Preventing hyperhomocysteinemia using vitamin B6 supplementation in Givosiran-treated acute intermittent porphyria: Highlights from a case report and brief literature review.

Acute hepatic porphyrias are inherited metabolic disorders of heme biosynthesis characterized by the accumulation of toxic intermediate metabolites responsible for disabling acute neurovisceral attacks. Givosiran is a newly approved siRNA-based treatment of acute hepatic porphyria targeting the first and rate-limiting δ-aminolevulinic acid synthase 1 (ALAS1) enzyme of heme biosynthetic pathway. We described a 72-year old patient who presented with severe inaugural neurological form of acute intermittent porphyria evolving for several years which made her eligible for givosiran administration. On initiation of treatment, the patient developed a major hyperhomocysteinemia (>400 µmol/L) which necessitated to discontinue the siRNA-based therapy. A thorough metabolic analysis in the patient suggests that hyperhomocysteinemia could be attributed to a functional deficiency of cystathionine ß-synthase (CBS) enzyme induced by givosiran. Long-term treatment with vitamin B6, a cofactor of CBS, allowed to normalize homocysteinemia while givosiran treatment was maintained. We review the recently published cases of hyperhomocysteinemia in acute hepatic porphyria and its exacerbation under givosiran therapy. We also discuss the benefits of vitamin B6 supplementation in the light of hypothetic pathophysiological mechanisms responsible for hyperhomocysteinemia in these patients. Our results confirmed the importance of monitoring homocysteine metabolism and vitamin status in patients with acute intermittent porphyria in order to improve management by appropriate vitamin supplementation during givosiran treatment.

High Homocysteine-Thiolactone Leads to Reduced MENIN Protein Expression and an Impaired DNA Damage Response: Implications for Neural Tube Defects.

DNA damage is associated with hyperhomocysteinemia (HHcy) and neural tube defects (NTDs). Additionally, HHcy is a risk factor for NTDs. Therefore, this study examined whether DNA damage is involved in HHcy-induced NTDs and investigated the underlying pathological mechanisms involved. Embryonic day 9 (E9) mouse neuroectoderm cells (NE4C) and homocysteine-thiolactone (HTL, active metabolite of Hcy)-induced NTD chicken embryos were studied by Western blotting, immunofluorescence. RNA interference or gene overexpression techniques were employed to investigate the impact of Menin expression changes on the DNA damage. Chromatin immunoprecipitation-quantitative polymerase chain reaction was used to investigate the epigenetic regulation of histone modifications. An increase in γH2AX (a DNA damage indicator) was detected in HTL-induced NTD chicken embryos and HTL-treated NE4C, accompanied by dysregulation of phospho-Atr-Chk1-nucleotide excision repair (NER) pathway. Further investigation, based on previous research, revealed that disruption of NER was subject to the epigenetic regulation of low-expressed Menin-H3K4me3. Overexpression of Menin or supplementation with folic acid in HTL-treated NE4C reversed the adverse effects caused by high HTL. Additionally, by overexpressing the Mars gene, we tentatively propose a mechanism whereby HTL regulates Menin expression through H3K79hcy, which subsequently influences H3K4me3 modifications, reflecting an interaction between histone modifications. Finally, in 10 human fetal NTDs with HHcy, we detected a decrease in the expression of Menin-H3K4me3 and disorder in the NER pathway, which to some extent validated our proposed mechanism. The present study demonstrated that the decreased expression of Menin in high HTL downregulated H3K4me3 modifications, further weakening the Atr-Chk1-NER pathway, resulting in the occurrence of NTDs.

Adult-onset combined methylmalonic acidemia and hyperhomocysteinemia, cblC type with aortic dissection and acute kidney injury: a case report.

