Mecobalamin Group Research Articles

Perineural Injection of Mecobalamin Versus Dextrose 5% Against Clinical Changes and Electrophysiological Features of Carpal Tunnel Syndrome Patients at Dr. Mohammad Hoesin General Hospital, Palembang, Indonesia

Background: Carpal tunnel syndrome (CTS) is a common compression neuropathy with symptoms of pain, tingling, and numbness in the hands. Perineural injections of steroids and mecobalamin have been shown to be effective in relieving CTS symptoms. This study aims to compare the effectiveness of the perineural injection of mecobalamin and 5% dextrose on clinical changes and electrophysiological features in CTS sufferers.
 Methods: This research is a pilot study open-label randomized controlled trial conducted at Dr. Mohammad Hoesin General Hospital Palembang. A total of 24 CTS patients were randomly divided into two groups: the mecobalamin group (n=12) and the 5% dextrose group (n=12). Patients in both groups received a single perineural injection.
 Results: In the mecobalamin group, there were significant improvements in pain scores (NPRS), Boston carpal tunnel questionnaire (BCTQ) - symptom severity scale (SSS) and functional status scale (FSS), as well as median nerve motor and sensory conduction after 2 weeks. In the 5% dextrose group, there were significant improvements in pain scores and BCTQ-SSS but not in BCTQ-FSS and nerve conduction. Comparison between groups showed significant differences in BCTQ-SSS and sensory conduction amplitude.
 Conclusion: Perineural injection of mecobalamin and 5% dextrose is effective in improving clinical symptoms of CTS. Mecobalamin showed better effects on BCTQ-SSS and sensory conduction amplitude than 5% dextrose.

Efficacy of tokishakuyakusan and mecobalamin on post-infectious olfactory dysfunction: A prospective multicenter study

ObjectiveTo determine if tokishakuyakusan (TSS) is effective for treating post-infectious olfactory dysfunction (PIOD) compared with vitamin B12 (mecobalamin). MethodsWe conducted a randomized, nonblinded clinical trial. Patients with PIOD enrolled in 17 hospitals and clinics from 2016 to 2020 were randomly divided into two groups, and we administered TSS or mecobalamin for 24 weeks. Their olfactory function was examined using interviews and T&T olfactometry. The improvement of olfactory dysfunction was assessed following the criteria of the Japanese Rhinologic Society. ResultsOverall, 82 patients with PIOD were enrolled in this study. In the TSS and mecobalamin groups, 39 patients completed the medication regimen. In the TSS and mecobalamin groups, olfactory dysfunction was significantly improved based on self-reports and olfactory test results. The improvement rate of olfactory dysfunction was 56% in the TSS group and 59% in the mecobalamin group. Early intervention within 3 months produced a better prognosis than the treatment initiated after 4 months. Furthermore, age and sex differences were not observed. Both medications produced no severe adverse events. ConclusionThe present study showed that TSS and mecobalamin might be useful for treating PIOD.

Ferulic acid alleviates sciatica by inhibiting peripheral sensitization through the RhoA/p38MAPK signalling pathway

