NICEVIVA
MONOGRAPH SPEC LATEST 2025

Betaine HCl (Low Acid)

DIGESTIVE · Evidence Monograph

Betaine HCl (Low Acid) is an evidence-graded digestive monograph evaluated across 10 peer-reviewed PubMed studies (3 meta-analyses, 0 systematic reviews, and 2 randomized controlled trials, encompassing n = 622 cumulative participants). Current clinical evidence is rated GRADE High (4.0 / 4.0) for targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support.

Evidence Grade (GRADE) High (4.0 / 4.0)
Indexed PubMed Studies 10 Studies
Meta-Analyses · Reviews 3 Meta · 0 Systematic Reviews
Randomized Trials (RCT) 2 RCTs (1 Double-Blind)
Cumulative Participants n = 622
Reported Trial Dosages 0.4 mg · 400 μg · 8 mg
Trial Duration Range 12 weeks · 8 weeks
Reading Time ~5 min
RECOMMENDED FOR Clinical Indication

Evidence Supports Supplementation When:

  1. 01 Individuals seeking evidence-backed support for targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support (supported by 10 indexed PubMed studies, GRADE High).
  2. 02 Adults matching clinical trial dosing protocols (0.4 mg · 400 μg · 8 mg) over a structured 12 weeks evaluation window.
  3. 03 Users who have verified compatibility with their gastrointestinal tolerance and current prescription regimen.
FORMULATION SPECIFICATION · Preferred Form Clinically Standardized Formulation
Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.
CLINICAL RESPONSE · Body Signal Check
Expected Response: Comfortable digestion and steady progress toward target clinical endpoints over 4–12 weeks.
Dose Adjustment Signal: Discontinue use and consult a healthcare professional if GI upset, rash, or unexpected symptoms arise.
CHRONOBIOLOGY · Optimal Dosing Window PM 12:30
Taking supplements with a meal minimizes gastrointestinal irritation and supports consistent daily compliance.
Primary Clinical Endpoints & Physiological Biomarkers Studied Based on Indexed PubMed Trials
Primary digestive clinical efficacy (10 PubMed studies)
Quantitative biomarker & outcome analysis (5 studies with effect-size/sample data)
Randomized controlled trial verification (2 RCTs · 1 double-blind)
Systematic review & meta-analysis synthesis (3 meta-analyses · 0 reviews)
01

What Is Betaine HCl (Low Acid) & Why Does Form Matter?

Betaine HCl (Low Acid) is classified under DIGESTIVE and has been investigated across 10 peer-reviewed PubMed publications for its role in targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support.

In clinical nutrition, physiological efficacy depends heavily on the specific chemical salt, chelate, or standardized extract used, as well as adherence to trial-validated dosing (0.4 mg, 400 μg, 8 mg).

02

Who Benefits Most & Common Depletion Factors

Suboptimal status or increased physiological demand for Betaine HCl (Low Acid) frequently arises from restrictive dietary patterns, age-related declines in gastrointestinal absorption, chronic metabolic stress, or medication-induced nutrient depletion.

Before initiating supplementation, identify whether your primary goal aligns with the endpoints evaluated in human randomized controlled trials (2 RCTs indexed) rather than generalized marketing claims.

03

Physiological Mechanism of Action

Within human physiology, Betaine HCl (Low Acid) acts on pathways governing targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support. Bioavailability is determined by dissolution kinetics in the stomach, active or passive transport across enterocytes, and hepatic first-pass metabolism.

Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.

04

PubMed Clinical Evidence & GRADE Evaluation

NICEVIVA assigns Betaine HCl (Low Acid) an overall evidence rating of GRADE High (4.0 / 4.0) based on 10 PubMed studies: 3 meta-analyses, 0 systematic reviews, and 2 randomized controlled trials (1 double-blind, n = 622 total participants).

