Search

Objective: The objective of this study was to investigate whether intraperitoneally administered pirfenidone could enhance the sensory activity of the lateral spinothalamic tract in rats after compression injury to the spinal cord. Method: Injury induction at the T7 spinal cord level was achieved using a 70-gram force aneurysm clip in rats. The study involved three groups: Group A received a daily placebo, Group B received a daily dose of 200 mg/kg pirfenidone, and Group C received a daily dose of 500 mg/kg pirfenidone. Subsequently, each group was further divided into two sub-groups, labelled as groups 1 (14 days experimental duration) and 2 (28 days experimental duration), each consisting of 5 rats. On the last day of the experiment, lateral spinothalamic tract activity as pain and temperature sensations in the hind limbs of all rats were assessed. Results: Scores from the Von Frey test, hot plate test, and acetone drop test exhibited statistical differences both between and within groups. In comparison to non-pirfenidone-treated spinal cord injury groups, those treated with pirfenidone demonstrated a decline in all these scores. Conclusion: Pirfenidone with its anti-fibrotic and anti-inflammatory action, is likely to enhance the functionality of the lateral spinothalamic tract following spinal cord injury. [ABSTRACT FROM AUTHOR]

The present study sought to investigate the effects of chronic prenatal alcohol exposure (PAE) on nociceptive responses to mechanical and thermal stimuli in rats. The Von Frey and Hot Plate tests were employed to assess the nociceptive responses of 10 control rats and 7 experimental rats whose mothers had been administered ethanol from day 5 to day 20 of gestation. In healthy animals, a decrease in pain sensitivity was observed between days 28 and 70, which was not observed in the experimental group. The findings also indicated that rats with PAE exhibited diminished sensitivity to nociceptive stimuli during the early postnatal period, as evidenced by a higher threshold response to mechanical stimuli at day 28 than in the control group. However, those observations did not apply to thermal stimuli. It appears that this may be a result of distinctiveness in neural pain pathways for particular stimuli at the receptor or ion channel level, while a disruption in the equilibrium between the sympathetic and parasympathetic nervous systems may be a contributing factor. The results of this study highlight a critical aspect of the harmful systemic effects of alcohol, while also underscoring the need for further research to elucidate the underlying mechanisms, including the role of the hypothalamic-pituitary-adrenal axis and the serotonergic system in modulating pain responses in individuals prenatally exposed to alcohol. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The ability of synthetic 1,4-naphthoquinones (1,4-NQs) to prevent adenosine triphosphate (ATP)-induced and purinergic P2X7 receptor (P2X7R) mediated inflammation in macrophage and neurodegeneration of neuronal cells in vitro was previously established. The aim of the present study was to investigate analgesic-like and anti-inflammatory activity of 1,4-NQs thioglucoside derivatives, compounds U-286 and U-548, in in vivo experiments. Methods: Spectrofluorimetry approach and YO-PRO-1 fluorescent dye uptake determination were applied to study the effect of 1,4-NQs upon ATP-induced P2X7R mediated macropore formation in mouse neuroblastoma Neuro-2a cells and macrophages RAW 264.7 cells. An acetic acid-induced writhing test, hot plate test, and carrageenan-induced paw edema test were used as an in vivo mouse models to study the ability of 1,4-NQs to inhibit pain and inflammation. In the in vivo experiments, compounds were administered to mice intraperitoneally at dosages of 0.1 mg/kg, 1.0 mg/kg and 10.0 mg/kg. A group of animals that received injections of sterile water was used as a control. Each dosage group and the control group consisted of 6 mice. Results: In the present work the analgesic-like and anti-inflammatory activity of 1,4-NQs, U-286 and U-548, was demonstrated. Compound U-548 showed a significant inhibitory effect in antinociceptive tests reducing the number of mouse writhings and eliminating the latent time of mouse hind paw licking, correspondingly. Selected compounds were able to almost completely reduce the size of carrageenan-induced paw edema 24 h after injection and had a potent anti-inflammatory activity. Observed effects were accompanied with aptitude of studied 1,4-NQs to inhibit the formation of purinergic P2X7R macropore associated with inflammation and nociceptive pain. Conclusions: The results obtained allow to consider compounds U-286 and U-548 and as a pharmacological basis for the development of new analgesic-like and anti-inflammatory drugs.

The hot plate test and writhing test were both employed to investigate the analgesic effects of Citrullus colocynthis fruit resin and Cyperus rotundus tuber resin at varying concentrations and time intervals. The hot-plate test results revealed that Citrullus colocynthis fruit resin demonstrated significant dose-dependent and time-dependent analgesic effects. In contrast, Cyperus rotundus Tuber resin did not exhibit substantial analgesic effects in the hot-plate test. In the writhing test, Citrullus colocynthis fruit resin exhibited clear dose-dependent analgesic effects at higher concentrations. Cyperus rotundus Tuber resin demonstrated significant analgesic effects in reducing writhing responses, although its efficacy was not as potent as the positive control indomethacin. These results offer insights into the potential use of these natural resins for pain management while also highlighting the importance of understanding the underlying mechanisms of their analgesic effects for further clinical applications.

This article, published in the National Journal of Physiology, Pharmacy & Pharmacology, examines the pain-relieving properties of the antibiotic minocycline in Swiss albino mice. The study compares the effects of minocycline with the commonly used analgesic tramadol. The results indicate that minocycline, at doses of 5 mg/kg and 10 mg/kg, has a significant pain-relieving effect in the mice. However, the pain relief provided by minocycline is not as strong as that of tramadol. The study suggests that minocycline may have potential as an analgesic, but further research is necessary. [Extracted from the article]