BackgroundNonsteroidal anti-inflammatory drugs are used to relieve sciatica, but their effects are not satisfactory. PurposeThis study aimed to explore the therapeutic effects of ferulic acid on sciatica. MethodsThirty-two SD rats were randomly divided into 4 groups, i.e., sham operation group, chronic constriction injury (CCI) group, mecobalamin group, and ferulic acid group. We conducted behavioural tests, ELISA, PCR, Western blots, and immunofluorescence analysis. Specific inhibitors were used in cell experiments to explore the related mechanisms. ResultsThermal hyperalgesia was induced after CCI operation, and ferulic acid relieved thermal hyperalgesia. In addition, ferulic acid decreased the IL1β, IL6, TNF-α, and CRP mRNA levels; the IBA-1, iNOS, IL1β, RhoA, RhoA-GTP, COX2, Rock1, TRPV1, TRPA1, and p-p38MAPK levels in dorsal root ganglion (DRG) neurons; and the LPS, CRP, substance P (SP), and prostaglandin E2 (PGE2) levels in serum, and these levels were higher in the CCI group. In the cell experiments, LPS induced M1 polarization of GMI-R1 cells via the RhoA/Rock pathway. Ferulic acid attenuated LPS-induced M1 polarization by decreasing the levels of M1 polarization markers, including IL1β, IL6, TNF-α, iNOS, and CD32, and increased M2 polarization by increasing the levels of M2 polarization markers, including CD206 and Arg-1. LPS treatment clearly increased the iNOS, IL1β, RhoA, Rock1, Rock2 and p-p38 MAPK levels and reduced Arg-1 expression, and ferulic acid reversed these changes. ConclusionFerulic acid can inhibit peripheral sensitization by reducing the levels of inflammatory factors, TRPA1 and TRPV1 through the RhoA/p38 MAPK pathway to alleviate sciatica.

Therapeutic effect of paeoniflorin on chronic constriction injury of the sciatic nerve via the inhibition of Schwann cell apoptosis.

Therapeutic drugs of chronic neuralgia have a high risk of addiction, making it crucial to identify novel drugs for chronic neuralgia. This study aimed to explore the therapeutic effect of paeoniflorin on chronic sciatica via inhibiting Schwann cell apoptosis. 28 SD rats were randomly divided into four groups, including the sham operation group, chronic constriction injury (CCI) group, mecobalamin group, and paeoniflorin group. The therapeutic effect and mechanism of paeoniflorin were evaluated via rat and cell experiments. Mechanical, hot, or cold hyperalgesia was induced in the rats after CCI operation, while paeoniflorin relieved chronic neuralgia. Besides, paeoniflorin decreased the levels of IL1, IL6, TNF‐α, CRP, and LPS and increased the level of IL10 in serum. As for the sciatic nerve, the number of inflammatory cells was decreased, and Schwann cells were present after paeoniflorin treatment, and paeoniflorin promoted the recovery of nerve structure. In cell experiments, LPS induced Schwann cell apoptosis via the TLR4/NF‐kB pathway. And paeoniflorin attenuated LPS‐induced Schwann cell apoptosis by decreasing the levels of TLR4, p‐NF‐kB, caspase3, cleaved‐caspase3, and cleaved‐caspase7. Overall, these results suggest that paeoniflorin alleviates chronic sciatica by decreasing inflammatory factor levels and promotes the repair of damaged nerves by reducing Schwann cell apoptosis.

No Effect of Oral Mecobalamin on Skin Numbness at 3 Months After Total Knee Arthroplasty: A Randomized, Double-Blinded, Placebo-Controlled Superiority Trial.

Background:An area of skin numbness (AON) around an incision commonly occurs following total knee arthroplasty (TKA). Mecobalamin has been shown to facilitate peripheral nerve recovery in various conditions; accordingly, the present study aimed to investigate the ameliorative effect of mecobalamin on AON following TKA, as compared with a placebo.Methods:This superiority study was a double-blinded, randomized controlled trial. All patients undergoing primary TKA were assessed for eligibility. Included patients were randomized to receive either mecobalamin (500 µg, twice daily) or placebo (corn starch powder; 500 µg, twice daily) for 3 months. The primary outcome was the change in the AON around the surgical site from 2 weeks to 3 months after TKA. Secondary outcomes included the rates of different adverse events, functional outcomes, and visual analogue scale patient satisfaction scores.Results:A total of 154 patients were enrolled, with 77 patients each in the mecobalamin and placebo groups. The mean AON among patients in the mecobalamin group was 61.6 cm2 at baseline (2 weeks) and 29.1 cm2 at 3 months, compared with 55.9 cm2 and 33.2 cm2 among patients in the placebo group, respectively. Intention-to-treat analysis showed no significant difference in the change in AON around the surgical site between the 2 groups (mean difference, 7.5; 95% confidence interval, −4.2 to 25.3; p = 0.159). The rates of adverse events, functional outcomes, and visual analogue scale patient satisfaction score were also not significantly different between groups.Conclusions:Mecobalamin did not demonstrate superiority over a placebo in reducing the AON around the surgical site at 3 months after primary TKA.Level of Evidence:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Effects of Mecobalamin on Cerebral Ischemia-Reperfusion Injury of Spontaneously Hypertensive Stroke Prone Rats