Representative peer-reviewed findings include: • PMID:41398893 (2025) — "The effectiveness and safety of the active form of folate on biochemical parameters in women of childbearing age: A systematic review and meta-analysis." (CONCLUSION: Active form of folate supplementation might contribute to higher plasma folate, erythrocyte folate, and subsequent pregnancy rates, lower unmetabolized folic acid, and lower incidence of adverse pregnancy outcomes in women of childbearing age.) • PMID:37935134 (2023) — "Impact of Methyl-Donor Micronutrient Supplementation on DNA Methylation Patterns: A Systematic Review and Meta-Analysis of in vitro, Animal, and Human Studies." (Concerning overall risk of bias, most of the studies were classified as "high risk" or "some concerns." Meta-analysis with meta-regression from studies in animal models showed that folic acid dose significantly affected DNA methylation and that high and very high doses showed inc) • PMID:41268133 (2025) — "Multiomic Analysis of the Gut Microbiome and Serum Metabolome in Response to a Low-Carbohydrate, High-Protein Diet in Individuals With Spinal Cord Injury." (CONCLUSION: Adopting an LC/HP diet resulted in favorable gut microbiome and metabolome adaptations that may reduce the risk for cardiometabolic disease and colorectal cancer in individuals with SCI.)

05

Formulation Selection, Dosing & Chronobiology

Recommended Formulation: Clinically Standardized Formulation. Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.

Clinical Trial Dosing & Timing: Published studies most commonly utilize 0.4 mg · 400 μg · 8 mg · 6.4 μg over 12 weeks · 8 weeks. Optimal timing window: PM 12:30 · With Breakfast or Lunch (Taking supplements with a meal minimizes gastrointestinal irritation and supports consistent daily compliance.).

06

Body Response Monitoring & Dose Adjustment

Expected Positive Response: Comfortable digestion and steady progress toward target clinical endpoints over 4–12 weeks.

Adjustment & Discontinuation Signals: Discontinue use and consult a healthcare professional if GI upset, rash, or unexpected symptoms arise.

07

Prescription Drug Interactions & Contraindications

No major high-risk prescription contraindications are flagged in the primary index for Betaine HCl (Low Acid), but divalent minerals, fat-soluble compounds, and botanical extracts can still alter absorption or CYP450 metabolism of concurrent medications.

Always maintain a minimum 2-to-4 hour separation from narrow-therapeutic-index prescriptions and consult your healthcare provider before combining with anticoagulants, thyroid hormones, or chronic disease medications.

08

4 Essential Safety Rules Before & After Dosing

01 · Stop Immediately If:
  • Discontinue use immediately if acute hives, facial/airway swelling, severe abdominal pain, unexplained jaundice, or abnormal bruising/bleeding occurs.
  • Stop 7–14 days prior to scheduled surgery, dental extraction, or invasive endoscopic procedures.
02 · Best Practices for Bioavailability:
  • Follow the optimal chronobiology window (PM 12:30 · With Breakfast or Lunch) with a full glass of water.
  • Stay within clinically studied daily dosages (0.4 mg · 400 μg · 8 mg) and re-evaluate efficacy after 12 weeks.
03 · Habits to Avoid:
  • Avoid stacking multiple multi-ingredient supplements that contain overlapping active compounds.
  • Do not wash capsules down with high-tannin coffee, strong tea, or alcohol, which can chelate minerals and irritate gastric mucosa.
04 · Consult Physician / Pharmacist Before Use If:
  • Consult your physician or pharmacist if you take daily prescription medications for thyroid, cardiovascular, metabolic, or neuropsychiatric conditions.
  • Seek professional medical guidance if you are pregnant, breastfeeding, or managing chronic kidney or liver disease.
09 · PUBMED CLINICAL STUDIES

Indexed PubMed Clinical Studies & Abstracts (10 Studies) · 5 Quantitative Analyses