BACKGROUND: Combined methylmalonic acidemia (MMA) and hyperhomocysteinemia, cobalamin C (cblC) type, also named cblC deficiency is a rare autosomal recessive genetic metabolic disease. It progressively causes neurological, hematologic, renal and other system dysfunction. The clinical manifestations are relatively different due to the onset time of disease. CASE PRESENTATION: This report describes a rare case of a 26 year old man with cblC deficiency who developed life-threatening aortic dissection and acute kidney injury (AKI) and showed neuropsychiatric symptoms with elevated serum homocysteine and methylmalonic aciduria. After emergent operation and intramuscular cobalamin supplementation therapy, the male recovered from aortic dissection, neurological disorder and AKI. Finally, two previously published compound heterozygous variants, c.482G > A (p.R161Q) and c.658_660del (p.K220del) in the MMACHC gene were detected in this patient and he was confirmed to have cblC deficiency. CONCLUSIONS: Poor cognizance of presenting symptoms and biochemical features of adult onset cblC disease may cause delayed diagnosis and management. This case is the first to depict a case of adult-onset cblC deficiency with aortic dissection. This clinical finding may contribute to the diagnosis of cblC deficiency.

A micronutrient supplement modulates homocysteine levels regardless of vitamin B biostatus in elderly subjects.

Elevated homocysteine (Hcy) levels (≥15 µmol/L) in the elderly are frequently associated with a higher risk of cardiovascular disease and cognitive decline. Several studies have already shown an Hcy-lowering effect of B vitamin supplementation in cohorts deficient in these nutrients. The aim of this randomized, double-blinded 12-week intervention study was to investigate whether Hcy levels in healthy elderly subjects (75.4±4.5 years, n=133) could be lowered with a micronutrient supplement (i.e., 400 µg folic acid, 100 µg cobalamin). Difference in mean initial Hcy levels between intervention (17.6±7.1 µmol/L, n=65) and placebo group (18.9±6.1 µmol/L, n=68) was not significant. The prevalence of cobalamin and folate deficiency in the total study population was low: 27% had serum-cobalamin levels ≤150 pmol/L, 12% holo-transcobalamin (Holo-TC) levels ≤50 pmol/L, 13% low cobalamin status using the aggregated cobalamin marker 4cB12 and 10% red blood cell (RBC) folate ≤570 nmol/L. Nevertheless, the treated subjects still showed improved cobalamin and folate biostatus (serum cobalamin Δt12-t0: 63±48 pmol/L; Holo-TC Δt12-t0: 17±19 pmol/L; RBC folate Δt12-t0: 326±253 nmol/L) and Hcy levels (Δt12-t0: -3.6±5.7 µmol/L). The effects were statistically significant compared to the placebo group with p=0.005 (serum cobalamin), p=0.021 (Holo-TC), p=0.014 (RBC-folate) and p<0.001 (Hcy). The Hcy-lowering effect was dependent on the initial Hcy levels (p<0.001). Our findings suggest that elevated Hcy levels in elderly subjects can be lowered regardless of the initial cobalamin and folate biostatus.

Characteristics, differential diagnosis, individualized treatment, and prevention of hyperhomocysteinemia in newborns.

OBJECTIVES: This study aimed to investigate the incidence rate, clinical phenotype, gene variation spectrum, and prognosis of neonatal hyperhomocysteinemia (HHcy) and explore its diagnosis, individualised treatment, and prevention strategies. METHODS: We screened 84722 neonates for HHcy using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with biochemical detection, urine gas chromatography-mass spectrometry (GC-MS), and next-generation sequencing (NGS) for gene analysis to comprehensively differentiate and diagnose diseases. RESULTS: 18 children (P1-P18) were diagnosed with methylmalonic acidemia (MMA) and HHcy, and fourteen known and one new variant of the MMACHC gene were found. Five children showed poor mental reactions, brain dysplasia, lethargy, hyperbilirubinemia, and jaundice, whereas the other 13 children had no evident abnormalities. These children were all cobalamin- and folic acid-reactive types, and they were mainly supplemented with cobalamin, L-carnitine, betaine, and folic acid. The mother of P12 had a prenatal diagnosis at the next pregnancy; the results showed that MMACHC gene was not pathogenic and she gave birth to a healthy baby. One child (P19) was diagnosed with methylenetetrahydrofolate reductase (MTHFR) deficiency, and one new mutation was detected in the MTHFR gene. Patient P19 showed congenital brain dysplasia, neonatal anaemia, and hyperbilirubinemia, and treatment consisted mainly of betaine and cobalamin supplementation. One child (P20) was confirmed to have methionine adenosyltransferase I (MAT I) deficiency but had no clinical manifestations. After treatment, all the children had a good prognosis. CONCLUSION: The incidence of neonatal HHcy in the Zibo area was 1/4236, and the common pathogenic variants were c.609G>A, c.80A>G, and c.482G>A in the MMACHC gene. Patients with HHcy can achieve a good prognosis if pathogenic factors and targeted treatment are identified. Gene analysis and prenatal diagnosis contribute to the early prevention of HHcy.