We aimed to evaluate the effects of mecobalamin on the cerebral ischemia-reperfusion injury of spontaneously hypertensive stroke prone rats. 72 male rats were randomly divided into control group, model group, nimodipine group, high-dose mecobalamin group, middle-dose mecobalamin group and low-dose mecobalamin group (n=12). All groups were administrated intragastrically every morning once a day for 7 continuous days. The model of 2 h of focal cerebral ischemia and 24 h of reperfusion was established by blocking middle cerebral artery. Neurological deficits were graded with reference to the Longa method. Cerebral edema was determined using the wet-dry weighing method. The volume of cerebral infarction was measured by triphenyltetrazolium chloride staining and the levels of tumour necrosis factor alpha, interleukin-1 beta and interleukin-8 were measured by radioimmunoassay. High and middle-dose mecobalamin significantly reduced the volume of cerebral infarction, alleviated cerebral edema and improved nerve function compared with those of the model group (p<0.05). Compared with the model group, high and middle-dose mecobalamin significantly reduced the levels of tumour necrosis factor alpha, interleukin-1 beta and interleukin-8 in cerebral tissue (p<0.05). Mecobalamin protected spontaneously hypertensive stroke prone rats from cerebral ischemia-reperfusion injury, which may be related to the decreased levels of tumour necrosis factor alpha, interleukin-1 beta and interleukin-8 in cerebral tissue.

Therapeutic Effect of Tetrapanax papyriferus and Hederagenin on Chronic Neuropathic Pain of Chronic Constriction Injury of Sciatic Nerve Rats Based on KEGG Pathway Prediction and Experimental Verification.

Background Hederagenin is one of the main components of Tetrapanax papyriferus, and Tetrapanax papyriferus is one of the ingredients of Danggui Sini decoction. To explore whether Tetrapanax papyriferus and hederagenin can alleviate mechanical pain, thermal hyperalgesia, and cold pain at the same time, we comprehensively investigated the effects of two drugs on the levels of p38 MAPK phosphorylation, TRP proteins, and IL1β, IL6, and TNF-α in serum. Methods Firstly, we obtained pain-related targets and performed KEGG pathway enrichment on these targets. Then, 42 SD rats were separated randomly into six groups: sham operation group, CCI group, pregabalin group, mecobalamin group, Tetrapanax papyriferus group, and hederagenin group. All drugs were given orally. Rats in the sham operation group and CCI group were gavaged with saline. Rats in the pregabalin group were given pregabalin, while rats in the mecobalamin group were given mecobalamin. Rats in the Tetrapanax papyriferus group were given Tetrapanax papyriferus, while rats in the hederagenin group were given hederagenin. Besides, we conducted behavioral tests including acetone test, hot plate experiment, and von Frey filaments, and then dorsal root ganglion neurons were taken out on the 21st day after operation. Then, western blot, ELISA, and hematoxylin-eosin staining were conducted. Results Rats in the CCI group were more sensitive to hyperalgesia and allodynia to mechanical and thermal stimuli, as well as cold pain. All four drugs could relieve these pains. Pregabalin, mecobalamin, and Tetrapanax papyriferus can reduce the levels of IL1β, IL6, and TNF-α in serum compared to those of the CCI group. The expression of TRPM8, TRPA1, TRPV1, TRPV4, and phosphorylated p38 MAPK in DRG increased evidently on the 21st day after the operation in the CCI group. All four drugs could reduce the expressions of TRPM8, TRPA1, TRPV1, TRPV4, and phosphorylated p38 MAPK in dorsal root ganglion compared to those of the CCI group. Conclusion Tetrapanax papyriferus and hederagenin relieved sciatica by reducing inflammation levels, inhibiting p38 MAPK phosphorylation, and decreasing the levels of dorsal root ganglion proteins.

