Pharmacokinetic profiles of methylcobalamin in rats after multiple administration routes by a simple LC-MS/MS assay with a small volume of plasma.

Methylcobalamin (MBL) is a vitamin B12 coenzyme and is effective for treating peripheral neuropathies. Little is known about pharmacokinetics (PK) of MBL in animals, we have developed a simple assay for MBL by using only 0.01 mL of plasma for PK of MBL in rats. Under minimal light exposure (<5 lx), MBL was extracted by a simple protein precipitation using methanol and detected by liquid chromatography with tandem mass spectrometry. MBL in rat plasma at 20-10,000 ng/mL was quantified using only 0.01 mL of plasma. Relative error and relative standard deviation met the acceptance criteria in reproducibility assessments, indicating the robustness of the assay. PK of MBL was evaluated after intravenous, intramuscular, and subcutaneous administration. PK of MBL was dose proportional at 5-20 mg/kg in both intramuscular and subcutaneous administrations. Bioavailability after the two dosing routes was complete (ca. 100 %). The incurred sample reanalysis also supported that the assay is robust. The established assay was successfully applied to PK studies in rats to find that MBL showed high bioavailability after intramuscular and subcutaneous administrations.

Nanoparticles of nucleotide-free analogue of vitamin B12 formed in protein nanocarriers and their neuroprotective activity in vivo.

Recently, we have described the first supermolecular nanoentities of vitamin B12 derivative, viz. monocyano form of heptabutyl cobyrinate, unique nanoparticles with strong noncovalent intermolecular interactions, emerging optical and catalytic properties. Their nearest analogue, heptamethyl cobyrinate (ACCby), exhibits bioactivity. Here, we demonstrate the first example of the formation of nanoparticles of this nucleotide-free analogue of vitamin B12 in protein nanocarriers and neuroprotective activity in vivo of the own nanoform of the drug. The preparation and characterization of nanocarriers based on bovine serum albumin (BSA) loaded with vitamin B12 (viz. cyano- and aquacobalamins) and ACCby were performed. Nucleotide-free analogue of vitamin B12 is tightly retained by the protein structure and exists in an incorporated state in the form of nanoparticles. The effect of encapsulated drugs on the character and severity of primary generalized seizures in rats induced by the pharmacotoxicant thiosemicarbazide was studied. Cyanocobalamin and ACCby exhibited a neuroprotective effect. The best influence of the encapsulation on the effectiveness of the drugs was achieved in the case of AСCby, whose bioavailability as a neuroprotector did not change upon introduction in BSA particles, i.e., 33 % of surviving animals were observed upon ACCby administration in free form and in encapsulated state. No surviving rats were observed without the administration of drugs. Thus, BSA nanocarriers loaded by nanoparticles of nucleotide-free analogues of vitamin B12, including hydrophobic ones, can be recommended for neuroprotection and targeted delivery.

Structural investigation of the complexation between vitamin B12 and per- and polyfluoroalkyl substances: Insights into degradation using density functional theory.

Environmental remediation of per- and polyfluoroalkyl substances (PFAS) has become a significant research topic in recent years due to the fact that these materials are omnipresent, resistant to degradation and thus environmentally persistent. Unfortunately, they have also been shown to cause health concerns. PFAS are widely used in industrial applications and consumer products. Vitamin B12 (B12) has been identified as being catalytically active towards a variety of halogenated compounds such as PFAS. It has also been shown to be effective when using sulfide as a reducing agent for B12. This is promising as sulfide is readily available in the environment. However, there are many unknowns with respect to PFAS interactions with B12. These include the reaction mechanism and B12's specificity for PFAS with certain functionalization(s). In order to understand the specificity of B12 towards branched PFAS, we examined the atomistic interactions between B12 and eight different PFAS molecules using Density Functional Theory (B3LYP/cc-pVDZ). The PFAS test set included linear PFAS and their branched analogs, carboxylic acid and sulfonic acid headgroups, and aromatic and non-aromatic cyclic structures. Conformational analyses were carried out to determine the lowest energy configurations. This analysis showed that small chain PFAS such as perfluorobutanoic acid interact with the cobalt center of B12. Bulkier PFAS prefer to interact with the amine and carbonyl groups on the sidechains of the B12 ring system. Furthermore, computed complexation energies determined that, in general, branched PFAS (e.g. perfluoro-5-methylheptane sulfonic acid) interact more strongly than linear molecules (e.g. perfluorooctanesulfonic acid). Our results indicate that it may be possible to alter the interactions between B12 and PFAS by synthetically modifying the sidechains of the ring structure.