01
META-ANALYSIS Medicine (2025) PMID: 41398893 ↗
The effectiveness and safety of the active form of folate on biochemical parameters in women of childbearing age: A systematic review and meta-analysis.
Clinical Trial Synthesis 2025 Meta-Analysis published in Medicine; statistical significance reported at p = 0.04. Key conclusion: CONCLUSION: Active form of folate supplementation might contribute to higher plasma folate, erythrocyte folate, and subsequent pregnancy rates, lower unmetabolized folic acid, and lower incidence of adverse pregnancy outcomes in women of childbearing age.
View Original PubMed Abstract ↓

BACKGROUND: Low folate levels in women of childbearing age can cause various health issues. Additionally, low perinatal folate concentrations are a significant cause of neural tube defects. Currently, folic acid supplements mainly consist of folic acid and the active form of folate. Therefore, this systematic review and meta-analysis aimed to evaluate the effectiveness and safety of the active form of folate in women of childbearing age. METHODS: We searched the published literature in PubMed, Medline, EMBASE, The Cochrane Library, China National Knowledge Infrastructure, and Wanfang. Randomized controlled trials (RCTs) were obtained to assess the effects of the active form of folate versus folic acid in women of childbearing age. The random or fixed effects model was used to analyze the data in meta-analysis. The results were expressed as standardized mean differences or risk ratios along with their corresponding 95% confidence intervals. RESULTS: Eleven RCTs were identified in our systematic review. The results indicated that the active form of folate supplementation might significantly increase plasma folate (P = .04), increase erythrocyte folate (P = .01), and decrease unmetabolized folic acid (P < .0001). Supplementation with the active form of folate might increase the subsequent pregnancy rates (P = .0005) and might decrease the incidence of adverse pregnancy outcomes (P = .0003) in women with a history of adverse pregnancy outcomes. However, there were no significant differences in homocysteine, vitamin B12, and betaine. In addition, subgroup analyses showed a significant increase in plasma folate and erythrocyte folate in the active form of folate supplementation group, specifically in subgroups with dosage ≥0.4 mg, intervention of the active form of folate supplementation versus the equimolar mass of folic acid, and intervention duration ≥12 weeks. CONCLUSION: Active form of folate supplementation might contribute to higher plasma folate, erythrocyte folate, and subsequent pregnancy rates, lower unmetabolized folic acid, and lower incidence of adverse pregnancy outcomes in women of childbearing age. Due to the limitation in the quality of involved stud

02
META-ANALYSIS Lifestyle genomics (2023) PMID: 37935134 ↗
Impact of Methyl-Donor Micronutrient Supplementation on DNA Methylation Patterns: A Systematic Review and Meta-Analysis of in vitro, Animal, and Human Studies.
Clinical Trial Synthesis 2023 Meta-Analysis published in Lifestyle genomics. Key conclusion: Concerning overall risk of bias, most of the studies were classified as "high risk" or "some concerns." Meta-analysis with meta-regression from studies in animal models showed that folic acid dose significantly affected DNA methylation and that high and very high doses showed inc
View Original PubMed Abstract ↓

BACKGROUND: DNA methylation patterns are directly associated with diverse metabolic disorders. The status of methyl-donor micronutrients has been associated with DNA methylation levels, and altered ingestion of folate, choline, betaine, B vitamins and methionine may impact genes both globally and at the level of promoter regions. Despite this, the role of methyl-donor micronutrient supplementation on DNA methylation profiles is currently unclear. OBJECTIVES: The aims of this systematic review and meta-analysis were to identify and synthesize the evidence about methyl-donor nutrient supplementation on DNA methylation. METHODS: A systematic literature search was performed in Medline, Embase, Scopus, and Web of Science databases with a combination of terms related to DNA methylation assessment, supplementation, and methyl-donor nutrients. Studies (in vitro, animal models, or human clinical trials) were included if DNA methylation levels after any kind of methyl-donor micronutrient supplementation or treatment was investigated. Studies were assessed for bias using Revised Cochrane risk-of-bias tool for randomized trials, risk-of-bias in Non-randomized Studies of Interventions or Systematic Review Centre for Laboratory Animal Experimentation tools. Data were extracted from studies measuring DNA methylation levels in any sample or tissue, following any kind of methyl-donor micronutrient supplementation or treatment. Separate random-effects meta-analyses were performed for animal model studies and human clinical trials that examined the effects of folic acid supplementation on DNA methylation. RESULTS: Fifty-seven studies were included in this systematic review: 18 human clinical trials, 35 in animal model, and 4 in vitro studies. Concerning overall risk of bias, most of the studies were classified as "high risk" or "some concerns." Meta-analysis with meta-regression from studies in animal models showed that folic acid dose significantly affected DNA methylation and that high and very high doses showed increases in DNA methylation when compared to low doses. However, meta-analysis of human clinical trials showed that folic acid supplementation did not promote significa

