Pain Reaction Time Research Articles

Boswellia dalzielii Methanol Stem Bark Extract Demonstrates Significant Analgesic Activity in Swiss Albino Mice

Medicinal plants are gaining popularity as safer and more natural alternatives to orthodox medicines for managing health challenges and diseases. One such plant is Boswellia dalzielii, a renowned tree in northern Nigeria extensively used due to its ethnomedicinal importance. To determine the analgesic properties of Boswellia dalzielii methanol extract (BDME), the extract was screened in mice using thermal and acetic acid-induced pain models. The extract's acute toxicity and phytochemical constituents were determined using standard protocols. The results showed that the acute toxicity of the methanol stem bark extract was greater than 2000 mg/kg. Phytochemical screening of BDME revealed the presence of flavonoids, tannins, saponins, and glycosides. The extract, at the dose of 50 mg/kg significantly (p < 0.05) prolonged the pain reaction time at 15 and 30 minutes in the hot plate test, and reduced acetic acid-induced writhing at the 12.5, 25, and 50 mg/kg doses. The analgesic activity of the extract may be attributed to the phytochemical contents. The findings suggest that BDME have analgesic properties and could be beneficial in alleviating painful conditions.

Effect of different suspension moxibustion methods on syndrome characteristics of rats with rheumatoid arthritis of heat bi syndrome based on "moxibustion can be used for heat syndrome"

To observe the effects of different suspension moxibustion methods on the syndrome characteristics and inflammatory factors of rats with rheumatoid arthritis (RA) of heat bi syndrome and to prove the concept of "moxibustion can be used for heat syndrome". Among seventy Wistar rats, 12 rats were randomly selected as a normal group, and the remaining rats were induced by collagen combined with wind, dampness, and heat environmental stimulation to establish the RA model of heat bi syndrome. Forty-eight rats with successful model establishment were further randomly divided into a model group and three moxibustion groups (mild moxibustion group, rotating moxibustion group and sparrow-pecking moxibustion group), with 12 rats in each group. The acupoints "Quchi" (LI 11), "Dazhui" (GV 14) and ashi point were used in all moxibustion groups, with mild moxibustion, rotating moxibustion, and sparrow-pecking moxibustion intervention given respectively, each acupoint was treated with moxibustion for 10 min a day, and 6 days were considered one course of treatment, with a total of three courses. After the intervention, the arthritis index (AI), the Evans blue (EB) extravasated volume in the soft tissue of the right hind paw, and the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-10 in the serum were measured by ELISA in each group. The volume of the bilateral hind paw was measured; the infrared thermal imaging was collected to analyze the temperature of the plantar area of the bilateral foot pads, and the reaction time of plantar heat pain was calculated before and after modeling, as well as after the 1st, 2nd and 3rd courses of interrention. The ankle dorsiflexion angle of the right hind foot was also measured before and after modeling, as well as after the intervention. After modeling, compared with the normal group, the rats in the model group had more high-temperature areas in the bilateral hind limbs, abnormal AI score, abnormal bilateral hind paw volume, abnormal temperature of the plantar area of the bilateral foot pads, abnormal foot pain response time, abnormal right hind ankle dorsiflexion angle, abnormal right hind paw soft tissue EB extravasation, and abnormal serum TNF-α and IL-10 levels (P<0.01, P<0.05). After the intervention, compared with the model group, the rats in each moxibustion group had decreased or disappeared high-temperature areas in the bilateral hind limbs, EB extravasated volume in the soft tissue of the right hind paw was reduced (P<0.05), and the right ankle dorsiflexion angle was increased (P<0.05), serum level of TNF-α was reduced, and level of IL-10 increased (P<0.05); the AI scores in the mild moxibustion group and the sparrow-pecking moxibustion group was decreased (P<0.01, P<0.05). After the 1st, 2nd and 3rd courses of intervention, compared with the model group, the bilateral hind paw volume of rats in each moxibustion group was decreased (P<0.05, P<0.01), and plantar heat pain reaction time was increased (P<0.05). After the 2nd course and the 3rd course of intervention, the temperature of the right hind paw pad area was decreased in each moribustion group (P<0.05); after the 3rd courses of intervention, the temperature of the left hind paw pad area was decreased in the mild moxibustion group (P<0.05). Suspension moxibustion could adjust the serum levels of TNF-α and IL-10 to improve the syndrome characteristics of RA rats of heat bi syndrome, such as joint redness, swelling, heat, pain and activity restriction. The effect of mild moxibustion is the most prominent. The findings could provide scientific basis for "moxibustion can be used for heat syndrome".

