A novel automated method for measuring the effect of analgesics on formalin-evoked licking behavior in rats

Ointment-Based Combination of Dittrichia viscosa L. and Marrubium vulgare L. Accelerate Burn Wound Healing

Burns constitute a major challenge in medical science, and plants can be part of the solution. Dittrichia viscosa L. (Asteraceae) and Marrubium vulgare L. (Lamiaceae) are widely used in Moroccan traditional medicine to treat several diseases and possess high potency to cure wounds. This study aimed to investigate in vivo the analgesic, anti-inflammatory, and burn-healing effects of both plants and their mixture. The hydro-ethanolic extract of both plants was analyzed using high-performance liquid chromatography with diode-array detection (HPLC-DAD). Burns were conducted on dorsal part of rats, and the wound healing process was evaluated during 21 days. Gallic acid, caffeic acid, ferulic acid, and quercetin were identified in M. vulgare extract. The analysis recorded the presence of caffeic acid, rosmarinic acid, rutin, and quercetin in D. viscosa. The group treated with the mixture showed the lowest abdominal contractions (30.4 ± 7.52) with the highest percentage of inhibition (69.12 ± 7.04%). The inhibition of paw inflammation for M. vulgare was 47.65%, followed by D. viscosa (33.86%) and the mixture (30.41%). The mixture showed the highest wound contraction at day 7 (33.16 ± 14.33%) and day 14 (87.54 ± 3.98%). D. viscosa showed the highest wound contraction on the 21st day (99.28 ± 0.44%). In conclusion, both plants and their combination showed promising results for burn healing.

Methanol, ethyl acetate and n-hexane extracts of Tragia involucrata L. leaves exhibit anxiolytic, sedative and analgesic activity in Swiss albino mice

INTRODUCTION

Tragia involucrata L. have been utilized as traditional medicine in Indian subcontinent for the treatment of numerous illnesses such as inflammation, pain and skin infection. In this current study we sought to assess the anxiolytic, sedative and analgesic activity of Tragia involucrata L. leaves extract.

MATERIALS AND METHODS

We first performed a phytochemical screening test of the leaves extracts following standard phytochemical screening protocols. We next examined the anxiolytic and sedative activity of crude methanol (TIME), ethyl acetate (TIEAE) and n-Hexane (TIHE) extract of Tragia involucrata L. leaves using mouse behavioral models such as elevated plus-maze test and pentobarbital-induced sleeping time test, respectively. Likewise, we evaluated the analgesic activity using acetic acid induced writhing test and formalin induced paw licking test. Additionally, we performed a quantitative analysis of heavy metals content of Tragia involucrata L. leaves by overnight digestion in concentrated nitric acid (HNO3).

RESULTS

Phytochemical screening demonstrated that TIME, TIEAE and TIHE contain flavonoids, alkaloids, tannins, phenols, terpenoids and sterols. Administration of these extracts resulted in higher number of open arm entry, lower number of close arm entry and higher time spent in open arm compared to control treatment (p < 0.05). Moreover, these treatments decreased the onset of sleep time and increased the duration of sleep compared to control treated mice (all p < 0.05). Likewise, extracts treated mice exhibited decreased number of writhing as well as lower acute phase and late phase duration compared to control treatment (all p < 0.05). The average level of As and Fe in Tragia involucrata L. leaves was 5.16 ± 0.012 ppm and 2.76 ± 0.015 ppm, respectively.

CONCLUSION

Results from this study support that Tragia involucrata L. leaves extracts exhibit an anxiolytic, sedative and analgesic activity in mice.

Machine learning-based automated phenotyping of inflammatory nocifensive behavior in mice

The discovery and development of new and potentially nonaddictive pain therapeutics requires rapid, yet clinically relevant assays of nociception in preclinical models. A reliable and scalable automated scoring system for nocifensive behavior of mice in the formalin assay would dramatically lower the time and labor costs associated with experiments and reduce experimental variability. Here, we present a method that exploits machine learning techniques for video recordings that consists of three components: key point detection, per frame feature extraction using these key points, and classification of behavior using the GentleBoost algorithm. This approach to automation is flexible as different model classifiers or key points can be used with only small losses in accuracy. The adopted system identified the behavior of licking/biting of the hind paw with an accuracy that was comparable to a human observer (98% agreement) over 111 different short videos (total 284 min) at a resolution of 1 s. To test the system over longer experimental conditions, the responses of two inbred strains, C57BL/6NJ and C57BL/6J, were recorded over 90 min post formalin challenge. The automated system easily scored over 80 h of video and revealed strain differences in both response timing and amplitude. This machine learning scoring system provides the required accuracy, consistency, and ease of use that could make the formalin assay a feasible choice for large-scale genetic studies.

