Clinical use of cyclooxygenase inhibitors impairs vitamin B-6 metabolism

Cardiovascular safety of celecoxib in rheumatoid arthritis and osteoarthritis patients: A systematic review and meta-analysis

OBJECTIVE

To assess the cardiovascular safety of celecoxib compared to non-selective non-steroid anti-inflammatory drugs or placebo.

METHODS

We included randomized controlled trials of oral celecoxib compared with a non-selective NSAID or placebo in rheumatoid arthritis and osteoarthritis patients. We conducted searches in EMBASE, Cochrane CENTRAL, MEDLINE, China National Knowledge Infrastructure, VIP, Wanfang, and Chinese Biomedical Literature Database. Study selection and data extraction were done by two authors independently. The risk of bias was assessed using Cochrane's risk-of-bias Tool for Randomized Trials. The effect size was presented as a risk ratio with their 95% confidence interval.

RESULTS

Until July 22nd, 2021, our search identified 6279 records from which, after exclusions, 21 trials were included in the meta-analysis. The overall pooled risk ratio for Antiplatelet Trialists Collaboration cardiovascular events for celecoxib compared with any non-selective non-steroid anti-inflammatory drugs was 0.89 (95% confidence interval: 0.80-1.00). The pooled risk ratio for all-cause mortality for celecoxib compared with non-selective non-steroid anti-inflammatory drugs was 0.81 (95% confidence interval: 0.66-0.98). The cardiovascular mortality rate of celecoxib was lower than non-selective non-steroid anti-inflammatory drugs (risk ratio: 0.75, 95% confidence interval: 0.57-0.99). There was no significant difference between celecoxib and non-selective non-steroid anti-inflammatory drugs or placebo in the risk of other cardiovascular events.

CONCLUSION

Celecoxib is relatively safe in rheumatoid arthritis and osteoarthritis patients, independent of dose or duration. But it remains uncertain whether this would remain the same in patients treated with aspirin and patients with established cardiovascular diseases.

MTHFR Knockdown Assists Cell Defense against Folate Depletion Induced Chromosome Segregation and Uracil Misincorporation in DNA

Folate depletion causes chromosomal instability by increasing DNA strand breakage, uracil misincorporation, and defective repair. Folate mediated one-carbon metabolism has been suggested to play a key role in the carcinogenesis and progression of hepatocellular carcinoma (HCC) through influencing DNA integrity. Methylenetetrahydrofolate reductase (MTHFR) is the enzyme catalyzing the irreversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate that can control folate cofactor distributions and modulate the partitioning of intracellular one-carbon moieties. The association between MTHFR polymorphisms and HCC risk is inconsistent and remains controversial in populational studies. We aimed to establish an in vitro cell model of liver origin to elucidate the interactions between MTHFR function, folate status, and chromosome stability. In the present study, we (1) examined MTHFR expression in HCC patients; (2) established cell models of liver origin with stabilized inhibition of MTHFR using small hairpin RNA delivered by a lentiviral vector, and (3) investigated the impacts of reduced MTHFR and folate status on cell cycle, methyl group homeostasis, nucleotide biosynthesis, and DNA stability, all of which are pathways involved in DNA integrity and repair and are critical in human tumorigenesis. By analyzing the TCGA/GTEx datasets available within GEPIA2, we discovered that HCC cancer patients with higher MTHFR had a worse survival rate. The shRNA of MTHFR (shMTHFR) resulted in decreased MTHFR gene expression, MTHFR protein, and enzymatic activity in human hepatoma cell HepG2. shMTHFR tended to decrease intracellular S-adenosylmethionine (SAM) contents but folate depletion similarly decreased SAM in wildtype (WT), negative control (Neg), and shMTHFR cells, indicating that in cells of liver origin, shMTHFR does not exacerbate the methyl group supply in folate depletion. shMTHFR caused cell accumulations in the G2/M, and cell population in the G2/M was inversely correlated with MTHFR gene level (r = −0.81, p < 0.0001), MTHFR protein expression (r = −0.8; p = 0.01), and MTHFR enzyme activity (r = −0.842; p = 0.005). Folate depletion resulted in G2/M cell cycle arrest in WT and Neg but not in shMTHFR cells, indicating that shMTHFR does not exacerbate folate depletion-induced G2/M cell cycle arrest. In addition, shMTHFR promoted the expression and translocation of nuclei thymidine synthetic enzyme complex SHMT1/DHFR/TYMS and assisted folate-dependent de novo nucleotide biosynthesis under folate restriction. Finally, shMTHFR promoted nuclear MLH1/p53 expression under folate deficiency and further reduced micronuclei formation and DNA uracil misincorporation under folate deficiency. In conclusion, shMTHFR in HepG2 induces cell cycle arrest in G2/M that may promote nucleotide supply and assist cell defense against folate depletion-induced chromosome segregation and uracil misincorporation in the DNA. This study provided insight into the significant impact of MTHFR function on chromosome stability of hepatic tissues. Data from the present study may shed light on the potential regulatory mechanism by which MTHFR modulates the risk for hepatic malignancies.

