Mechanistic assessment of the analgesic, anti-inflammatory and antipyretic actions of Dalbergia saxatilis in animal models

Himalayan Pyracantha crenulata (D.Don) M.Roem. leaf and fruit extracts alleviate algesia through COX-2 and Mu-opioid receptor mediated pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Pyracantha crenulata (D.Don) M.Roem., a plant of high nutritional and medicinal value is traditionally employed for its analgesic property in joint and body pain in the Kumaun region of Western Himalaya.

AIM OF THE STUDY

To validate the traditional claims for analgesic property of Pyracantha crenulata.

METHODS

Hydroethanolic extract of P. crenulata leaves and fruits were tested for their analgesic potential in rodent models for algesia by tail immersion test, tail flick test, Eddy's hot plate model, and formalin induced paw irritation test in Wistar rats. Molecular docking and dynamics studies were also performed to understand the possible mechanisms.

RESULTS

Both P. crenulata fruit extract and leaf extract exhibited significant amelioration in all the tested experimental models of algesia acting through central and peripheral mechanisms. The efficacy in reducing nociception was found comparable to diclofenac that was used as a reference standard. Molecular docking and dynamic simulation studies further established binding affinity of gallic acid (confirmed to be present in P. crenulata leaf extract through HPTLC profiling) with cyclooxygenase-2 (COX-2) and mu-opioid receptors, suggesting the modulatory effect of these extracts on COX-2 and mu-opioid receptors in combating algesia.

CONCLUSION

P. crenulata extracts produce analgesic effects plausibly through COX-2 and mu-opioid receptor mediated pathways.

Epigenetics and the role of nutraceuticals in health and disease

In the post-genomic era, the data provided by complete genome sequencing could not answer several fundamental questions about the causes of many noninfectious diseases, diagnostic biomarkers, and novel therapeutic approaches. The rapidly expanding understanding of epigenetic mechanisms, as well as widespread acceptance of their hypothesized role in disease induction, facilitated the development of a number of novel diagnostic markers and therapeutic concepts. Epigenetic aberrations are reversible in nature, which enables the treatment of serious incurable diseases. Therefore, the interest in epigenetic modulatory effects has increased over the last decade, so about 60,000 publications discussing the expression of epigenetics could be detected in the PubMed database. Out of these, 58,442 were published alone in the last 10 years, including 17,672 reviews (69 historical articles), 314 clinical trials, 202 case reports, 197 meta-analyses, 156 letters to the editor, 108 randomized controlled trials, 87 observation studies, 40 book chapters, 22 published lectures, and 2 clinical trial protocols. The remaining publications are either miscellaneous or a mixture of the previously mentioned items. According to the species and gender, the publications included 44,589 human studies (17,106 females, 14,509 males, and the gender is not mentioned in the remaining papers) and 30,253 animal studies. In the present work, the role of epigenetic modulations in health and disease and the influencing factors in epigenetics are discussed.

In vivo evaluation of analgesic and anti-inflammatory activity of hydroalcoholic extracts from Handroanthus impetiginosus and their chemical composition by UPLC/MS analysis

This study demonstrates in vivo analgesic and anti-inflammatory properties of hydroalcoholic extracts of leaves, bark and flowers from the Handroanthus impetiginosus (Bignoniaceae) plant, recognized as 'Ipê roxo' in Brazil. The extracts were evaluated in male Swiss albino mice via oral administration. Moreover, results of the in vivo paw oedema test induced by carrageenan revealed that extracts of leaves and bark displayed relevant anti-inflammatory activity potential at the dosage of 100 mg/kg, 300 mg/kg, and 500 mg/kg. Likewise, the results obtained for leaves and flowers extracts suggested potent analgesic action in the conventional hot plate test. UPLC/MS analysis of the hydroalcoholic extracts samples identified metabolites belonging to several classes, mainly naphthoquinones and iridoids derivatives as well as flavonoids. Thus, the obtained results indicate that the extracts of H. impetiginosus plant parts could be considered as a complementary herbal medicine for the treatment of pain and inflammation disorders.