Pharmacological studies on the antinociceptive, anxiolytic and antidepressant activity of Tinospora crispa

Pharmacological studies were performed in mice on the methanol extract of Tinospora crispa (TC), and of its hexane (HF) and chloroform (CF) fractions. Significant antinociceptive activity was observed for TC, HF, and CF in the acetic acid-induced writhing and formalin-induced paw licking tests. Anxiolytic and antidepressant activities were assessed using the open field, hole board, and elevated plus maze (EPM) tests. TC, HF, and CF demonstrated a significant decrease in spontaneous locomotor activity. They also showed an increase in the number of head-dippings in the hole-board test, suggesting decreased fearfulness. TC, and most of its fractions, showed a significant increase of the time spent in the opened arm of the EPM, indicating reduced anxiety. This study provides some support to explain the traditional use of T. crispa as a remedy for pain.

In vivo neuroprotective, antinociceptive, anti-inflammatory potential in Swiss albino mice and in vitro antioxidant and clot lysis activities of fractionated Holigarna longifolia Roxb. bark extract

Background The study investigated the in vivo neuroprotective, antinociceptive, anti-inflammatory potential and in vitro antioxidant and clot lysis activities of crude methanol extract with its different solvent-soluble fractions like petroleum ether (PESF), carbon tetrachloride (CTSF), chloroform (CSF) and aqueous (AQSF) of Holigarna longifolia Roxb. Methods Phenobarbitone-induced sleeping time method was used for the neuroprotective activity, writhing response experimental model introduced by acetic acid was designed for antinociceptive efficacy, carrageenan-induced paw edema model was carried out for anti-inflammatory activity, DPPH free radical scavenging activity was assessed for antioxidant activity and clot lysis model was investigated for the thrombolytic potential of the plant. Results On investigation it was found that methanol extract and CS fraction revealed statistically meaningful (p<0.05) neuroprotective activity by increasing phenobarbitone-induced sleeping time of mice, produced substantial (p<0.05) inflammation inhibitory efficacy compared to standard diclofenac sodium and also exhibited statistically significant (p<0.01) oxidative stress inhibitory efficacy by inhibiting free radical formation compared to ascorbic acid as standard. Only methanol extract produced significant (p<0.05) antinociceptive activity by inhibiting abdominal writhes produced by acetic acid compared to standard analgesic drug diclofenac sodium. And only aqueous soluble fraction exhibited moderate clot lysis activity compared to streptokinase as standard. Conclusion The findings demonstrate that H. longifolia could be potential neuroprotective due to its justified antioxidative capacity as well as clot lysis properties.

Antinociceptive and Anxiolytic and Sedative Effects of Methanol Extract of Anisomeles indica: An Experimental Assessment in Mice and Computer Aided Models

Anisomeles indica (L.) kuntze is widely used in folk medicine against various disorders including allergy, sores, inflammation, and fever. This research investigated the antinociceptive, anxiolytic and sedative effects of A. indica methanol extract. The antinociceptive activity was assessed with the acetic acid-induced writhing test and formalin-induced flicking test while sedative effects with open field and hole cross tests and anxiolytic effects with elevated plus maze (EPM) and thiopental-induced sleeping time tests were assayed. Computer aided (pass prediction, docking) analyses were undertaken to find out the best-fit phytoconstituent of total 14 isolated compounds of this plant for aforesaid effects. Acetic acid treated mice taking different concentrations of extract (50, 100, and 200 mg/kg, intraperitoneal) displayed reduced the writhing number. In the formalin-induced test, extract minimized the paw licking time of mice during the first phase and the second phase significantly. The open field and hole-cross tests were noticed with a dose-dependent reduction of locomotor activity. The EPM test demonstrated an increase of time spent percentage in open arms. Methanol extract potentiated the effect of thiopental-induced hypnosis in lesser extent comparing with Diazepam. The results may account for the use of A. indica as an alternative treatment of antinociception and neuropharmacological abnormalities with further intensive studies. The compound, 3,4-dihydroxybenzoic acid was found to be most effective in computer aided models.

Assessing complex movement behaviors in rodent models of neurological disorders

Behavioral phenotyping is a crucial step in validating animal models of human disease. Most traditional behavioral analyses rely on investigator observation of animal subjects, which can be confounded by inter-observer variability, scoring consistency, and the ability to observe extremely rapid, small, or repetitive movements. Force-Plate Actimeter (FPA)-based assessments can quantify locomotor activity and detailed motor activity with an incredibly rich data stream that can reveal details of movement unobservable by the naked eye. This report describes four specific examples of FPA analysis of behavior that have been useful in specific rat or mouse models of human neurological disease, which show how FPA analysis can be used to capture and quantify specific features of the complex behavioral phenotypes of these animal models. The first example quantifies nociceptive behavior of the rat following injection of formalin into the footpad as a common model of persistent inflammatory pain. The second uses actimetry to quantify intense, rapid circling behaviors in a transgenic mouse that overexpresses human laminin α5, a basement membrane protein. The third example assesses place preference behaviors in a rat model of migraine headache modeling phonophobia and photophobia. In the fourth example, FPA analysis revealed a unique movement signature emerged with age in a digenic mutant mouse model of Tourette Syndrome. Taken together, these approaches demonstrate the power and usefulness of the FPA in the examination and quantification of minute details of motor behaviors, greatly expanding the scope and detail of behavioral phenotyping of preclinical models of human disease.