Objective: This study aims to experimentally evaluate the impact of 20(S)-ginsenoside Rg3 on the progression of neuropathy induced by streptozotocin (STZ)-induced diabetes. Materials and Methods: Adult male Wistar rats were randomly divided into three groups: control, untreated diabetic, and 20(S)-ginsenoside Rg3-treated diabetic groups (n=6 each). The rats were intraperitoneally injected with a single dose of STZ (50 mg/kg) to induce diabetes, which was verified by the presence of hyperglycemia (>300 mg/dl). Treatment involved administering a daily dose of 20(S)-ginsenoside Rg3 at 5 mg/kg/day through oral gavage for five weeks. Control rats received an equivalent volume of saline phosphate buffer (pH 7.4). Nociceptive alterations were assessed using tail flick and hot plate tests in the fourth week. Distal latency and nerve conduction velocity were measured in vivo from the exposed sciatic nerve in the fifth week. Results: While STZ-induced diabetes led to a significant decline in body weight, an increase in blood glucose levels, and delays in both sensory and motor responses, 20(S)-ginsenoside Rg3 treatment favorably corrected these adverse effects. This treatment effectively alleviated weight loss, lowered blood glucose levels, protected the sciatic nerve, and thus clearly demonstrated a protective role against the progression of neuropathy. Conclusion: Treatment with 20(S)-ginsenoside Rg3 holds the potential to be used as a neuroprotective agent for diabetic neuropathy. It may also exert preventive actions against post-diabetic events at the molecular level, and the mechanisms underlying these actions need further exploration. [ABSTRACT FROM AUTHOR]

Objective: The research was designed to assess the consequences of Azadirachta indica aqueous leaf extract (AILE) on neuropathic pain in Wister rats and the role of the ATP-dependent potassium channel (KATP) as an underlying mechanism. Materials and Methods: This experimental layout was conducted on Wistar rats (n = 120) having 150 to 200 gm of body weight. On the foundation of the experimental design, rats were divided into group I (normal saline, 5 ml/kg/body weight) and group II (sham surgery and treatment with NS), group III [chronic constriction injury (CCI) in the sciatic nerve; and treated with NS], group IV (CCI and treated with AILE 400 mg/kg body weight), Group V (CCI, pretreated with Glibenclamide 15 mg/kg followed by treated with AILE 400 mg/kg). All the treatments were given once daily for a consecutive 21 days via the oral route, except Glibenclamide. Glibenclamide was given once through the intraperitoneal route on the day of the experiment. Results: Based on the neuropathic pain evaluation test, all groups were again sub-divided into subgroup "a" (walking tract analysis), "b" (cold tail immersion test), "c" (Von Frey test), and "d" (hot plate test). AILE showed a significantly higher sciatic functional index (p < 0.05) in walking track analysis, tail flick latency (p ≤ 0.05) in the cold tail immersion test, and paw withdrawal threshold (p ≤ 0.05) in the Von Frey test compared to CCI control. In addition, a nonsignificant difference in all these above-mentioned variables between the rats with CCI plus AILE and the CCI plus AILE plus glibenclamide group indicated that the KATP channel was not involved in the beneficial analgesic effects of AILE. Conclusions: The outcome of the present study indicates that AILE prevented worsening of neu¬ropathic pain after chronic constriction injury in the sciatic nerve of Wistar rats in which the KATP channel was not involved. [J Adv Vet Anim Res 2022; 9(3.000): 359-368]

The effects on stress-induced analgesia (SIA) from endogenous cannabinoid system (ECS) and nitric oxide (NO) interaction after 1 h of restraint stress were evaluated in male Wistar rats. The animals were subjected to 1 h of restraint and then injected with different combinations of cannabinoid receptor type 1 agonist anandamide (AEA) or antagonist AM251 along with an NO donor, NO precursor, or inhibitor of NO synthase. Nociception was evaluated using paw pressure (PP) or hot plate (HP) tests. AEA was administered immediately after the end of restraint-SIA (r-SIA). Administration of NO precursor reversed the pronociceptive effect of the CB1 agonist on r-SIA. Both the CB1 antagonist and the NOS inhibitor neutralized the pro-analgesic effect of L-arginine (L-arg). Administration of an NO donor, instead, increased r-SIA. Our experiments confirmed that the endogenous cannabinoid and the NO-ergic systems interact in the modulation of r-SIA. This interaction probably implies NO as a second messenger of the ECS. [ABSTRACT FROM AUTHOR]

Objective: The research was designed to assess the consequences of Azadirachta indica aqueous leaf extract (AILE) on neuropathic pain in Wister rats and the role of the ATP-dependent potassium channel (KATP) as an underlying mechanism. Materials and Methods: This experimental layout was conducted on Wistar rats (n = 120) having 150 to 200 gm of body weight. On the foundation of the experimental design, rats were divided into group I (normal saline, 5 ml/kg/body weight) and group II (sham surgery and treatment with NS), group III [chronic constriction injury (CCI) in the sciatic nerve; and treated with NS], group IV (CCI and treated with AILE 400 mg/kg body weight), Group V (CCI, pretreated with Glibenclamide 15 mg/kg followed by treated with AILE 400 mg/kg). All the treatments were given once daily for a consecutive 21 days via the oral route, except Glibenclamide. Glibenclamide was given once through the intraperitoneal route on the day of the experiment. Results: Based on the neuropathic pain evaluation test, all groups were again sub-divided into subgroup "a" (walking tract analysis), "b" (cold tail immersion test), "c" (Von Frey test), and "d" (hot plate test). AILE showed a significantly higher sciatic functional index (p < 0.05) in walking track analysis, tail flick latency (p ≤ 0.05) in the cold tail immersion test, and paw withdrawal threshold (p ≤ 0.05) in the Von Frey test compared to CCI control. In addition, a nonsignificant difference in all these above-mentioned variables between the rats with CCI plus AILE and the CCI plus AILE plus glibenclamide group indicated that the KATP channel was not involved in the benefi- cial analgesic effects of AILE. Conclusions: The outcome of the present study indicates that AILE prevented worsening of neuropathic pain after chronic constriction injury in the sciatic nerve of Wistar rats in which the KATP channel was not involved. [ABSTRACT FROM AUTHOR]

Abstract Background The aerial parts of Baccharis trimera (Less.) are frequently used as a tea to treat several diseases. Therefore, the aim of this study was to identify the constituents of an aqueous extract of B. trimera, focusing on their antioxidant, anti-inflammation, and antinociception activities and properties. For that, the researchers performed in vivo assays using the formalin test and Freund’s Complete Adjuvant (FCA) to measure the acute and chronic inflammatory pain in mice. Moreover, the myeloperoxidase enzyme (MPO) was analyzed in the subcutaneous tissue after the FCA injection, together with the counting of lymphocytes in the peripheral blood of the mice. Results The qualitative phytochemical analysis indicated the presence of flavonoids and saponins in the B. trimera aqueous extract. The high-performance liquid chromatography (HPLC) analyses showed the presence of phenolic compounds, such as chlorogenic acid, ellagic acid, rosmarinic acid, as well as flavonoids, such as rutin, quercetin, and luteolin. The DPPH assay was used in order to measure the antioxidant activity of the aqueous extract of B. trimera and this showed an IC50 of 118.18 ± 1.02 μg/mg. The data from the formalin test demonstrated that a single dose of the aqueous extract of B. trimera was not able to decrease the nociceptive behavior during the neurogenic phase, at any of the tested doses (20, 40, or 80 mg/kg p.o.). However, during the inflammatory phase of this test, the aqueous extract of B. trimera at 80 mg/kg (p.o.) significantly decreased the nociceptive behavior, showing more effectiveness when compared to the other tested doses (p

