The anxiolytic effect of salicylic acid is mediated via the GABAergic system in the fear potentiated plus maze behavior in rats

BACKGROUND

Salicylic acid (SA) is a natural phenolic compound in plants with many beneficial effects for humans. The anxiolytic effect of this compound has been reported in animal models, but its mechanism of action remains unclear. In this study, by using the fear potentiated plus maze test, we evaluated the effect of salicylic acid on the gene expression of the main form of GABA (gamma aminobutyric acid) synthesizing enzyme i.e., the enzyme glutamic acid decarboxylase 67 (GAD67) which is called GAD1, in the ventral subiculum of the hippocampus, one of the main brain structures, in anxiety circuits. Also, the hypnotic effect of Salicylic acid was evaluated.

METHODS

Animals were divided into the solvent, (SA) and diazepam treated groups (n = 6). For evaluating the anxiolytic effect of Salicylic acid, animals were subjected to 2 h of isolation, before placing them in the elevated plus maze (EPM). Afterward, the ventral part of the hippocampus was removed for evaluating the change in GAD1 gene expression by the reverse transcription-quantitative polymerase chain reaction (RTqPCR) technique. The hypnotic effect of Salicylic acid was evaluated in the ketamine induced sleeping test.

RESULTS

Salicylic acid at 10 and 30 (mg/kg) increased time spent and entries to the open arms in the (EPM) (p < 0.05). (RTqPCR) revealed that 30 mg/kg of Salicylic acid increased GAD1 gene expression (p < 0.001). Salicylic acid (30 and 300 mg/kg) also increased the duration of sleep, in ketamine induced sleeping test (p < 0.05).

CONCLUSION

Our results showed that Salicylic acid has anxiolytic and hypnotic effects and it exerts its anxiolytic effect partly, via up the regulation of GAD1 in the ventral part of the hippocampus.

Visible-light-driven photocatalysis of carbon dioxide and organic pollutants by MFeO2 (M = Li, Na, or K)

In recent years, lithium-containing ceramic materials have attracted considerable research attention as high-temperature adsorbents of carbon dioxide. The recycling of electrode materials from spent lithium-ion batteries for use as photocatalysts in recovering CO₂ and degrading organic pollutants is worthy of exploration. Solid, magnetic ferrite-containing photocatalysts are easily separated from reaction solutions by using magnetic devices. Solid catalysts (e.g., LiFeO₂, LiFe₅O₈, NaFeO₂, and K₂Fe₂O₄) were prepared through the calcination of Fe₂O₃ and M₂CO₃. CO₂ was photoreduced and crystal violet (CV) and 2-hydroxybenzoic acid (2-HBA) were photodegraded under visible light irradiation. The optimized K₂Fe₂O₄ photocatalyst increased the rate of photocatalytic conversion from CO₂ to methane at 20.9 µmol g^-1 h^-1. The catalytic efficiency indicated that the optimized reaction rate constants of CV with LiFeO₂, NaFeO₂, and K₂Fe₂O₄ were 2.98 × 10^-1, 5.32 × 10^-1, and 4.36 × 10^-1 h^-1, respectively. The quenching effect achieved through the use of various scavengers and the electron paramagnetic resonance in CV degradation revealed the substantial contribution of the reactive superoxide anion radical O₂^- and the minor roles of h⁺ and the OH radical. Its usefulness in the synthesis of solid-base catalyst MFeO₂ is promising for environmental control and relevant applications, particularly in solar energy manufacturing.