Probiotics and Amelioration of Rheumatoid Arthritis: Significant Roles of Lactobacillus casei and Lactobacillus acidophilus

Rheumatoid arthritis is a chronic autoimmune disorder that can lead to disability conditions with swollen joints, pain, stiffness, cartilage degradation, and osteoporosis. Genetic, epigenetic, sex-specific factors, smoking, air pollution, food, oral hygiene, periodontitis, Prevotella, and imbalance in the gastrointestinal microbiota are possible sources of the initiation or progression of rheumatoid arthritis, although the detailed mechanisms still need to be elucidated. Probiotics containing Lactobacillus spp. are commonly used as alleviating agents or food supplements to manage diarrhea, dysentery, develop immunity, and maintain general health. The mechanism of action of Lactobacillus spp. against rheumatoid arthritis is still not clearly known to date. In this narrative review, we recapitulate the findings of recent studies to understand the overall pathogenesis of rheumatoid arthritis and the roles of probiotics, particularly L. casei or L. acidophilus, in the management of rheumatoid arthritis in clinical and preclinical studies.

Concurrent zinc and vitamin B6 deficiencies in acutely exacerbated inflammatory bowel disease: Case reports

BACKGROUND

Limited evidence is available to describe the prevalence, causes, and consequences of zinc and vitamin B₆ deficiencies in those with acutely exacerbated inflammatory bowel disease (IBD). Zinc is important for immune function and wound healing, and B₆ is needed for metabolic and neurological function. Patients with IBD are at risk of micronutrient deficiencies, particularly during flares.

PRESENTATIONS

The cases of 2 patients with IBD exacerbations were reviewed in which deficiencies of both zinc and vitamin B₆ were identified.

CONCLUSIONS

These cases highlight the need for increased screening for zinc and pyridoxine deficiencies in IBD population, especially during disease exacerbation. Therefore, we recommend a comprehensive nutrition workup with physical exam, diet history, and a complete micronutrient panel while ruling out contributing factors. If patients are susceptible to deficiencies during flares, prophylactic oral zinc and pyridoxine supplementation may be considered, with close monitoring for subsequent iron and copper deficiencies.

Evaluation of Nutritional Status and Methods to Identify Nutritional Risk in Rheumatoid Arthritis and Spondyloarthritis

Patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) experience several nutritional challenges and are prone to develop malnutrition. This observational study aimed to perform a comprehensive nutritional assessment of outpatients diagnosed with RA and SpA, as well as to evaluate methods to identify nutritional risk. Nutritional status was investigated by anthropometric measures, body composition (DXA, dual energy X-ray absorptiometry), and handgrip strength (HGS). Nutritional risk was classified by Nutritional Risk Screening 2002 (NRS2002) and malnutrition was defined by the Global Leadership Initiative on Malnutrition (GLIM) criteria and fat-free mass index (FFMI; kg/m², <16.7 (M), <14.6 (F)). Out of 71 included patients, 46 (66%) were abdominally obese, 28 (39%) were obese in terms of body mass index (BMI), and 33 (52%) were obese in terms of the fat mass index (FMI; kg/m², ≥8.3 (M), ≥11.8 (F)). Malnutrition was identified according to FFMI in 12 (19%) patients, according to GLIM criteria in 5 (8%) patients, and on the basis of BMI (<18.5 kg/m²) in 1 (1%) patient. None were identified by NRS2002 to be at nutritional risk. Our study revealed high prevalence of abdominal obesity and low FFMI. Waist circumference was a good indicator of FMI. BMI, NRS2002, and HGS did not capture patients with malnutrition identified by DXA.