Hemorrhagic Cerebrovascular Disease: An Unusual Presentation of Hyperhomocysteinemia / Accidente cerebrovascular hemorrágico: una inusual presentación de hiperhomocisteinemia / Acidente vascular cerebral hemorrágico: uma apresentação incomum da hiper-homocisteinemia

Introduction: Stroke is a major cause of morbidity and mortality worldwide, with hemorrhagic stroke being the deadliest form of acute stroke. Therefore, the cause of the event should be determined to direct the associated therapy and take preventive measures. Hyperhomocysteinemia has been described as a rare etiology of stroke. Although hyperhomocysteinemia has been associated with venous thrombotic events, altered endothelial function, and procoagulant states, its clinical role in stroke remains controversial. Case description: We present a case of a 60-year-old male patient with primary autoimmune hypothyroidism who presented with dysarthria, facial paresis, and left upper-limb monoparesis after sexual intercourse. A simple skull computed tomography scan showed hyperintensity in the right basal ganglion, indicating an acute hemorrhagic event. Etiological studies were performed, including ambulatory blood pressure monitoring, cerebral angiography, and transthoracic echocardiogram, which ruled out underlying vascular pathology. During follow-up, vitamin B12 deficiency and hyperhomocysteinemia were detected, without other blood biochemical profile alterations. Supplementation was initiated, and homocysteine levels gradually decreased, without new neurological deficits observed during follow-up. Conclusion: Quantification of homocysteine should be considered in patients with a cerebrovascular disease without apparent cause, as documenting hyperhomocysteinemia and correcting its underlying etiology are essential not only for providing appropriate management but also for preventing future events.

Introducción: el accidente cerebrovascular es una causa importante de morbilidad y mortalidad en todo el mundo, y el accidente cerebrovascular hemorrágico es la forma más mortífera de accidente cerebro- vascular agudo. La determinación de la causa del evento es esencial para dirigir la terapia asociada y poder tomar medidas preventivas. La hiperhomocisteinemia se ha descrito como una etiología poco frecuente de accidente cerebrovascular. Aunque esta se ha asociado con eventos trombóticos venosos, disfunción endotelial alterada y estados procoagulantes, sigue siendo controvertido su papel clínico en el accidente cerebrovascular. Descripción del caso: se presenta el caso de un hombre de 60 años con hipotiroidismo autoinmune primario que presentó disartria, paresia facial y monoparesia del miembro superior izquierdo después de un encuentro sexual. Una simple tomografía computarizada de cráneo mostró hipointensidad en la región del ganglio basal derecho, que indicaba un evento hemorrágico agudo. Se realizaron estudios etiológicos, incluyendo monitorización ambulatoria de la presión arterial, angiografía cerebral y ecocardiograma transtorácico, que descartaron patología vascular subyacente. Durante el seguimiento, se detectó deficiencia de vitamina B12 e hiperhomocisteinemia, sin otras alteraciones en el perfil bioquímico sanguíneo. Se inició la suplementación y los niveles de homocisteína disminuyeron gradualmente, sin observar nuevos déficits neurológicos durante el seguimiento. Conclusión: la cuantificación de homocisteína debe ser considerada en casos de enfermedad cerebrovascular sin causa aparente, dado que documentar la hiperhomocisteinemia y corregir su etiología subyacente es esencial no solo para proporcionar un manejo adecuado, sino también para prevenir eventos futuros.