Effects of turmeric curcuminoids and metformin against central sensitivity to pain in mice

The reported experimental study was conducted to compare the effects of repeated daily oral doses of curcuminoids (CLE) with metformin as potential antidepressants and analgesics. Effects of a single and ten daily oral doses of CLE (5, 20, 80 mg/kg/day) and of 50 mg/kg/day metformin (MET) were compared in mice hot plate test (HPT) for analgesics. On the 11th treatment day, all animals were subjected to foot shock stress triggered hyperthermia test, and on the 12th treatment day to tail suspension test (TST) for antidepressants. Immediately thereafter, their blood levels of glucose, insulin and cortisol were quantified. Dose dependent analgesic activity of CLE was observed in HPT, whereas the metformin dose tested suppressed only pain hypersensitivity in the test. But statistically significant effects of both of them were observed in TST, and both of them also afforded protections against body weight loss and slight elevation in core temperatures induced by daily handling and repeated testing. CLE or metformin had no significant effects in foot shock stress triggered transient hyperthermic responses or on blood glucose, insulin and cortisol levels. Reported results reveal that curcuminoids as well as metformin are stress response modifiers with antidepressants like activities, but only low dose curcuminoids possess centrally acting analgesics like activities. They suggest that the bio-assay system used in this study is well suited for identifying curcuminoids like plant metabolites with analgesic and anti-stress activities, and that low dose curcuminoids are more effective as analgesics than low dose metformin.

Low dose aspirin like analgesic and anti-inflammatory activities of mono-hydroxybenzoic acids in stressed rodents

AIMS

To compare analgesic and anti-inflammatory activities of aspirin and mono-hydroxybenzoic acids after their daily oral doses.

MAIN METHODS

Efficacies of repeated daily stress response suppressing low oral doses (20mg/kg) of aspirin and 2-, 3-, and 4-hydroxybenzoic acids in mice hot plate test for centrally acting analgesics, and in acetic acid induced writing test were compared. Effects of their same daily doses and treatment regimen in cotton pellet granuloma and carrageenan edema test for anti-inflammatory drugs in stressed rats were compared in a second experiment. Effects of treatments on body weights, basal rectal temperatures, organ weights and plasma glucose, insulin and cortisol levels in stressed animals were compared also.

KEY FINDINGS

Although stress response suppressing effects of aspirin and all the three hydroxybenzoic acids in both mice and rats were almost equal, effectiveness of 3- and 4-hydroxybenzoic acids as analgesic and anti-inflammatory agents were lower than those of aspirin or salicylic acid.

SIGNIFICANCE

Observations made after single oral doses of aspirin or of mono-hydroxybenzoic acids are not very reliable predictors of their pharmacologically interesting bioactivity profiles and efficacies. Prostaglandin synthesis inhibition is not involved in low dose anti-inflammatory activities of 3- and 4-hydroxybenzoic acids. After their repeated daily low oral doses they are almost as potent stress response desensitizers as aspirin or salicylic acid.

Preventive potentials of piperlongumine and a Piper longum extract against stress responses and pain

AIM

To compare stress resistance increasing and analgesic activities of piperlongumine and a methanolic Piper longum fruit extract (PLE).

METHODS

Efficacies of a single and repeated daily oral doses (1-256 mg/kg/day) of PLE, piperlongumine, and 50 mg/kg/day doxycycline against foot shock stress triggered alteration in body weights and core temperatures, and of their 11 daily doses on antidepressants like activity in tail suspension test and on pentobarbital induced sedation in male mice were compared. In another experiment, analgesic activities of single and repeated daily 5 mg/kg oral doses of piperlongumine and PLE in mice hot plate test and in acetic acid induced writing tests were compared with those of aspirin and doxycycline.

RESULTS

After their single oral doses no effects of piperlongumine or PLE or doxycycline were observed in the footshock stress induced hyperthermia test or in hot plate test. However, significant effects of piperlongumine and PLE in both the tests were observed after their 5 or more daily doses. Both of them also dose dependently suppressed daily handling and repetitive testing triggered alterations in body weights and core temperatures. Their doxycycline like antidepressant activity in tail suspension test and aspirin like analgesic effects in acetic acid writhing test were observed after their 11 daily 5 mg/kg oral dose.

CONCLUSION

Piperlongumine is another bioactive secondary metabolite of P. longum and other plants of piper species with stress response suppressing, analgesic, and anti-inflammatory activities. Its bactericidal activities can also contribute to its therapeutically interesting bio-activity profile.