Effect of Diclofenac and Andrographolide Combination on Carrageenan-Induced Paw Edema and Hyperalgesia in Rats

Studies into drug combination at low doses are a promising approach to the management of pain and inflammation. The aim of this study was to evaluate the anti-edema and anti-hyperalgesic effects of a combination of diclofenac and andrographolide. Male Sprague-Dawley rats were first treated with diclofenac or andrographolide alone (3–100 mg/kg), as well as a combination of the 2 drugs. Carrageenan was then injected into the right hind paw of rats, and changes in paw volume and sensitivity to mechanical (von Frey) and thermal (Hargreaves test) stimuli measured. Results showed drug combination produced synergistic effects at reducing paw edema especially at lower doses, with a Loewe synergy score of 13.02 ± 8.75 in SynergyFinder and a combination index of .41 ± .18 after isobolographic analysis. Again synergy scores for decreasing response to 1.0 and 3.6 g force application of von Frey filaments after drug combination were 10.127 ± 5.68 and 8.554 ± 6.53, respectively, in SynergyFinder. Synergistic effects were also seen after drug combination in the Hargreaves test with a synergy score of 5.136 ± 16.38. In conclusion, combination of diclofenac with andrographolide showed better pharmacologic effects after carrageenan injection and was more synergistic at low-dose combinations.

Dalbergiones lower the inflammatory response in oral cells in vitro

Objectives

Periodontitis is a global health burden that underlines the demand for anti-inflammatory treatment. Dalbergia melanoxylon being a rich source of flavonoids has been widely used in traditional medicine but the potential anti-inflammatory activity of its dalbergiones remains to be shown.

Material and methods

We have isolated 3′-hydroxy-4,4′-dimethoxydalbergione, 4-methoxydalbergione, and 4′-hydroxy-4-methoxydalbergione from Dalbergia melanoxylon and tested their potential anti-inflammatory activity.

Results

All dalbergiones are potent inhibitors of an LPS-induced inflammatory response of RAW 264.7 macrophages. This is specified by IL1β and IL6 production, and the p65 nuclear translocation. Consistently, in primary macrophages, the dalbergiones caused an M1-to-M2 polarization switch indicated by the decreased ration of IL1β and IL6 versus arginase 1 and YM1 expression. To implement oral cells, we have used gingival fibroblasts exposed to IL1β and TNFα. Consistently, all dalbergiones reduced the expression of IL6 and IL8 as well as the nuclear translocation of p65.

Conclusion

These findings increase the accumulating knowledge on dalbergiones and extend it towards its capacity to lower the inflammatory response of oral cells.

Clinical relevance

These findings are another piece of evidence that supports the use of herbal medicine to potentially lower inflammatory events related to dentistry.

Comparative evaluation of anti-inflammatory activity between n-butanol fraction, leaf and stem methanolic extract obtained from Olaxpsittacorum

ETHNOPHARMACOLOGICAL RELEVANCE

Olax psittacorum (Lam.) Vahl. traditionally used by the tribal communities of 'INDIA' to heal conditions such as pain, psoriasis, mouthulcer, anemia, constipation as well as diabetes followed by scientific evidences like antipyretic, anti-inflammatory, antimicrobial, anti-viral, and anti-cancer property too.

AIM OF THE EXPERIMENT

Solvent fractionation process by using chloroform, distilled water and n-butanol has been developed to get the precipitate as a fraction (encrypted as FrAE-ISO) of leaf methanolic extract (LME) and established GC-MS and antiinflammatory evaluation. The aim was to enumerate the potency against inflammation of FrAE-ISO comparing with LME, SME (Stem methanolic extract) and Diclofenac. TLC of LME extract has been developed too for separation & evaluation of the compounds appeared as bands obtained by scraping process. The motive of the experiment was to acquire an isolate from LME that can able to show an emense anti-inflammatory action compared to LME and SME.

