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Major depressive disorder (MDD) is a debilitating illness that affects millions of people worldwide. Currently available antidepressants often take weeks to months to reach their full effect, which leads to an increased risk of suicidal behavior in patients with MMD. Intranasally, esketamine has emerged as an alternative to current antidepressants because of its rapid onset and long-lasting effects in patients with MDD. Animal models are useful for the initial pharmacological screening and for a better understanding of the mechanisms underlying the effects of new drugs with potential against MDD. There is a lack of data on alternative routes of drug administration, either oral or injectable, that can be used in preclinical studies. This study aimed to test whether ketamine has antidepressant-like effects in mice when administered via nebulization using a low-cost apparatus. When mice whose depressive-like behavior was induced by corticosterone were treated with nebulized ketamine at concentrations of 1.3, 2.6, and 5.2 mg/mL, immobility was reduced by 38.6 %, 62.0 %, and 61.1 %, respectively, in the forced swimming test (FST) and 43.6 %, 42.1 %, and 57.9 %, respectively, in the tail suspension test (TST). When depression-like behavior was induced by dexamethasone, nebulization with ketamine reduced immobility by 79.7 %, 49.2 %, and 44.4 % in the FST and 80.9 %, 71.4 %, and 80.4 %, respectively, in the TST. When depression-like behavior was induced by the association between dexamethasone and unpredictable chronic mild stress (UCMS) exposure, immobility was reduced by 26.1 %, 55.3 %, and 19.1 % in FST. Mice treated with nebulized ketamine did not show significant changes in the distance covered or in the time spent moving in the open field test. The efficacy of intraperitoneal and nebulized ketamine is equivalent, which shows that nebulization can be an alternative inexpensive route of drug administration for behavioral studies in rodents., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Cannabis sativa is a millenary medicinal plant. However, contrary to worldwide paradigm-shifting, countries like Brazil still prohibit C. sativa cultivation and its medicinal use, even though many populations use aerial parts and roots of this plant for healthcare. As such, the objective of this work was to identify substances in the samples of the C. sativa roots, tracing a correlation with antitussive and expectorant effects. Therefore, samples of C. sativa roots were donated by the Polícia Federal Brasileira, and its aqueous extract (AECsR) was prepared with subsequent lyophilization, to maintain the material stability. After that, the material was analyzed by LC-MS to observe its chemical profile. Four samples (AECsR-A, B, C, and D) were tested in animal models of citric acid-induced cough (0.4 M) and phenol red expectoration (500 mg/kg). Using LC-MS it was possible to identify 5 molecules in C. sativa roots: p -coumaroyltyramine, tetrahydrocannabinol-C4, feruoiltyramine, anhydrocanabisativine, and cannabisativine. In experimental protocols, male mice ( Mus musculus ) were treated with samples of AECsR at doses of 12.5, 25, or 50 mg/kg regardless of the pharmacological test. In these tests, all samples showed the potential to treat cough and promote fluid expectoration, differing only in the dose at which these effects were observed. Therefore, the data showed that the C. sativa roots of the Brazilian Northeast showed antitussive and expectorant effects, even with intense secondary metabolites' variation, which alters its potency, but not its effect. This highlights the importance of this medicinal plant for future therapy and corroborates to traditional use., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Background: Depression is a psychiatric disorder with limited therapy options. Psychedelics are new antidepressant candidates, being the ayahuasca one of the most promising ones. A synergistic combination of N,N -dimethyltryptamine (DMT) and β-carbolines allows ayahuasca antidepressant properties. Another psychedelic and DMT-containing beverage is the jurema wine used religiously by indigenous people from Northeastern Brazil., Aims: To evaluate the antidepressant-like effect of standardized extract of Mimosa tenuiflora (SEMT), associated or not with harmine (β-carboline), in behavioral models of depression., Methods: The SEMT was submitted to (+) ESI-IT-LC/MS analysis for DMT quantification. To assess the antidepressant-like effect of SEMT, the open field (OFT), tail suspension (TST), and forced swim (FST) tests were performed. To verify the participation of serotonergic systems, the 5-hydroxytryptophan (5-HTP)-induced head twitch test was performed., Results: The content of DMT found in SEMT was 24.74 ± 0.8 mg/g. Yuremamine was also identified. SEMT presented an antidepressant-like effect in mice submitted to the TST and FST, independent from harmine, with no significant alterations on the OFT. The sub-dose interaction between SEMT and ketamine also produced an anti-immobility effect in the TST, with no changes in the OFT. SEMT potentiated the head twitch behavior induced by 5-HTP and ketanserin prevented its antidepressant-like effect in the TST ( p  < 0.05)., Conclusions: SEMT presented a harmine-independent antidepressant-like effect in mice submitted to the TST and FST. This effect occurs possibly via activation of serotonergic systems, particularly the 5-HT 2A/2C receptors.