Effect of Buyang Huanwu decoction on NF-κB/MuRFl expression in rats with denervated tibial muscle atrophy

We aim to study the effect of Buyang Huanwu decoction (Astragali Radix, Angelicae Sinensis Radix, Paeoniae Radix Alba, Pheretima, Chuanxiong Rhizoma, Carthami Flos and Persicae Semen) on NF-κB/MuRFl signaling pathway in the denervated tibial muscle atrophy of rats and explore its protection mechanisms. Sixty Sprague-Dawley rats were subjected to common peroneal nerve crush models of 5 mm injury, and then were randomly divided into six groups for daily intragastric administration of drugs： sham operation group, model group, Buyang Huanwu decoction high, middle and low dose groups, and mecobalamin group (as a positive control). After drug administration for 10 days and 21 days, the gene and protein expression levels of NF-κB and MuRFl in the tibial muscle of rats were detected by qRT-PCR and Western blot respectively. The results showed that, as compared with the model group, RNA and protein expression levels of NF-κB and MuRF1 were significantly reduced in Buyang Huanwu decoction middle and high-dose groups (P<0.05 or P<0.01). These results indicated that Buyang Huanwu decoction could inhibit ubiquitin proteasome system probably by activating NF-κB/MuRF1 signal pathway to protect the denervated tibial muscle atrophy of rats.

Clinical efficacy of acupoint injection for chemotherapy-induced peripheral neuropathy of patients with breast cancer

ObjectiveTo observe the clinical efficacy of acupoint injection for chemotherapy-induced peripheral neuropathy (CIPN). MethodsNinety CIPN patients with breast cancer conforming to inclusive criteria were randomly divided into an acupuncture group (group A), a mecobalamin group (group B) and an acupoint injection group (group C) according to random number table, with 30 cases in each group. In group A, acupuncture was conducted at bilateral Qāchí (▪ LI 11), Hégu (▪ LI 4), Zúsānli (▪ ST 36), Sānyīnjiāo (▪ SP 6) and Xuèhai (▪ SP 10); in group B, intramuscular injection with 1 mL of mecobalamin injection was conducted; and in group C, acupoint selection was the same as group A, and 0.1 mL of mecobalamin injection was injected into each acupoint, respectively. The treatment was conducted once every three days in each group, and the changes of clinical efficacy, nerve electrophysiology and hemorrheology indicators after treatment for 10 times were observed. ResultThe total effective rate of group C was 93.1% (27/29), which was higher than 78.6% (22/28) in group A and 83.3% (25/30) in group B, and the differences among three groups were statistically significant (all P<0.01); conduction velocity of lesion nerves was improved in group B and group C, the improvement in group C was obviously superior to the other two groups (all P<0.01), hemorrheology indicator was improved in group A and group C (both P<0.05). ConclusionThe efficacy of acupoint injection with mecobalamin for breast cancer CIPN was significant, which can not only improve the nerve conduction velocity, but also improve the hemorrheology indicator.

Cardiac Dysregulation and Myocardial Injury in a 6-Hydroxydopamine-Induced Rat Model of Sympathetic Denervation.