Anthocleista vogelii (Planch) stem bark ethanol extract prevents inflammatory and pain phenotypes in experimental rodent models by modulating oxido-inflammatory mediators

Ethnopharmacological relevanceThe Anthocleista species are used to treat pain, inflammation, and stomach disorders, but the mechanism by which Anthocleista vogelii Planch stem bark ethanol extract (AVSBE) elicits its anti-pain activity is not fully understood. AimThis study elucidates the phytochemical signatures of AVSBE along with its anti-nociceptive, anti-inflammatory, and antioxidant activities in animal models of pain and inflammation. MethodsThe Gas Chromatography and Mass Spectrometry (GC-MS) and Lorke's methods were used for the phytochemical characterization and LD50 determination of AVSBE. Male and female Wistar rats and Swiss mice were given oral pre-treatment of AVSBE (100, 200, and 400 mg/kg), indomethacin (10 mg/kg), morphine (10 mg/kg), and vehicle (10 mL/kg). Subsequently, various models were employed to evaluate AVSBE's anti-nociceptive and anti-inflammatory effects. Specifically, the acetic acid-induced mice writhing, formalin-induced paw licking, and hot plate models were used to assess AVSBE's anti-nociceptive activity, while the carrageenan-induced paw edema and air pouch models were used to evaluate AVSBE's anti-inflammatory activity. ResultsAVSBE (100, 200, and 400 mg/kg) reduced writhes, paw licking, and pain reaction time. It also decreased rat paw size and inflammatory exudate volume. AVSBE (200 and 400 mg/kg) lowered oxido-nitrosative stress, inflammatory mediators, and leukocyte counts in the exudate fluid. Animals administered with AVSBE showed no stomach ulceration. The LD50 of AVSBE is over 5000 mg/kg, p.o. GC-MS analysis revealed 19 phytochemical compounds in AVSBE, including eicosanoic, octadecatrienoic, linoleic, palmitoleic, and 9,12-octadecanoic acids, phytol, among others. ConclusionThese findings suggest that AVSBE demonstrated activities that can reduce inflammation and alleviate pain by inhibiting oxido-nitrosative stress and inflammatory mediators, contributing validity to the ethnomedicinal benefit of AVSBE in managing inflammatory and pain-related crisis.

Effects of wearing fixed orthodontic appliance on dynamic balance, reaction time, and pain perception in adolescents and young adult elite athletes

ABTRACT Objective To investigate the effects of using fixed orthodontic appliance on dynamic balance, auditory/visual reaction times, as well as pain perception in adolescent and young adult elite athletes. Methods A total of 34 elite athletes (n = 19 males) aged 16–21 years from different sports (track and field sprint, long jump and discus throw) were randomly allocated to treatment (n = 17) or control (n = 17) groups. The treatment group received self-ligating brackets with 0.04 cm super-elastic nickel-titanium arch wire, placed in the brackets to correct the teeth position. Perceived pain (i.e., visual analogue scale), dynamic balance (i.e., Y balance test), and auditory reaction time and visual reaction time using Direct RT software were assessed before (day−1), and on five occasions after fixed orthodontic appliance placement (day+1, +3, +7, +14, and +30). The two groups’ quantitative data [expressed as mean (standard deviation)] for each occasion were compared using the Student’s t-test. Comparisons of the Y-balance test, auditory reaction time, visual reaction time, and pain visual analogue scale data were each made between the 6 occasions via a factorial A × B analysis of variance in order to check for the possible interaction between the two groups and the (6) consecutive days (occasions). Results Compared to the control group, the treatment group showed significantly (i) lower values of anterior reach for both the dominant ([78(4) vs. 75(3)%, respectively]) and the non-dominant [76(3) vs. 74(4)%, respectively] legs at day+3, and (ii) higher values of pain visual analogue scale at day+1, day+3, and day+7 [0.00(0.00) vs. 4.94(1.25); 0.00(0.00) vs. 4.12(1.17), and 0.00(0.00) vs. 0.41(0.51), respectively). Factorial analysis of variance revealed that only pain visual analogue scale values were different between the two groups at day+1 and day+3. Conclusion FOA induced a high pain level during the first week following its placement in elite athletes.