Jatropha mutabilis (Pohl) Baill is an endemic species of the Caatinga biome, little studied in terms of chemical composition. The objective of this work was to develop an analytical methodology to quantify vitexin in the ethanolic extract of J. mutabilis and to evaluate the expectorant and antitussive activities in mice. The expectorant activity was performed by measuring the phenol red obtained from the bronchoalveolar fluid in animals and the antitussive activity was evaluated by the cough method induced by citric acid (0.4 M). The method developed by HPLC-DAD proved to be simple, linear, precise, accurate, robust and specific. Besides, both vitexin (0.2, 1 and 5 mg/kg) and the extract of J. mutabilis (20, 102, 510 mg/kg) showed efficacy in decrease cough and increase aqueous mucus in mice, but vitexin was more potent. Lastly, the identification of vitexin opens the possibility of new studies for J. mutabilis .

Ethnopharmacological Relevance: Many studies are performed with the aerial parts of Cannabis sativa L. (Cannabaceae). However, roots remain poorly studied, despite citations in the scientific literature. The C. sativa roots are indicated for the treatment of pain, inflammation, fever, among other health problems., Aim of the Study: This study aimed to evaluate the antinociceptive, antipyretic, antiasthmatic, and spasmolytic activities of C. sativa roots in experimental models using mice and rats., Material and Methods: The chemical composition of the aqueous extract of C. sativa roots (AECsR) was evaluated by LC-MS. The antinociceptive activity was assessed in mice by the induction of writhing with acetic acid, paw licking with formalin, and reactivity in the hot plate test. Fever was induced by the administration of a suspension of Saccharomyces cerevisiae in young rats. The asthmatic activity was performed with ovalbumin (OVA)-immunized mice with cellular and histological analysis. Finally, the spasmolytic activity was performed using mice isolated trachea. For in vivo studies, the doses were 12.5, 25, or 50 mg/kg whereas for in vitro, the concentration of AECsR was 729 μg/mL., Results: From the LC-MS data, we identified p-coumaroyltyramine, feruloyltyramine canabissativine in AECsR. The extract promoted a reduction of writhing in all tested doses (12.5, 25, or 50 mg/kg). Similarly, it reduced the pain in the formalin test at doses of 12.5 and 50 mg/kg (first phase) and 12.5 and 25 mg/kg (second phase). In the hot plate test, the doses of 12.5, 25, and 50 mg/kg promoted antinociceptive effect at different times, and the lowest dose maintained its action in the analyzes performed at 60, 90, and 120 min after administration. The anti-inflammatory activity of AECsR was observed in the mouse model of asthma, reducing the total leukocyte count in the bronchoalveolar fluid (BALF) at a dose of 25 mg/kg, as well as reducing eosinophilia in all tested doses (12.5, 25, and 50 mg/kg). Histological analysis of lungs stained with H&E and PAS showed a reduction in the number of inflammatory cells in the perivascular and peribronchial region, as well as reduced mucus production., Conclusion: The results suggest that AECsR promotes pain control, either by a central or inflammatory mechanism, and has antiasthmatic activity. However, there was no antipyretic or spasmolytic effect., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Asthma is a chronic inflammatory disease that targeting lower airways, being characterized by bronchial smooth muscle hyper responsiveness and mucus hypersecretion. Asthma is considered the most common respiratory disease in the world, affecting approximately 235 million individuals. The main therapy sometimes fails to establish clinical improvement in patients, which leads to a constant search for new alternatives. Camphor is a transparent solid monoterpene with a strong aroma, which due to its high lipophilicity is insoluble in water. Nanostructured carrier systems have shown promise as a delivery system for lipophilic compounds such as monoterpenes. Therefore, the objective of this work was to evaluate the relaxant effect of nanoemulsified camphor (NEC), as well as the mechanism of action of that monoterpene, in isolated rat trachea. The results obtained demonstrated that NEC promote relaxation of the isolated rat trachea when smooth muscle contraction was induced by both carbachol (CCh) and KCl, presenting