Evaluation of antinociceptive effect and pharmacological mechanisms of thiocyanoacetamide in rats

OBJECTIVE

Acute pain is the most common type of pain. The aim of the present work was carried out to study the antinociceptive effect and pharmacological mechanisms of thiocyanoacetamide (Thm) in rats exposed to thermal pain stimulus.

MATERIALS AND METHODS

The anti-nociceptive effect of the newly synthesized compound, Thm was studied in comparison to that of paracetamol (Para), dexamethasone (Dex), and morphine (Morph) at different doses using a hot plate test at a constant temperature of 48.0 ± 0.5°C. During this test, the latency time (LT) was measured when rats express pain behavior. Then, the pharmacological mechanisms were determined using receptor-antagonist drugs.

RESULTS

Firstly, the obtained result showed pain modulation of the pretreated rats with Thm at 10 mg/kg dose proved by the delay of latency time during the thermal test. This significant antinociceptive activity of the thiocyanoacetamide was more effective than that of paracetamol or dexamethasone and less than that of morphine. Second, the pretreatment with acebutolol or risperidone antagonist drugs of, respectively, adrenergic and serotonin receptors demonstrated the elimination of pain modulation with Thm 10 mg/kg dose proved by a short latency time of rat's response in hot plate test. In this case, the pharmacological mechanism of Thm was characterized by the involvement of adrenergic and serotoninergic systems.

CONCLUSIONS

It may be concluded that Thm constitutes a promising antinociceptive drug including beta-adrenergic and serotoninergic targets. The present study warrants further investigation to determine the side effects of this compound.

Modulation of inflammatory mediators involved in the antinociceptive and anti-inflammatory effects of a new thioamide derivative: thiocyanoacetamide

Inflammatory pain is part of the body's defense mechanism and plays an important role in the healing process. Although some drugs are efficient and intensively used for their potent anti-inflammatory properties, they present problematic side effects. The aim of this study was to evaluate the anti-nociceptive effect of the thiocyanoacetamide (Thm) compared to paracetamol (Para), dexamethasone (Dex) and morphine (Morph) and to study inflammatory mediators on models of acute inflammatory pain in rats using the formalin injection test in the hind paw of rats as chemical stimulus. The obtained results showed significant modulation of pain by Thm pretreatment with a maximum at an effective dose (10 mg/kg) proved by the absence of licking and biting of the affected paw during the early and late phases of inflammation. This effect was comparable to Dex at 10 mg/kg, Para at 400 mg/kg and less than Morph at 5 mg/kg pretreatment doses. The study of anti-inflammatory targets showed that Thm pretreatment maintained plasma serotonin release at normal level compared to the negative control group (T-) and corrected the decrease in the plasma level of prostaglandins after inflammatory induction with no variation in the level of histamine in different groups. The evaluation of inflammation mediators demonstrated that the pretreatment with Thm induced the decrease in the amount of both IL-1 Beta and TNF alpha in plasma and the increase in their amount in the tissue of the injection site. The Thm has been promoted as an anti-nociceptive drug that induces modulation of inflammatory mediators.