Phytochemical characterization, Antioxidant and Analgesic potentials of Aerial Parts of Eruca vesicaria

Our work is based on the phytochemical study, the antioxidant and the analgesic activities of a hydroalcoholic extract of Eruca vesicaria aerial part very used in traditional medicine. The phytochemical screening highlighted the presence of tannins, flavonoids, sterols, flavonoid glucosides, saponins, phenols and alkaloids. The determination of total phenols of hydromethanolic extract by the Folin-ciocalteu method revealed a content equal to 4.63 ± 0.017 mg GAE / g extract. The amount of flavonoids by AlCl3 method achieved a content equal to 2.14 ± 0.025 mg QE/ g extract. The antiradical activities were evaluated by two chemical tests ; DPPH and FRAP. The obtained results showed a high reducing activity. Besides, the acute toxicity and the analgesic activity of the plant extract was evaluated on rats, using a pain model induced by chemical stimuli, hot plate and tail immersion methods. The extract was used at various doses 100, 200 and 300 mg/kg, whereas acetylsalicylic acid was used as the standard drug (200 mg/kg). In the acetic acid-induced model, the plant extracts and the standard drug significantly (p&lt;0.05) reduced the abdominal writhing in rats compared to the control group by increasing the percentage of writhing inhibition in a dose-dependent manner. In the hot plate and the tail immersion models, the plant extracts and the standard drug acetylsalicylic acid demonstrated a good analgesic activity and significantly (p&lt;0.05) increasing the pain reaction time. These results indicate that the E. vesicaria plant has a significant analgesic potential that can act through peripheral and central mechanisms.

Extract of Glycyrrhiza glabraroot attenuates nociception in experimental pain models: The role of BKCa channels

The aim of this study was to evaluate the functional interaction of Glycyrrhiza glabraroot extract (GGRE) on the large conductance Ca2+-activated K+(BKCa) channels expressed in the peripheral nervous system by using nociception and inflammation models in rodents in vivo. Besides toxicity studies and open field tests, nociception and inflammation tests were performed on rodents. Different doses of GGRE were given orally to rats and mice. Naloxone, indomethacin, morphine, NS1619 and iberiotoxin (IbTX) were administered. GGRE had both anti-nociceptive and anti-inflammatory activity in rats and mice. GGRE exhibited an analgesic effect by decreasing the time-course of the pain threshold or reaction time insome nociceptive tests. Furthermore, GGRE reduced level of pro-inflammatory cytokines, including TNF-α and IL-1β. As a conclusion, GGRE can alleviate the pain sensation of the afferent nerves and can reduce inflammation and associated pain by activating BKCa channels and reducing the levels of TNF-α, IL1β.

Chemical and Pharmacological Profiling of Wrightia coccinea (Roxb. Ex Hornem.) Sims Focusing Antioxidant, Cytotoxic, Antidiarrheal, Hypoglycemic, and Analgesic Properties.

