Potential of the Blue Calm® food supplement in the treatment of alcohol withdrawal-induced anxiety in adult zebrafish (Danio rerio).

Alcohol use disorder (AUD) is characterized by a set of behavioral, cognitive, nutritional, and physiological phenomena derived from the uncontrolled use of alcoholic beverages. There are cases in which AUD is associated with anxiety disorder, and when untreated, it requires careful pharmacotherapy. Blue Calm® (BC) is a food supplement indicated to aid restorative sleep, which has traces of medicinal plant extracts, as well as myo-inositol, magnesium bisglycinate, taurine, and L-tryptophan as its main chemical constituents. In this context, this study aimed to evaluate the potential of the BC in the treatment alcohol withdrawal-induced anxiety in adult zebrafish (aZF). Initially, BC was submitted to antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl radical. Subsequently, the aZF (n = 6/group) were treated with BC (0.1 or 1 or 10 mg/mL; 20 µL; p.o.), and the sedative effect and acute toxicity (96 h) were evaluated. Then, the anxiolytic-like effect and the possible GABAergic mechanism were analyzed through the Light & Dark Test. Finally, BC action was evaluated for treating alcohol withdrawal-induced anxiety in aZF. Molecular docking was performed to evaluate the interaction of the major chemical constituents of BC with the GABAA receptor. BC showed antioxidant potential, a sedative effect, was not toxic, and all doses of BC had an anxiolytic-like effect and showed potential for the treatment of alcohol withdrawal-induced anxiety in aZF. In addition to the anxiolytic action, the main chemical constituents of BC were confirmed in the molecular docking, thus suggesting that BC is an anxiolytic that modulates the GABAergic system and has pharmacological potential for the treatment of alcohol withdrawal-induced anxiety.

Oleanolic acid promotes orofacial antinociception in adult zebrafish (Danio rerio) through TRPV1 receptors.

This study aimed to evaluate the antinociceptive effect of oleanolic acid using adult zebrafish models of orofacial pain. Acute nociception was induced by formalin, capsaicin, cinnamaldehyde, menthol, acidified saline or glutamate (cutaneous modes) and hypertonic saline (corneal model). In another set of experiments, animals were pre-treated with naloxone, L-NAME, methylene blue, ketamine, camphor, HC-030031, mefenamic acid, ruthenium red or amiloride to investigate the mechanism of antinociception. The involvement of central afferent C-fibers was also investigated. A molecular docking was performed using the TRPV1 channel. Motor activity was evaluated with the open field test. Pre-treatment with oleanolic acid significantly reduced nociceptive behavior associated with acute pain. Antinociception was effectively inhibited by ruthenium red and capsaicin-induced desensitization. Presence of trpv1 was confirmed by RT-PCR in cerebral tissue of zebrafish. In line with in vivo experiments, docking studies indicated that oleanolic acid may interact with TRPV1. Results confirm the potential pharmacological relevance of oleanolic acid as an inhibitor of orofacial nociception mediated by TRPV1.

Molecular mechanism underlying orofacial antinociceptive activity of Vanillosmopsis arborea Baker (Asteraceae) essential oil complexed with ß-cyclodextrin.

BACKGROUND: Vanillosmopsis arborea Baker has recognized economic value owing to the high content of (-)-α-bisabolol (BISA) in the essential oil of its stem (EOVA). The antinociceptive effect of EVOA has already been demonstrated, and ß-cyclodextrin (ßCD) is known to improve the analgesic effect of various substances. PURPOSE: Thus, we aimed to evaluate the orofacial antinociceptive effect of a complex containing EOVA-ßCD in rodents. METHODS: EOVA was obtained by simple hydrodistillation, and the essential oil was complexed with ßCD. The animals (n = 6/group) were treated orally with EOVA-ßCD (10 or 50 mg/kg), or vehicle (control), and subjected to cutaneous orofacial nociception (formalin, capsaicin, acidic saline or glutamate), corneal (hypertonic saline) or temporomandibular (formalin) tests. The expression of FOS protein was analyzed in the spinal cord. Molecular docking was performed using the 5-HT3 and M2 receptors and BISA. RESULTS: The oral administration of EOVA-ßCD reduced nociceptive behaviour. Moreover, EOVA-ßCD decreased FOS expression. The molecular docking study indicates that BISA interacts with 5-HT3 and M2 receptors, indicating the potential mechanism of action of the tested compound. CONCLUSIONS: Our results indicate that EOVA-ßCD possesses orofacial antinociceptive effect, indicating that this complex can be used in analgesic drug development.

Antinociceptive activity of ethanolic extract of Azadirachta indica A. Juss (Neem, Meliaceae) fruit through opioid, glutamatergic and acid-sensitive ion pathways in adult zebrafish (Danio rerio).