Hypothalamo-neurohypophysial oxytocin (OXT) plays an essential role in reproduction and in several socio-physiological functions, including stress reduction, anxiety relief, feeding suppression, social recognition, and trust building. Recent studies suggest that the central OXT system is also involved in antinociceptive and anti-inflammatory functions. Kamikihi-to (KKT), a Japanese traditional herbal (Kampo) medicine composed of 14 herbal ingredients, is clinically prescribed for patients with psychological symptoms, including anxiety, depression, and insomnia, and it has been associated with OXT expression. We investigated the antinociceptive response and OXT expression according to sex and the effects of KKT pre administration in a rat model. We found that nociceptive responses measured via the hot plate and formalin tests were attenuated following the administration of KKT-enriched feed for 4 weeks. The observation of mRFP1 fluorescence in OXT-mRFP1 transgenic rats revealed that KKT-administered rats showed increased expression of OXT in the magnocellular and parvocellular paraventricular nucleus of the hypothalamus. Food intake in the KKT-pre-administered group significantly decreased after cholecystokinin (CCK)-8 administration. Our results suggest that KKT is involved in the attenuation of nociceptive stress in female rats by enhancing the expression of OXT in the hypothalamus. [ABSTRACT FROM AUTHOR]

Cancer pain management is mostly done by opioids; however, they have further pharmacological effects apart from analgesia including angiogenesis. In this study, peripherally acting ligands of µ opioid receptor (MOR) were synthesized and evaluated as a tool to investigate peripheral effects of opioids in controlling angiogenesis. For this purpose, the designed compounds were synthesized from thebaine and N-(4-dimethylaminophenyl)maleimide under Diels-Alder and nucleophilic substitution (SN) reactions with different alkyl halides to form quaternary ammonium salts. In silico study conducted by docking these compounds on active (5C1M) and inactive (4DKL) form of MOR. Results of in silico study indicate that all compounds were more likely to be an antagonist of MOR based on their interaction patterns with MOR. For biological assessment, they were tested on human umbilical vein endothelial cells using a proliferation MTT test. Also, these compounds were studied by in vivo hot plate test to examine the ability of compounds to cross the blood-brain barrier (BBB). In biological tests, these compounds showed double-faced results with pro-angiogenic effect in lower doses and anti-angiogenic effect in higher doses. Their pro-angiogenic effect was comparable with VEGF. The in vivo study proved their peripherally acting nature. The contradictory effects of opioids on angiogenesis could be explained by its two different targets including MOR and opioid growth factor receptor. This gives a privilege to opioids for use as an angiogenesis controller. By developing more peripherally acting opioids with minimizing central effects, more research in this area is hoped. [ABSTRACT FROM AUTHOR]

Abstract Background There are limited studies on the utilization of analgesics in testudines. Management of pain in reptiles is by use of analgesics generally used in other vertebrate species. Evidently, some analgesics considered to be generally effective in reptiles are not effective in certain reptile species. Objective The purpose of this study was to examine the effect of amitriptyline hydrochloride on nociceptive behaviour in Speke's hinge‐back tortoise. Methods Twenty‐four adult Speke‐hinged tortoises weighing 500–700 g were used. The effects of amitriptyline hydrochloride on nociception were evaluated using the formalin, capsaicin and hot plate nociceptive tests. Amitriptyline was administered intracoelomically at doses of 0.5, 1.0 and 3.0 mg/kg. Results The higher doses of amitriptyline hydrochloride caused an increase in nociceptive behaviour (time spent in hindlimb withdrawal) on the formalin and capsaicin nociceptive tests, suggesting a potentiating effect. However, the doses used had no significant change in nociceptive behaviour on withdrawal response in the hot plate test. Conclusions The study showed that amitriptyline hydrochloride which is widely used in management of neuropathic pain potentiates nociceptive effects in the formalin and capsaicin nociceptive tests in the Speke's hinge‐back tortoise. The hot plate test, which previously has not been reported in these animals, gave results not in line with the other tests and therefore more testing and validation of the test is required. Amitriptyline modulates chemical and thermal pain differently.

The leaf of Nymphaea lotus has been used traditionally for the management of pain and inflammatory diseases. The methanol leaf extract of Nymphaea lotus (NLE) was evaluated for possible anti-nociceptive and anti-inflammatory activities in rats and mice (at the doses of 250, 500 and 1,000 mg/kg) to investigate the existence of scientific basis for the folkloric use of the plant. The standard drugs used were piroxicam (10 mg/kg) and morphine (10 mg/kg). The possible pharmacological mechanism involved in the anti-nociceptive activity was also investigated. The acute toxicity was determined in mice and rats using method of Lorke. The anti-nociceptive activity was evaluated using acetic acid-induced writhing and hot plate tests in mice, while the anti-inflammatory activity was evaluated using carrageenan-induced hind paw edema model in rats. The oral median lethal dose of NLE was found to be greater than 5,000 mg/kg in rats and mice. NLE demonstrated significant and dose-dependent protection against acetic acid induced writhes and increased the reaction time of mice in hot plate test. Pretreatment of the animals with naloxone (2 mg/kg) significantly (p