BackgroundCardiac sympathetic denervation is found in various cardiac pathologies; however, its relationship with myocardial injury has not been thoroughly investigated.MethodsTwenty-four rats were assigned to the normal control group (NC), sympathectomy control group (SC), and a sympathectomy plus mecobalamin group (SM). Sympathectomy was induced by injection of 6-OHDA, after which, the destruction and distribution of sympathetic and vagal nerve in the left ventricle (LV) myocardial tissue were determined by immunofluorescence and ELISA. Heart rate variability (HRV), ECG and echocardiography, and assays for myocardial enzymes in serum before and after sympathectomy were examined. Morphologic changes in the LV by HE staining and transmission electron microscope were used to estimate levels of myocardial injury and concentrations of inflammatory cytokines were used to reflect the inflammatory reaction.ResultsInjection of 6-OHDA decreased NE (933.1 ± 179 ng/L for SC vs. 3418.1± 443.6 ng/L for NC, P < 0.01) and increased NGF (479.4± 56.5 ng/mL for SC vs. 315.85 ± 28.6 ng/mL for NC, P < 0.01) concentrations. TH expression was reduced, while ChAT expression showed no change. Sympathectomy caused decreased HRV and abnormal ECG and echocardiography results, and histopathologic examinations showed myocardial injury and increased collagen deposition as well as inflammatory cell infiltration in the cardiac tissue of rats in the SC and SM groups. However, all pathologic changes in the SM group were less severe compared to those in the SC group.ConclusionsChemical sympathectomy with administration of 6-OHDA caused dysregulation of the cardiac autonomic nervous system and myocardial injuries. Mecobalamin alleviated inflammatory and myocardial damage by protecting myocardial sympathetic nerves.

Study on preventive and therapeutic effects of Astragali Radix on denervated tibial muscle atrophy in rats

To study the effect of Astragali Radix on the denervated tibial muscle atrophy in rats, and discuss its mechanism. Totally 60 SPF-grade Sprague-Dawley rats were selected in the common peroneal nerve crush model, and then randomly divided into 6 groups: Astragali Radix high-dose, medium-dose, low-dose groups, the Mecobalamin group, the model group, and the sham operation group. They were administered with drugs after the operation. At 18 d, the pathological section staining and morphological analysis were performed. The wet-weight ratio and section area of tibial muscles were also measured. The real-time fluorescence quantification was adopted to detect the differential expression between Angptl4 and PI3K genes. (1) Wet-weight ratio: The wet-weight ratio in Astragali Radix high-dose, medium-dose groups was much higher than that in the model group (P < 0.05 or P < 0.01). (2) Section area: The sham operation group was higher, with regular morphology; Whereas the model group showed significant decrease, with chaotic structure and obvious connective tissue proliferation; Astragali Radix groups and the mecobalamin group showed relatively small section areas, with chaotic structure and unobvious connective tissue proliferation. Compared with the model group, Astragali Radix groups showed significant increase (P < 0.01). (3) Motor end plate: The sham operation group was in uniform brownish black color and oval or round shape; Astragali Radix medium-dose and high-dose group and the mecobalamin group showed rough line edges; Astragali Radix medium-dose and low-dose groups and the model group showed decline in the number, with irregular morphology, rough line edges and a light color. (4) Angptl4 and PI3K: Compared with the model group, the Astragali Radix high-dose group showed significant increase (P < 0.05). Astragali Radix has a significant effect in preventing and treating denervated tibial muscle atrophy. It may delay the muscle atrophy by increasing Angptl4 and PI3K gene expressions.