The aim of the study was to conduct phytochemical and pharmacological investigations of Wrightia coccinea (Roxb. ex Hornem.) Sims via several in vitro, in vivo, and in silico models. A total of four compounds were identified and isolated from the methanol extract of the bark and the methanol extract of the seed pulp of W. coccinea through successive chromatographic techniques and were characterized as 3β-acetyloxy-olean-12-en-28-ol (1), wrightiadione (2), 22β-hydroxylupeol (3), and β-sitosterol (4) by spectroscopic analysis. The aqueous fraction of the bark and chloroform fraction of the fruits provided the most potent antioxidant capacity (IC50 = 7.22 and 4.5 µg/mL, respectively) in DPPH free radical scavenging assay compared with the standard ascorbic acid (IC50 = 17.45 µg/mL). The methanol bark extract and the methanol fruit coat extract exerted anti-diarrheal activity by inhibiting 74.55 ± 0.67% and 77.78 ± 1.5% (mean ± SEM) of the diarrheal episode in mice, respectively, after four hours of loading the samples. In the hypoglycemic test, the methanol bark extract and the methanol fruit coat extract (400 mg/kg) produced a significant (p < 0.05) reduction in the blood glucose level in mice. Both doses of the plant extracts (200 mg/kg and 400 mg/kg) used in the study induced a significant (p < 0.05) increase in pain reaction time. The in vitro and in vivo findings were supported by the computational studies. The isolated compounds exhibited higher binding affinity compared with the standard drugs towards the active binding sites of glutathione reductase, epidermal growth factor receptor (EGFR), kappa opioid receptor, glucose transporter 3 (GLUT 3), Mu opioid receptor, and cyclooxygenase 2 (COX-2) proteins due to their potent antioxidant, cytotoxic, anti-diarrheal, hypoglycemic, and central and peripheral analgesic properties, respectively. The current findings concluded that W. coccinea might be a potential natural source for managing oxidative stress, diarrhea, hyperglycemia, and pain. Further studies are warranted for extensively phytochemical screening and establishing exact mechanisms of action.

In vitro and in vivo Evaluation of Pharmacological Potential of Lasia spinosa Linn.

Lasia spinosa Linn. (Family: Araceae) is an important medicinal plant, which is traditionally used for treatment of different human ailments. The present study was undertaken to evaluate the in vitro thrombolytic, antiinflammatory and in vivo analgesic and hypoglycemic potentials of n-hexane, chloroform and aqueous soluble fractions of methanol extract of L. spinosa whole plant. Additionally, phytochemical screening was carried out by qualitative tests, which confirmed the presence of alkaloids, glycosides, steroids, tannins, saponin in this plant. During in vitro thrombolytic assay, the aqueous fraction at a dose of 500 μg/100 μl showed the maximum 33.15% lysis of the blood clot, as compared to the standard streptokinase (80.10%). The in vitro anti-inflammatory test was performed by inhibition of egg albumin denaturation assay and RBC membrane stabilization method. The chloroform fraction exhibited maximum anti-inflammatory potential by inhibiting 51.53% denaturation of albumin and by inhibiting 54.8% hemolysis of RBC membrane against hypotonic solution. Analgesic activity was evaluated by tail immersion method for central mechanism and by formalin-induced lick test for peripheral mechanism in mice. In tail immersion method, all the solvent fractions of L. spinosa at a dose of 500 mg/kg body weight exhibited a significant (p&lt;0.05) elongation in pain reaction time. In peripheral analgesic activity test, the chloroform fraction at a dose of 500 mg/kg body weight inhibited a maximum of 35.44% licking response induced by formalin, as compared to the standard aspirin (53.22%). In the hypoglycemic activity test, all the fractions showed a moderate effect in reducing the blood glucose level in mice treated with 10% glucose. In conclusion, the plant L. spinosa can be considered as a promising source of bioactive compounds for the development of new phytomedicine.&#x0D; Dhaka Univ. J. Pharm. Sci. 20(1): 111-119, 2021 (June)