Introdução: o acidente vascular cerebral (AVC) é uma das principais causas de morbidade e mortalidade em todo o mundo, sendo o AVC hemorrágico a forma mais letal de AVC agudo. A determinação da causa do evento é essencial para direcionar a terapia associada e poder tomar medidas preventivas. A hiperhomocisteinemia tem sido descrita como uma etiologia rara de acidente vascular cerebral. Embora a hiper-homocisteinemia tenha sido associada a eventos trombóticos venosos, disfunção endotelial alterada e estados pró-coagulantes, seu papel clínico no AVC permanece controverso. Descrição do caso: apresentamos o caso de um homem de 60 anos com hipotireoidismo autoimune primário que apresentou disartria, paresia facial e monoparesia do membro superior esquerdo após relação sexual. A tomografia computadorizada de crânio mostrou hipointensidade na região do gânglio da base direito, indicando evento hemorrágico agudo. Foram realizados estudos etiológicos, incluindo monitorização ambulatorial da pressão arterial, angiografia cerebral e ecocardiograma transtorácico, que descartaram patologia vascular subjacente. Durante o acompanhamento, foram detectados deficiência de vitamina B12 e hiper-homocistei- nemia, sem outras alterações no perfil bioquímico sanguíneo. A suplementação foi iniciada e os níveis de homocisteína diminuíram gradualmente, sem novos déficits neurológicos observados durante o acompanhamento. Conclusão: a quantificação da homocisteína deve ser considerada em casos de doença vascular cerebral sem causa aparente, pois documentar a hiper-homocisteinemia e corrigir sua etiologia subjacente é essencial não apenas para fornecer manejo adequado, mas também para prevenir eventos futuros.

Cerebral venous thrombosis with hyperhomocysteinemia due to loss of heterozygosity at methylenetetrahydrofolate reductase (MTHFR) locus: a case report.

BACKGROUND: Loss of heterozygosity (LOH) at methylenetetrahydrofolate reductase (MTHFR) locus has been reported in tumor tissue. But the mutation was never reported in cerebral venous thrombosis (CVT) with hyperhomocysteinemia (HHcy) before. CASE PRESENTATION: A 14-year-old girl was admitted with an intermittent headache and nausea for 2 months. The plasma homocysteine level was 77.2 µmol/L. Lumbar puncture revealed an intracranial pressure > 330 mmH2O. Cerebral MRI and MRV revealed superior sagittal sinus thrombosis. Whole-exome sequencing revealed LOH at Chr1:11836597-11,867,232 affects exons 10-21 of C1orf167, the entire MTHFR, and exons 1-2 of the CLCN6 gene. The normal allele was the c.665 C > T/677 C > T variant in MTHFR. The patient was treated with nadroparin for 2 weeks, followed by oral rivaroxaban. Supplemental folate and vitamins B12 and B6 were prescribed. One month later, she had no headache and the intracranial pressure had decreased to 215 mmH2O. MRI showed shrinkage of the thrombosis in the superior sagittal sinus, the degree of stenosis had significantly decreased. CONCLUSIONS: Rare LOH at the MTHFR locus should be analyzed in CVT with HHcy. With anticoagulation treatment, the prognosis was good.

Effects of low-dose B vitamins plus betaine supplementation on lowering homocysteine concentrations among Chinese adults with hyperhomocysteinemia: a randomized, double-blind, controlled preliminary clinical trial.

PURPOSE: To test the hypothesis that daily supplementation with low-dose B vitamins plus betaine could significantly reduce plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia and free from background mandatory folic acid fortification. METHODS: One hundred apparently healthy adults aged 18-65 years with hyperhomocysteinemia were recruited in South China from July 2019 to June 2021. They were randomly assigned to either the supplement group (daily supplementation: 400 µg folic acid, 8 mg vitamin B6, 6.4 µg vitamin B12 and 1 g betaine) or the placebo group for 12 weeks. Fasting venous blood was collected at baseline, week 4 and week 12 to determine the concentrations of homocysteine, folate, vitamin B12 and betaine. Generalized estimation equations were used for statistical analysis. RESULTS: Statistically significant increments in blood concentrations of folate, vitamin B12 and betaine after the intervention in the supplement group indicated good participant compliance. At baseline, there were no significant differences in plasma homocysteine concentration between the two groups (P = 0.265). After 12-week supplementation, compared with the placebo group, there was a significant reduction in plasma homocysteine concentrations in the supplement group (mean group difference - 3.87; covariate-adjusted P = 0.012; reduction rate 10.1%; covariate-adjusted P < 0.001). In the supplement group, the decreased concentration of plasma homocysteine was associated with increments of blood concentrations of both folate (ß = -1.680, P = 0.004) and betaine (ß = -1.421, P = 0.020) after 12 weeks of supplementation. CONCLUSIONS: Daily supplementation with low-dose B vitamins plus betaine for 12 weeks effectively decreased plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT03720249 on October 25, 2018. Website: https://clinicaltrials.gov/ct2/show/NCT03720249 .