Bacterial mercury methylation modulated by vitamin B9: An overlooked pathway leads to increased environmental risks.

There has been a serious health and environmental concern in conversion of inorganic mercury (Hg) to the neurotoxin, methylmercury (MeHg) by anaerobic microbes, while very little is known about the potential role of vitamin B9 (VB9) regulator in the biochemical generation of MeHg. This study innovatively investigated bacterial Hg methylation by Geobacter sulfurreducens PCA in the presence of VB9 under two existing scenarios. In the low-complexing scenario, the bacterial MeHg yield reached 68 % higher than that without VB9 within 72 h, which was attributed to free VB9-protected PCA cells relieving oxidative stress, as manifested by the increased expression of Hg methylation gene (hgcAB cluster by 19-48 %). The high-complexing scenario emphasized the intracellular Hg accumulation (38-45 %) after 12 h, as indicated by the increased expression of outer membrane protein-related and mercuric reductase-encoding genes, indicating the inefficient bioavailability of Hg due to a gradual shift from Hg reduction toward Hg0 re-oxidation controlled by competitive ligand exchange. These results suggested that VB9 application significantly raised the potential for bacterial Hg methylation and cellular accumulation, thus proposing insights into the biochemical behaviors of hazardous Hg in farming environments where vulnerable organisms are more possibly co-exposed to higher levels of Hg and VB9.

Ultra-high dose methylcobalamin and other emerging therapies for amyotrophic lateral sclerosis.

PURPOSE OF REVIEW: Recent development in understanding the pathophysiology of amyotrophic lateral sclerosis (ALS) has led to increasing number of promising test drugs in the pipeline along with the existing ones. We will review these agents focusing on ultra-high dose methylcobalamin, which is pending approval in Japan. Clinical trial design best suited for ALS will also be discussed. RECENT FINDINGS: The most recent phase 3 trial (JETALS) of ultra-high dose methylcobalamin demonstrated significant slowing of ALSFRSR changes (0.5/month), with marked reduction of serum homocysteine levels in the initial double-blind period. The post hoc analysis of the previous phase 2/3 study (E761 trial; Eisai) showed that it prolonged survival of ALS patients, if started within 1 year of onset, but the previous studies suggested its efficacy even in later stages, depending upon the rate of progression. Phase 3 trial of AMX0035 or Relyvrio on the other hand showed negative results despite the promising phase 2 data. The latter did not adjust the disease progression rate before entry. SUMMARY: Ultra-high dose methylcobalamin is not a vitamin supplement but a novel disease-modifying therapy for ALS, and it emphasizes homocysteine as a key factor in the disease process. Clinical trial design must include entering patients early and with similar rates of progression using pretrial observation periods for meaningful results, since ALS is a chronologically heterogenous condition with similar phenotypes.

A Noble Metal Substitution Leads to B12 Cofactor Mimicry by a Rhodibalamin.