Recent studies indicate presence of a strong link between adipokines and neuropathic pain. However, the effects of asprosin, a novel adipokine, on neuropathic pain have not been studied in animal models. Mouse models were employed to investigate the antinociceptive effectiveness of asprosin in the treatment of three types of neuropathic pain, with metabolic (streptozocin/STZ), toxic (oxaliplatin/OXA), and traumatic (sciatic nerve ligation/CCI [chronic constriction nerve injury]) etiologies, respectively. Changes in nociceptive behaviors were assessed relative to controls using thermal (the hot plate and cold plate tests, at 50 °C and 4 °C respectively) and mechanical pain (von Frey test) tests after intraperitoneal (i.p.) administration of asprosin (10 µg/kg) and gabapentin (50 mg/kg) in several times intervals. Besides, possible effect of asprosin on the motor coordination of mice was assessed with a rotarod test. Serum level of asprosin was quantified by ELISA. In neuropathic pain models (STZ, OXA, and CCI), asprosin administration significantly reduced both mechanical and thermal hypersensitivity, indicating that it exhibits a clear-cut antihypersensitivity effect in the analyzed neuropathic pain models. The most effective time of asprosin on pain threshold was observed 60 min after its injection. Also, asprosin displayed no notable effect on the motor activity. Asprosin levels were significantly lower in neuropathic pain compared to healthy group (p < 0.05). The results yielded by the present study suggest that asprosin exhibits an analgesic effect in the neuropathic pain models and may have clinical utility in alleviating chronic pain associated with disease and injury originating from peripheral structures. [ABSTRACT FROM AUTHOR]

Abstract Background Cannabis contains Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) as the primary constituents responsible for pharmacological activity. However, there are numerous additional chemically-related structures to Δ9–THC and CBD that are pharmacologically active and may influence the pharmacological properties of Δ9-THC and CBD. This study chemically characterized the cannabinoid constituents in a series of cannabis chemovar extracts and investigated the potential cannabinoid entourage effect in two behavioral assays. Methods Six chemovar extracts were compared to pure Δ9-THC, CBD and morphine for effects on the following behavioral assays in mice: hot plate and tail suspension. The battery of behavioral tests was conducted post intravenous administration of cannabis chemovar extract. Cannabinoid profiles of extracts were analyzed using high performance liquid chromatography. Cannabis extracts were administered at equal doses of Δ9-THC to investigate the role of their cannabinoid profiles in modulating the effects of Δ9-THC. Dose response curves were fit using a log[inhibitor] vs response three parameter model and differences between group means were determined using a one-way ANOVA followed by a post hoc test. Results Cannabis chemovars tested in this study exhibited substantially different cannabinoid profiles. All chemovars produced dose-dependent immobility in the tail suspension assay and dose-dependent antinociception in the hot plate assay. The maximum antinociceptive effect and ED50 was comparable between cannabis chemovars and Δ9-THC. Two cannabis chemovars produced significantly greater immobility in the tail suspension test, with no significant differences in ED50. Conclusions Commercially available cannabis chemovars vary widely in cannabinoid content, but when equalized for Δ9-THC content, they produce similar behavioral effects with two exceptions. These findings provide only limited support for the entourage hypothesis. Further studies are necessary to characterize the nature of these pharmacological differences between cannabis chemovars and pure Δ9-THC.

Background: The aerial parts of Baccharis trimera (Less.) are frequently used as a tea to treat several diseases. Therefore, the aim of this study was to identify the constituents of an aqueous extract of B. trimera, focusing on their antioxidant, anti-inflammation, and antinociception activities and properties. For that, the researchers performed in vivo assays using the formalin test and Freund's Complete Adjuvant (FCA) to measure the acute and chronic inflammatory pain in mice. Moreover, the myeloperoxidase enzyme (MPO) was analyzed in the subcutaneous tissue after the FCA injection, together with the counting of lymphocytes in the peripheral blood of the mice. Results: The qualitative phytochemical analysis indicated the presence of flavonoids and saponins in the B. trimera aqueous extract. The high-performance liquid chromatography (HPLC) analyses showed the presence of phenolic compounds, such as chlorogenic acid, ellagic acid, rosmarinic acid, as well as flavonoids, such as rutin, quercetin, and luteolin. The DPPH assay was used in order to measure the antioxidant activity of the aqueous extract of B. trimera and this showed an IC50 of 118.18 ± 1.02 μg/mg. The data from the formalin test demonstrated that a single dose of the aqueous extract of B. trimera was not able to decrease the nociceptive behavior during the neurogenic phase, at any of the tested doses (20, 40, or 80 mg/kg p.o.). However, during the inflammatory phase of this test, the aqueous extract of B. trimera at 80 mg/kg (p.o.) significantly decreased the nociceptive behavior, showing more effectiveness when compared to the other tested doses (p < 0.05). Importantly, in the chronic inflammatory model on the 5th day of treatment, the aqueous extract of B. trimera (80 mg/kg p.o.) significantly reduced mechanical allodynia (p < 0.01), heat thermal hyperalgesia (p < 0.001), and paw edema (p < 0.05). There were no changes in the MPO activity, but the data exhibited an equivalent decrease in the number of lymphocytes in the blood of the mice that were treated with B. trimera (80 mg.kg− 1 p.o.) and diclofenac sodium. Conclusion: Taken together, the present data reinforces the potential of the B. trimera aqueous extract as an anti-inflammatory and analgesic compound. [ABSTRACT FROM AUTHOR]

Desalegn Getnet Demsie,1,2 Ebrahim M Yimer,1 Abera Hadgu Berhe,1 Birhanetensay Masresha Altaye,3 Derbew Fikadu Berhe11Department of Pharmacology and Toxicology, College of Health Sciences, Mekelle University, Mekelle, Ethiopia; 2Department of Pharmacy, College of Medicine and Health Sciences, Adigrat University, Adigrat, Ethiopia; 3Department of Pharmacy, College of Medicine, Debre Berhan University, Debre Berhan, EthiopiaBackground: Societies in developing countries use traditional medicine as alternatives for management of pain and inflammation. The plant Cucumis ficifolius has been used in Ethiopia to treat many ailments including inflammation and pain. The objective of this study was to evaluate the antinociceptive and anti-inflammatory activities of the crude root extract and solvent fractions of C. ficifolius.Methods: The analgesic activity of crude extract and solvent fractions of C. ficifolius was evaluated with acetic acid-induced writhing, hot plate, and formalin-induced paw licking tests. The anti-inflammatory effect of crude methanolic root extract and solvent fractions of C. ficifolius was evaluated using carrageenan-induced paw edema. The crude extract was given at 200, 400 and 800 mg/kg. Butanol and aqueous fractions were given at 100 and 200 mg/kg doses. The negative control groups were treated with distilled water (10 mL/kg). Standard drugs used wereacetylsalicylic acid(ASA) in acetic acid, formalin tests and carrageenan-induced paw edema and morphine (20 mg/kg) in hot plate test.Results: The crude extract, at its maximum dose, produced comparable analgesic activity (72.5%) to ASA in acetic acid writhing test. In the hot plate test, both the crude extract and solvent fractions exhibited a significant prolongation of nociception reaction time. Formalin test result indicated a significant reduction of mean lick time with maximal protection of 64% (early phase) and 83% (late phase). Aqueous and butanol fractions showed good analgesic activity in the three models. Inflammation was decreased by 69% with butanol (200 mg/kg); 71% (800 mg/kg) of crude extract and by 41% and 56% with the use of aqueous fraction at 100 and 200 mg/kg, respectively (p

