Update on Safety Profiles of Vitamins B1, B6, and B12: A Narrative Review

The Role of Cobalamin in Multiple Sclerosis: An Update

Multiple sclerosis (MS) is a neurodegenerative condition that results in axonal and permanent damage to the central nervous system, necessitating healing owing to autoimmune reactions and persistent neuroinflammation. Antioxidant and anti-inflammatory drugs are essential for the management of oxidative stress and neuroinflammation. Additionally, multivitamin supplementation, particularly vitamin B12 (cobalamin), may be beneficial for neuronal protection. Although there is no documented connection between vitamin B12 deficiency and MS, researchers have explored its potential as a metabolic cause. This review highlights the therapeutic benefits of cobalamin (Cbl) in patients with MS.

Expert consensus guidelines for community pharmacists in the management of diabetic peripheral neuropathy with a combination of neurotropic B vitamins

This consensus guidance is for community pharmacists in diabetic peripheral neuropathy (DPN) management with a combination of neurotropic B vitamins. A multidisciplinary team including endocrinology, neurology, and pharmacy from Thailand discussed and aligned the practical scheme of DPN management in the community pharmacy setting, using the literature review and having face-to-face meeting. Five major statements have been endorsed as consensus recommendations for DPN care with strong acknowledgment. The aims of DPN management included reducing symptoms and the risk of complications, minimising adverse reactions from treatment regimens, and improving patients' knowledge and adherence to the treatment strategies. An initial screening process using a 7 items interview of Douleur Neuropathique 4 (DN4) questionnaire should be implemented to identify patients at risk of developing DPN. Subsequently, pharmacologic, and non-pharmacologic treatment should be employed based on patient-centered care. An interesting approach is combination of neurotropic B vitamins, which may be used as monotherapy or combination therapy to control DPN symptoms. The combined therapy potentially exhibits a synergistic effect and improves patient adherence. The consensus would be further considered in context of harmonisation of routine practice and country requirements.

Pathophysiological-Based Nutritional Interventions in Cirrhotic Patients with Sarcopenic Obesity: A State-of-the-Art Narrative Review

In recent decades, following the spread of obesity, metabolic dysfunction has come to represent the leading cause of liver disease. The classical clinical presentation of the cirrhotic patient has, therefore, greatly changed, with a dramatic increase in subjects who appear overweight or obese. Due to an obesogenic lifestyle (lack of physical activity and overall malnutrition, with an excess of caloric intake together with a deficit of proteins and micronutrients), these patients frequently develop a complex clinical condition defined as sarcopenic obesity (SO). The interplay between cirrhosis and SO lies in the sharing of multiple pathogenetic mechanisms, including malnutrition/malabsorption, chronic inflammation, hyperammonemia and insulin resistance. The presence of SO worsens the outcome of cirrhotic patients, affecting overall morbidity and mortality. International nutrition and liver diseases societies strongly agree on recommending the use of food as an integral part of the healing process in the comprehensive management of these patients, including a reduction in caloric intake, protein and micronutrient supplementation and sodium restriction. Based on the pathophysiological paths shared by cirrhosis and SO, this narrative review aims to highlight the nutritional interventions currently advocated by international guidelines, as well as to provide hints on the possible role of micronutrients and nutraceuticals in the treatment of this multifaceted clinical condition.

Antinociceptive effects of vitamin B-complex: A behavioral and histochemical study in rats

B-vitamins have been evaluated as a useful adjuvant therapy to treat pain. In spite of clinical and experimental evidence indicating the analgesic effect of B-vitamins, few studies have investigated their effect on aspects of the inflammatory pain response. In the present study, we investigated the analgesic effect of chronic application of B-complex vitamins (Neurobion) using an inflammatory experimental pain model in rats. Nociceptive behavioral responses were evaluated in male Wistar rats after plantar injection of formalin, comparing the treatment group (TG) with Neurobion pretreatment to the control group (CG) without the pretreatment. In addition, neuronal activity in the central pain pathway was evaluated using c-Fos immunohistochemical reactivity and NADPH-d histochemistry. A highly significant reduction of painful behaviors such as licking and flinching were observed in TG, especially during the secondary phase of the formalin test compared to CG. Results suggest that long-term pre-treatment using Neurobion can have a beneficial effect in reducing the chronic phase of pain. In addition, we observed a downregulation of c-Fos and NADPH-d in dorsal spinal neurons, suggesting that the antinociceptive effect induced by Neurobion could be due to a suppression of nociceptive transmission at the spinal level, particularly in the afferent regions of the dorsal spinal horn, which these neurons utilizing nitric oxide at least as one of their pain neurotransmitters.