a pCE 50 of 2.25 ± 0.27 and 3.30 ± 0.07, respectively. In the presence of dexamethasone (DEXA), tetraethylammonium (TEA), glibenclamide (GLIB), 1H-[1,2,4]-oxadiazole-[4,3,-a]-quinoxaline-1-one (ODQ) and ruthenium red (RR) there was a significant difference in at least one of the evaluated pharmacological parameters, such as concentration-response curves shape, E max or pCE 50 . As conclusion, NEC may be involved with β-adrenergic receptors, channels for K + sensitive to ATP (K ATP ) or Channels for K+ opened by Ca 2+ (K Ca ), increase in prostanoids and with receptor channel with transient potential (TRPv). In conclusion, β-adrenergic receptors, prostanoids, nitric oxide (NO), ATP-sensitive K + channels (K ATP ), Ca 2+ -opened K + channels (K Ca ), and transient receptor potential cation channel subfamily V (TRPV) are involved in the relaxing effect of NEC. In addition, the mechanism of action of NEC may be involved with the signal transduction pathway Nitric Oxide/soluble guanylyl cyclase/cGMP/cGMP-activated protein kinase. NEC, therefore, demonstrates spasmolytic activity when presenting tracheal relaxation compared to CCh and KCl contracturants., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: There are many studies and therapeutic properties attributed to the flowers and leaves of the Cannabis species, but even with few pharmacological studies, Cannabis sativa L. (Cannabaceae) roots presents several therapeutic indications in folk medicine., Aim of the Study: This study aimed to evaluate the anti-inflammatory and spasmolytic effects as well as the toxicological profile of the aqueous extract of Cannabis sativa roots (CsAqEx) in mice., Materials and Methods: We assessed the anti-inflammatory effect with carrageenan-induced leukocyte migration assay, and carrageenan and histamine-induced paw edema methods; The spasmolytic effect was assessed through in vitro assays with isolated mice trachea. To assess motor coordination and mobility, mice went through the rotarod and open field tests, respectively. For the single-dose toxicity study, we administered CsAqEx at the dose of 1000 mg/kg by gavage. In a repeated dose toxicity study, animals received CsAqEx at doses of 25 mg or 100 mg/kg for 28 days., Results: The CsAqEx inhibited the migration of leukocytes at the doses of 25, 50, and 100 mg/kg. The CsAqEx showed anti-inflammatory activity after the intraplantar injection of carrageenan, presenting a reduction in edema formation at all tested doses (12.5, 25, 50 and 100 mg/kg). The dose of 12.5 mg/kg of CsAqEx prevented edema formation after intraplantar injection of histamine. In an organ bath, 729 μg/mL of CsAqEx did not promote spasmolytic effect on isolated mice tracheal rings contracted by carbachol (CCh) or potassium chloride (KCl). We did not observe clinical signs of toxicity in the animals after acute treatment with CsAqEx, which suggested that the median lethal dose (LD 50 ) is greater than 1000 mg/kg. Repeated dose exposure to the CsAqEx did not produce significant changes in hematological, biochemical, or organ histology parameters., Conclusions: The results suggest that the anti-inflammatory effect of CsAqEx is related to the reduction of vascular extravasation and migration of inflammatory cells, without effects on the central nervous system. Moreover, there was no spasmolytic effect on airway smooth muscle and no toxicity was observed on mice., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The frequent use of acaricides against the tick Rhipicephalus microplus increases the risk of development of resistance. Recent studies have revealed that Neoglaziovia variegata, an indigenous plant species known in Brazil as 'caroá', has a deleterious effect against R. microplus. In the current study, extracts of N. variegata were studied for their possible acaricidal properties. A hexane extract of N. variegata leaves was fractionated in a chromatography column and the fractions were tested in adult tick immersion tests in triplicate using three concentrations (5, 10 and 25 mg/ml). All the fractions had harmful effects on the ticks. However, three fractions were more efficaceous. Phytochemical analysis indicated that stigmast-5-en-3-ol and stigmastanol were most abundant; they might be responsible for the acaricidal effects, making them potentially useful as alternative agents to control the tick R. microplus.