Introduction: Artemisia persica is an indigenous plant of Iran that has been traditionally used to relieve neurological and visceral pain. The aim of this study was to evaluate the analgesic effects of Artemisia persica essential oil on pain induced by hot plate and formalin in mice. Materials and Methods: In this experimental study, male Balb/c mice were divided into 5 groups including normal saline, Artemisia persica essential oil (50, 75 and 100 mg/kg) and morphine (10 mg/kg). The hot plate test was performed at, 15, 30, 45 and 60 minutes after the IP injection of drugs. In the formalin test, 30 minutes after the IP injection of drugs, 20 ml of 4% formalin was injected in the animalchr('39')s paw and the frequency of paws licking, clopping and lifting were recorded at 0-5 (acute phase) and after injection (acute phase) and 15-30 (chronic phase) minutes. Data were analyzed by SPSS16 software. Results: Injection of Artemisia persica essential oil (75 and 100 mg/kg), 15, 30, 45 and 60 minutes before the hot plate test, significantly decreased pain threshold compared to the control group (p< 0.05) Artemisia persica essential oil at a dose of 100 mg/kg significantly decreased the frequency of paws licking, clopping and lifting at the first and second phase of formalin test (p

Introduction: The role of phosphodiesterase (PDE) inhibitors in reducing neuropathic pains is uncertain. In this study, the antinociceptive effects of theophylline, milrinone, and tadalafil were investigated on sciatic nerve ligation-induced neuropathic pain (NP). Methods: Male mice (25-30 g) were purchased and housed in controlled environmental conditions before and during the experiments. The mice received identical diet and water ad libitum. Two weeks after sciatic nerve ligation, either theophylline (75 mg/kg), milrinone (4.5 mg/kg), or tadalafil (20 mg/kg) was intraperitoneally (IP) injected for either 1, 3, or 7 consecutive days. Antinociceptive effects were evaluated using the hot plate test. Negative controls received time course IP injections of saline (5 mL/kg). A single dose of imipramine (40 mg/kg,) was intraperitoneally administrated to the mice in the positive control group. Results: As was found for this study, a single-dose IP injection of either theophylline (75 mg/ kg), milrinone (4.5 mg/kg), or tadalafil (20 mg/kg) on day 14th following sciatic nerve ligation induced significant antinociceptive effects at 30 minutes (P

Background: There are limited studies on the utilization of analgesics in testudines. Management of pain in reptiles is by use of analgesics generally used in other vertebrate species. Evidently, some analgesics considered to be generally effective in reptiles are not effective in certain reptile species. Objective: The purpose of this study was to examine the effect of amitriptyline hydrochloride on nociceptive behaviour in Speke's hinge‐back tortoise. Methods: Twenty‐four adult Speke‐hinged tortoises weighing 500–700 g were used. The effects of amitriptyline hydrochloride on nociception were evaluated using the formalin, capsaicin and hot plate nociceptive tests. Amitriptyline was administered intracoelomically at doses of 0.5, 1.0 and 3.0 mg/kg. Results: The higher doses of amitriptyline hydrochloride caused an increase in nociceptive behaviour (time spent in hindlimb withdrawal) on the formalin and capsaicin nociceptive tests, suggesting a potentiating effect. However, the doses used had no significant change in nociceptive behaviour on withdrawal response in the hot plate test. Conclusions: The study showed that amitriptyline hydrochloride which is widely used in management of neuropathic pain potentiates nociceptive effects in the formalin and capsaicin nociceptive tests in the Speke's hinge‐back tortoise. The hot plate test, which previously has not been reported in these animals, gave results not in line with the other tests and therefore more testing and validation of the test is required. Amitriptyline modulates chemical and thermal pain differently. [ABSTRACT FROM AUTHOR]

The aim of this work was to synthesize a diethyl phenylcarbamothioyl phosphonate (EThmP) and evaluate its biological activities. ThmP has been prepared with high yields and its conformation was determined. This phosphonothioamidate derivative was characterized by IR, and NMR Spectroscopy (1H, 13C, and 31P). On the component of EThmP, the Hirshfeld surface analysis indicates that the major contributions for the crystal packing are H···H (53.3%), H···O (12.9%) H···S (14.5%), and C···H (17.6%) interactions. An anti-nociceptive test (the formaline test) showed that the EThmP modulates the pain during the early and late phases proved by rat behavior characterized by absence of licking, biting and shaking of the affected paw. The modulation of pain by the EThmP may be due to its anti-inflammatory effect. The Hot Plate test showed that the pretreatment with the EThmP did not modulate the pain nociception induced by maintaining the rat at a fixed temperature of 48°C. The treated rats' behavior was characterized by elevating, licking the paw, jumping and fleeing. EThmP did not affect the memory capacity and acetylcholinesterase activity. The morbidity of rats was normal with no mortality or sign of toxicity. The in vitro study showed that the EThmP has no antibacterial, antifungal and antioxidant activities. The EThmP has an important dose dependent anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the efficacy of atmospheric pressure cold plasma jet and plasma activated medium (PAM) on sciatic nerve injury (SNI)., Materials and Methods: Rats were divided into 6 groups (n = 10); group 1 (Sham), group 2 (SNI), group 3 (SNI + Atmospheric pressure cold plasma jet 5 min), group 4 (SNI + Atmospheric pressure cold plasma jet 10 min), group 5 (SNI + PAM 5 min), group 6 (SNI + PAM 10 min). On the 1st, 8th, 15th, 22nd days of the study, atmospheric pressure cold plasma jet was applied to rats in groups 3 and 4, and PAM was applied to rats in groups 5 and 6. Hot plate test was applied to all rats on the same days. On day 28, the experiment was terminated and sciatic nerve tissues were removed for histopathologic evaluations., Results: According to the 4-week average of the hot plate tests, a significant relationship was found between group 2 and group 4 and group 6 (p < 0.05). When evaluated within each week, significant differences were found between group 2 and group 4 in week 1, between group 2 and group 5 and group 6 in week 2, between group 2 and group 4 in week 3, and between group 2 and group 4 and group 6 in week 4 (p < 0.05). As a result of histopathologic analysis, except for the control group, the other groups had similar characteristics in terms of axonal degeneration, periaxonal swelling and axon density., Conclusions: As a result of our study, we found that plasma application showed an improvement in the duration of the hot plate test, but did not show any improvement histopathologically.