Evaluating the association of biallelic OGDHL variants with significant phenotypic heterogeneity

BACKGROUND

Biallelic variants in OGDHL, encoding part of the α-ketoglutarate dehydrogenase complex, have been associated with highly heterogeneous neurological and neurodevelopmental disorders. However, the validity of this association remains to be confirmed. A second OGDHL patient cohort was recruited to carefully assess the gene-disease relationship.

METHODS

Using an unbiased genotype-first approach, we screened large, multiethnic aggregated sequencing datasets worldwide for biallelic OGDHL variants. We used CRISPR/Cas9 to generate zebrafish knockouts of ogdhl, ogdh paralogs, and dhtkd1 to investigate functional relationships and impact during development. Functional complementation with patient variant transcripts was conducted to systematically assess protein functionality as a readout for pathogenicity.

RESULTS

A cohort of 14 individuals from 12 unrelated families exhibited highly variable clinical phenotypes, with the majority of them presenting at least one additional variant, potentially accounting for a blended phenotype and complicating phenotypic understanding. We also uncovered extreme clinical heterogeneity and high allele frequencies, occasionally incompatible with a fully penetrant recessive disorder. Human cDNA of previously described and new variants were tested in an ogdhl zebrafish knockout model, adding functional evidence for variant reclassification. We disclosed evidence of hypomorphic alleles as well as a loss-of-function variant without deleterious effects in zebrafish variant testing also showing discordant familial segregation, challenging the relationship of OGDHL as a conventional Mendelian gene. Going further, we uncovered evidence for a complex compensatory relationship among OGDH, OGDHL, and DHTKD1 isoenzymes that are associated with neurodevelopmental disorders and exhibit complex transcriptional compensation patterns with partial functional redundancy.

CONCLUSIONS

Based on the results of genetic, clinical, and functional studies, we formed three hypotheses in which to frame observations: biallelic OGDHL variants lead to a highly variable monogenic disorder, variants in OGDHL are following a complex pattern of inheritance, or they may not be causative at all. Our study further highlights the continuing challenges of assessing the validity of reported disease-gene associations and effects of variants identified in these genes. This is particularly more complicated in making genetic diagnoses based on identification of variants in genes presenting a highly heterogenous phenotype such as "OGDHL-related disorders".

Persistent post-COVID-19 neuromuscular symptoms

Neuromuscular symptoms may develop or persist after resolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Besides residual sensorimotor symptoms associated with acute neuromuscular complications of coronavirus disease-2019 (COVID-19), such as Guillain-Barré syndrome, critical illness neuromyopathy, and rhabdomyolysis, patients may report persistent autonomic symptoms, sensory symptoms, and muscle symptoms in the absence of these acute complications, including palpitations, orthostatic dizziness and intolerance, paresthesia, myalgia, and fatigue. These symptoms may be associated with long COVID, also known as post-COVID-19 conditions or postacute sequelae of SARS-CoV-2 infection, which may significantly impact quality of life. Managing these symptoms represents a challenge for health-care providers. Recent advances have identified small-fiber neuropathy as a potential etiology that may underlie autonomic dysfunction and paresthesia in some long COVID patients. The pathogenic mechanisms underlying myalgia and fatigue remain elusive and need to be investigated. Herein we review the current state of knowledge regarding the evaluation and management of patients with persistent post-COVID-19 neuromuscular symptoms.

Biotics (Pre-, Pro-, Post-) and Uremic Toxicity: Implications, Mechanisms, and Possible Therapies

In recent years, more scientific data have pointed out the close connection between intestinal microbial community, nutritional habits, lifestyle, and the appearance of various affections located at certain anatomical systems. Gut dysbiosis enhances the formation and accumulation of specific metabolites with toxic potential that induce the appearance of kidney-associated illnesses. Intestinal microbes are involved in the degradation of food, drugs, or other ingested products that lead to the formation of various metabolites that end up in renal tissue. Over the last few years, the possibilities of modulating the gut microbiota for the biosynthesis of targeted compounds with bioactive properties for reducing the risk of chronic illness development were investigated. In this regard, the present narrative review provides an overview of the scientific literature across the last decade considering the relationship between bioactive compounds, pre-, pro-, and post-biotics, uremic toxicity, and kidney-associated affections, and the possibility of alleviating the accumulation and the negative effects of uremic toxins into the renal system.