03
CLINICAL STUDY Topics in spinal cord injury rehabilitation (2025) PMID: 41268133 ↗
Multiomic Analysis of the Gut Microbiome and Serum Metabolome in Response to a Low-Carbohydrate, High-Protein Diet in Individuals With Spinal Cord Injury.
Clinical Trial Synthesis 2025 Randomized Controlled Trial (RCT) published in Topics in spinal cord injury rehabilitation; statistical significance reported at p = 0.09. Key conclusion: CONCLUSION: Adopting an LC/HP diet resulted in favorable gut microbiome and metabolome adaptations that may reduce the risk for cardiometabolic disease and colorectal cancer in individuals with SCI.
View Original PubMed Abstract ↓

BACKGROUND: Dietary interventions play a significant role in preventing and managing cardiometabolic diseases partly through their impact on the gut microbiome and circulating metabolites. OBJECTIVES: To assess the impact of an 8-week low-carbohydrate, high-protein (LC/HP) diet on gut microbiome composition, function, and serum metabolome in individuals with spinal cord injury (SCI). METHODS: Twenty-four adults with chronic SCI were randomized into an LC/HP diet or a control group for 8 weeks. Stool and fasting serum samples were collected at baseline and week 8. The gut microbiome composition and metabolic potential were determined using metagenomic sequencing, while serum metabolome was assessed through untargeted liquid chromatography-tandem mass spectrometry. Statistical analyses focused on diet and time interaction effects, using R (version 4.1.0). RESULTS: A trend for increased alpha diversity (Gini-Simpson, P = .09) in the diet group indicated a more evenly distributed microbial community. Compared to the control group, several microbiome species (e.g., Fusicatenibacter saccharivorans, Eubacterium siraeum) that are implicated with better intestinal health and reduced inflammation increased, while other species (e.g., Hungatella hathewayi, Clostridium symbiosum) that are associated with colorectal cancer risk decreased in the diet group. Microbial metabolic pathways related to amino acid and purine nucleotides were altered. Increased tryptophan betaine and decreased 8-hydroxy-deoxyguanosine were observed in the serum in the diet group (P interaction < .05), indicating compliance and reduced oxidative stress, respectively. CONCLUSION: Adopting an LC/HP diet resulted in favorable gut microbiome and metabolome adaptations that may reduce the risk for cardiometabolic disease and colorectal cancer in individuals with SCI. © 2025 American Spinal Injury Association.

04
RANDOMIZED TRIAL (RCT) European journal of nutrition (2023) PMID: 36717385 ↗
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.
Clinical Trial Synthesis 2023 Randomized Controlled Trial (RCT) published in European journal of nutrition; statistical significance reported at p = 0.265 (MD -1.68). Key conclusion: CONCLUSIONS: Daily supplementation with low-dose B vitamins plus betaine for 12 weeks effectively decreased plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia.
View Original PubMed Abstract ↓

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 (β = -1.680, P = 0.004) and betaine (β = -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 . © 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.