In the field of experimental pharmacology, researchers continuously investigate new relaxant agents of the airway smooth muscle cells (ASMCs), since the pathophysiology of respiratory illnesses, such as asthma, involves hyperresponsiveness and changes in ASMC homeostasis. In this scenario, labdane-type diterpenes, like forskolin (FSK), are a class of compounds known for their relaxing action on smooth muscle cells (SMCs), being this phenomenon related to the direct activation of AC-cAMP-PKA pathway. Considering the continuous effort of our group to study the mechanism of action and prospecting for compounds isolated from natural sources, in this paper, we presented how the diterpene 8(17),12E,14-labdatrien-18-oic acid (LBD) promotes relaxant effect on ASMC, performing in vitro experiments using isolated guinea pig trachea and in silico molecular docking/dynamics simulations. In vitro experiments showed that in the presence of aminophylline, FSK and LBD had their relaxant effect potentiated (EC 50 from 1.4 ± 0.2 × 10 -5 M to 1.5 ± 0.3 × 10 -6 M for LBD and from 2.0 ± 0.2 × 10 -7 M to 6.4 ± 0.4 × 10 -8 M for FSK) while in the presence of Rp-cAMPS this effect was attenuated (EC 50 from 1.4 ± 0.2 × 10 -5 M to 3 × 10 -4 M for LBD and from 2.0 ± 0.2 × 10 -7 to 3.1 ± 1.0 × 10 -6 M for FSK). Additionally, in silico simulations evidenced that the lipophilic character of LBD is probably responsible for its stability on AC binding site. LBD presented two preferential orientations, where the double bonds of the isoprene moiety as well as the unique polar group (carboxylic acid) in this compound form important anchoring points. In this sense, we consider that the LBD can interact stabilizing the catalytic dimmer of AC as the FSK, although less efficiently.

Ethnopharmacological Relevance: Lippia alnifolia Mart. & Schauer, known as "alecrim-do-mato", "alecrim-de-vaqueiro" and "pedrécio", is used in folk medicine as antiseptic and to treat diseases that affect respiratory system, like bronchitis and asthma., Aim of the Study: The aim of this work was to investigate the spasmolytic activity and relaxant mechanism of the Lippia alnifolia essential oil (EOLA) on isolated guinea-pig trachea and to correlate with its use in folk medicine., Materials and Methods: Leaves from L. alnifolia were collected in Pico das Almas, Chapada Diamantina, situated in the city of Rio de Contas, Bahia, Brazil. EOLA was extracted by hydrodistillation, analyzed by GC/FID and GC/MS and the volatile constituents were identified. Spasmolytic activity was assayed in isolated guinea-pig trachea pre-contracted with carbachol 1 μM or histamine 10 μM. Relaxant mechanism of EOLA was determined comparing concentration-response curves in the presence or absence of different blockers., Results: Chemical analysis revealed the presence of carvone (60 ± 0.8%) as major constituent. EOLA (1-243 μg/mL) relaxed isolated guinea-pig trachea pre-contracted with carbachol 1 μM [EC 50  = 53.36 (44.75-63.51) μg/mL] or histamine 10 μM [EC 50  = 5.42 (4.42-6.65) μg/mL]. The pre-incubation of 4-aminopyridine in histamine-induced contractions did not alter significantly the relaxant effect of EOLA. However, the presence of cesium chloride, glibenclamide, tetraethylammonium, propranolol, indomethacin, dexamethasone, hexamethonium, atropine, L-NAME, methylene blue or ODQ reduced EOLA relaxant effect. EOLA 18 μg/mL pre-incubation in calcium-free medium reduced histamine-evoked contractions, but did not alter histamine contractions in the presence of nifedipine., Conclusions: Lippia alnifolia essential oil has spasmolytic activity on isolated guinea-pig trachea and its mechanism of action possibly involves the activation of multiple signal transduction pathways, which culminate in potassium channels activation and cytosolic calcium reduction., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lippia thymoides ('alecrim-do-mato' or 'alecrim-do-campo') is used in Brazilian folk medicine