Antinociceptive Effect of Hydroalcoholic Extract of Iranian Green tea in the Formalin Test in Rats

BACKGROUND

Tea (Camellia sinensis) has been utilised, since time immemorial, as a beverage possessing encouraging health benefits. Little scientific evidence exists in literature on the effect of this plant on pain.

OBJECTIVES

To investigate the antinociceptive activity of Iranian green tea extract.

MATERIALS AND METHODS

The hydroalcoholic extract was administered to male Wistar rats. Formalin paw test was used to evaluate the antinociceptive activity. Plant extract (25, 50, 100 and 200 mg/kg, i.p.) (n = 6 for each group) or vehicle (n = 6) was administered 30 min before the subplantar formalin injection.

RESULTS

The extract caused a significant dose-related (50, 100, 200 mg /kg, i.p.) inhibition of the first phase and onset of chronic phase (200 mg /kg, i.p.) of formalin induced nociception. The results showed that the pre-treatment of rats with naloxone (1 mg/kg, i.p.) significantly (P < 0.001) reversed antinociception by Green tea extract (GTE) (200 mg/kg, i.p.) in the inflammatory phase and had no effect on phase 1.

CONCLUSIONS

These results indicate that GTE produces dose-related antinociception in chemical pain model and one of its possible mechanisms involves opioid pathways.

Antinociceptive effect of an ethanolic extract of the aerial parts of Hilleria latifolia (Lam.) H. Walt. (Phytolaccaceae)

Background:

Hilleria latifolia (Lam.) H. Walt. (Phytolaccaceae) is a perennial herb used in Ghanaian traditional medicine for the treatment of various painful conditions. Little scientific evidence exists in literature on the effect of this plant on pain.

Materials and Methods:

The present study examined the antinociceptive effect of the ethanolic extract of the aerial parts of H. latifolia in chemical (acetic acid-induced abdominal writhing, glutamate, formalin, and capsaicin tests) and thermal (tail immersion test) behavioral pain models in rodents. The possible mechanisms of the antinociceptive action were also assessed with various antagonists in the formalin test.

Results:

The H. latifolia extract (HLE) together with morphine and diclofenac (positive controls), showed significant antinociceptive activity in all the models used. The antinociceptive effect exhibited by HLE in the formalin test was partly or wholly reversed by the systemic administration of naloxone, theophylline, and atropine. Glibenclamide, ondansetron, yohimbine, nifedipine, and N^G-L-nitro-arginine methyl ester (L-NAME), however, did not significantly block the antinociceptive effect of the extract. HLE, unlike morphine, did not induce tolerance to its antinociceptive effect in the formalin test after chronic administration; morphine tolerance did not also cross-generalize to HLE. Interestingly, also, the chronic concomitant administration of HLE and morphine significantly suppressed the development of morphine tolerance.

Conclusion:

Together, these results indicate that HLE produces dose-related antinociception in several models of chemical and thermal pain, without tolerance induction, through mechanisms that involve an interaction with adenosinergic, muscarinic cholinergic, and opioid pathways.

Formalin-induced acute pain upregulates the expression of annexin 5 mRNA in the stomach and submandibular gland of rats

AIM: To investigate the effects of formalin-induced acute pain on the expression of annexin 5 mRNA in the stomach and submandibular gland of Sprague-Dawley (SD) rats.

METHODS: Acute pain was induced in SD rats by subcutaneous injection of 2 mL of 50 g/L formalin into the plantar surface of the left hindpaw. Control rats were injected with equal volume of normal saline solution. The samples of the stomach and submandibular gland were collected under terminal anaesthesia with ketamine (40 mg/kg) at 1, 6, 24 and 72 h after formalin injection. The expression of annexin 5 mRNA in the stomach and submandibular gland was analyzed by fluorescent quantitative polymerase chain reaction (PCR).

RESULTS: Fluorescent quantitative PCR showed that the expression of annexin 5 mRNA in the stomach significantly increased at 1 h after formalin injection compared to that in control mice (7.43 ± 2.67 vs 1.00 ± 0.00, P < 0.01), and then decreased to basic level at 6 h (P > 0.05). In the submandibular gland, the expression of annexin 5 mRNA also increased at 1 h after formalin injection (4.33 ± 1.50 vs 1.00 ± 0.00, P < 0.01), and returned to normal level at 72 h (P > 0.05).

CONCLUSION: Formalin injection-induced acute pain upregulats the expression of annexin 5 mRNA in the stomach and submandibular gland of rats. Annexin 5 may be an acute stress response protein in the digestive system.