MATERIALS AND METHODS

Priliminary phytochemical screening upon LME, SME and FrAE-ISO preformed by the standard methods of literatures. Scrapped portions of developed TLC plate (G-254 graded silica) of LME (n-Hexane:Ethylacetate; 7.5:2.5) were introduced to GC-MS evaluation. FrAE-ISO has introduced at a minute quantity (5 and 10 mg/kg/bw) within Wister albino rats (per os) against inflammation (model: carrageenan-induced paw edema) to evaluate its potency as compared to LME (25 mg/kg/bw), SME (25 mg/kg/bw) and Diclofenac (100 mg/kg). GC-MS evaluation has been conducted in both FrAE-ISO and scrapped sections to evaluate the presence of compounds qualitatively.

RESULTS

LME and SME, qualitatively through different screening processes confirm the presence of glycosides, flavonoids, amino acids, tannins, and saponins respectively. According to the quantitative study of the extracts concerning total phenolic, flavonoid, tannin, and saponin content equivalent to gallic acid, quercetin, tannic acid, and diosgenin respectively have shown less amount of phenolic, flavonoid, and saponin content in SME (30.95, 205.33 and 30.82 mg/g extract respectively) as compared to LME (95.68, 713.33 and 66.41 mg/g extract respectively). Quantitative estimation has shown the presence of 825.27 mg of saponin equivalent to diosgenin per gram of FrAE-ISO. The GC-MS study has revealed that every section of the leaf extract has " Hexadecanoic acid, methyl ester " in common with other important compounds responsible for its potent contribution towards the anti-inflammatory property. The scrapped portions of the TLC plate having mixture of compounds but FrAE-ISO has shown a sharp peak in GC-MS (up to 34 min of run time) as well as few crystals like structures under the binocular microscope. Compact doses of FrAEISO (yield = 1.645%) i.e. 5 and 10 mg/kg body weight was able to compete with 100 mg/kg Diclofenac portraying 88%-95% inhibition respectively throughout all phases of inflammation with no-significant differences compared to standard evaluated by ANOVA (in SPSS).

CONCLUSION

Olax psittacorum (Lam.) Vahl. could be a good choice to explore its importance within the pharmacognostic field of drug development and might be a better source of herbal-derived lead compounds which can help to treat other various activities like ulcer healing or anti-anemic property etc.

An in vivo evaluation of anti-inflammatory, analgesic and anti-pyretic activities of newly synthesized 1, 2, 4 Triazole derivatives

Background

In recent years, 1, 2, 4-triazole and its derivatives have been reported to be pharmacologically significant scaffolds. They possess analgesic, anti-tubercular, anti-inflammatory, anti-convulsant, anti-oxidant, anti-fungal, anti-cancer, anxiolytic and anti-depressant activity. This study was designed and conducted to evaluate the potential anti-inflammatory, analgesic and antipyretic activities of Triazole derivatives.

Methods

Swiss albino (male and female) mice weighing 20-30 g (10-24 weeks female), (5-14 weeks male) and Wister Kyoto rats (male and female) weighing 200-300 g (8-10 weeks old) were used for the present study. Anti-inflammatory activity was checked using Lambda carrageenan (λ) and egg albumin-induced paw edema models. Analgesic via Writhing Reflex induced by acetic acid and formalin, furthermore anti-pyretic activity was assessed by yeast induced pyrexia.

Results

Both of the test compounds exhibited encouraging anti-inflammatory analgesic and antipyretic results when compared with standard drug ibuprofen. The maximum inhibition of edema for the compound (S)-1-(4-Amino-5-mercapto-4H-1,2,4-triazole-3-yl) ethanol [3] was found to be (91)% as compared to reference drug ibuprofen (82)%, while (S)-1-(6-Phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)ethanol [5e] showed equipotent results to ibuprofen (81)%. The derivatives were also screened for their anti-nociceptive activity by Acetic acid writhing and tail immersion test. Compound 3 showed a significant reduction in wriths (83)% as compared to standard drug ibuprofen 71.5% and [5] showed comparable results to ibuprofen by exhibiting 70% reduction in writh at the same dose as that of standard drug, moreover, there were no signs of toxicity being observed after administration of high doses of test compounds to mice.