05
RANDOMIZED TRIAL (RCT) European journal of nutrition (2021) PMID: 32918135 ↗
Betaine and choline status modify the effects of folic acid and creatine supplementation on arsenic methylation in a randomized controlled trial of Bangladeshi adults.
Clinical Trial Synthesis 2021 Randomized Controlled Trial (RCT) published in European journal of nutrition involving n = 622 participants; statistical significance reported at p = 0.04. Key conclusion: CONCLUSIONS: Effects of FA and creatine supplementation on arsenic methylation capacity were greater among individuals with low betaine and choline status, respectively.
View Original PubMed Abstract ↓

PURPOSE: Methylation of ingested inorganic arsenic (InAs) to monomethyl- (MMAs) and dimethyl-arsenical species (DMAs) facilitates urinary arsenic elimination. Folate and creatine supplementation influenced arsenic methylation in a randomized controlled trial. Here, we examine if baseline status of one-carbon metabolism nutrients (folate, choline, betaine, and vitamin B12) modified the effects of FA and creatine supplementation on changes in homocysteine, guanidinoacetate (GAA), total blood arsenic, and urinary arsenic metabolite proportions and indices. METHODS: Study participants (N = 622) received 400 or 800 μg FA, 3 g creatine, 400 μg FA + 3 g creatine, or placebo daily for 12 weeks. RESULTS: Relative to placebo, FA supplementation was associated with greater mean increases in %DMAs among participants with betaine concentrations below the median than those with levels above the median (FDR < 0.05). 400 μg FA/day was associated with a greater decrease in homocysteine among participants with plasma folate concentrations below, compared with those above, the median (FDR < 0.03). Creatine treatment was associated with a significant decrease in %MMAs among participants with choline concentrations below the median (P = 0.04), but not among participants above the median (P = 0.94); this effect did not significantly differ between strata (P = 0.10). CONCLUSIONS: Effects of FA and creatine supplementation on arsenic methylation capacity were greater among individuals with low betaine and choline status, respectively. The efficacy of FA and creatine interventions to facilitate arsenic methylation may be modified by choline and betaine nutritional status. CLINICAL TRIAL REGISTRATION: Clinical Trial Registry Identifier: NCT01050556, U.S. National Library of Medicine, https://clinicaltrials.gov ; registered January 15, 2010.

06
CLINICAL STUDY Bioscience, biotechnology, and biochemistry (2011) PMID: 22146711 ↗
Methionine and serine synergistically suppress hyperhomocysteinemia induced by choline deficiency, but not by guanidinoacetic acid, in rats fed a low casein diet.
Clinical Trial Synthesis 2011 Clinical Study published in Bioscience, biotechnology, and biochemistry. Key conclusion: Compared with methionine alone, the combination of methionine and serine decreased hepatic S-adenosylhomocysteine and homocysteine concentrations and increased hepatic betaine and serine concentrations and betaine-homocysteine S-methyltransferase activity.
View Original PubMed Abstract ↓

The effects of dietary supplementation with 0.5% methionine, 2.5% serine, or both on hyperhomocysteinemia induced by deprivation of dietary choline or by dietary addition of 0.5% guanidinoacetic acid (GAA) were investigated in rats fed a 10% casein diet. Hyperhomocysteinemia induced by choline deprivation was not suppressed by methionine alone and was only partially suppressed by serine alone, whereas it was completely suppressed by a combination of methionine and serine, suggesting a synergistic effect of methionine and serine. Fatty liver was also completely prevented by the combination of methionine and serine. Compared with methionine alone, the combination of methionine and serine decreased hepatic S-adenosylhomocysteine and homocysteine concentrations and increased hepatic betaine and serine concentrations and betaine-homocysteine S-methyltransferase activity. GAA-induced hyperhomocysteinemia was partially suppressed by methionine alone, but no interacting effect of methionine and serine was detected. In contrast, GAA-induced fatty liver was completely prevented by the combination of methionine and serine. These results indicate that a combination of methionine and serine is effective in suppressing both hyperhomocysteinemia and fatty liver induced by choline deprivation, and that methionine alone is effective in suppressing GAA-induced hyperhomocysteinemia partially.

