• Journal of Acupuncture Research
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• v.17 no.2
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• pp.139-152
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• 2000

This study was designed to evaluate the analgesic effect of bee venom (BV) Acupuncture into different treatment points, Chok-samni (ST36) and blank loci of the gluteal muscle and back. We investigated the changes in formalin-induced pain behavior according to the pretreatment with different concentrations of BV, thirty minutes before the formalin injection. The results were summarized as follows: 1. The formalin-induced pain behavior was suppressed by pretreatment with BV into Chok-samni (ST36) in a dose dependent manner. During the early phase, 0.08mg/kg of BV showed a statistically significant suppression in the formalin-induced pain behavior. Moreover, 0.008mg/kg, 0.016mg/kg, and 0.08mg/kg of BV, except 0.0016mh/kg of BV, had significant suppresive effects on the formalin-induced pain behavior during the late phase. Therefore, these data indicated that the suppressive effect of BV acupuncture on the formalin-induced pain behavior was stronger in the late phase rather than the early phase 2. In order to investigate the analgesic effect of BV acupuncture into different treatment points, the experimental animals were divided into three groups: Chok-samni (ST36) group, gluteal group and back group. In the Chok-samni (ST36) group, the formalin-induced pain behavior during all the phases was significantly reduced as compared with that of the back group. However, as compared with that of the gluteal group, the formalin-induced pain behavior in the Chok-samni (ST36) group was decreased only in the late phase, not in the early phase. The formalin-induced pain behavior in the gluteal group was significantly reduced as compared with that of the back group in the late phase, not in the early phase. We suggested that the analgesic effect of BV acupuncture into Chok-samni (ST36) was most effective among Chok-samni (ST36), gluteal, and the back groups in formalin-induced pain behavior.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.137-141
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• 2006

Background: It has been known that melatonin is involved in the modulation of nociceptive transmission. However, the effect of melatonin administered spinally has not been examined. Therefore, we examined the effect of melatonin on the formalin-induced or thermal-induced nociception at the spinal level. Methods: Intrathecal catheter was inserted into the subarachnoid space of male Sprague-Dawley rats. Pain was assessed by formalin test (induced by injection of $50{\mu}l$ of a 5% formalin solution to the hindpaw) or Hot-Box test (induced by radiant heat application to the hindpaw). The effect of intrathecal melatonin was examined on flinching behavior in the formalin test or withdrawal response in Hot-Box test. Results: Intrathecal melatonin produced a limited, but dose-dependent reduction of the flinching response during phase 1 and 2 in the formalin test. In addition, melatonin delivered at evening also decreased the flinching response in both phases of the formalin test. Melatonin restrictively increased the withdrawal latency in Hot-Box test. Conclusions: These results suggest that melatonin is active against the formalin- and thermal-induced nocicpetion at the spinal level, but the effect is limited.

• The Journal of Korean Medicine
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• v.23 no.2
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• pp.97-107
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• 2002

Objective : Acupuncture is a method used to treat many kinds of pain in oriental cultural medicine. Especially when hetero-segmental area acu-points are stimulated, the therapeutic effects of pain control have more critical properties than other methods of acupuncture. However, the mechanism of pain control by acupuncture is contradictory so far. The present study examined the effects of electroacupuncture (EA) applied to the acu-point of the hetero-segmental area on modulation of formalin-induced pain in Sprague-Dawley rats. Methods : In order to apply EA to acu-points in the plantar area of right forepaws, a pair of Teflon-coated stainless steel wires were implanted in HT 7 (Shin-Moon) and PC 7 (Dae-Reung) 7 days before the behavioral test. A behavioral test was performed by means of video camera after injection of 5% formalin ($50{\;}\mu\textrm{l}$) into the lateral plantar region of the left hind paw. EA was delivered by a constant DC current stimulator at 4~5 mA, 2 ms, and 10 Hz for 30 min. c-Fos protein expression was measured in the lumbar spinal cord at 2 hr and 4 hr after formalin injection. Results : Behavioral responses including favoring, flinching and biting occurred in the biphasic pattern, such as the 1st phase (0~5 min) and the 2nd phase (20~45 min) after formalin injection. However, EA (4~5 mA, 2 ms, 10 Hz) significantly inhibited the behavioral responses. Injection of formalin expressed c-Fos protein on the ipsilateral dorsal horn neurons in L3 - L5 and the expression was sustained more than 4 hrs after formalin injection. However, EA decreased c-Fos protein expression at dorsal horn neurons in the lumbar spinal cord till 4hrs after formalin injection. Conclusions : These results suggest that EA modulates formalin-induced pain and this inhibitory action may be elicited by the descending inhibitory system.