In mammals, cobalamin is an essential cofactor that is delivered by a multitude of chaperones in an elaborate trafficking pathway to two client enzymes, methionine synthase and methylmalonyl-CoA mutase (MMUT). Rhodibalamins, the rhodium analogs of cobalamins, have been described as antimetabolites due to their ability to inhibit bacterial growth. In this study, we have examined the reactivity of adenosylrhodibalamin (AdoRhbl) with two key human chaperones, MMACHC (also known as CblC) and adenosyltransferase (MMAB, also known as ATR), and with the human and Mycobacterium tuberculosis MMUT. We demonstrate that while AdoRhbl binds tightly to all four proteins, the Rh-carbon bond is resistant to homolytic (on MMAB and MMUT) as well as heterolytic (on MMACHC) rupture. On the other hand, MMAB catalyzes Rh-carbon bond formation, converting rhodi(I)balamin in the presence of ATP to AdoRhbl. We report the first crystal structure of a rhodibalamin (AdoRhbl) bound to a B12 protein, i.e., MMAB, in the presence of triphosphate, which shows a weakened but intact Rh-carbon bond. The structure provides insights into how MMAB cleaves the corresponding Co-carbon bond in a sacrificial homolytic reaction that purportedly functions as a cofactor sequestration strategy. Collectively, the study demonstrates that while the noble metal substitution of cobalt by rhodium sets up structural mimicry, it compromises chemistry, which could be exploited for targeting human and bacterial B12 chaperones and enzymes.

Effect of Methylfolate, Pyridoxal-5'-Phosphate, and Methylcobalamin (SolowaysTM) Supplementation on Homocysteine and Low-Density Lipoprotein Cholesterol Levels in Patients with Methylenetetrahydrofolate Reductase, Methionine Synthase, and Methionine Synthase Reductase Polymorphisms: A Randomized Controlled Trial.

Exploring the link between genetic polymorphisms in folate metabolism genes (MTHFR, MTR, and MTRR) and cardiovascular disease (CVD), this study evaluates the effect of B vitamin supplements (methylfolate, pyridoxal-5'-phosphate, and methylcobalamin) on homocysteine and lipid levels, potentially guiding personalized CVD risk management. In a randomized, double-blind, placebo-controlled trial, 54 patients aged 40-75 with elevated homocysteine and moderate LDL-C levels were divided based on MTHFR, MTR, and MTRR genetic polymorphisms. Over six months, they received either a combination of methylfolate, P5P, and methylcobalamin, or a placebo. At the 6 months follow-up, the treatment group demonstrated a significant reduction in homocysteine levels by 30.0% (95% CI: -39.7% to -20.3%) and LDL-C by 7.5% (95% CI: -10.3% to -4.7%), compared to the placebo (p < 0.01 for all). In the subgroup analysis, Homozygous Minor Allele Carriers showed a more significant reduction in homocysteine levels (48.3%, 95% CI: -62.3% to -34.3%, p < 0.01) compared to mixed allele carriers (18.6%, 95% CI: -25.6% to -11.6%, p < 0.01), with a notable intergroup difference (29.7%, 95% CI: -50.7% to -8.7%, p < 0.01). LDL-C levels decreased by 11.8% in homozygous carriers (95% CI: -15.8% to -7.8%, p < 0.01) and 4.8% in mixed allele carriers (95% CI: -6.8% to -2.8%, p < 0.01), with a significant between-group difference (7.0%, 95% CI: -13.0% to -1.0%, p < 0.01). Methylfolate, P5P, and methylcobalamin supplementation tailored to genetic profiles effectively reduced homocysteine and LDL-C levels in patients with specific MTHFR, MTR, and MTRR polymorphisms, particularly with homozygous minor allele polymorphisms.

Effectiveness of Mesotherapy in Post-COVID Pain Syndrome: Retrospective Cohort Study of 96 Patients.