The aim of the present study was to investigate the analgesic effects and mechanism of action of Trametes versicolor (Tv) mycelium powder. Wistar rats were randomly divided into the following three or four groups: i) Saline group, fed saline; ii) Tv 500 group, fed 500 mg/kg Tv; iii) ASA 50 group, fed 50 mg/kg acetylsalicylic acid (ASA); and iv) ASA 100 group, fed 100 mg/kg ASA. Chemical formalin tests and thermal hot plate tests were used to investigate the analgesic effects of each group. ELISAs were performed to detect cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) plasma levels, and high-performance liquid chromatography (HPLC) was used for quality control the active component, oleanolic acid (OA) in Tv that had the analgesic effect. The OA content in aqueous Tv extract was found to be 11.92 % by HPLC assays. The licking frequencies in the early phase and late phase of the formalin test were significantly lower in the Tv 500 and ASA 100 groups than the saline group. The licking time in the late phase were also significantly lower in the Tv 500 and ASA 100 groups than the saline group. The plasma levels of COX-2 and PGE2 were decreased significantly in the Tv 500 and ASA 100 groups compared with that of the saline group at 60 min in the formalin test. In addition, oral feeding with 500 mg/kg Tv may effectively reduce physical pain triggered by hot plates in Wistar rats.Taken together, the acetylsalicylic acid-like analgesic effects of Tv in Wistar rats may be associated with the reduction of the plasma COX-2 and PGE2 levels.

Abstract Background The objective of this study was to compare the changes in the electroencephalogram (EEG) in response to noxious stimuli with tail flick and hot plate responses of rats administered opiorphin. Methods Female Sprague -Dawley rats (n = 8 per group) randomly received intravenous (IV) injection of morphine (1 mg/kg,) or opiorphin (2 mg/kg,) or saline (0.5 ml,) in each of the three testing methods (EEG, tail flick and hot plate). Each type of test (n = 24 per test) was conducted in different population of rats on separate occasions. The tail flick and hot plate latencies were recorded until 5 min after test drug administration to conscious rats. The EEG was recorded in anaesthetised rats subjected to noxious thermal and electrical stimuli after test drug administration. At the end of 5 min in each of the testing methods rats were administered naloxone subcutaneously (SC) (1 mg/kg) and the test procedure was repeated. Results There was no significant increase in the median frequency and spectral edge frequency (F50 & F95) of EEG, indicators of nociception, of morphine and opiorphin groups after noxious stimulation. Noxious stimuli caused a significant increase in both F50 and F95 of the saline group. An injection of naloxone significantly increased the F50, thus blocking the action of both opiorphin and morphine. There was a significant increase in the tail flick latency after administration of opiorphin and morphine as compared to the baseline values. Rats of morphine group spent significantly longer on the hot plate when compared to those of the opiorphin and saline groups. There was no significant difference in the hot plate latencies of opiorphin and saline groups. Conclusion The results of this study suggest that the analgesic effect of opiorphin occurs at the spinal level and it is not as effective as morphine at supraspinal level. It may be due to rapid degradation of opiorphin or limited ability of opiorphin to cross the blood brain barrier or a higher dose of opiorphin is required for its action in the brain. Pharmacokinetic/pharmacodynamics studies along with in vivo penetration of opiorphin in the cerebrospinal fluid are required for further evaluation of opiorphin analgesia.

Objective: Berberis vulgaris has antioxidant, hepato--renal protective, antibacterial, lipid lowering, anti-inflammatory and antinociceptive activities. The genus Berberis, has another member called Berberisintegerrima which has not been studied for antinociceptive activity and therefore, this study was aimed to examine the antinociceptive effect oftotal extract and alkaloid fractions of Berberis integerrima root in mice. Materials and Methods: Methanolic total extract and alkaloid fractions of the plant namely, fractions A, B, C and D were prepared according to standard methods. Male Swiss mice (20-25 g) were used (n=6 in each group). Acetic acid-induced writhing, formalin and hot-plate tests were used to assess the antinociceptive activity. In hot plate and formalin tests, morphine (10 mg/kg, i.p.) and in acetic acid test, indomethacin (10 mg/kg, i.p.) were used as reference drugs. Results: The total extract and fractions A, B and D significantly reduced abdominal twitches in acetic acid test and licking behavior of both acute and chronic phases of formalin test. In hot-plate test, morphine as the standard drug demonstrated significant antinociception while the plant extract and fractions were ineffective. The dose of 5 mg/kg of fraction C showed slight analgesia only in acetic acid test and a dose of 10 mg/kg caused severe toxicity and even death in some animals. Conclusion: Berberis integerrima total extract and its alkaloid fractions showed antinociceptive effect and it seems that the mechanism of this action is peripherally mediated since they were effective in formalin test and acetic acid- induced writhing but not in hot-plate test.

New hexahydro-2H-chromenes were synthesized by reactions of monoterpenoid (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol with aliphatic ketones in the presence of montmorillonite clay H+-K10. The compounds formed and isolated as a pair of diastereoisomers were evaluated for their analgesic activity in vivo. It was found that the analgesic activity of (4aR,8R,8aR)-4,7-dimethyl-3,4,4a,5,8,8a-hexahydrospiro[chromene-2,1ʹ-cyclohexane]-4,8-diol 8b significantly exceeds (two orders of magnitude higher) the activity of diclofenac sodium in the acetic acid-induced writhing test. It has low acute toxicity and is very promising for further development. [ABSTRACT FROM AUTHOR]