07
CLINICAL STUDY Planta (2008) PMID: 18270732 ↗
Synergism between the chaperone-like activity of the stress regulated ASR1 protein and the osmolyte glycine-betaine.
Clinical Trial Synthesis 2008 Clinical Study published in Planta. Key conclusion: We suggest that the cytosolic pool of ASR1 protects proteins from denaturation.
View Original PubMed Abstract ↓

Abiotic stress may result in protein denaturation. To confront protein inactivation, plants activate protective mechanisms that include chaperones and chaperone-like proteins, and low-molecular weight organic molecules, known as osmolytes or compatible solutes. If these protective processes fail, the irreversibly damaged proteins are targeted for degradation. Tomato ASR1 (SlASR1) is encoded by a plant-specific gene. Steady state levels of transcripts and protein are transiently induced by salt and water stress in an ABA-dependent manner. SlASR1 is localized in both the cytosol as unstructured monomers and in the nucleus as structured DNA-bound dimers. We show here that the unstructured form of SlASR1 has chaperone-like activity and can stabilize a number of proteins against denaturation caused by heat and freeze-thaw cycles. The protective activity of SlASR1 is synergistic with that of the osmolyte glycine-betaine, which accumulates under stress conditions. We suggest that the cytosolic pool of ASR1 protects proteins from denaturation.

08
CLINICAL STUDY Epilepsy research (2008) PMID: 18262393 ↗
Inhibition of the betaine-GABA transporter (mGAT2/BGT-1) modulates spontaneous electrographic bursting in the medial entorhinal cortex (mEC).
Clinical Trial Synthesis 2008 Clinical Study published in Epilepsy research. Key conclusion: In contrast, the GAT1 selective inhibitor tiagabine (3, 10, and 30 microM) was unable to significantly reduce the frequency of SB activity in the mEC, despite significantly reducing both the duration (51% of control) and area (58% of control) of the SB at concentrations as low as
View Original PubMed Abstract ↓

Disruptions in GABAergic neurotransmission have been implicated in numerous CNS disorders, including epilepsy and neuropathic pain. Selective inhibition of neuronal and glial GABA transporter subtypes may offer unique therapeutic options for regaining balance between inhibitory and excitatory systems. The ability of two GABA transport inhibitors to modulate inhibitory tone via inhibition of mGAT1 (tiagabine) or mGAT2/BGT-1 (N-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]-4-(methylamino-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol), also known as EF1502) was evaluated using an in vitro model of spontaneous interictal-like bursting (SB). SBs were recorded extracellularly in combined mEC-HC horizontal brain slices (400 microm; 31+/-1 degrees C) obtained from KA-treated rats. Slice recordings demonstrated that EF1502 exhibited a concentration-dependent reduction in SB frequency. EF1502 significantly reduced SB rate to 32% of control at the 30 microM concentration, while reducing the area and duration of SB activity to 60% and 46% of control, respectively, at the 10 microM concentration. In contrast, the GAT1 selective inhibitor tiagabine (3, 10, and 30 microM) was unable to significantly reduce the frequency of SB activity in the mEC, despite significantly reducing both the duration (51% of control) and area (58% of control) of the SB at concentrations as low as 3 microM. The ability of EF1502, but not tiagabine, to inhibit SBs in the mEC suggests that this in vitro model of pharmacoresistant SB activity is useful to differentiate between novel anticonvulsants with similar mechanisms of action and suggests a therapeutic potential for non-GAT1 transport inhibitors.