to treat various illnesses, including diarrhea. This work aimed to evaluate in vitro spasmolytic and in vivo antidiarrheal activities of the L. thymoides essential oil (OOS) and to correlate with the traditional use of this plant. In isolated guinea-pig ileum, OOS presented a concentration-dependent spasmolytic activity in preparations pre-contracted with KCl 40 mM [EC 50  = 16.89 (11.56-24.66) μg/mL], and antagonized phasic contractions induced by 1 μM carbachol [IC 50  = 42.71 (37.35-48.83) μg/mL] or histamine [IC 50  = 32.38 (27.44-38.20) μg/mL]. In mice, OOS at 400 mg/kg reduced intestinal transit, at 200 and 400 mg/kg reduced total stool mass and at 400 mg/kg reduced intestinal fluid accumulation. It was shown that the antidiarrheal effect of OOS is related to the inhibition of smooth muscle contraction and may be due to the presence of major compound β-caryophyllene in this essential oil.

Introduction: The evaluation of expectorant activity has been extensively studied in murine models, involving the secretion of phenol red in the trachea or bronchus to estimate the secretory capacity of lower airway mucosa. However, differences in the experimental protocols of several studies evidenced the need of to standardize the quantification of phenol red in the bronchoalveolar fluid (BALF)., Methods: The analytical methodology for the quantification of phenol red in the BALF was optimized by investigation of pH influence, quantity of the alkali agent added and appropriate wavelength for quantification of phenol red by UV-VIS spectroscopy. Different phenol red suspensions (0.05, 0.5, 1.25, 2.5 and 5%) were prepared and administered intraperitoneally in mice at doses 5, 25, 50, 250 or 500 mg/kg., Results: It was shown that phenol red should be used at dose 500 mg/kg and intraperitoneal administration should be performed from a suspension at 1.25% (w/v). Furthermore, the alkalinizing agent of choice would be NaOH (0.1 M). The pharmacological validation of the analytical method showed that ambroxol (30, 60 or 120 mg/kg), guaifenesin (100 mg/kg), NH 4 Cl (2000 mg/kg) or salbutamol (4 mg/kg) can be used as positive controls., Discussion: The phenol red quantification in the BALF is a rapid and low cost assay for the discovery of new expectorant drugs. Thus, it was proposed a standardization of the analytical and pharmacological methods to ensure the reliability of BALF processing and reproducibility of phenol red quantification for data analysis., (Copyright © 2019. Published by Elsevier Inc.)

The monoterpene alcohol (-)-borneol has many biological effects such as sedative, anti-inflammatory, analgesic, anti-nociceptive, antithrombotic and vasorelaxant effects. Our objective in this study was to investigate the mechanism of action of (-)-borneol and determine its vasorelaxant effect. (-)-Borneol was tested on isolated aortic rings contracted with PE (10 -6  m). This study was performed in the absence or in the presence of endothelium, L-NAME (100 μm), indomethacin (10 μm), TEA (1 and 10 mm), 4-AP (1 mm) or glibenclamide (1 mm) to assess the participation of EDRF, nitric oxide, prostanoids and potassium channels on the relaxing effect of (-)-borneol. In this work, (-)-borneol induced a relaxant effect in aortic rings, with and without endothelium, in a concentration-dependent manner. The pharmacological characterization obtained using L-NAME, indomethacin, TEA, 4-AP and glibenclamide demonstrates that the effect of (-)-borneol was modified in the presence of L-NAME, indomethacin and glibenclamide showing that these signal transduction pathways are involved in the relaxing effect of the monoterpene. (-)-Borneol has a vasorelaxant effect that depends on the presence of vascular endothelium, with the participation of nitric oxide and prostanoids. Also, (-)-borneol displayed a direct action on the vascular smooth muscle, greatly dependent on K ATP channels., (© 2018 Société Française de Pharmacologie et de Thérapeutique.)