Novel aryl/alkyl azole derivative compounds C1 and C2 were screened for in vivo anti-nociceptive and anti-inflammatory activities by using the hot plate test and formalin-induced hind paw edema test, respectively. The ability of these compounds to inhibit cyclooxygenase-1/2 (COX-1/2) and 5/15-lipoxygenase (5/15-LOX) were evaluated in vitro by using a colorimetric method. C1 (30 and 50 mg/kg, i.p.) and C2 (3 and 30 mg/kg, i.p.) increased the latency to withdrawal in the hot plate test, indicating an anti-nociceptive activity. C1(30 and 50 mg/kg) and C2 (3,30 and 50 mg) were able to decrease formalin-induced edema, indicating their anti-inflammatory properties. C1and C2 exhibited inhibitory effects on the activity of COX(1-2) and 15-LOX. However, neither C1 nor C2 showed an inhibitory effect on 5-LOX. This study demonstrates that C1 and C2 have anti-nociceptive and anti-inflammatory activities, that are partially mediated by inhibition of COX and LOX enzymes. Our results suggest that C1and C2, novel aryl/alkyl azole compounds, could serve as lead compounds to develop novel therapeutic options for the treatment of pain and inflammation. [ABSTRACT FROM AUTHOR]

A neuropsychiatric drug overdose impairs physiological function via central nervous system (CNS) depression. In drug-related deaths, only the drug concentration can currently provide information regarding CNS depression in victims. In this study, using a drug overdose model, we investigated the ability of neurotransmitters in the cerebrospinal fluid (CSF) to serve as biomarkers for CNS depression. Four groups of rats were orally administered diazepam (200 mg/kg) and/or phenobarbital (100 mg/kg) or vehicle. In a hot plate test performed to assess physiological impairment, drug-administered animals showed prolongation of the response latency. Serum drug concentrations were also sufficient to observe the effect of drug overdose. The levels of benzoyl-derivatized neurotransmitters were measured using liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Noradrenaline, adrenaline, serotonin, melatonin, phosphoethanolamine, and histamine levels in the CSF decreased as the response latencies in the hot plate test increased. These reduced CSF neurotransmitter levels may represent physiological dysfunction through CNS depression. [ABSTRACT FROM AUTHOR]

In the present study we have monitored dose dependent effects of midazolam; a benzodiazepine (CNS depressant). It is the primary drug of choice for procedural sedation, preoperative sedation, and in emergency departments. Repeated administration of this drug is reported to have abuse potential and may cause this by increasing dopaminergic neurotransmission. Since an important role of 5-hydroxy tryptamine (5-HT) is there in the pathophysiology of anxiety and addiction, administration of midazolam may involve altered 5-HT metabolism as well. Present study was designed to monitor dose-dependent effects of midazolam and select the optimum dose for further experiments. Effects of midazolam were monitored on food intake, growth rate, activities in familiar and novel environments, light dark box activity, hot plate test, forced swim test and levels of dopamine, 5-HT and their metabolites. Midazolam was administered orally (0mg/kg, 2.5mg/kg, 5.0mg/kg and 10mg/kg) and behaviors were monitored post single midazolam administrations. Rats were decapitated and whole brain samples were collected and stored at -70°C until neurochemical analysis by HPLC-EC. Findings from the present study could be implicated to increased therapeutic utility of midazolam and related benzodiazepines. [ABSTRACT FROM AUTHOR]

Comparative studies using reptiles as experimental animals in pain research could expand our knowledge on the evolution and adaptation of pain mechanisms. Currently, there are no data reported on the involvement of voltage-gated sodium ion channels on nociception in reptiles. The aim of this study was to investigate the involvement of Nav1.3, Nav1.7, and Nav1.8 ion channels in nociception in Speke's hinge-back tortoise. ICA 121341 (selective blocker for Nav1.1/Nav1.3), NAV 26 (selective blocker for Nav1.7), and A803467 (selective blocker for Nav1.8) were used to investigate the involvement of Nav1.3, Nav1.7, and Nav1.8, respectively. The chemicals were administered intracoelomically thirty minutes before the start of nociceptive tests. ICA 121341 did not cause a significant decrease in the time spent in pain-related behavior in all the nociceptive tests. NAV 26 and A8034667 caused a statistically significant decrease in the mean time spent in pain-related behavior in the formalin and capsaicin tests. Only A803467 caused a statistically significant increase in the mean latency to pain-related behavior in the hot plate test. NAV 26 and A803467 had no observable side effects. In conclusion, Nav1.7 and Nav1.8 are involved in the processing of chemically induced inflammatory pain in Speke's hinge back tortoise. In addition, Nav1.8 are also significantly involved in the development of thermal-induced pain-related behavior in this species of reptile. However, our results do not support the involvement of Nav1.3 on the development of chemical or thermal induced pain-related behavior in the Speke's hinge back tortoise., (© 2023 The Authors. Journal of Neuroscience Research published by Wiley Periodicals LLC.)

The present study reports on the in vivo biocompatibility investigation and evaluation of the effects of liposomes containing dexketoprofen in somatic sensitivity in rats. Method: The liposomes were prepared by entrapping dexketoprofen in vesicular systems stabilized with chitosan. The in vivo biocompatibility was evaluated after oral administration in white Wistar rats: Group I (DW): distilled water 0.3 mL/100 g body weight; Group II (DEX): dexketoprofen 10 mg/kg body weight (kbw); Group III (nano-DEX): liposomes containing dexketoprofen 10 mg/kbw. Blood samples were collected from caudal lateral vein one day and seven days after the substance administration, to assess the eventual hematological, biochemical, and immunological changes. The investigation of somatic pain reactivity was performed using the hot plate test, to count the latency time response evoked by the thermal paws’ noxious stimulation. Results: Original liposomes entrapping dexketoprofen, with mean size of 680 nm and good stability, were designed. Laboratory analysis indicated no substantial variances between the three treated groups. The treatment with liposomes containing dexketoprofen resulted in a prolongation of the latency time response, statistically significant in the interval between 90 min and 10 h, in the hot plate test. Conclusions: The use of liposomes with dexketoprofen proved a good in vivo biocompatibility in rats and prolonged analgesic effects in the hot plate test.

