, así como de las propiedades antimicrobianas d e los aceites escenciales de A. menghaiensis . El artículo discute el análisis comparativo de los aceites escenciales de A. menghaiensis .

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Pain is characterized by the unpleasant sensory and emotional sensation associated with actual or potential tissue damage, whereas nociception refers to the mechanism by which noxious stimuli are transmitted from the periphery to the CNS. The main drugs used to treat pain are nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics, which have side effects that limit their use. Therefore, in the search for new drugs with potential antinociceptive effects, essential oils have been studied, whose constituents (monoterpenes) are emerging as a new therapeutic possibility. Among them, linalool and its metabolites stand out. The present study aims to investigate the antinociceptive potential of linalool and its metabolites through a screening using an in silico approach. Molecular docking was used to evaluate possible interactions with important targets involved in antinociceptive activity, such as α2-adrenergic, GABAergic, muscarinic, opioid, adenosinergic, transient potential, and glutamatergic receptors. The compounds in the investigated series obtained negative energies for all enzymes, representing satisfactory interactions with the targets and highlighting the multi-target potential of the L4 metabolite. Linalool and its metabolites have a high likelihood of modulatory activity against the targets involved in nociception and are potential candidates for future drugs.

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Plant-based insecticides offer advantages such as negligible residual effects, reduced risks to both humans and the environment, and immunity to resistance issues that plague conventional chemicals. However, the practical use of monoterpenes in insect control has been hampered by challenges including their poor solubility and stability in aqueous environments. In recent years, the application of nanotechnology-based formulations, specifically nanoemulsions, has emerged as a prospective strategy to surmount these obstacles. In this study, we developed and characterized nanoemulsions based on cymene and myrcene and assessed their toxicity both in vitro using human keratinocytes (HaCAT) cells and in an in vivo model involving Galleria mellonella larvae. Additionally, we investigated the insecticidal efficacy of monoterpenes against the mosquito Aedes aegypti, the primary dengue vector, via larval bioassay. Employing a low-energy approach, we successfully generated nanoemulsions. The cymene-based nanoemulsion exhibited a hydrodynamic diameter of approximately 98 nm and a zeta potential of -25 mV. The myrcene-based nanoemulsion displayed a hydrodynamic diameter of 118 nm and a zeta potential of -20 mV. Notably, both nanoemulsions demonstrated stability over 60 days, accompanied by controlled release properties and low toxicity towards HaCAT cells and Galleria mellonella larvae. Moreover, the nanoemulsions exhibited significant lethality against third-instar Aedes aegypti larvae at a concentration of 50 mg/L. In conclusion, the utilization of nanoemulsions encapsulating cymene and myrcene presents a promising avenue for overcoming the limitations associated with poor solubility and stability of monoterpenes. This study sheds light on the potential of the nanoemulsions as effective and environmentally friendly insecticides in the ongoing battle against mosquito-borne diseases.

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Pectis brevipedunculata (Gardner) Sch.Bip., known in Brazil as alecrim do campo, is a small Asteraceae family plant with a calming effect and consumed as tea. This species contains components, such as neral and geranial, that display various biological activities, such as leishmanicidal. The aim was to chemically characterize the essential oil (EO) obtained from P. brevipedunculata (EO-PB) by hydrodistillation and a microemulsion formulated with EO (ME-PB), Tween 80 and Transcutol P, assess the leishmanicidal effect against Leishmania (L.) amazonensis promastigotes and cytotoxicity against RAW 264.7. EO-PB and ME-PB were analyzed by Gas Chromatography Mass Spectrometry (GC/MS). Monoterpene hydrocarbons were noteworthy among the identified compounds. The main EO-PB constituents were α-pinene and limonene, followed by neral and geranial, which were maintained in ME-PB. EO-PB presented an inhibitory concentration (IC50) of 20 µg/mL and ME-PB of 0.93 µg/mL. ME-PB inhibition towards the parasite was 20-fold higher than that of EO-PB. This indicated that EO incorporation to the microemulsion resulted in optimized biological activity. Selectivity indices indicate that ME-PB is more selective concerning parasite inhibition. Thus, ME-PB may comprise an adequate approach against Leishmania, as the inhibitory concentration (IC50) promastigotes was lower than that considered toxic for cells cell cytotoxicity of 50% (CC50).

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Abstract This is a nonclinical, controlled, and triple-blind study to investigate the effects of codeine-associated geraniol on the modulation of orofacial nociception and its potential central nervous system depressing effect in an animal model. The orofacial antinociceptive activity of geraniol in combination with codeine was assessed through the following tests: (i) formalin-induced pain, (ii) glutamate-induced pain, and (iii) capsaicin-induced pain. Six animals were equally distributed into six groups and received the following treatments, given intraperitoneally (i.p.) 30 minutes before the experiments: a) geraniol/codeine 50/30 mg/kg; b) geraniol/codeine 50/15 mg/kg; c) geraniol/codeine 50/7.5 mg/kg; d) geraniol 50 mg/kg; e) codeine 30 mg/kg (positive control); or f) 0.9% sodium chloride (negative control). We performed pain behavior analysis after the injection of formalin (20 µL, 20%), glutamate (20 µL, 25 µM), and capsaicin (20 µL, 2.5 µg) into the paranasal region. Rubbing time of the paranasal region by the hind or front paw was used as a parameter. In the neurogenic phase of the formalin test, the geraniol/codeine at 50/7.5 mg/kg was able to promote the maximum antinociceptive effect, reducing nociception by 71.9% (p < 0.0001). In the inflammatory phase of the formalin test, geraniol/codeine at 50/30 mg/kg significantly reduced orofacial nociception (p < 0.005). In the glutamate test, geraniol/codeine at 50/30 mg/kg reduced the rubbing time by 54.2% and reduced nociception in the capsaicin test by 66.7% (p < 0.005). Geraniol alone or in combination does not promote nonspecific depressing effects on the central nervous system. Based on our findings, we suggest the possible synergy between geraniol and codeine in the modulation of orofacial pain.