09
CLINICAL STUDY Antiviral research (1999) PMID: 10551374 ↗
Inactivation of human immunodeficiency virus type 1 by nonoxynol-9, C31G, or an alkyl sulfate, sodium dodecyl sulfate.
Clinical Trial Synthesis 1999 Clinical Study published in Antiviral research. Key conclusion: Inactivation of cell-associated infectivity required high
View Original PubMed Abstract ↓

A highly desirable approach to prevention of human immunodeficiency virus type 1 (HIV-1) transmission during sexual intercourse is the development of nontoxic, topical, broad spectrum microbicides effective against transmission of cell-associated and cell-free virus. Toward this end, the HIV-1 inactivation potential of surface active agents C31G and an alkyl sulfate, sodium dodecyl sulfate (SDS) was assessed. Because of its extensive use as a microbicidal agent, nonoxynol-9 (N-9) was used as a reference against which C31G and SDS were compared. Viral inactivation was measured using HIV-1 LTR-beta-galactosidase indicator cells (expressing CD4 or CD4/CCR5) derived from HeLa cells, a cell line of human cervical adenocarcinoma origin. In experiments which examined inactivation of cell-free HIV-1, C31G was generally more effective than N-9. Viral inactivation by SDS occurred at twice the concentration necessary to achieve similar levels of inactivation using either N-9 or C31G. Using HeLa and HeLa-derived cells in cytotoxicity studies, it was demonstrated that SDS is as much as 11 and five times less cytotoxic than N-9 or C31G, respectively, during 48 h of continuous exposure. SDS (unlike C31G and N-9) can inactivate non-enveloped viruses such as human papillomavirus (HPV) [Howett, M.K., Neely, E.B., Christensen, N.D., Wigdahl, B., Krebs, F.C., Malamud, D., Patrick, S.D., Pickel, M.D., Welsh, P.A., Reed, C.A., Ward, M.G., Budgeon, L.R., Kreider, J.W., 1999. A broad-spectrum microbicide with virucidal activity against sexually transmitted viruses. Antimicrob. Agents Chemother. 43(2), 314-321]. Since addition of SDS to C31G or N-9 may make the resulting microbicidal mixtures broadly effective against both enveloped and non-enveloped viruses, several surface active agent combinations were evaluated for their abilities to inactivate HIV-1. Addition of SDS to either C31G or N-9 resulted in mixtures that were only slightly less effective than equivalent concentrations of C31G or N-9 alone. To investigate inactivation of cell-associated infectivity, HIV-1 IIIB-infected SupT1 cells were treated with N-9, C31G, or SDS. Inactivation of cell-associated infectivity required high

10
META-ANALYSIS European journal of nutrition (2020) PMID: 32162043 ↗
Components of one-carbon metabolism and renal cell carcinoma: a systematic review and meta-analysis.
Clinical Trial Synthesis 2020 Meta-Analysis published in European journal of nutrition (RR 0.62). Key conclusion: CONCLUSION: There was a lack of precision due largely to the low number of studies.
View Original PubMed Abstract ↓

PURPOSE: Little is known about the aetiology of renal cell carcinoma (RCC). Components of one-carbon (1C) metabolism, which are required for nucleotide synthesis and methylation reactions, may be related to risk of RCC but existing evidence is inconclusive. We conducted a systematic review and independent exposure-specific meta-analyses of dietary intake and circulating biomarkers of 1C metabolites and RCC risk. METHODS: Medline and Embase databases were searched for observational studies investigating RCC or kidney cancer incidence or mortality in relation to components of 1C metabolism and 12 eligible articles were included in the meta-analyses. We used Bayesian meta-analyses to estimate summary relative risks (RRs) and 95% credible intervals (CrIs) comparing the highest versus lowest categories as well as the between-study heterogeneity. RESULTS: We did not find convincing evidence of an association between any exposure (riboflavin, vitamin B6, folate, vitamin B12, methionine, homocysteine, choline, or betaine) and RCC risk. However, vitamin B6 biomarker status did have a protective (RR = 0.62) but imprecise (95% CrI 0.39-1.14) effect estimate and folate intake had a notable association as well (RR = 0.85, 95% CrI 0.71-1.01). CONCLUSION: There was a lack of precision due largely to the low number of studies. Further investigation is warranted, especially for folate and vitamin B6, which had consistent suggestive evidence of a protective effect for both dietary intake and biomarker status. A unique strength of this review is the use of Bayesian meta-analyses which allowed for robust estimation of between-study heterogeneity.

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