Conclusions

It is evident from the results that compounds 3(compound A) and 5(compound B) are a potential candidate for anti-inflammatory, analgesic and anti-pyretic and the scaffold could be used for further structural modifications. Further studies would help to evaluate their molecular mechanism of action regarding these beneficial activities.

Chemical diversity analysis and biological activities evaluation of different polyphenolic extracts of Marrubium deserti De Noé from Algeria

ETHNOPHARMACOLOGICAL RELEVANCE

Marrubium deserti De Noé (Lamiaceae) commonly known as desert horehound, is a small perennial herb distributed in arid climates. This plant has been used in Algeria for the treatment of cold, cough, fever and inflammation.

AIM OF THE STUDY

This study aimed to perform a phytochemical analysis and to evaluate the effect of diethyl ether (ExDiEth), n-butanol (ExBut) and hydroalcoholic (ExHyD) extracts of the aerial parts of M. deserti De Noé on inflammation, nociceptive response and fever in animal models.

MATERIALS AND METHODS

The total phenolic content and the different phenolic fraction (flavones-flavonols, free aglycones, anthocyanidins, C-glycosides and flavonic heterosides) were quantified in order to study the chemical diversity. The anti-inflammatory effect was evaluated using carrageenan-induced paw oedema test and the nociceptive response was determined by the chemical method using acetic acid-induced writhing response and formalin-induced paw licking tests and by the thermal method using the hot plate in mice. In addition, anti-fever was investigated using yeast-induced pyrexia in rats.

RESULTS

Quantitative analysis revealed that among all extracts, ExBut had a higher phenolic content and the aerial parts of M. deserti De Noé collected from two different sites (Biskra and Tamanresset) had a significant difference in the contents of flavonic heterosids and flavones-flavonols. PCA and CA showed a strong intra-specific variability of M. deserti De Noé individuals. Our results showed that the ExDiEth, ExBut and ExHyD treatments prevented the increase of paw oedema by 56.25%, 66.65% and 45.56% inhibition percent, respectively. Moreover, treatments with these extracts significantly (p<0.05) decreased the number of writhing and increased the reaction time to thermal stimulation as well as demonstrated reduction in paw licking time both at early and late phases. Likewise, they also showed a significant reduction of yeast-induced pyrexia till 4 h of treatment.

CONCLUSION

Results from this study show that M. deserti De Noé aerial parts exhibited anti-inflammatory, analgesic with central and peripheral actions and antipyretic activities which could be associated with the presence of some phytochemicals as flavones, flavonols, flavonic heterosids and phenolic acids.

Anti-neuropathic pain activity of a cationic palladium (II) dithiocarbamate by suppressing the inflammatory mediators in paclitaxel-induced neuropathic pain model

BACKGROUND

Neuropathic pain is a chronic pain state that negatively impacts the quality of life. Currently, available therapies for the treatment of neuropathic pain often lack efficacy and tolerability. Therefore, the search for novel drugs is crucial to obtain treatments that effectively suppress neuropathic pain.

OBJECTIVES

The present study was undertaken to investigate the antinociceptive properties of (1,4-bis-(diphenylphosphino) butane) palladium (II) chloride monohydrate (Compound 1) in a paclitaxel (PTX)-induced neuropathic pain model.

METHODS

Initially, behavioral tests such as mechanical and cold allodynia as well as thermal and tail immersion hyperalgesia were performed to investigate the antinociceptive potential of Compound 1 (5 and 10 mg/kg, b.w). RT-PCR was performed to determine the effect of Compound 1 on the mRNA expression level of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines such as tumor necrosis factor-alpha (TNF)-α, interleukin (IL)-1β, and IL-6. In addition, antioxidant protein, nitric oxide (NO), and malondialdehyde (MDA) levels were also determined.