PURPOSE: Musculoskeletal pain may occur after becoming infected with SARS-Cov2. This study was designed to evaluate the efficacy of mesotherapy in treating chronic pain following COVID-19 infection. METHODS: A retrospective review was conducted of the records of 96 patients with post-COVID pain syndrome. Those who were eligible for oral therapy or mesotherapy, included in the study. Patients receiving oral treatment with diclofenac potassium, thiocolchicoside and cyanocobalamin were included in one group (n = 46), and patients receiving intradermal mesotherapy with 2% lidocaine + cyanocobalamin were included in another group (n = 50). The results of the Visual Analogue Scale (VAS) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were individually assessed before and one week after the treatment. FINDINGS: The participants were 40.2 ± 11.1 years old on average. Of the participants, 35.4% (n = 34) were male and 64.6% (n = 62) were female. Before treatment, there was no statistically significant difference between the patients in terms of VAS and LANSS scores. Following the treatment, a notable positive response was observed in both groups. Nevertheless, when compared to the oral treatment group, the mesotherapy group exhibited a more pronounced enhancement in VAS and LANSS scores (P < 0.001, P < 0.001, respectively). IMPLICATIONS: While both mesotherapy and oral therapy offer benefits in reducing pain and alleviating neuropathic symptoms in post-COVID pain syndrome, mesotherapy stands out as an especially effective and well-tolerated treatment method, surpassing the efficacy of the oral alternative.

A Randomized Control Trial of Dexketoprofen/Vitamin B (Thiamine, Pyridoxine and Cyanocobalamin) Fixed-Dose Combination in Post-Traumatic Grade I-II Cervical Sprains.

BACKGROUND: Musculoskeletal disorders are an important cause of work absence. Clinical practice guidelines recommend nonsteroidal anti-inflammatory drugs (NSAIDs) for grade I-II cervical sprains. The combination of thiamine + pyridoxine + cyanocobalamin vitamins has been used, alone and in combination with NSAIDs, for pain and inflammation in musculoskeletal disorders. OBJECTIVE: The objective of this study was to demonstrate the analgesic synergy of dexketoprofen, and the combination of vitamins thiamine + pyridoxine + cyanocobalamin in a fixed-dose combination (FDC) for the treatment of acute pain caused by grade I-II cervical sprains. METHODS: We conducted a multicentre, prospective, randomized, double-blind, phase IIIb clinical study comparing two treatment groups: (1) dexketoprofen 25 mg/vitamin B (thiamine 100 mg, pyridoxine 50 mg and cyanocobalamin 0.50 mg) in an FDC (two or more active ingredients combined in a single dosage form) versus (2) dexketoprofen 25 mg monotherapy (single drug to treat a particular disease), one capsule or tablet orally, every 8 h for 7 days. Final mean, average change, and percentage change in pain perception (measured using a visual analogue scale [VAS]) were compared with baseline between groups. A p value < 0.05 was considered statistically significant. Analyses were conducted using SPSS software, v.29.0. RESULTS: A statistically significant reduction in pain intensity was observed from the third day of treatment with the FDC compared with monotherapy (- 3.1 ± - 1.5 and - 2.6 ± - 1.1 cm, respectively) measured using the VAS (p = 0.011). Regarding the degree of disability, using the Northwick Park Neck Pain Questionnaire (NPQ), statistical difference was observed for the final measurement (7.5%, interquartile range [IQR] 2.5, 10.5; vs. 7.9%, IQR 5.0, 13.8; p = 0.028). A lower proportion of adverse events was reported when using the FDC. CONCLUSIONS: The FDC of dexketoprofen/thiamine + pyridoxine + cyanocobalamin vitamins demonstrated superior efficacy and a better safety profile compared with dexketoprofen monotherapy for pain treatment in patients with grade I-II cervical sprains. CLINICAL TRIALS REGISTRATION: NCT05001555, registered 29 July 2021 ( https://clinicaltrials.gov/study/NCT05001555 ).

Impact of vitamin B12 supplement intake cessation on vitamin B12 status in a healthy vegan: A close interval monitoring case study.