Isolated Pyridoxine Deficiency Presenting as Muscle Spasms in a Patient With Type 2 Diabetes: A Case Report and Literature Review

Pyridoxine is an important co-factor for many biochemical reactions in cellular metabolism related to the synthesis and catabolism of amino acids, fatty acids, neurotransmitters. Deficiency of pyridoxine results in impaired transcellular signaling between neurons and presents with muscular convulsions, hyperirritability, and peripheral neuropathy. Deficiency of pyridoxine is usually found in association with other vitamin B deficiencies such as folate (vitamin B9) and cobalamin (vitamin B12). Isolated pyridoxine deficiency is extremely rare. We present the case of a 59-year old female with type 2 diabetes who complained of painful muscle spasms. Her muscle spasms involved in both feet, which have spread proximally to her legs. She also experienced intermittent muscle spasms in her left arm, which is not alleviated by baclofen, cyclobenzaprine. Her plasma pyridoxal 5-phosphate confirmed pyridoxine deficiency. Vitamins B1, B3, B12, and folate were within normal limits. The patient received standard-dose intramuscular pyridoxine injections for three weeks followed by oral supplements for 3 months and her symptoms resolved. This case illustrates the rare instance of isolated pyridoxine deficiency in type 2 diabetes patient manifesting as myoclonic muscle spasms involving the legs and arms in the absence of objective polyneuropathy. Pyridoxine level should, therefore, be assessed in patients with type 2 diabetes, including newly diagnosed patients.

Blood plasma B vitamins in depression and the therapeutic response to electroconvulsive therapy

A growing body of research has indicated a role for B vitamins in depression, with some previous studies suggesting that B vitamin status in patients with depression can impact on antidepressant response. Here we aimed to investigate B vitamin plasma concentrations in medicated patients with depression (n ​= ​94) compared to age- and sex-matched healthy controls (n ​= ​57), and in patients with depression after electroconvulsive therapy (ECT) in a real-world clinical setting. Our results show that nicotinamide (vitamin B3), N1-methylnicotinamide (vitamin B3 metabolite), and pyridoxal 5'-phosphate (PLP; vitamin B6) concentrations were significantly reduced in patients with depression compared to controls. The Cohen's d effect sizes for nicotinamide, N1-methylnicotinamide, and PLP were moderate-large (-0.47, -0.51, and -0.59, respectively), and likely to be of clinical relevance. Functional biomarkers of vitamin B6 status (PAr index, 3-hydroxykynurenine: hydroxyanthranilic acid ratio, 3-hydroxykynurenine: xanthurenic acid ratio, and HKr) were elevated in depressed patients compared to controls, suggestive of reduced vitamin B6 function. Over 30% of the patient cohort were found to have low to deficient PLP concentrations, and exploratory analyses revealed that these patients had higher IL-6 and CRP concentrations compared to patients with PLP levels within the normal range. Treatment with ECT did not alter B vitamin concentrations, and B vitamin concentrations were not associated with depression severity or the therapeutic response to ECT. Overall, reduced plasma PLP, nicotinamide, and N1-methylnicotinamide concentrations could have wide ranging effects on pathways and systems implicated in depression. Further studies are required to understand the reasons why patients with depression present with low plasma B vitamin concentrations.