EFFECTS OF ADMINISTRATION OF SIMVASTATIN ON THE THRESHOLD OF THERMAL PAIN TOLERANCE IN ADULT MALE RATS WITH HFD

Background: Increased consumption of high-fat diets has become a global health problem. Obesity by result of various endocrine changes and release of inflammatory cytokines that may contribute to the pathogenesis of pain. Simvastatin is a statin that inhibits the 3-hydroxy-methyl-glutaryl coenzyme A (HMG-CoA) reductase and has anti-inflammatory effects. The aim of the present study was to assess the antinociceptive activity of simvastatin following the use of high-fat diet in Male rats. Methods and materials: Forty adult male Wistar rats divided into six groups: control, high-fat diet, high-fat diet treated with 2 and 20 mg/Kg simvastatin and normal diet treated with 2 and 20 mg/kg simvastatin. Rats were maintained on a high-fat or normal diet for 45 days. Simvastatin was daily given through gavage from two weeks after starting of the study and continued for 30 days. Hot plate and blood biochemistry tests were performed to evaluate the threshold of thermal pain t tolerance. Results: Total cholesterol, LDL, and triglyceride, and body weight in the group that maintained a high fat diet was significantly higher compared with the other groups, especially the control group. But serum TNF-α and IL-6 were not found in a detectable production inall groups. High fat diet significantly reduced thermal pain reaction time. Simvastatin administration significantly decreased thermal hyperalgesia. Conclusion: The results indicate that simvastatin administration is a suitable way for reducing heat hyperalgesia following use of a high fat diet, but there is need to do further research.

EVALUATION OF THE ANALGESIC ACTIVITY OF AQUEOUS AND ALCOHOLIC EXTRACT OF FLOWERS OF PLUMERIA ALBA LINN IN EXPERIMENTAL ANIMALS

Objective: Plumeria alba (Apocynaceae), commonly known as “Frangipani” is an important medicinal plant, widely distributed throughout Southern India. In the traditional medicinal system, different parts of this plant have been mentioned to be useful in a wide variety of diseases. In this study, analgesic activity of aqueous and alcoholic extract of flowers of P. alba Linn was evaluated by hot-plate and acetic acid-induced writhing methods to substantiate and expand its clinical applications.&#x0D; Methods: The flowers of P. alba were collected from the local area in and around Coimbatore (India). The flowers were dried, powdered, and were extracted using soxhlet apparatus for 12 h using water and 95% of ethanol as a solvent. The test extracts were administered orally at a dose of 100 &amp; 200 mg/kg while diclofenac sodium (10 mg/kg) served as standard.&#x0D; Results: The ethanolic flower extract of 200 mg/kg had significant analgesic activity in acetic acid-induced abdominal writhing response (***p&lt;0.001) when compared to control and standard drug diclofenac. It also exhibited significant analgesic activity (***p&lt;0.001) by increasing the pain reaction time of the rats in comparison to control and standard in hot plate method.&#x0D; Conclusion: The results suggest that ethanolic flower extracts of P. alba possess potent analgesic properties, which support its use in traditional medicine and suggesting that the plant should be further investigated for its pharmacological active natural products.

Anti-inflammatory and analgesic effects of methanol extract of red cultivar Allium cepa bulbs in rats and mice.

Several cultivars of Allium cepa L. have been studied for anti-inflammatory and analgesic activities but there is inadequate information on such biological activities of the concentrated extracts of the Nigerian grown red cultivar A.cepa bulb. The anti-inflammatory models used in this study were Carrageenan-induced paw oedema and formalin-induced paw lick in rats, while acetic acid-induced abdominal writhing, hot plate reaction, hot water tail flick tests in mice were the analgesic models. At 30min post-induction (pi), the inhibition of paw oedema (62.50%) by 200mg/kg of methanol extract of red cultivar A.cepa bulb (MERCACB) was significantly (p<0.001) higher than that of indomethacin (15.63%) at 10mg/kg. The paw oedema inhibition at 60min pi by MERCACB (76.92%) was significantly higher than that of indomethacin (41.03%). At the early phase of formalin paw-lick test, the pain reaction time (PRT) of rat treated with MERCACB (400mg/kg) was significantly lower than that of indomethacin and the control groups. The hotplate test revealed that PRT of mice treated with 800mg/kg of MERCACB were significantly (p<0.01) longer in comparism to indomethacin and control groups. The PRT of mice subjected to thermal pain due to hot water and treated with 800mg/kg of MERCACB was significantly (p<0.05) longer than that of the control group. These findings indicate that MERCACB possesses potent anti-inflammatory and analgesic properties which confirm the traditional use of the plant for the treatment of inflammatory diseases and may be useful as a future therapeutic agent.