Background: Leonotis nepetifolia (Family Lamiaceae) is a medicinal plant from which the flavonoid cirsiliol with sedative, hypnotic, anti-inflammatory and cytotoxic activity has been extracted., Methods: Seedlings were cultivated under different levels of shade in native or fertilized modes. The content of cirsiliol was measured monthly by high-performance liquid chromatography and the total phenolic content by the Folin-Ciocalteu method. Monitoring of growth was carried out with the weekly measurement of height until the stabilization of growth., Results: The application of fertilizing and/or shading does not alter significantly the cirsiliol content. However, this content varies throughout the year, reaching the peak production in the summer, independently of the treatment applied. This same profile, with production in the summer, was also verified for phenolic compounds, reaching 58.15 ± 9.35 mg of equivalents of gallic acid per g of extract in the summer, content 1.84 times greater than the content verified in winter (31.56 ± 4.09 mg of gallic acid/g of extract). Although shading and fertilizing had no effect on cirsiliol content, the results also showed a positive influence on the height and biomass of the plant, which can causes a higher yield of extractable material., Discussion: Biotic and abiotic stresses are able to increase or decrease the production of secondary metabolites, including phenolic compounds in medicinal plants and, as the stress response is peculiar to each species, cultivation studies become necessary. The present study reports by the first time the influence of shading, fertilizing and seasons in cirsiliol content in L. nepetifolia . Among analyzed variables, the seasons showed a larger influence in expression of cirsiliol and among seasons, our results showed that the summer is the ideal season for collections. In summer, the photoperiod is larger than in other seasons of the year and due to that, the plants need greater protection against the long photoperiod. For this, the plants increase the production of phenolic compounds as observed in this study. Although they do not influence the production of cirsiliol, the shading and nutrients in soil favor growth and leaf area of several plants, explaining, thus, the higher height and biomass obtained., Competing Interests: The authors declare there are no competing interests.

The relaxant effect of 8(17),12E,14-labdatrien-18-oic acid (LBD) was investigated on isolated aortic rings and compared with forskolin (FSK), a standard and potent activator of adenylyl cyclase (AC) with relaxing effect. The presence of potassium channel blockers, such as glibenclamide (ATP-blocker), apamin (SKCa-blocker), charybdotoxin (BKCa-blocker) did not significantly affect either the LBD or FSK concentration-response curves. However, in the presence of 4-aminopyridine (KV-blocker), the relaxant effect for both diterpenes was significantly attenuated, with reduction of its relative potencies. Moreover, the relaxation induced by 8-Br-cAMP, an analog of cAMP, was also significantly attenuated in the same conditions, i.e., in the presence of 4-aminopyridine. The presence of aminophylline, a nonselective phosphodiesterase inhibitor, caused a significant increasing in the potency for both LBD and FSK. On the other hand, the presence of Rp-cAMPS, a selective PKA-inhibitor, significantly attenuated the relaxant effect of LBD. In this work, in the same experimental conditions, both labdane-type diterpenes presented remarkably similar results; FSK, however, presented a higher potency (100-fold) than LBD. Thus, the hypothesis that LBD could be a novel AC-activator emerged. To assess that hypothesis, computational molecular docking studies were performed. Crystallographic structure of adenylyl cyclase/forskolin complex (1AB8) was obtained from RSCB Protein Data Bank and used to compare the modes of interaction of the native ligand and LBD. The computational data shows many similarities between LBD and FSK concerning the interaction with the regulatory site of AC. Taken together, the results presented here pointed to LBD as a novel AC-activator., (Copyright © 2015 Elsevier B.V. All rights reserved.)