Observation on clinical therapeutic efficacy of moxibustion combined with mecobalamin on diabetic perineuropathy and effects on patients' blood homocysteine

ObjectiveTo observe the therapeutic efficacy of moxibustion combined with mecobalamin on diabetic perineuropathy and the effects on blood homocysteine in patients with diabetic perineuropathy. MethodsOne hundred and fifty patients with diabetic perineuropathy meeting with the inclusive criteria were randomized into a moxibustion group, a mecobalamin group and a therapeutic alliance group by using random digits table. Moxibustion was carried out on Tàixī (▪ KI 3), Sānyīnjiāo (▪ SP 6), Zúsānl▪ (▪ ST 36), Hégŭ (▪ LI 4) and Qūchí (▪ LI 11) for the patients in the moxibustion group, the treatments were carried out once every other day, treatments for ten times were considered as a treatment course, and totally three treatment courses were carried out. The patients in the mecobalamin group were orally administered with mecobalamin tablet 500 μg once, three times a day, 20 days were considered as a treatment course, and totally three treatment courses were carried out. Moxibustion was carried out on the basis of oral administration with mecobalamin tablet in the therapeutic alliance group. The clinical symptoms, nerve conductive velocities and changes in blood homocysteine were observed before and after the treatments in the three groups. ResultsThe total effective rate in the moxibustion group was 74.0% (37/50), 82.0% (41/50) in the mecobalamin group, 94.0% (47/50) in the therapeutic alliance group, and the total effective rate in the therapeutic alliance group was significantly better than the other two groups (P<0.01). The nerve conductive velocities in the mecobalamin group and the therapeutic alliance group after the treatments were significantly increased and the blood homocysteine level decreased in comparison to those before the treatments (P<0.01), while the nerve conductive velocity increased and the blood homocysteine level decreased in the therapeutic alliance group after the treatments in comparison to those in the other two groups (P<0.01). ConclusionTreatments on diabetic perineuropathy by therapeutic alliance of moxibustion and mecobalamin can not only improve symptoms of patients, increase nerve conductive velocity in affected limbs, but also decrease blood homocysteine level. The method is simple, economical and safe, and it deserves being generalized in clinical practices.

Peripheral Nerve Regeneration Following Crush Injury to Rat Peroneal Nerve by Aqueous Extract of Medicinal Mushroom Hericium erinaceus (Bull.: Fr) Pers. (Aphyllophoromycetideae)

Nerve crush injury is a well-established axonotmetic model in experimental regeneration studies to investigate the impact of various pharmacological treatments. Hericium erinaceus is a temperate mushroom but is now being cultivated in tropical Malaysia. In this study, we investigated the activity of aqueous extract of H. erinaceus fresh fruiting bodies in promoting functional recovery following an axonotmetic peroneal nerve injury in adult female Sprague-Dawley rats by daily oral administration. The aim was to investigate the possible use of this mushroom in the treatment of injured nerve. Functional recovery was assessed in behavioral experiment by walking track analysis. Peroneal functional index (PFI) was determined before surgery and after surgery as rats showed signs of recovery. Histological examinations were performed on peroneal nerve by immunofluorescence staining and neuromuscular junction by combined silver-cholinesterase stain. Analysis of PFI indicated that return of hind limb function occurred earlier in rats of aqueous extract or mecobalamin (positive control) group compared to negative control group. Regeneration of axons and reinnervation of motor endplates in extensor digitorum longus muscle in rats of aqueous extract or mecobalamin group developed better than in negative control group. These data suggest that daily oral administration of aqueous extract of H. erinaceus fresh fruiting bodies could promote the regeneration of injured rat peroneal nerve in the early stage of recovery.

Effects of Qichu Fujin Recipe on regeneration and repair of injured sciatic nerve in rats