Toxic encephalopathy and peripheral neuropathy of poisoning by Avermectin Pyridine: a case report and a review of the literature

Background

Avermectin Pyridaben (AVP) is an insecticide with extreme neurotoxicity in human, causing critical symptoms such as nausea, vomiting, coma and respiratory failure within a short time after oral ingestion. Neurological sequelae or even death may occur because of delayed treatment or excessive toxic dose.

Case presentation

We report a 15-year-old girl who presented with coma, respiratory failure, limb weakness, ataxia symptoms after ingestion of a toxic dose of AVP. Soon after the poisoning, the patient was treated with life-saving mechanical ventilation and haemodialysis. Subsequently brain Magnetic Resonance Imaging (MRI) and nerve conduction study (NCS) and electromyography (EMG) demonstrated toxic encephalopathy and peripheral nerve injury. Over the next 2 months the patient's limb function gradually recovered under treatment with hyperbaric oxygen, glucocorticoid pulses and neurotrophic drugs.

Conclusion

This case documents a rare presentation of toxic encephalopathy complicated with peripheral neuropathy following AVP poisoning. Seven other similar cases of poisoning in terms of common symptoms and effective treatment have also been summarised for providing clinicians with experience in diagnosis and therapy.

Positive Association of Serum Vitamin B6 Levels with Intrapulmonary Lymph Node and/or Localized Pleural Metastases in Non-Small Cell Lung Cancer: A Retrospective Study

The relationship between vitamin B levels and the development and progression of lung cancer remains inconclusive. We aimed to investigate the relationship between B vitamins and intrapulmonary lymph nodes as well as localized pleural metastases in patients with non-small cell lung cancer (NSCLC). This was a retrospective study including patients who underwent lung surgery for suspected NSCLC at our institution from January 2016 to December 2018. Logistic regression models were used to evaluate the associations between serum B vitamin levels and intrapulmonary lymph node and/or localized pleural metastases. Stratified analysis was performed according to different clinical characteristics and tumor types. A total of 1498 patients were included in the analyses. Serum vitamin B₆ levels showed a positive association with intrapulmonary metastasis in a multivariate logistic regression (odds ratio (OR) of 1.016, 95% confidence interval (CI) of 1.002-1.031, p = 0.021). After multivariable adjustment, we found a high risk of intrapulmonary metastasis in patients with high serum vitamin B₆ levels (fourth quartile (Q4) vs. Q1, OR of 1.676, 95%CI of 1.092 to 2.574, p = 0.018, p for trend of 0.030). Stratified analyses showed that the positive association between serum vitamin B₆ and lymph node metastasis appeared to be stronger in females, current smokers, current drinkers, and those with a family history of cancer, squamous cell carcinoma, a tumor of 1-3 cm in diameter, or a solitary tumor. Even though serum vitamin B₆ levels were associated with preoperative NSCLC upstaging, B₆ did not qualify as a useful biomarker due to weak association and wide confidence intervals. Thus, it would be appropriate to prospectively investigate the relationship between serum vitamin B₆ levels and lung cancer further.

Nutritional Support for Alcoholic Liver Disease

Malnutrition is a common finding in alcohol use disorders and is associated with the prognosis of patients with alcoholic liver disease (ALD). These patients also frequently show deficiencies in vitamins and trace elements, increasing the likelihood of anemia and altered cognitive status. The etiology of malnutrition in ALD patients is multifactorial and complex and includes inadequate dietary intake, abnormal absorption and digestion, increased skeletal and visceral protein catabolism, and abnormal interactions between ethanol and lipid metabolism. Most nutritional measures derive from general chronic liver disease recommendations. Recently, many patients with ALD have been diagnosed with metabolic syndrome, which requires individualized treatment via nutritional therapy to avoid overnutrition. As ALD progresses to cirrhosis, it is frequently complicated by protein–energy malnutrition and sarcopenia. Nutritional therapy is also important in the management of ascites and hepatic encephalopathy as liver failure progresses. The purpose of the review is to summarize important nutritional therapies for the treatment of ALD.