Neem fruit (Azadirachta indica A. Juss.) are popularly used to treat infections, diarrhea, fever, bronchitis, skin diseases, infected burns and hypertension. Although the antinociceptive and anti-inflammatory potential of A. indica has already been investigated in experimental models of pain and inflammation in mice, the current research is the first to report the evaluation of the capacity of A. indica fruit ethanolic extract (EtFrNeem) in acute pain attenuation using the adult zebrafish (Danio rerio) as an alternative model to the use in rodents. EtFrNeem was submitted to antioxidant action, preliminary chemical prospecting, FT-IR and determination of phenol and flavonoid content tests. Subsequently, EtFrNeem was tested for acute nociception and abdominal inflammation, locomotor activity, and acute toxicity in adult zebrafish. Possible neuromodulation mechanisms were also evaluated. EtFrNeem showed low antioxidant activity, but was shown to be rich in flavonoids. EtFrNeem showed no anti-inflammatory action, did not alter the locomotor system, and it was not toxic. However, EtFrNeem significantly reduced the nociceptive behavior induced by formalin, glutamate and acidic saline, when compared to the control group. These effects of EtFrNeem were significantly similar to those of morphine, used as a positive control. The antinociceptive effect of EtFrNeem was inhibited by naloxone, ketamine and amiloride. EtFrNeem has the pharmacological potential for acute pain treatment and this effect is modulated by the opioid system, NMDA receptors and ASICs channels. These results lead us to studies of isolation and characterization of EtFrNeem bioactive principles, using adult zebrafish as an experimental model.

Orofacial antinociceptive effect of Mimosa tenuiflora (Willd.) Poiret.

Mimosa tenuiflora (Willd.) Poiret, popularly known in Brazil as "jurema-preta" is widely used against bronchitis, fever, headache and inflammation. Its antioxidant, anti-inflammatory and antinociceptive potential has already been reported. To assess the orofacial antinociceptive effect of M. tenuiflora, ethanolic extracts of M. tenuiflora (leaves, twigs, barks and roots) were submitted to in vitro tests of antioxidant activity. The extract with the highest antioxidant potential was partitioned and subjected to preliminary chemical prospecting, GC-MS, measurement of phenolic content and cytotoxicity tests of the fraction with the highest antioxidant activity. The nontoxic fraction with the highest antioxidant activity (FATEM) was subjected to tests of acute and chronic orofacial nociception and locomotor activity. The possible mechanisms of neuromodulation were also assessed. The EtOAc fraction, obtained from the ethanolic extract of M. tenuiflora barks, was the one with the highest antioxidant potential and nontoxic (FATEM), and Benzyloxyamine was the major constituent (34.27%). FATEM did not alter the locomotor system of mice and reduced significantly the orofacial nociceptive behavior induced by formalin, glutamate, capsaicin, cinnamaldehyde or acidic saline compared to the control group. FATEM also inhibited formalin- or mustard oil-induced temporomandibular nociception. In addition, it also reduced mustard oil-induced orofacial muscle nociception. However, FATEM did not alter hypertonic saline-induced corneal nociception. Neuropathic nociception was reversed by treatment with FATEM. The antinociceptive effect of FATEM was inhibited by naloxone, L-NAME and glibenclamide. FATEM has pharmacological potential for the treatment of acute and neuropathic orofacial pain and this effect is modulated by the opioid system, nitric oxide and ATP-sensitive potassium channels. These results lead us to studies of isolation and characterization of bioactive principles.

Frutalin reduces acute and neuropathic nociceptive behaviours in rodent models of orofacial pain.

Orofacial pain is a highly prevalent clinical condition, yet difficult to control effectively with available drugs. Much attention is currently focused on the anti-inflammatory and antinociceptive properties of lectins. The purpose of this study was to evaluate the antinociceptive effect of frutalin (FTL) using rodent models of inflammatory and neuropathic orofacial pain. Acute pain was induced by formalin, glutamate or capsaicin (orofacial model) and hypertonic saline (corneal model). In one experiment, animals were pretreated with l-NAME and naloxone to investigate the mechanism of antinociception. The involvement of the lectin domain in the antinociceptive effect of FTL was verified by allowing the lectin to bind to its specific ligand. In another experiment, animals pretreated with FTL or saline were submitted to the temporomandibular joint formalin test. In yet another, animals were submitted to infraorbital nerve transection to induce chronic pain, followed by induction of thermal hypersensitivity using acetone. Motor activity was evaluated with the rotarod test. A molecular docking was performed using the TRPV1 channel. Pretreatment with FTL significantly reduced nociceptive behaviour associated with acute and neuropathic pain, especially at 0.5 mg/kg. Antinociception was effectively inhibited by l-NAME and d-galactose. In line with in vivo experiments, docking studies indicated that FTL may interact with TRPV1. Our results confirm the potential pharmacological relevance of FTL as an inhibitor of orofacial nociception in acute and chronic pain mediated by TRPA1, TRPV1 and TRPM8 receptor.