RESULTS

The results demonstrated that once-daily dosing of Compound 1 significantly suppressed the PTX-induced behavioral pain responses dose-dependently. The mRNA gene expressions of iNOS, COX-2, and inflammatory cytokines were markedly reduced by Compound 1. Furthermore, it enhanced the level of antioxidant enzymes and lowered the level of MDA and NO production.

CONCLUSION

These findings suggest that the antinociceptive potential of Compound 1 in the PTX-induced neuropathic pain model is via suppression of oxidative stress and inflammation. Thus, Compound 1 might be a potential candidate for the therapeutic management of PTX induced neuropathic pain.

Determination of the temperature causing a nociceptive response in the tail of albino BALB/c mice

INTRODUCTION

Designs for determining nociceptive response in rodents are of great use in neurology and experimental neuroscience. Immersing mice's tails in warm water is one of the most widely used procedures to evaluate this response; however, a wide range of temperatures are used in different studies. Knowing the temperature that produces a powerful nociceptive response in the tail of BALB/c mice is extremely useful.

METHODS

Eight 2-month-old male BALB/c mice were used. A 14-cm high beaker was filled with water up to 13cm. The animals' tails were immersed in the container with a starting temperature of 36°C. The water temperature was raised in 1°C increments until we identified the temperatures that produced nociceptive responses. That response was determined by counting the time taken before the mouse shook its tail to remove it from the water.

RESULTS

Six of the 8 mice began shaking their tails at the temperature of 51°C. All animals removed their tails from the water at the temperatures of 54°C, 55°C, and 56°C, taking a mean time of 8.54, 7.99, and 5.33seconds, respectively. ANOVA applied to the response times for each of the 3 temperatures indicated revealed a value of F=2.8 (P=.123).

CONCLUSIONS

The response time was statistically similar for the temperatures of 54°C, 55°C, and 56°C; however, the data were less dispersed for the latter temperature.

Phytochemical and pharmacological investigations of different extracts of leaves and stem barks of Macropanax dispermus (Araliaceae): a promising ethnomedicinal plant

Background

Macropanax dispermus is traditionally used to treat various diseases by ethnic people. The present research reports the pharmacological properties with phytochemical profiling of the crude extracts of M. dispermus leaves (MDML), its n-hexane (MDHL), carbon tetrachloride (MDTL), chloroform (MDCL), ethyl acetate (MDEL), and aqueous (MDAL) fractions, and crude methanol extracts of its stem barks (MDMS). The in vitro thrombolytic activity was done on human erythrocytes whereas the cytotoxic activity was done by brine shrimp lethality assay. The in vivo analgesic activity was examined by acetic acid-induced writhing, tail immersion, and formalin-induced paw licking method. In contrast, antipyretic activity was done by the brewer’s yeast-induced pyrexia method.

Results

MDHL and MDMS showed 37.05% and 42.21% of significant (p < 0.01) thrombolytic activity, respectively. MDCL and MDMS showed the lower LC50 values of 23.15 and 37.11 µg/ml during cytotoxicity test, respectively. In acetic acid writhing method, MDTL and MDEL showed significant (p < 0.001) inhibition of writhing by 79.34% and 80.17%, respectively. MDMS showed significant (p < 0.001) maximal possible effect (%MPE) of 45.95%, 62.26%, 65.79%, 89.69% and elongation of time in pain reaction of 48.53%, 60.28%, 58.76%, and 70.14% at 30, 60, 90, and 120 min intervals, respectively. MDML at 400 mg/kg exhibited significant (p < 0.001) 82.72% of inhibition of pain at the late phases. MDEL at 400 mg/kg of dose exhibited significant (p < 0.001) reduction of rectal temperature by 36.31%, 62.42%, 89.81%,, and 96.82% at 1, 2, 3, and 4 h intervals, respectively.

Conclusion

The current research suggests that the plant extracts possess potential thrombolytic, cytotoxic, analgesic, and antipyretic activities.