Gender-specific changes in energy metabolism and protein degradation as major pathways affected in livers of mice treated with ibuprofen

Ibuprofen, an inhibitor of prostanoid biosynthesis, is a common pharmacological agent used for the management of pain, inflammation and fever. However, the chronic use of ibuprofen at high doses is associated with increased risk for cardiovascular, renal, gastrointestinal and liver injuries. The underlying mechanisms of ibuprofen-mediated effects on liver remain unclear. To determine the mechanisms and signaling pathways affected by ibuprofen (100 mg/kg/day for seven days), we performed proteomic profiling of male mice liver with quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) using ten-plex tandem mass tag (TMT) labeling. More than 300 proteins were significantly altered between the control and ibuprofen-treated groups. The data suggests that several major pathways including (1) energy metabolism, (2) protein degradation, (3) fatty acid metabolism and (4) antioxidant system are altered in livers from ibuprofen treated mice. Independent validation of protein changes in energy metabolism and the antioxidant system was carried out by Western blotting and showed sex-related differences. Proteasome and immunoproteasome activity/expression assays showed ibuprofen induced gender-specific proteasome and immunoproteasome dysfunction in liver. The study observed multifactorial gender-specific ibuprofen-mediated effects on mice liver and suggests that males and females are affected differently by ibuprofen.

Design, Synthesis and Anti-tuberculosis Activity of Hydrazones and N-acylhydrazones Containing Vitamin B6 and Different Heteroaromatic Nucleus

Background:

The term vitamin B6 refers to a set of six compounds, pyridoxine,pyridoxal ,and pyridoxamine and their phosphorylated forms, among which pyridoxal 5´-phosphate (PLP) is the most important and active form acting as a critical cofactor. These compounds are very useful in medicinal chemistry because of their structure and functionalities and are also used in bioinorganic chemistry as ligands for complexation with metals.

Methods:

In this study, a series of hydrazones 1a-g and N-acylhydrazones 2a-f containing vitamin B6 have been synthesized from commercial pyridoxal hydrochloride and the appropriate aromatic or heteroaromatic hydrazine or N-acylhydrazine. All synthesized compounds have been fully characterized and tested against Mycobacterium tuberculosis.

Results:

Among the N-acylhydrazones derivatives 2a-f, 2d (para- pyridine substituted Nacylhydrazone; MIC = 10.90 µM) exhibited the best activity. The ortho-pyridine derivative 2b exhibited intermediate activity (MIC = 87.32 µM), and the meta-pyridine derivative 2c was inactive. In case of the hydrazone series 1a-g, 7-chloroquinoxaline derivative 1f (MIC = 72.72 µM) showed the best result, indicating that the number of nitrogen and chlorine atoms in the radical moiety play an important role in the anti-tuberculosis activity of the quinoxaline derivatives (1f and 1g).

Conclusion:

The data reported herein indicates that the isoniazid derivative 2d (MIC = 10.90 µM) exhibited the best activity in the N-acylhydrazone series and; the quinoxaline nucleus derivative 1f (MIC = 72.72 µM) was the most active compound in the hydrazone series.

Direct and Functional Biomarkers of Vitamin B6 Status

Measures of B6 status are categorized as direct biomarkers and as functional biomarkers. Direct biomarkers measure B6 vitamers in plasma/serum, urine and erythrocytes, and among these plasma pyridoxal 5'-phosphate (PLP) is most commonly used. Functional biomarkers include erythrocyte transaminase activities and, more recently, plasma levels of metabolites involved in PLP-dependent reactions, such as the kynurenine pathway, one-carbon metabolism, transsulfuration (cystathionine), and glycine decarboxylation (serine and glycine). Vitamin B6 status is best assessed by using a combination of biomarkers because of the influence of potential confounders, such as inflammation, alkaline phosphatase activity, low serum albumin, renal function, and inorganic phosphate. Ratios between substrate-products pairs have recently been investigated as a strategy to attenuate such influence. These efforts have provided promising new markers such as the PAr index, the 3-hydroxykynurenine:xanthurenic acid ratio, and the oxoglutarate:glutamate ratio. Targeted metabolic profiling or untargeted metabolomics based on mass spectrometry allow the simultaneous quantification of a large number of metabolites, which are currently evaluated as functional biomarkers, using data reduction statistics.