• The Korean Journal of Pain
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• v.27 no.2
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• pp.118-124
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• 2014

Background: The chronic pain can disturb physical, psychological, and social performances. Analgesic agents are widely used but some antidepressants (ADs) showed analgesia also. Bupropion is using for smoke cessation but it can change morphine withdrawal signs such as pain. This study tested the acute systemic effect of bupropion on formalin induced pain behavior in rats. Methods: Wistar male healthy rats were divided into 7 groups (control, sham, and 5 treated groups with 10, 30, 90, 120, and 200 mg/kg of bupropion, i.p.). The bupropion injected 3 hours prior to formalin induced pain behavior. Formalin (50 ${\mu}l$, 2.5%) was injected subcutaneously in dorsal region of right hindpaw in all animals. Nociceptive signs were observed continuously on-line and off-line each minute. Common pain scoring was used for pain assessment. Results: The analysis of data by one-way ANOVA showed that bupropion can reduce pain scores in the second phase but not in first phase. Bupropion decreased the licking/biting duration significantly in first and second phase of formalin test. Conclusions: The results showed that bupropion has analgesic effects at systemic application. The change of second phase of the pain behavior was significant and it revealed that central mechanisms involve in bupropion analgesia.

• The Journal of Korean Medicine
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• v.24 no.2
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• pp.193-203
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• 2003

Objectives : In this study, we investigated the effect and pathway of contralateral heterotropic electroacupuncture (EA) on pain induced by fonualin in rats. Methods : Acu-points in the right forepaws, HT 7 and PC 7 were stimulated with 3~4mA, 2ms, and 10Hz after 5% formalin (50ul) s.c. injection to the left hind paw. In addition, it was investigated whether the dorsolateral funiculus (DLF), known to be related the descending inhibition, mediates analgesic effects of the contralateral heterotropic EA or whether administration of naltrexone, an opioid antagonist, blocks the effect of EA. Results : The results showed that contralateral heterotropic electroacupuncture (EA) inhibited late phase (63.311.7%) of pain induced by fonualin in the behavioral test, but sham-EA had little effect on pain behavior (85.616.8%) and no analgesic effects after transection of the dorsolateral funiculus (95.718.7%). The pretreatment of naltrexone (10mg/kg, i.p.) could not inhibit the analgesic effects of EA on formalin-induced pain behavior (70.713.1%). Also,EA suppressed formalin injection induced expression of cFos like protein (cFL) in the dorsal homo but not sham-EA. Suppressed expressions of cFL in the spinal cord were eliminated after transection of the ipsilateral dorsolateral funiculus at T10-11 leve1s. However, pretreatment of naltrexone could not prevent the suppressive expressions of cFL at the spinal cord. Conclusions : These results suggest that the analgesic effect of contralateral heterotropic electroacupuncture may be modulated through the dorsolateral funiculus constituting the descending inhibition.

• The Journal of Korean Medicine
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• v.28 no.3 s.71
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• pp.261-272
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• 2007

Objectives : This study was conducted to determine the analgesic effect of Acanthopanax sessiliflorus using the model of neuropathic pain and formalin-induced pain. Methods : A model of neuropathic pain was made by injuring the tibial nerve and sural nerve while the common peroneal nerve was maintained. After 2 weeks, the Acanthopanax sessiliflorus was orally administered to rats. The author performed behavioral teststo try out mechanical allodynia using von frey filament and cold allodynia using acetone, which are calculated by counting withdrawal response on foot. Thirty minutes after the Acanthopanax sessiliflorus injection in the abdominal cavity, the formalin test was performed. 2% formalin in a volume of $20{\mu}l$was injected subcutaneously into the plantar surface of the hindpaw with 26-G needle. To access formalin-induced pain behavior, paw licking time was measured every 5 min. Results : The Acanthopanax sessiliflorus 400mg/10ml/kg group showed significant decrease the withdrawal response of mechanical allodynia using von frey filament in the 10min, 30min, 60min and 120min increments compared with the control group. There were no significant differences in each group in the withdrawal response of cold allodynia using acetone. The Acanthopanax sessiliflorus group showed significant decrease in the formalin-induced pain behavior in the 15min, 20min and 25min increments compared with the control group. Conclusions : The Acanthopanax sessiliflorus may have a significant analgesic effect on the general pain as well as nerve injury pain.