BACKGROUND: Healthy plant-based diets, such as the lacto-ovo-vegetarian and the vegan diet, offer numerous benefits to human health. Poorly designed plant-based diets, however, bear the risk for vitamin- and micronutrient deficiencies. Vitamin B12 (B12, cobalamin) is a nutrient of particular concern in both diets, and should be readily supplemented on a continuous basis to ensure adequate B12 levels and to prevent deficiencies. CASE REPORT: This case reports describes the history of a healthy man in his mid-30s who adopted a vegan diet approximately 10 y ago. Well informed about the risks of vitamin B12 deficiency on a plant-based diet, he regularly supplemented methylcobalamin for years (single oral dose: 500 µg, 3-4 times a week) in order to maintain an adequate vitamin B12 status. In late 2023, however, he decided to cease B12 supplementation for undisclosed reasons. Subsequent to this decision, we closely monitored his B12 status and longitudinally measured serum B12, homocysteine, and holotranscobalamin (holo-TC). Total serum folate was also determined as it is a modifier of homocysteine concentration. A gradual decrease in holo-TC and vitamin B12 levels was observed after 4 weeks and supplements had to be re-introduced after 16 weeks. Homocysteine increased concomitantly up to 18.2 µmol/L after 20 weeks. CONCLUSIONS: While a short-term B12 supplement intake cessation might be well tolerated by vegans with an adequate B12 status, an interruption of more than 8 weeks could signify B12 loss approaching suboptimal status. This case report reiterates the need for continuous B12 supplementation in persons following an unfortified plant-based diet.

Efficacy of Danzhixiaoyao tablets combined with methylcobalamin tablets in the treatment of burning mouth syndrome: an open-label, randomized controlled trial.

OBJECTIVES: This randomized controlled trial compared the efficacy and tolerability of danzhixiaoyao pills in the accurate treatment of patients with burning mouth syndrome (BMS). METHOD: Collect a total of 78 patients (75 female patients and 3 male patients) from the oral mucosa department who were considered eligible fromOctober 2020 to October 2022.The patients were randomized and divided into trial group and control group.The trail group received danzhixiaoyao pills and mecobalamine tablets while the control group was given mecobalamine tablets.The Visual Analogue Scale (VAS), Beck Anxiety Inventory(BAI), Beck Depression Inventory (BDI), Oral Health Impact Profile (OHIP-14), Traditional Chinese medicine(TCM) syndrome integral and adverse reactions were performed at baseline and after 2, 4, and 6 weeks of treatment. Descriptive statistics, including the Wilcoxon rank-sum test and the Chi-square test for median comparisons between different times, were used. RESULT: 1.After treatment, the VAS, BDI,OHIP-14, and TCM syndrome integral in the trial group had a significant decrease than the control group(P< 0.05).However, there was no statistical difference in the BAI scores between the two groups (P> 0.05). 2.According to the efficacy determination criteria , the total effective rate of the test group was 73.68% , the control group was 52.94% and the recurrence rate was 0. There was a significant difference between the two groups (Z=-2.688, P < 0.05). The results showed that the curative effect of test group was better than that of control group.3. No adverse effects occurred in patients in either group. CONCLUSION: Danzhixiaoyao pills has demonstrated to have a positive effect in relieving BMS symptoms and in improving a patient's overall quality of life with no AEs compared with the control group. The efficacy evaluation systems that can be verified and complementary in this study provide a perfect, effective and referential evaluation system for the use of Chinese patent medicine in the treatment of oral mucosal diseases. TRIAL REGISTRATION: Registry name: Chinese Clinical trail Registry Registration number: ChiCTR2000038189 Date of Registration: 2020-09-13 Please visit ( https://www.chictr.org.cn/showproj.html?proj=61462 ) to the protocol.

Modulation of polyaniline memristive device switching voltage by nucleotide-free analogue of vitamin B12.