Evaluation of anti-inflammatory, analgesic and TNF-α inhibition (upon RAW 264.7 cell line) followed by the selection of extract (leaf and stem) with respect to potency to introduce anti-oral-ulcer model obtained from Olax psittacorum (Lam.) Vahl in addition to GC-MS illustration

ETHNOPHARMACOLOGICAL RELEVANCE

Olax psittacorum (Lam.) Vahl., belongs to family olacaceae claimed as an "Issan folk medicine" portray the ethnomedicinal value like curative property of infection in the urinary tract, analgesic, antipyretic, skin-ulcer, antianemic (bark) as well as food additives (leaves). Research articles have proven the presence of anti-swelling property, laxative action, and antiviral activity against poliovirus moreover, the antioxidant property too.

AIM OF THE EXPERIMENT

Evaluation of antiulcer property (induced within the oral mucosa) of the extract selected amongst two extracts based upon better property towards the ability of anti-inflammatory and analgesia through the in-vivo model as well as the inhibitory property of TNF-α (cell line RAW264.7). To justify the presence of activity extracts were introduced for GC-MS investigation.

MATERIALS AND METHODS

Methanolic extracts (leaf; LME and stem; SME) were collected through maceration and introduced to carrageenan-induced paw edema to evaluate the anti-inflammatory activity and formalin-induced as well as tail-flick in-vivo models to evaluate the analgesic property. Anti-oral ulcer property was analyzed through the acetic-acid induced in-vivo model. The cytotoxicity was performed on mouse macrophages and fibroblast cells to find a toxic concentration of test substances and to evaluate their modulatory effect of TNF-α inhibition property against LPS induced toxicity.

RESULTS

As compared to diclofenac (100 mg/kg) only LME and SME 200 mg/kg dose group have insignificant (P < 0.05) difference and P-values are 0.99 and 0.88 respectively. From the overall outcome, it can be concluded that compared to the diclofenac (100 mg/kg) group from 4th hours onwards LME (200 mg/kg) group was able to sustain the inflammation so similar. According to statistical consideration, LME (200 mg/kg) dose has also shown better results in formalin-induced analgesia as well as tail-flick. Cytotoxicity (CTC₅₀) concentrations of LME and SME are 419.60 ± 4.09 and 230.21 ± 0.79 μg/ml respectively on RAW264.7 cell line. According to CTC₅₀ the highest concentration of LME and SME is 400 and 200 μg/ml respectively has chosen to evaluate percentage inhibition of TNF-α as compared to diclofenac sodium (25 μg/ml). 50% inhibition was achieved by LME as well as diclofenac i.e. 51.2 ± 2.6% and 50.3 ± 0.8% instead of SME i.e. 45.2 ± 1.7%. As compared to the negative group on DAY-4, LME 200 mg/kg/bw dose shown proper growth of epithelial or mucosal layer which reveals proper healing of the surface of the tongue with no sign of injury. GC-MS results also reveal that, LME and SME both have Cyclohexasiloxane, dodecamethyl; Hexadecanoic acid, methyl ester which are responsible for anti-inflammatory and analgesic activity but besides, LME has more 4 compounds responsible for activities these are methyl salicylate; phytol; β-Sitosterol; 9,12,15-Octadecatrienoic acid,2,3-bis[(trimethylsilyl)oxy]propyl ester, (Z, Z, Z).

CONCLUSION

The overall outcomes of the study encapsulate that LME extract with a dose of 200 mg/kg/bw will be a good choice to overcome the above-cited ailments. Further studies upon this plant are needed to establish its importance in the human society through quantitative isolation of the metabolites and their pharmacokinetic as well as pharmacodynamic evaluation to establish the proper pathway of action.

Phytochemical and pharmacological activities of methanol extract of Artemisia vulgaris L. leaves

Background

Artemisia vulgaris commonly known as “mugwort” is a very important medicinal plant which is used widely for the treatment of various ailments traditionally. The present studies aimed to conduct preliminary phytochemical screening and evaluate antioxidants and analgesic activities of leaves extract.