• The Korean Journal of Pain
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• v.25 no.4
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• pp.238-244
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• 2012

Background: Vitamin E is widely known to be one of the reactive oxygen species (ROS) scavengers and a drug that can easily be obtained, and it has been shown to attenuate the pain responses induced by various causes in animal pain models. Thus, this experiment was conducted to assess the antinociceptive effects of vitamin E by comparing intraperitoneal and intrathecal injections in rats subjected to the formalin test. Methods: After the intraperitoneal and intrathecal injections of vitamin E were carried out, respectively (IP: 500 mg/kg, 1 g/kg, and 2 g/kg, IT: 3 mg/kg, 10 mg/kg, and 30 mg/kg), the formalin test was perfumed. As soon as 5% formalin was injected into left hind paw, the number of flinches induced by pain was measured at 5-minute intervals for 1 hour. Results: Formalin injected into the left hind paw induced biphasic nociceptive behavior in all animals. Intraperitoneal injection of vitamin E diminished the nociceptive behavior in a dose-dependent manner during the early and late phase. Intrathecal vitamin E diminished nociceptive behavior dose dependently during the late phase but showed no significant difference in the early phase. Conclusions: Vitamin E attenuated acute nociception when it was injected systemically, while both systemic and intrathecal injection produced analgesia in a rat model of formalin-induced hyperalgesia.

• Biomedical Science Letters
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• v.24 no.3
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• pp.239-244
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• 2018

Recently, many researches regarding the natural products which alternate with chemical products have been done. Among them, boswellia is well known for effect on anti-oxidative effect and inflammation. The aim was the effect boswellia of formalin- induced orofacial and temporomandibular joint (TMJ) pain on experimental animals was investigated. Experiments were carried out using subcutaneous (SC) pain model and TMJ pain model that were induced by the injection of 5% formalin into the right vibrissa pad (SC, $50{\mu}L$) or TMJ ($30{\mu}L$) of rats, respectively. In both models, formalin (5%), formalin after distilled water (vehicle), formalin after boswellia extract (p.o., concentrations of 15, 30 mg/kg) (n=6). The number of scratching on the injected region was scored during the 9 successive periods of 5 min intervals following injection of formalin. Oral administration of boswellia (15, 30 mg / kg) reduced formalin-induced SC orofacial pain behavioral responses. SC orofacial pain behavioral responses was significantly reduced at 20~35 min. In the experimental group injected into temporomandibular joints, the pain response was significantly reduced by $276.2{\pm}8.20$ and $78.3{\pm}4.7$ after oral administration of boswellia (15, 30 mg / kg) at $398.3{\pm}24.8$ times. As a result of the passage of time, the oral administration of boswellia showed a significant effect of reducing the temporomandibular joint pain 30 minutes after the injection of formalin. This study confirmed that oral administration of boswellia modulated the pain behavior in both models. In conclusion, boswellia extract may be a potential therapeutic treatment for orofacial pain.

• Journal of Korean society of Dental Hygiene
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• v.17 no.5
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• pp.911-919
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• 2017

Objectives: The baobab tree is a multipurpose, widely-used species with medicinal properties and numerous food uses. The aim of study was to evaluate the effect of oral administration of baobab on the formalin-induced inflammatory pain in rat model injected into the orofacial regions. Methods: Male Sprague-Dawley rats weighing 260-280 g were used. Pain in the orofacial region was induced using two models, 5% formalin was injected $50{\mu}l$ subcutaneously or $30{\mu}l$ in temporomandibular joint (TMJ), respectively. Rats were divided into 4 groups (n=6); formalin, formalin after distilled water (vehicle) or baobab (150, 300 mg/kg). The number of noxious behavioral responses with scratching the facial region was recorded for 9 successive 5-min intervals following formalin injection. Results:There was no significant difference in the first response to the pain between the formalin induced group and the drug administration group. However, in the secondary infusion group, all of the pain medication were responded (Bao 150, 300 mg/kg) (p<0.05). Conclusions:The results showed analgesic effect of baobab on formalin-induced orofacial inflammatory pain. This suggests that the natural product is an effective alternative to the postinflammatory pain control.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.2
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• pp.207-213
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• 2011

Purpose: The purpose of this study was to determine the preventive effect of joint mobilization on biphasic pain response induced formalin test. Methods: Sprague-dawley rats(n=30) were ramdomly divided into the control group without intervention, sham control group with application of hand contact without mobilization, joint mobilization group with application of hand contact with mobilization. Joint mobilization of knee procedure involved an grade III extension mobilization basically with anterior-posterior gliding of the tibia on the femur. Formalin injection caused biphasic pain response which is lated for 60 minute. The first phase result from primary afferent sensory fiber, wheareas the second phase has been proposed to central sensitization in the central nervous system. Behavioral analysis was performed by digital camera after 5% formalin subcutaneous injection into the dorsal foot. Results: Pain response of joint mobilization group show significant lower than control gorup and sham control group. Conclusion: This result suggest that pre-application of joint mobilization may be effective intervention to prevent the formalin induced pain.