Memristive devices offer essential properties to become a part of the next-generation computing systems based on neuromorphic principles. Organic memristive devices exhibit a unique set of properties which makes them an indispensable choice for specific applications, such as interfacing with biological systems. While the switching rate of organic devices can be easily adjusted over a wide range through various methods, controlling the switching potential is often more challenging, as this parameter is intricately tied to the materials used. Given the limited options in the selection conductive polymers and the complexity of polymer chemical engineering, the most straightforward and accessible approach to modulate switching potentials is by introducing specific molecules into the electrolyte solution. In our study, we show polyaniline (PANI)-based device switching potential control by adding nucleotide-free analogue of vitamin B12, aquacyanocobinamide, to the electrolyte solution. The employed concentrations of this molecule, ranging from 0.2 to 2 mM, enabled organic memristive devices to achieve switching potential decrease for up to 100 mV, thus providing a way to control device properties. This effect is attributed to strong aromatic interactions between PANI phenyl groups and corrin macrocycle of the aquacyanocobinamide molecule, which was supported by ultraviolet-visible spectra analysis.

Elucidating the structural basis of vitamin B12 derivatives as novel potent inhibitors of PTP1B: Insights from inhibitory mechanisms using Gaussian accelerated molecular dynamics (GaMD) and in vitro study.

Vitamin B12 is a group of biologically active cobalamin compounds. In this study, we investigated the inhibitory effects of methylcobalamin (MeCbl) and hydroxocobalamin acetate (OHCbl Acetate) on protein tyrosine phosphatase 1B (PTP1B). MeCbl and OHCbl Acetate exhibited an IC50 of approximately 58.390 ± 2.811 µM and 8.998 ± 0.587 µM, respectively. The Ki values of MeCbl and OHCbl Acetate were 25.01 µM and 4.04 µM respectively. To elucidate the inhibition mechanism, we conducted a 500 ns Gaussian accelerated molecular dynamics (GaMD) simulation. Utilizing PCA and tICA, we constructed Markov state models (MSM) to examine secondary structure changes during motion. Our findings revealed that the α-helix at residues 37-42 remained the most stable in the PTP1B-OHCbl Acetate system. Furthermore, upon binding of OHCbl Acetate or MeCbl, the WPD loop of PTP1B moved inward to the active pocket, forming a closed conformation and potentially obstructs substrate entry. Protein-ligand interaction analysis and MM-PBSA showed that OHCbl Acetate exhibited lower binding free energy and engaged in more residue interactions with PTP1B. In summary, our study confirmed the substantial inhibitory activity of OHCbl Acetate against PTP1B, with its inhibitory potency notably surpassing that of MeCbl. We demonstrated potential molecular mechanisms of OHCbl Acetate inhibiting PTP1B.

The structure of the rat vitamin B12 transporter TC and its complex with glutathionylcobalamin.

Vitamin B12 (cobalamin or Cbl) functions as a cofactor in two important enzymatic processes in human cells, and life is not sustainable without it. B12 is obtained from food and travels from the stomach, through the intestine, and into the bloodstream by three B12-transporting proteins: salivary haptocorrin (HC), gastric intrinsic factor, and transcobalamin (TC), which all bind B12 with high affinity and require proteolytic degradation to liberate Cbl. After intracellular delivery of dietary B12, Cbl in the aquo/hydroxocobalamin form can coordinate various nucleophiles, for example, GSH, giving rise to glutathionylcobalamin (GSCbl), a naturally occurring form of vitamin B12. Currently, there is no data showing whether GSCbl is recognized and transported in the human body. Our crystallographic data shows for the first time the complex between a vitamin B12 transporter and GSCbl, which compared to aquo/hydroxocobalamin, binds TC equally well. Furthermore, sequence analysis and structural comparisons show that TC recognizes and transports GSCbl and that the residues involved are conserved among TCs from different organisms. Interestingly, haptocorrin and intrinsic factor are not structurally tailored to bind GSCbl. This study provides new insights into the interactions between TC and Cbl.

The restoration of hippocampal nerve de-myelination by methylcobalamin relates with the enzymatic regulation of homocysteine level in a rat model of moderate grade hepatic encephalopathy.