Effects of Simvastatin on The Threshold of Thermal Pain Tolerance Following Using of High-Fat Diet in Male Rats

Objectives: Increased consumption of high-fat diets has become a global health problem. Obesity by result of various endocrine changes and release of inflammatory cytokines that may contribute to the pathogenesis of pain. Simvastatin is a statin that inhibits the 3-hydroxy-methyl-glutaryl coenzyme A (HMG-CoA) reductase and has anti-inflammatory effects. The aim of the present study was to assess the antinociceptive activity of simvastatin following the use of high-fat diet in Male rats.Methods and materials: Forty adult male Wistar rats divided into five groups: control, high-fat diet, high-fat diet treated with 2 and 20 mg simvastatin and normal diet treated with 20 mg simvastatin. Rats were maintained on a high-fat or normal diet for 45 days. Simvastatin was daily given through gavage from two weeks after starting of the study and continued for 30 days. Hot plate and blood biochemistry tests were performed to evaluate the threshold of thermal pain tolerance.Results. Total cholesterol, LDL, and triglyceride, and body weight in the group that maintained a high fat diet was significantly higher compared with the other groups, especially the control group. But plasma TNF-α and IL-6 were not found in a detectable production in all groups. High fat diet significantly reduced thermal pain reaction time. Simvastatin administration significantly decreased thermal hyperalgesiaConclusion: The results indicate that simvastatin administration is a suitable way for reducing heat hyperalgesia following use of a high fat diet, but need to do further research.

ANTINOCICEPTIVE ACTIVITY OF MAGNOLIA GRANDIFLORA LINN. LEAVES

Magnolia grandiflora (Magnoliaceae) is an evergreen tree with fragrant and showy flowers native to southeastern USA but widely cultivated all over the world and used in cosmetics industry in treatment of skin diseases. To estimate the different extracts of Magnolia grandiflora leaves by performing pharmacological screening of analgesic activity (Hot plate method and tail immersion method). In the present study the two methods were performed the mice was placed on a hot plate maintained at the temperature of 55 ± 1°C and the pain reaction time (PRT) or latency period determined with a stop watch was recorded and then about 2-3cm of the tail of each of the mice was dipped into a water bath containing warm water maintained at a temperature of 50 ± 1°C and the time taken for the mice to flick its tail or withdraw it from the warm water known as the pain reaction time (PRT) was recorded. Here, we report on the Pharmacological investigation of different extracts of Magnolia grandiflora Linn leaves. The results were demonstrated on that ethyl acetate extract (P &lt; 0.01) exhibited significant dose dependent analgesic activity in all tested models for analgesia. The time course for analgesia revealed maximum activity after 30 min in both tail immersion and hot plate methods, which was prolonged to 24 hours. The study concludes that the ethyl acetate extract from leaves of Magnolia grandiflora possess analgesic activity at doses 250, 500 and 100 mg/kg I. p.

Gender differences on pain threshold, body temperature and reaction time among elderly population after alternate nostril breathing exercises-A comparative study

Introduction: It is a known fact that elderly males have a faster reaction time than females, and females exhibit greater pain sensitivity than males. Results on body core temperature between genders are inconsistent. Alternate Nostril Breathing (ANB) exercises were known to modulate the autonomic nervous system. The present study was done to find whether such differences between elderly males and females on pain sensitivity, body temperature and reaction time still persisted after ANB exercises. Objectives: 1. To measure the pain sensitivity, body temperature and reaction time in elderly males and females; 2: To compare the effects of 30 minutes of ANB exercises on all these parameters between elderly males and females. Materials and Methods: 30 elderly males (n=14) and females (n=16) with a mean age of 70.3 years participated in the study. Pain sensitivity was measured with digital algometer, temperature with clinical thermometer and reaction time with choice time apparatus before and immediately after ANB exercises. Results: A significant decrease (

Evaluation of the Stem Bark Extract Picralima nitida for Antinociceptive Property