Results

Phytochemical screening showed the presence of saponins, glycosides, flavanoids, protein, triterpenoids in leaves extract. In DPPH, percentage inhibition of the scavenging activity (68.06%) by the extract in comparison with ascorbic acid (93.53%) at 60 μg/ml while in reducing power assay, the result shown the reducing power increases with the increase of concentration as (0.13 ± 0.02), (0.27 ± 0.03), (0.42 ± 0.03), (0.62 ± 0.05), (0.79 ± 0.02), (0.95 ± 0.05) at concentration of 5, 10, 15, 30, 60 and 100 μg/ml respectively. The evaluation of analgesic activities revealed that at the dose of 200 and 400 mg/kg of the extract showed significantly inhibited the writhing response induced by acetic acid by 8.60% and 32.03% comparatively with indomethacin at a dose of 10 mg/kg b. wt. exhibited 56.87% inhibition. Whereas, in the tail immersion methods, at the dose of 400 mg/kg b. wt. was showed higher deflexion value as 3.40 ± 0.300, while 200 mg/kg b. wt. was resulted at 2.90 ± 0.200 value in dose dependent manner at the maximum time of the studies (60 min). Comparatively, the reference drug indomethacin at dose 10 mg/kg b. wt. has shown the highest deflexion value (5.134 ± 0.351).

Conclusion

This finding concludes that the methanolic leaves extract has a potent antioxidants and analgesic activities and it could be attributed to the presence of flavonoids, triterpenoids, saponin, glycosides and proteins. A further study is required to find out the novel bioactive compound of Artemisia vulgaris L. which can lead more effective in various biological activities.

Overview of Neurological Mechanism of Pain Profile Used for Animal "Pain-Like" Behavioral Study with Proposed Analgesic Pathways

Pain is the most common sensation installed in us naturally which plays a vital role in defending us against severe harm. This neurological mechanism pathway has been one of the most complex and comprehensive topics but there has never been an elaborate justification of the types of analgesics that used to reduce the pain sensation through which specific pathways. Of course, there have been some answers to curbing of pain which is a lifesaver in numerous situations-chronic and acute pain conditions alike. This has been explored by scientists using pain-like behavioral study methodologies in non-anesthetized animals since decades ago to characterize the analgesic profile such as centrally or peripherally acting drugs and allowing for the development of analgesics. However, widely the methodology is being practiced such as the tail flick/Hargreaves test and Von Frey/Randall-Selitto tests which are stimulus-evoked nociception studies, and there has rarely been a complete review of all these methodologies, their benefits and its downside coupled with the mechanism of the action that is involved. Thus, this review solely focused on the complete protocol that is being adapted in each behavioral study methods induced by different phlogogenic agents, the different assessment methods used for phasic, tonic and inflammatory pain studies and the proposed mechanism of action underlying each behavioral study methodology for analgesic drug profiling. It is our belief that this review could significantly provide a concise idea and improve our scientists' understanding towards pain management in future research.

Determination of the temperature causing a nociceptive response in the tail of albino BALB/c mice

INTRODUCTION

Designs for determining nociceptive response in rodents are of great use in neurology and experimental neuroscience. Immersing mice's tails in warm water is one of the most widely used procedures to evaluate this response; however, a wide range of temperatures are used in different studies. Knowing the temperature that produces a powerful nociceptive response in the tail of BALB/c mice is extremely useful.

METHODS

Eight 2-month-old male BALB/c mice were used. A 14-cm high beaker was filled with water up to 13 cm. The animals' tails were immersed in the container with a starting temperature of 36°C. The water temperature was raised in 1°C increments until we identified the temperatures that produced nociceptive responses. That response was determined by counting the time taken before the mouse shook its tail to remove it from the water.

RESULTS

Six of the 8 mice began shaking their tails at the temperature of 51°C. All animals removed their tails from the water at the temperatures of 54°C, 55°C, and 56°C, taking a mean time of 8.54, 7.99, and 5.33seconds, respectively. ANOVA applied to the response times for each of the 3 temperatures indicated revealed a value of F=2.8 (P=.123).

CONCLUSIONS

The response time was statistically similar for the temperatures of 54°C, 55°C, and 56°C; however, the data were less dispersed for the latter temperature.