Sodium tanshinone IIA sulfonate protects against hyperhomocysteine-induced vascular endothelial injury via activation of NNMT/SIRT1-mediated NRF2/HO-1 and AKT/MAPKs signaling in human umbilical vascular endothelial cells.

Homocysteine (Hcy) is one of the independent risk factors of cardiovascular disease. Sodium tanshinone IIA sulfonate (STS) is a hydrophilic derivate of tanshinone IIA which is the main active constitute of Chinese Materia Medica Salviae Miltiorrhizae Radix et Rhizoma, and exhibits multiple pharmacological activities. However, whether STS could prevent from Hcy-induced endothelial cell injury is unknown. We found that STS dramatically reversed Hcy-induced cell death concentration dependently in human umbilical vascular endothelial cells (HUVECs). STS ameliorated the endothelial cell cycle progression, proliferation and cell migratory function impaired by Hcy, which might be co-related to the inhibition of intracellular oxidative stress and mitochondrial dysfunction. STS also elevated the phosphorylation of AKT and MAPKs and protein expression of sirtuin1 (SIRT1), NRF2 and HO-1 which were suppressed by Hcy. The protective effect of STS against Hcy-induced endothelial cell toxicity was partially attenuated by PI3K, AKT, MEK, ERK, SIRT1, NRF2 and HO-1 inhibitors. Besides, knockdown of SIRT1 by its siRNA dramatically decreased the endothelial protective effect of STS accompanied with suppression of SIRT1, NRF2, HO-1 and phosphorylated AKT. The activation of AKT or NRF2 partially reversed SIRT1-knockdown impaired cyto-protective effect of STS against Hcy-induced cell injury. Furthermore, STS prevented from Hcy-induced intracellular nicotinamide N-methyltransferase (NNMT) reduction along with elevation of intracellular methylnicotinamide (MNA), and MNA enhanced STS protecting against Hcy induced endothelial death. Knockdown of NNMT reduced the protective effect of STS against Hcy induced endothelial cell injury. Collectively, STS presented potent endothelial protective effect against Hcy and the underlying molecular mechanisms were involved in the suppression of intracellular oxidative stress and mitochondria dysfunction by activation of AKT/MAPKs, SIRT1/NRF2/HO-1 and NNMT/MNA signaling pathways.

Higher blood selenium level is associated with lower risk of hyperhomocysteinemia in the elderly.

BACKGROUND AND AIMS: Earlier studies have reported inconsistent association between selenium (Se) and homocysteine (Hcy) levels, while no evidence could be found from Chinese population. To fill this gap, we investigated the association between blood Se and hyperhomocysteinemia (HHcy) of rural elderly population in China. METHODS: A cross-sectional study on 1823 participants aged 65 and older from four Chinese rural counties was carried out in this study. Whole blood Se and serum Hcy concentrations were measured in fasting blood samples. Analysis of covariance and restricted cubic spline models were used to examine the association between Se and Hcy levels. Logistic regression models were used to evaluate the risk of prevalent HHcy among four Se quartile groups after adjusting for covariates. RESULTS: For this sample, the mean blood Se concentration was 156.34 (74.65) µg/L and the mean serum Hcy concentration was 17.25 (8.42) µmol/L. A significant non-linear relationship was found between blood Se and serum Hcy, the association was inverse when blood Se was less than 97.404 µg/L and greater than 156.919 µg/L. Participants in the top three blood Se quartile groups had significantly lower risk of prevalent HHcy compared with the lowest quartile group. When defined as Hcy> 10 µmol/L, the odds ratios and 95% confidence interval of HHcy were 0.600 (0.390, 0.924), 0.616 (0.398, 0.951) and 0.479 (0.314, 0.732) for Q2, Q3, and Q4 Se quartile groups compared with the Q1 group, respectively. When defined as Hcy≥ 15 µmol/L, the odds ratios and 95% confidence interval of HHcy were 0.833 (0.633, 1.098) and 0.827 (0.626, 1.092), 0.647 (0.489, 0.857) for Q2, Q3, and Q4 Se quartile groups compared with Q1 group. CONCLUSIONS: Our findings suggest that higher blood Se level could be a protective factor for HHcy in the elderly.