This article describes how methylcobalamin (MeCbl) restores nerve myelination in a moderate- grade hepatic encephalopathy (MoHE) model of ammonia neurotoxicity. The comparative profiles of myelin basic protein (MBP), homocysteine (Hcy) and methionine synthase (MS: a MeCbl- dependent enzyme) activity versus nerve myelination status were studied in the hippocampus of the control, the MoHE (developed by administering 100 mg/kg bw thioacetamide i.p. for 10 days) and the MoHE rats treated with MeCbl (500 µg/kg BW i.p.) for 7 days. Compared to those of control rats, the hippocampal CA1 and CA3 regions of the MoHE rats showed significantly lower myelinated areas and MBP immunostaining. This coincided with the deranged myelin layering in TEM images, decreased MBP protein and its transcript levels in hippocampus of MoHE rats. However, all these parameters recovered to normal levels after MeCbl treatment. MeCbl is a cofactor of MS that catalyzes the conversion of Hcy to methionine as a feeder step of methylation reactions. We observed significantly increased serum and hippocampal Hcy levels in MoHE rats, however, these levels were restored to control values with a concordant activation of MS due to MeCbl treatment. A significant recovery in neurobehavioral impairments in the MoHE rats due to MeCbl treatment was also observed. These findings suggest that MoHE pathogenesis is associated with deranged nerve myelination in the hippocampus and that MeCbl treatment is able to restore it mainly by activating MS, a MeCbl-dependent Hcy-metabolizing enzyme.

Combined effect of Neurotropin® and methylcobalamin on postherpetic neuralgia in mice infected with herpes simplex virus type-1.

BACKGROUND: Postherpetic pain (PHP) is difficult to control. Although Neurotropin® (NTP) and methylcobalamin (MCB) are often prescribed to treat the pain, the efficacy of combined treatment for PHP remains imcompletely understood. OBJECTIVE: In this study, we investigate the combined effects of NTP and MCB on PHP in mice. METHODS: NTP and MCB were administered from day 10-29 after herpes simplex virus type-1 (HSV-1) infection. The pain-related responses were evaluated using a paint brush. The expression of neuropathy-related factor (ATF3) and nerve repair factors (GAP-43 and SPRR1A) in the dorsal root ganglion (DRG) and neurons in the skin were evaluated by immunohistochemical staining. Nerve growth factor (NGF) and neurotrophin-3 (NT3) mRNA expression levels were evaluated using real-time PCR. RESULTS: Repeated treatment with NTP and MCB after the acute phase inhibited PHP. Combined treatment with these drugs inhibited PHP at an earlier stage than either treatment alone. In the DRG of HSV-1-infected mice, MCB, but not NTP, decreased the number of cells expressing ATF3 and increased the number of cells expressing GAP-43- and SPRR1A. In addition, MCB, but not NTP, also increased and recovered non-myelinated neurons decreased in the lesional skin. NTP increased the mRNA levels of NTF3 in keratinocytes, while MCB increased that of NGF in Schwann cells. CONCLUSION: These results suggest that combined treatment with NTP and MCB is useful for the treatment of PHP. The combined effect may be attributed to the different analgesic mechanisms of these drugs.

Disease-modifying therapies for diabetic peripheral neuropathy: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Alpha-lipoic acid, epalrestat, and mecobalamin are widely used as monotherapies for diabetic peripheral neuropathy. However, whether a triple-combination therapy with these three drugs is superior to monotherapy or dual therapy remains debatable. METHODS: Nine randomized controlled trials were identified through a search on electronic databases such as PubMed, Web of Science, and Cochrane Library. The trial participants (N = 1153) were divided into the experimental group who received the triple-combination therapy and the control group who received conventional or dual therapy with the aforementioned drugs. RESULTS: Therapeutic outcomes were better in the experimental group than in the control group (odds ratio: 3.74; 95 % confidence interval: 2.57-5.45; I2 = 0 %; p < 0.00001). No statistic difference was noted in adverse effects. Compared with the control group, the experimental group exhibited significant improvements in median motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV), peroneal MNCV, peroneal SNCV, and vibration perception thresholds (VPT) in the left and right lower limbs. In the control group, a subgroup analysis by treatment strategy revealed similar improvements in total efficacy, MNCV, and SNCV. CONCLUSIONS: For diabetic peripheral neuropathy, the triple-combination therapy may be more effective than monotherapy or dual therapy.