Aims: To investigate the antinociceptive property of Picralima nitida stem bark methanol extract. Place and duration of study: Department of Veterinary Physiology and Pharmacology, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria from February to July, 2020.&#x0D; Methodology: The extraction was done by cold maceration of the pulverised P. nitida stem bark in 80% methanol for 48 hours. Acute toxicity study was done using up and down method. The antinociceptive study was carried out using tail flick and hot plate antinociceptive models. The extract was used at the doses of 100, 200 and 400 mg/kg while pentazocine 3 mg/kg was used as the standard reference drug (positive group) and 5 ml/kg distilled water was used for the negative group.&#x0D; Results: In the tail flick test, P. nitida at the doses of 100 and 400 mg/kg with the standard drug pentazocine significantly (P = 0.05) increased the pain reaction time (PRT), increasing the PRT from 1.80 ± 0.08 sec in the negative group (distilled water 5 ml/kg) to 2.90 ± 0.18 sec at the dose of 200 mg/kg group of mice representing 62.06% increase. Also, in the hot plate model, the PRT was increased from 2.03 ± 0.02 sec in distilled water treated group of mice to 9.58 ± 0.99 sec in the 400 mg/kg dose of the extract.&#x0D; Conclusion: The stem bark methanol extract of P. nitida demonstrated a good level of antinociceptive activity in the models used in this study.

Chronic Musculoskeletal Pain and Foot Reaction Time in Older Adults

This cross-sectional study examines the association between chronic musculoskeletal pain and foot reaction time (RT) among older community-living adults. Participants were 307 adults aged 71 years and older in the MOBILIZE Boston Study II. Pain severity, interference, and location were measured by the Brief Pain Inventory and a joint pain questionnaire. With participants seated, simple foot reaction time was measured as self-selected foot response time to an intermittent light, and choice foot reaction time was measured as response time to the light on the corresponding side of the sensored gait mat. We performed multivariable linear regression to determine associations of pain and foot RT, adjusted for sociodemographic and health characteristics, and serially adjusted for cognitive function (MMSE or Trail Making A). Pain severity and interference were associated with slower simple foot reaction time (P < .05). Pain severity and knee pain were associated with slower choice foot reaction time (P < .05). Adjustment for cognitive measures had little impact on the pain-RT relationship. This significant relationship was only observed among participants with less education. These results support the idea that chronic pain may lead to slower foot RT, thus could represent a fall hazard in older adults. Neuromotor mechanisms underlying the pain-fall relationship warrant further investigation. PerspectiveThis study provides insights on the mechanisms underlying the pain-fall relationship. Chronic pain may contribute to slower foot RT thus increase fall risk in older adults. This may help inform interventions such as stepping training to reduce fall risk in older adults living with chronic pain.

Effects of ethanol extract of the resin exudate of boswellia dalzielii hutch on pain in mice

This study aimed to determine the analgesic properties and the acute toxicity of Ethanol Extract of the Resin Exudate of Boswellia dalzielii (EERBD) in mice animal model. We used the writhing or acetic acid abdominal constriction, tail-immersion, and hot plate tests to assess the analgesic effect of EERBD at three doses (100, 200, and 400 mg/kg). To study the acute toxicity of EERBD, 24 female mice were divided into four groups (n=6) and were orally treated with EERBD at the doses of 0, 2000, 4000, and 5000 mg/kg, as per OECD (Organization for Economic Co-operation and Development) guidelines No. 420. In the acetic acid-induced writhing reflex model, the EERBD ministration decreased the mean total number of writhes at the two doses (100 and 400 mg/kg), which were found highly significant (P &lt; 0.001) compared to control group. In the tail immersion model, the EERBD administration at the dose of 400 mg/kg significantly increased the pain reaction time (P &lt; 0.001 as compared to control) at 30 min, but another tested sample had no significant latency. In the hot-plate model, the drug extract created significant (P &lt; 0.001) increase in the latency period compared to the control group at oral doses of 100 and 400 mg/kg when compared to initial time and control group (4.5 ± 1.29 s) with protective effect from 4.25 ± 1.50 s after 30 min. Administration of EERBD at the dose of 200 mg/kg showed no significant analgesic activity based on writing, tail immersion, and hot-plate tests. The extract did not show toxicity signs or death at dose of less than 5000 mg/kg per oral. The results suggest that EERBD contain bioactive substances with analgesics effects; hence, it might be a better alternative to conventional drug therapy for pain management.