Hyperhomocysteinemia in Adult Patients: A Treatable Metabolic Condition.

Hyperhomocysteinemia (HHcy) is recognized as an independent risk factor for various significant medical conditions, yet controversy persists around its assessment and management. The diagnosis of disorders afffecting homocysteine (Hcy) metabolism faces delays due to insufficient awareness of its clinical presentation and unique biochemical characteristics. In cases of arterial or venous thrombotic vascular events, particularly with other comorbidities, it is crucial to consider moderate to severe HHcy. A nutritional approach to HHcy management involves implementing dietary strategies and targeted supplementation, emphasizing key nutrients like vitamin B6, B12, and folate that are crucial for Hcy conversion. Adequate intake of these vitamins, along with betaine supplementation, supports Hcy remethylation. Lifestyle modifications, such as smoking cessation and regular physical activity, complement the nutritional approach to enhance Hcy metabolism. For individuals with HHcy, maintaining a plasma Hcy concentration below 50 µmol/L consistently is vital to lowering the risk of vascular events. Collaboration with healthcare professionals and dietitians is essential for developing personalized dietary plans addressing the specific needs and underlying health conditions. This integrated approach aims to optimize metabolic processes and reduce the associated health risks.

The Association Between Serum Homocysteine Levels and Placenta-Mediated Complications: A Narrative Review.

The most extremely unfavourable outcome of pregnancy is the death of the mother and newborn. Negative outcomes for mothers or babies can occur as a result of complications or issues during pregnancy, birth or the post-partum period. Early elevated maternal homocysteine (Hct) levels during pregnancy have been linked to altered placental development. There is evidence that suggests an elevated maternal blood Hct level is the new obstetrical risk factor, and the association between hyperhomocysteinemia (HHct) and numerous obstetrical problems was recently recognised. Hct is an essential amino acid, which contains sulphur and is formed from the metabolism of methionine. HHct has several known aetiologies, including genetic anomalies; a deficiency in folic acid, vitamin B6 and vitamin B12; hypothyroidism; old age; and renal illnesses. Vascular problems, coronary artery disease, atherosclerosis and embolic illnesses can all occur as a result of high blood levels of Hct. Hct levels are lower in normal pregnancies than it is in women who are not pregnant. Many pregnancy-related problems, including pre-eclampsia (PE), recurrent pregnancy loss (RPL), placental abruption, premature delivery and foetal growth restriction (FGR) have been connected to HHct in recent research. We looked for pertinent literature using a thorough and systematic search from PubMed, Medline, Embase, Cochrane Library, Google, etc., and articles that were published before August 2022 based on serum Hct levels and various placenta-mediated complications for this review. In this review, we described the synthesis and metabolism of Hct in humans, Hct levels at various phases of normal pregnancy and the association between Hct and placenta-mediated pregnancy complications. The outcomes discovered can help obstetricians increase the likelihood of a successful pregnancy in cases where placenta-mediated issues are present. Lowering Hct levels with a high dose of folic acid tablets during the subsequent pregnancy may be useful for women who experienced these difficulties in prior pregnancies as a result of HHct.

Epigallocatechin-3-gallate Enhances Cognitive and Memory Performance and Protects Against Brain Injury in Methionine-induced Hyperhomocysteinemia Through Interdependent Molecular Pathways.