To explore the effects of Qichu Fujin Recipe (QCFJR), a compound traditional Chinese medicine, in repairing sciatic nerve injury in rats. A total of 60 male Sprague-Dawley (SD) rats were randomly divided into four groups: normal control group, untreated group, mecobalamin group and QCFJR group. Except the normal control group, sciatic nerve injury was induced by crushing of left sciatic nerve. Rats in the mecobalamin group were intragastrically administered with mecobalamin solutions 150 microg/(kg x d), and rats in the QCFJR group were intragastrically administered with QCFJR 35.2 g/(kg x d), while rats in the untreated group were intragastrically administered with normal saline (0.5 mL/d), once a day for 4 weeks respectively. Sciatic function index (SFI) was determined by walking tract analysis 1 week and 2 and 4 weeks after crushing. Five rats in each group were sacrificed for histological observation at the different time points. The remnant rate of gastrocnemius wet weight and the diameter of gastrocnemius cells were calculated. Expression of S-100 protein in the distal stump of injured nerve was observed by using immunohistochemical method. Distal injured sciatic nerves were determined with toluidine blue staining and observed under a light microscope 1 week and 2 and 4 weeks after operation. Diameter of axon and depth of myelin sheath were calculated by an image analysis system. Ultrastructure of nerve fibers was determined with uranyl acetate and lead citrate staining and observed under an electron microscope. Compared with the normal control group, SFI, remnant rate of gastrocnemius wet weight, diameter of gastrocnemius cells, expression of S-100, diameter of axon and depth of myelin sheath in the mecobalamin group and the QCFJR group were significantly decreased at different time points (P<0.05), superior to those of the untreated group (P<0.05, P<0.01). Except the remnant rate of gastrocnemius wet weight and the diameter of gastrocnemius cells, there were no significant differences in other indexes between the mecobalamin group and the QCFJR group 1 week and 2 and 4 weeks after crushing (P>0.05). QCFJR can stimulate the regeneration and repair of nerve fiber and delay the skeletal muscle atrophy after sciatic nerve injury in rats.

&lt;b&gt;Correlation between emotion and pain in patients &lt;/b&gt;&lt;b&gt;with dental phobia: a clinical study &lt;/b&gt;

Background: Patients often enter clinical situations feeling a variety of emotions. It is important to relieve these emotions because there is a negative correlation between a patient's emotions and pain. In this study, we evaluated the correlation between pain and emotions such as anxiety and depression. We also examined whether a reduction in anxiety or depression could diminish pain by using the 5-HT1A agonist tandospirone citrate as an anxiolytic agent. Subjects and methods: A total of 270 patients were enrolled in two studies. These included 250 patients with dental phobia in Studies 1 and 2 (Study 1: 71 males, 107 females; Study 2: 33 males, 39 females), and 20 patients with no dental phobia in Study 2 only (10 males, 10 females). Anxiety was evaluated using the Spielberger State and Trait Anxiety Inventory (STAI) and depression was evaluated using the Zung Self-Rating Depression Scale (SDS). Venipuncture and cannulation were performed on the median cubital vein using a 22-gauge needle. Pain caused by the needle was measured immediately after the puncture using the Visual Analogue Scales (VAS). In Study 1, anxiety and depression were evaluated and the degree of trait anxiety, state anxiety and depression before venipuncture in the three groups was classified. We then compared these results with the VAS results in each group. In Study 2, anxiety was evaluated using the STAI measured previously (STAI-1). Subjects were divided into four groups as follows: no treatment group (NT: n=25, 11 males, 14 females); Mecobalamin group (ME: n=25, 12 males, 13 females); Tandospirone group (TA: n=22, 10 males, 12 females); and no dental phobia group (NP: n=20, 10 males, 10 females). The subjects in the ME and TA groups were given 1.5 mg of Mecobalamin or 30 mg of Tandospirone, respectively, and anxiety was examined sixty minutes after the medication was administered (STAI-2). The second evaluation was followed immediately by venipuncture, and pain caused by the needle was assessed. Results: The VAS for each group in Study 1 increased significantly with regards to degree of trait anxiety and state anxiety, but not with depression. In Study 2, there was no significant change in trait anxiety in any of the four groups. In contrast, state anxiety increased significantly in the NT group, but not in the ME, TA or NP groups. Pain caused by the needle used for venipuncture was significantly lower in the TA group, and was similar to that recorded for the NP group. Conclusions: This study demonstrates that anxiety amplifies pain in patients with dental phobia. These results suggest that the suppression of patient anxiety could also lead to the reduction of pain.