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

OBJECTIVE: To determine if tokishakuyakusan (TSS) is effective for treating post-infectious olfactory dysfunction (PIOD) compared with vitamin B12 (mecobalamin). METHODS: We 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. RESULTS: Overall, 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. CONCLUSION: The present study showed that TSS and mecobalamin might be useful for treating PIOD.

Aquacobalamin Accelerates Orange II Destruction by Peroxymonosulfate via the Transient Formation of Secocorrinoid: A Mechanistic Study.

Besides its use in medicine, vitamin B12 (cobalamin) and its derivatives have found in numerous applications as catalysts. However, studies related to the activation of oxidants via cobalamin are scant. In this work, we showed how the addition of aquacobalamin (H2OCbl) accelerates the destruction of azo-dye Orange II by peroxymonosulfate (HSO5-) in aqueous solutions. In neutral and weakly alkaline media, the process is initiated by the modification of the corrin macrocycle with HSO5-, which requires the preliminary deprotonation of the aqua-ligand in H2OCbl to give hydroxocobalamin, producing 5,6-dioxo-5,6-secocobalamin or its isomer (14,15-dioxo-14,15-secocobalamin). In acidic solutions, where the concentration of hydroxocobalamin is negligible, the formation of dioxo-seco-species is not observed, and the reaction between H2OCbl and HSO5- results in slow chromophore bleaching. Using terephthalic acid, we demonstrated the formation of hydroxyl radicals in the mixture of H2OCbl with HSO5-, whereas the generation of sulfate radicals was proved by comparing the effects of ethanol and nitrobenzene on Orange II destruction using the H2OCbl/HSO5- system. The reaction mechanism includes the binding of HSO5- to the Co(III) ion of dioxo-secocobalamin, which results in its deprotonation and the labilization of the O-O bond, leading to the formation of sulfate and hydroxyl radicals which further react with Orange II.

The Utility of Oral Vitamin B1 and Mecobalamin to Improve Corneal Nerves in Dry Eye Disease: An In Vivo Confocal Microscopy Study.

Our purpose is to demonstrate the changes in cornea nerve parameters and symptoms and signs in dry eye disease (DED) patients after oral vitamin B1 and mecobalamin treatment. In this randomized double-blind controlled trial, DED patients were randomly assigned to either the treatment group (oral vitamin B1 and mecobalamin, artificial tears) or the control group (artificial tears). Corneal nerve parameters via in vivo confocal microscopy (IVCM), DED symptoms, and signs were assessed at baseline and 1 and 3 months post-treatment. In total, 398 eyes from 199 patients were included. In the treatment group, there were significant improvements in corneal nerve length, width, and neuromas, the sign of conjunctival congestion score (CCS), symptoms of dryness, pain, photophobia, blurred vision, total symptom score, and OSDI (OSDI) at 1/3 months post-treatment (all p < 0.05). Patients who received vitamin B1 and mecobalamin showed greater improvement in CCS, dryness scores at 1 month (p < 0.05), corneal fluorescein staining (CFS) (p = 0.012), photophobia (p = 0.032), total symptom scores (p = 0.041), and OSDI (p = 0.029) at 3 months. Greater continuous improvement in CFS (p = 0.045), dryness (p = 0.033), blurred vision (p = 0.031) and total symptom scores (p = 0.023) was demonstrated at 3 months than at 1 month post-treatment in the treatment group. We found that oral vitamin B1 and mecobalamin can improve corneal nerve length, width, reflectivity and the number of neuromas in IVCM, thereby repairing epithelial cells and alleviating some ocular symptoms. Thus, vitamin B1 and mecobalamin are potential treatment options for patients with DED.