Brain injury and cognitive impairment are major health issues associated with neurodegenerative diseases in young and aged persons worldwide. Epigallocatechin-3-gallate (EGCG) was studied for its ability to protect against methionine (Met)-induced brain damage and cognitive dysfunction. Male mice were given Met-supplemented in drinking water to produce hyperhomocysteinemia (HHcy)-induced animals. EGCG was administered daily concurrently with Met by gavage. EGCG attenuated the rise in homocysteine levels in the plasma and the formation of amyloid-ß and tau protein in the brain. Cognitive and memory impairment in HHcy-induced mice were significantly improved by EGCG administration. These results were associated with improvement in glutamate and gamma-aminobutyric acid levels in the brain. EGCG maintained the levels of glutathione and the activity of antioxidant enzymes in the brain. As a result of the reduction of oxidative stress, EGCG protected against DNA damage in Met-treated mice. Moreover, maintaining the redox balance significantly ameliorated neuroinflammation evidenced by the normalization of IL-1ß, IL-6, tumor necrosis factor α, C-reactive protein, and IL-13 in the same animals. The decreases in both oxidative stress and inflammatory cytokines were significantly associated with upregulation of the antiapoptotic Bcl-2 protein and downregulation of the proapoptotic protein Bax, caspases 3 and 9, and p53 compared with Met-treated animals, indicating a diminution of neuronal apoptosis. These effects reflect and explain the improvement in histopathological alterations in the hippocampus of Met-treated mice. In conclusion, the beneficial effects of EGCG may be due to interconnecting pathways, including modulation of redox balance, amelioration of inflammation, and regulation of antiapoptotic proteins.

Management of Hyperhomocysteinemia, Low Vitamin Levels, and Low Cortisol in Cannabis Users: A Report of 2 Cases.

Objective: The purpose of this study was to describe the management of 2 long-term users of cannabis with nutrition and psychotherapy. Clinical Features: A 28-year-old man presented with a medical history of asthma, depression, anxiety, and smoking, and was a long-term user of cannabis for 9 years (usually 3 times a week). A 39-year-old man presented with a medical history of anxiety and fatigue, and was a long-term user of cannabis for 14 years (usually twice a week). Laboratory tests showed altered blood levels of homocysteine, vitamins, and cortisol. Intervention and Outcome: Both patients were given supplements of vitamins (folic acid, methylcobalamin, and pyridoxine), vitamin D, Rhodiola rosea, and L-tyrosine. Psychotherapy also was provided to both patients. After 2 months of treatment, both patients improved and reduced their cannabis consumption. Conclusion: This study describes vitamin deficiencies, low cortisol levels, and hyperhomocysteinemia in 2 cannabis users who were managed with a combination of nutritional supplements and psychotherapy.

Pirfenidone alleviates vascular intima injury caused by hyperhomocysteinemia.

OBJECTIVES: Hyperhomocysteinemia (HHcy) can induce vascular inflammatory and oxidative damage and accelerate intimal hyperplasia. This study investigated the protective effect of pirfenidone (PFD) on the recovery process of injured endothelial arteries during HHcy. MATERIALS AND METHODS: Thirty rabbits were randomly separated into three groups: A control group (n=10, standard rabbit chow), a model group (n=10, control diet plus 30 g methionine/kg food), and a PFD group (n=10, model diet plus oral administration of 90 mg/day of PFD). After 14 weeks of arterial injury, histopathological changes were determined. Plasma homocysteine (Hcy) concentrations, lipid profiles and oxidant and antioxidant status were evaluated. Macrophage infiltration was assessed using immunohistochemical staining. RESULTS: PFD supplementation decreased macrophage infiltration of iliac artery significantly without changes in blood lipids and Hcy concentrations. Compared with the model group, PFD restored superoxide dismutase and glutathione peroxidase activities and reduced malondialdehyde and reactive oxygen species levels. A high-methionine diet significantly increased neointimal area and the ratio between neointimal and media area. Systemic administration of PFD inhibited neointimal formation. CONCLUSIONS: PFD can partly alleviate intimal hyperplasia by inhibiting inflammatory and oxidative stress response induced by HHcy during endothelial injury. It may be a potential therapeutic agent for the prevention and treatment of endothelial injury-associated diseases such as atherosclerosis.