Mechanisms of action of vitamin B1 (thiamine), B6 (pyridoxine), and B12 (cobalamin) in pain: a narrative review

Pain is a complex sensory and emotional experience with nociceptive, nociplastic, and neuropathic components. An involvement of neurotropic B vitamins (B1 - thiamine, B6 - pyridoxine, and B12 - cyanocobalamin) as modulators of inflammation and pain has been long discussed. New evidence suggests their therapeutic potential in different pain conditions. In this review, we discuss the main role of neurotropic B vitamins on different nociceptive pathways in the nervous system and to describe their analgesic action mechanisms. The performed literature review showed that, through different mechanisms, these vitamins regulate several inflammatory and neural mediators in nociceptive and neuropathic pain. Some of these processes include aiming the activation of the descending pain modulatory system and in specific intracellular pathways, anti-inflammatory, antioxidative and nerve regenerative effects. Moreover, recent data shows the antinociceptive, antiallodynic, and anti-hyperalgesic effects of the combination of these vitamins, as well as their synergistic effects with known analgesics. Understanding how vitamins B1, B6, and B12 affect several nociceptive mechanisms can therefore be of significance in the treatment of various pain conditions.

Pentoxifylline and thiamine ameliorate rhabdomyolysis-induced acute kidney injury in rats via suppressing TLR4/NF-κB and NLRP-3/caspase-1/gasdermin mediated-pyroptosis

Acute kidney injury (AKI) is a common complication of rhabdomyolysis (RM), a syndrome characterized by skeletal muscle damage resulting in renal tubular oxidative stress, inflammation, and activated toll like receptor-4 (TLR-4) and NOD-like receptor protein-3 (NLRP-3) inflammasome. Pyroptosis is a programmed cell death mediated by NLRP-3 leading to the activation of caspase-1 and gasdermin D (GSDMD), the hallmark of pyroptosis. This study aims to investigate the renoprotective effects of two antioxidants; pentoxifylline (PTX) and thiamine (TM) via targeting the aforementioned pathways. RM-AKI was induced in male Albino Wistar rats by intramuscular injection of glycerol (50% v/v, 10 ml/kg). PTX (100 mg/kg, oral) and TM (25 mg/kg, i.p) were administered for 12 days prior glycerol injection and continued for 3 days following induction of RM-AKI. Serum creatinine, blood urea nitrogen (BUN), creatin kinase, lipid peroxides, total antioxidant activity, inflammatory markers (tumor necrosis factor-α, interleukin-1β, and nuclear factor kappa B), TLR4, NLRP-3, caspase-1, GSDMD and c-myc (an apoptotic marker) were estimated. Compared to AKI model, co-administered drugs revealed a significant improvement in renal function and pathology as indicated by the reduction in serum creatinine, BUN and protein cast accumulation. The elevations of oxidative stress, and inflammatory markers as well as the over-expression of c-myc were alleviated. Protein levels of TLR4, NLRP3, cleaved caspase-1, and GSDMD were significantly elevated in RM-AKI model, and this elevation was attenuated by the tested drugs. In conclusion, PTX and TM could be a potential renoprotective approach for patients with RM through targeting TLR4/NF-κB and NLRP-3/caspase-1/gasdermin mediated-pyroptosis pathways.

Hyperhomocysteinemia in acute hepatic porphyria (AHP) and implications for treatment with givosiran

INTRODUCTION

Homocysteine is a sulfur-containing amino acid formed in the intermediary metabolism of methionine. Amino acid metabolism and heme biosynthesis pathways are complexly intertwined. Plasma homocysteine elevation, hyperhomocysteinemia (HHcy), has been reported in patients with acute hepatic porphyria (AHP), a family of rare genetic disorders caused by defects in hepatic heme biosynthesis.

AREAS COVERED

This article summarizes published case series in which givosiran, a subcutaneously administered small interfering RNA approved for AHP treatment, appeared to exacerbate dysregulated homocysteine metabolism in patients with AHP. A comprehensive exploratory analysis of ENVISION trial data demonstrated that on a population level, givosiran increased homocysteine but with wide interpatient variations, and there is no proof of correlations between HHcy and changes in efficacy or safety of givosiran.

