“An investigation of analgesic properties of clefma in trpa1 receptor agonist-mediated animal models of nocifensive behavior” aitc-induced eye wipe test

Back Ground: Pain can be defined simply as the subjective experience of harm in a part of one's body. In reality, however, there are multiple forms of pain, which involve a variety of distinct biological processes. Exposure to extreme heat, cold, or pressure can be noxious, triggering nociceptive pain. Inflammatory pain, involving the release of cytokines and the infiltration of immune cells, also occurs after injury but can be triggered independently by bacterial infections[1, 2]. Peripheral nociceptive neurons express a multitude of ion channels that have a key role in adaptive and maladaptive pain. These channels participate in the transduction of noxious stimuli into electrical activity in the periphery, enable the propagation of electrical signals along peripheral nerves, and gate the synaptic transmission of information in the spinal cord[1]. Like nociceptive pain, normal inflammatory pain signals that certain body parts have suffered damage and should therefore be protected from subsequent harm. However, inflammatory pain is triggered by the cross-talk between the immune and nervous systems. Interestingly, the recruitment of the immune system after tissue damage initiates a cascade of molecular and cellular processes that mediate the progressive repair of the injured tissues, thereby actively promoting healing. Many of the molecules involved in these processes are lipids and can be either proalgesic or analgesia [3, 4]. Aim & Objective: The present research program aimed to evaluate the analgesic properties of CLEFMA in TRPA1 receptor agonist-mediated animal models of nocifensive behavior by Evaluation of analgesic properties of CLEFMA in AITC-induced eye wipe test. Materials and Methods: AITC-induced eye wipe test: Protocol: Acclimatize rats for 2-3 minutes in a 30 X 30 X 30 cm plexiglass chamber. Prepare AITC 1000µM stock solution by dissolving it in 90% Ethanol. Dilute the stock solution to prepare 100 µM stock. Administer the drug before AITC application onto the eye. Administer 30µl of AITC (100 µM stock) to the left eye of the rat. Groups: Graded concentration of 3, 10, 30, 100, 300, 900 mg/kg/ml of CLEFMA samples, Positive Control (Tramadol 60mg/kg/10ml), Negative Control, Vehicle, 1-8 cineole (TRPA1 antagonist), 900mg/kg/ml + 1-8 cineole (TRPA1 antagonist) Observations: Keep the rat in the plexiglass chamber immediately after the application of AITC (100 µM stock) to the left eye of the rat. Start counting the number of eye wipes per minute. Count the number of eye wipes for 5 min. Results: The above results clearly show that CLEFMA 100 mg/kg, 300mg/kg, and 900 mg/kg significantly reduce the number of AITC-mediated eye wipes. The above results for CLEFMA validate the results of our previous experiment where CLEFMA acts only on phase one of formalin response. Moreover, in the presence of the TRPA1 antagonist CLEFMA 900mg/kg failed to contain the AITC-induced eye wipes indicating that CLEFMA mediated through TRPA1 receptors in AITC-induced nocifensive behavior. Both AITC and Formalin mediate through TRPA1 receptors. The antagonists acting on the TRPA1 receptors act mainly by desensitizing the receptors. The minimal drop in eye wipes might be due to the effect of CLEFMA on TRPV1 receptors. CLEFMA is known to interact with TRPA1 and TRPV1 receptors, however, the presence of an antagonist may mediate through the other available receptors. Conclusions: The current study was planned to elucidate the mechanism of CLEFMA-mediated suppression of TRPA1 agonist-mediated nocifensive behavior. From the above study, we observed that apart from TRPV1 receptors, CLEFMA mediates through TRPA1 receptors. The function of TRPA1 in those cells is still poorly understood. Given the widespread potential targets for TRPA1 modulators, it is essential to understand the genetics, biophysics, and physiological role of this fascinating TRPA1 channel.