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 ß-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.

The Roles of Long-Term Hyperhomocysteinemia and Micronutrient Supplementation in the AppNL-G-F Model of Alzheimer's Disease.

A causal contribution of hyperhomocysteinemia to cognitive decline and Alzheimer's disease (AD), as well as potential prevention or mitigation of the pathology by dietary intervention, have frequently been subjects of controversy. In the present in vivo study, we attempted to further elucidate the impact of elevated homocysteine (HCys) and homocysteic acid (HCA) levels, induced by dietary B-vitamin deficiency, and micronutrient supplementation on AD-like pathology, which was simulated using the amyloid-based AppNL-G-F knock-in mouse model. For this purpose, cognitive assessment was complemented by analyses of ex vivo parameters in whole blood, serum, CSF, and brain tissues from the mice. Furthermore, neurotoxicity of HCys and HCA was assessed in a separate in vitro assay. In confirmation of our previous study, older AppNL-G-F mice also exhibited subtle phenotypic impairment and extensive cerebral amyloidosis, whereas dietary manipulations did not result in significant effects. As revealed by proximity extension assay-based proteome analysis, the AppNL-G-F genotype led to an upregulation of AD-characteristic neuronal markers. Hyperhomocysteinemia, in contrast, indicated mainly vascular effects. Overall, since there was an absence of a distinct phenotype despite both a significant amyloid-ß burden and serum HCys elevation, the results in this study did not corroborate the pathological role of amyloid-ß according to the "amyloid hypothesis," nor of hyperhomocysteinemia on cognitive performance. Nevertheless, this study aided in further characterizing the AppNL-G-F model and in elucidating the role of HCys in diverse biological processes. The idea of AD prevention with the investigated micronutrients, however, was not supported, at least in this mouse model of the disease.

Extensive Cerebral Venous Thrombosis Secondary to Recreational Nitrous Oxide Abuse.

Nitrous oxide, colloquially known as "whippets," is a commonly abused inhalant by adolescents and young adults. There are limited data describing the adverse effects of this abuse. We present a 16-year-old girl with no medical history who presented to the emergency department for confusion, hallucinations, weakness, and headaches. Imaging revealed extensive cerebral thrombosis. She had no prior history of venous or arterial thrombosis. Hypercoagulability workup demonstrated an elevated homocysteine level. She was treated with effective anticoagulation and vitamin B12 folate supplementation. To our knowledge, there are a very few cases in the medical literature of cerebral venous thrombosis following the use of nitrous oxide. The pathophysiology of the disorder appears to be linked to the metabolism of vitamin B12 inducing hyperhomocysteinemia and a procoagulant state.

The role of B vitamins in stroke prevention.

Elevated plasma levels of homocysteine (Hcy) are a recognized risk factor for stroke. This relationship represents one aspect of the debated `Hcy hypothesis'. Elevated Hcy may be an independent and treatable cause of atherosclerosis and thrombotic vascular diseases. Further observations indicate that proper dietary supplementation with B-vitamins decreases total plasma Hcy concentrations and may be an effective intervention for stroke prevention. Metabolic vitamin B12 deficiency is a nutritional determinant of total Hcy and stroke risk. Genetic factors may link B vitamins with stroke severity due to the impact on Hcy metabolism of polymorphism in the genes coding for methylenetetrahydrofolate reductase, methionine-synthase, methionine synthase reductase, and cystathionine ß-synthase. Several meta-analyses of large randomized controlled trials exist. However, they are not completely in agreement about B vitamins' role, particularly folic acid levels, vitamin B12, and B6, in lowering the homocysteine concentrations in people at high stroke risk. A very complex relationship exists between Hcy and B vitamins, and several factors appear to modify the preventive effects of B vitamins in stroke. This review highlights the regulating factors of the active role of B vitamins active in stroke prevention. Also, inputs for further large, well-designed studies, for specific, particularly sensitive subgroups are given.