EXPERT OPINION

The strong correlation and co-increase of homocysteine and methionine suggest that HHcy associated with givosiran is likely attributable to the impaired trans-sulfuration pathway catalyzed by cystathionine β-synthase, which uses vitamin B6 as a cofactor. Data-based consensus supports monitoring total plasma homocysteine and vitamin B6, B12, and folate levels before and during givosiran treatment; supplementing with pyridoxine/vitamin B6 in patients with homocysteine levels >100 μmol/L; and involving patients with homocysteine levels >30 μmol/L in decisions to supplement.

Pharmacological treatment strategies for antipsychotic-induced hyperprolactinemia: a systematic review and network meta-analysis

Antipsychotic-induced hyperprolactinemia (AP-induced HPRL) occurs overall in up to 70% of patients with schizophrenia, which is associated with hypogonadism and sexual dysfunction. We summarized the latest evidence for the benefits of prolactin-lowering drugs. We performed network meta-analyses to summarize the evidence and applied Grading of Recommendations Assessment, Development, and Evaluation frameworks (GRADE) to rate the certainty of evidence, categorize interventions, and present the findings. The search identified 3,022 citations, 31 studies of which with 1999 participants were included in network meta-analysis. All options were not significantly better than placebo among patients with prolactin (PRL) less than 50 ng/ml. However, adjunctive aripiprazole (ARI) (5 mg: MD = -64.26, 95% CI = -87.00 to -41.37; 10 mg: MD = -59.81, 95% CI = -90.10 to -29.76; more than 10 mg: MD = -68.01, 95% CI = -97.12 to -39.72), switching to ARI in titration (MD = -74.80, 95% CI = -134.22 to -15.99) and adjunctive vitamin B6 (MD = -91.84, 95% CI = -165.31 to -17.74) were associated with significant decrease in AP-induced PRL among patients with PRL more than 50 ng/ml with moderated (adjunctive vitamin B6) to high (adjunctive ARI) certainty of evidence. Pharmacological treatment strategies for AP-induced HPRL depends on initial PRL level. No effective strategy was found for patients with AP-induced HPRL less than 50 ng/ml, while adjunctive ARI, switching to ARI in titration and adjunctive high-dose vitamin B6 showed better PRL decrease effect on AP-induced HPRL more than 50 ng/ml.

Safety and Efficacy of High-Dose Vitamin B6 as an Adjunctive Treatment for Antipsychotic-Induced Hyperprolactinemia in Male Patients With Treatment-Resistant Schizophrenia

This study aimed to investigate the safety and efficacy of high-dose vitamin B6 (vB6) as an adjunct treatment for antipsychotic-induced hyperprolactinemia (AIHP) in male patients with treatment-resistant schizophrenia (TRS). In this randomized double-blinded controlled study, patients were randomized (1:1) into a control group given aripiprazole (ARI; 10 mg/day; n = 100) or an intervention group given vB6 (300 mg/12 h for 16 weeks; n = 100). Prolactin levels, psychotic symptoms [Positive and Negative Syndrome Scale (PANSS)], cognitive function [MATRICS Consensus Cognitive Battery (MCCB)], liver function, kidney function, growth hormone level, micronutrient levels, blood lipids, and adverse secondary effects (ASEs)[Treatment Emergent Symptom Scale (TESS) and Barnes-Akathisia scale] were monitored. After a 16-week treatment period, the vB6 group showed a 68.1% reduction in serum prolactin levels (from 95.52 ± 6.30 μg/L to 30.43 ± 18.65 μg/L) while the ARI group showed only a 37.4% reduction (from 89.07 ± 3.59 μg/L to 55.78 ± 7.39 μg/L). During weeks 1-4, both treatments reduced prolactin similarly. Subsequently, the ARI effect plateaued, while the vB6 effect remained robust. The vB6 group showed better alleviation of psychotic symptoms and cognitive impairment. No serious ASEs were observed; ASEs were more frequent in the ARI group. AIHP reduction efficacy of vB6 was associated with baseline prolactin and triglyceride levels, total vB6 dosage, and education level. In conclusion, compared with the ARI group, TRS patients given vB6 showed better attenuation of AIHP, lower ASE scores, and greater improvements in clinical symptoms and cognitive impairments. These results support further consideration of vB6 as a putative treatment for AIHP. Trial Registration: ChiCTR1800014755.