Please empathize! Instructions to empathise strengthen response facilitation after pain observation

ABSTRACTRecent research has shown that observing others in pain leads to a general facilitation of reaction times. The current study sheds further light on the relationship between pain observation and reaction time by exploring how bottom-up processes, in the form of perceived pain intensity, and top-down processes, in the form of explicit instructions to empathise, influence response facilitation after pain observation. Participants watched videos of a hand getting pierced by a needle or touched by a Q-tip. To manipulate bottom-up information, participants saw videos depicting either deep or shallow insertion of the needle. To investigate potential top-down modulation, half the participants were explicitly requested to empathise with the person in the video, while the other half were told to simply watch and attend to the video. Results from two experiments corroborate previous results showing response facilitation after pain observation. Critically, experiment 2 provides robust evidence that explicit instructions to empathise with a person in pain strengthen response facilitation. We discuss these results considering social cognitive neuroscience and experimental psychology studies of empathy and pain observation.

Anti-inflammatory and analgesic activities of methanol extract of Helianthus annuus Linn. (Asteraceae) leaf

Abstract This study evaluate the anti-inflammatory and analgesic properties of Helianthus annuus Linn. in rats. Methanol extract of Helianthus annuus (HAE) leaf was used in this study. Formalin- and egg-albumin induced-paw edema were used to investigate the anti-inflammatory activities while acetic acid-induced writhing reflex and tail flick models were used to evaluate the analgesic properties. The doses of HAE used were 150, 300 and 600 mg/kg. Acetylsalicylic acid (ASA) was used as reference drug in the anti-inflammatory and writhing reflex models while pentazocine (reference drug) was used in tail flick model. The negative control was dosed 5% tween-20 (10 ml/kg). The HAE exhibited significant (P &lt; 0.05) dose-dependent anti-inflammatory and analgesic activities. At 3 hour (h) post treatment, the HAE (300 mg/kg) produced 33.33% and 32.94% while ASA produced 36.36% and 35.29% reduction in paw volume in the formalin and egg-albumin induced paw edema models respectively when compared with negative control. In the acetic acid-induced writhing reflex, ASA and HAE (600 mg/kg) produced 67.89% and 35.78% reduction in the number of writhing, respectively when compared with the negative control. Pentazocine and HAE (300 mg/kg) caused 67.62% and 35.24% increase in pain reaction time when compared with the negative control. The study affirms the folkloric uses of Helianthus annuus in the management of pain and inflammation.

Exercise-based interventions for physically active individuals with functional ankle instability: a systematic review of the literature.

Ankle instability is highly prevalent in physically active individuals and the effectiveness of rehabilitation programs based on exercise is still unclear. The objective of this study is to assess the effects of any type of exercise programs compared to any other intervention or no intervention for physically active individuals with functional ankle instability (FAI) and to explore whether the effects vary according to the characteristics of the exercise program and outcome variables. We searched English, French and Portuguese language publications from the following databases: PubMed (National Library of Medicine, Bethesda, MD), SPORTDiscus, Physiotherapy Evidence Database, Academic Search Complete, Science Direct and Scielo. Combinations of the following key words were used: functional, instability, ankle, sports, exercise, proprioception, coordination. Eligible studies were randomized control trials (RCT) or clinical control trials (CCT) that compared an intervention consisting of an exercise program in adult participants with functional ankle instability (FAI) and defined as physically active against other exercise programs, other interventions or no intervention. Two independent reviewers applied the selection criteria and assessed the quality of the studies. A total of 567 studies were retrieved from the literature search and eight articles met the inclusion criteria. Included studies assessed dynamic and static postural control, proprioception, strength, self-reported instability, range of motion, balance, pain and muscle reaction time. All studies compared an exercise program versus no intervention, one compared exercise against the same program with the addition of stochastic resonance, and two studies compared different exercise programs. Exercise programs focused on coordination, balance and proprioception appear to improve functional performance for physically active individuals with functional instability and reduce subjective instability. Exercise training presents as an option to improve postural control, joint position sense or recurrent injury rates. Further study is suggested in order to determine optimal exercise programs for specific sports populations.