• In the 6OHDA rat model, both low frequency and high frequency DBS increase sensory thresholds. • Gabapentin significantly reduces the improved mechanical thresholds seen with low-frequency deep brain stimulation. • Morphine brings a trending increase in thresholds compared to low-frequency DBS alone. Chronic pain is the most common non-motor symptom among Parkinson's disease (PD) patients, with 1.85 million estimated to be in debilitating pain by 2030. Subthalamic deep brain stimulation (STN DBS) programmed for treating PD motor symptoms has also been shown to significantly improve pain scores. However, even though most patients' pain symptoms improve or disappear, 74% of patients treated develop new pain symptoms within 8 years. Previously we have shown that duloxetine and STN high frequency stimulation (HFS) significantly increase mechanical thresholds more than either alone. The current project specifically investigates the effects of gabapentin and morphine alone and with high (150 Hz; HFS) and low (50 Hz; LFS) frequency stimulation in the 6-hydroxydopamine rat model for PD. We found that HFS, LFS, gabapentin 15 mg/kg and morphine 1 mg/kg all independently improve von Frey (VF) thresholds. Neither drug augments the HFS response significantly. Morphine at 1 mg/kg showed a trend to increasing thresholds compared to LFS alone (p = 0.062). Interestingly, gabapentin significantly reduced (p = 0.019) the improved VF thresholds and Randall Selitto thresholds seen with LFS. Thus, though neither drug augments DBS, we found effects of both compounds independently increase VF thresholds, informing use of our model of chronic pain in PD. Gabapentin's reversal of LFS effects warrants further exploration. [ABSTRACT FROM AUTHOR]

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.

Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3β-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n-hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity.

The study was carried out to evaluate the analgesic and anti-inflammatory properties of an hydro alcoholic syzygium aromaticum extract (SAE) .The analgesic activity was measured by using the hot plate test with Twenty four (24) mice divided randomly into four groups , T1, T2 received 100 , 200 mg /kg.bw of (SAE) while T3 dosed 50 mg /kg.bw of diclofanic acid and T4 used as control negative and dosed distilled water (D.W.) . The anti-inflammatory activity was measured by using formalin test with Twenty four (24) mice divided randomly into four groups , T1and T2 dosed with 100 and 200 mg /kg.bw respectively of (SAE) while T3 group dosed 0.3 mg/kg.bw of meloxicam and T4 dosed with (D.W.) , (all groups dosed orally before half hour of test) and then calculate the time of analgesia and anti-inflammatory effects . The result showed there is significant increase(p˂0.05) in time of analgesia and significant decreases (p˂0.05) in number of licking in animal exposed to (SAE) comparing with that of control , also there is significant increase(p˂0.05) in time of analgesia and decrease in licking in animals received diclofanic acid and meloxicam respectively comparing with those received (SAE) and D.W the increase was dose dependent manner. In conclusion the hydro-alcoholic extract of clove E.C showed analgesic and anti-inflammatory effect

Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3β-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n -hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity. [ABSTRACT FROM AUTHOR]

Chalcones possess Michael acceptor property due to the presence of α,β-unsaturated enone moiety in their structure. In the present study, molecular docking was performed to predict binding affinity of ring substituted chalcones with Monoacylglycerol lipase (MAGL), a serine hydrolase enzyme which can inhibited by Michael acceptors such as maleimide derivatives. 3, 4-Dimethoxy derivative, 3 h with -44.45 kJmol-1 of interaction energy, exhibited highest binding affinity and formed Pi-Sulphur interactions with methionine-123 residue of MAGL enzyme. As MAGL is an emerging target for antinociceptive drug development, ring substituted chalcones were synthesized and evaluated for their central antinociceptive activity using tail immersion and hot plate methods. The results revealed that compound 3 h chalcone bearing methoxy groups at 3rd and 4th positions of phenyl ring exhibited good antinociceptive activity in both the models. Good correlation was observed between antinociceptive activity and binding affinity toward MAGL in case of compound 3 hour. [ABSTRACT FROM AUTHOR]

Objective: Berberis vulgaris has antioxidant, hepato--renal protective, antibacterial, lipid lowering, anti-inflammatory and antinociceptive activities. The genus Berberis, has another member called Berberis integerrima which has not been studied for antinociceptive activity and therefore, this study was aimed to examine the antinociceptive effect of total extract and alkaloid fractions of Berberis integerrima root in mice. Materials and Methods: Methanolic total extract and alkaloid fractions of the plant namely, fractions A, B, C and D were prepared according to standard methods. Male Swiss mice (20-25 g) were used (n=6 in each group). Acetic acid-induced writhing, formalin and hot-plate tests were used to assess the antinociceptive activity. In hot plate and formalin tests, morphine (10 mg/kg, i.p.) and in acetic acid test, indomethacin (10 mg/kg, i.p.) were used as reference drugs. Results: The total extract and fractions A, B and D significantly reduced abdominal twitches in acetic acid test and licking behavior of both acute and chronic phases of formalin test. In hot-plate test, morphine as the standard drug demonstrated significant antinociception while the plant extract and fractions were ineffective. The dose of 5 mg/kg of fraction C showed slight analgesia only in acetic acid test and a dose of 10 mg/kg caused severe toxicity and even death in some animals. Conclusion: Berberis integerrima total extract and its alkaloid fractions showed antinociceptive effect and it seems that the mechanism of this action is peripherally mediated since they were effective in formalin test and acetic acid- induced writhing but not in hot-plate test. [ABSTRACT FROM AUTHOR]

The present study assessed the 2,3-substituted-1,3-thiazolidin-4-ones antinociceptive potential looking at the acute nociception model induced by thermal stimulation in mice. This was done to contribute to the development of new analgesic drugs, in addition to the fact that 4-thiazolidinones are an important scaffold associated with many pharmacological activities. The synthesized compounds were characterized by GC-MS and NMR of H and C and administered at a dose of 100 mg/kg hydrochloride salt (ip). Sodium dipyrone (250 and 500 mg/Kg; ip) and tramadol hydrochloride (25 and 50 mg/Kg; ip) were used as positive controls. The hot plate test was done at a temperature of 50 ± 0.1 °C and animals assessed at 30, 60, and 90 min after the drugs were administered. Among the fourteen compounds tested, nine ( 5Aa, 5Ab, 5Ac, 5Ad, 5Ba, 5Bb, 5Bd, 5Ea, and 5Fa) showed significant increases in latency time when compared to saline (negative control) and compared to sodium dipyrone (500 mg/Kg; ip) in a 30-min assessment. The highest latency times were obtained for 3-(2-piperidin-1-yl)ethyl)thiazolidin-4-one derivatives ( 5Ab, 5Ac, and 5Ad). This highlights three findings about the chemical structure that improve activity: (i) an ethylenic link; (ii) a six-membered piperidine; (iii) an aliphatic substituent at the 2-position of thiazolidinone ring. [ABSTRACT FROM AUTHOR]