Folic Acid Supplementation Reduces the Mutagenicity and Genotoxicity Caused by Benzo(a)pyrene

Amelioration of Cytogenotoxic Damage in Drug Abusers Supplemented with Folic Acid

BACKGROUND

Cytogenotoxic damage caused by the consumption of legal and illegal drugs in drug abusers has been demonstrated, primarily due to alterations in their antioxidant capacity, cellular repair mechanisms, and increased production of free radicals. Folic acid shows antioxidant activity by acting as a reducing agent, neutralizing present free radicals, and reducing genomic damage.

METHODS

The intervention involved administering 15 mg of folic acid, divided into three doses per day, to a group of 44 drug abusers. The frequency of nuclear abnormalities (NAs) was determined; micronuclei (MNs), nuclear buds (NBUDs), binucleated cells (BNs), abnormally condensed chromatin (CC), karyorrhexis (KX), pyknotic nuclei (PNs), and karyolysis (KL) were determined at different pre-treatment (baseline) and post-treatment time points at 15 and 30 days. Additionally, a group of 44 healthy individuals was used as the control group.

RESULTS

We observed a statistically significant decrease in the frequency of NAs in the drug abuser group (28.45 ± 17.74 before supplementation vs. 11.18 ± 7.42 at 15 days and 9.11 ± 10.9 at 30 days of supplementation). Specifically, it decreased the frequency of NBUDs, BNs, CC, KX, and PNs (p < 0.05).

CONCLUSION

Our study demonstrates a clear improvement in cytogenotoxic damage in drug abusers supplemented with folic acid.

FOLR1-induced folate deficiency reduces viral replication via modulating APOBEC3 family expression

Folate receptor alpha (FOLR1) is vital for cells ingesting folate (FA). FA plays an indispensable role in cell proliferation and survival. However, it is not clear whether the axis of FOLR1/FA has a similar function in viral replication. In this study, we used vesicular stomatitis virus (VSV) to investigate the relationship between FOLR1-mediated FA deficiency and viral replication, as well as the underlying mechanisms. We discovered that FOLR1 upregulation led to the deficiency of FA in HeLa cells and mice. Meanwhile, VSV replication was notably suppressed by FOLR1 overexpression, and this antiviral activity was related to FA deficiency. Mechanistically, FA deficiency mainly upregulated apolipoprotein B mRNA editing enzyme catalytic subunit 3B (APOBEC3B) expression, which suppressed VSV replication in vitro and in vivo. In addition, methotrexate (MTX), an FA metabolism inhibitor, effectively inhibited VSV replication by enhancing the expression of APOBEC3B in vitro and in vivo. Overall, our present study provided a new perspective for the role of FA metabolism in viral infections and highlights the potential of MTX as a broad-spectrum antiviral agent against RNA viruses.

The intervention mechanism of folic acid for benzo(a)pyrene toxic effects in vitro and in vivo

Folic acid is a necessary micronutrient for normal human growth and development. Benzo(a)pyrene (BaP) is a ubiquitously distributed environmental pollutant and its metabolite, benzo(a)pyrene-diol-epoxide, is known to exert a strong teratogenic and carcinogenic effect on the body’s tissues and cells. The aim of this study was to investigate the mechanism by which folic acid can inhibit the toxic effects of BaP both in vivo and in vitro. We measured changes in 16HBE cell activity affected by the intervention of folic acid on BaP using the cell counting kit-8 assay and that of cell cycle distribution by flow cytometry. At the same time, we assessed the xeroderma pigmentosum group A, xeroderma pigmentosum group C, excision repair cross complementation group 1, cyclinD1, and CKD4 mRNAs, and their related protein expression both in mouse lung tissue and in 16HBE cells. In conclusion, the mechanisms by which this effect is mediated were not entirely elucidated by our study, possibly because folic acid antagonizes the toxic effects of BaP by upregulating the levels of excision repair cross complementation group 1, xeroderma pigmentosum group A, and xeroderma pigmentosum group C gene expression to improve the rate of DNA repair, in turn accelerating the speed of repair for DNA damage caused by BaP. Meanwhile, folic acid could restrain BaP-induced cyclinD1 protein expression, which could help cells return to their normal cell cycle.

Folate deficiency increases chromosomal damage and mutations in hematopoietic cells in the transgenic mutamouse model

Folate deficiency causes megaloblastic anemia and neural tube defects, and is also associated with some cancers. In vitro, folate deficiency increases mutation frequency and genome instability, as well as exacerbates the mutagenic potential of known environmental mutagens. Conversely, it remains unclear whether or not elevated folic acid (FA) intakes are beneficial or detrimental to the induction of DNA mutations and by proxy human health. We used the MutaMouse transgenic model to examine the in vivo effects of FA deficient, control, and supplemented diets on somatic DNA mutant frequency (MF) and genome instability in hematopoietic cells. We also examined the interaction between FA intake and exposure to the known mutagen N-ethyl-N-nitrosourea (ENU) on MF. Male mice were fed the experimental diets for 20 weeks from weaning. Half of the mice from each diet group were gavaged with 50 mg/kg body weight ENU after 10 weeks on diet and remained on their respective diet for an additional 10 weeks. Mice fed a FA-deficient diet had a 1.3-fold increase in normochromatic erythrocyte micronucleus (MN) frequency (P = 0.034), and a doubling of bone marrow lacZ MF (P = 0.035), compared to control-fed mice. Mice exposed to ENU showed significantly higher bone marrow lacZ and Pig-a MF, but there was no effect of FA intake on ENU-induced MF. These data indicate that FA deficiency increases mutations and MN formation in highly proliferative somatic cells, but that FA intake does not mitigate ENU-induced mutations. Also, FA intake above adequacy had no beneficial or detrimental effect on mutations or MN formation. Environ. Mol. Mutagen. 59:366-374, 2018. © 2018 Her Majesty the Queen in Right of Canada 2018.

Folic acid improve developmental toxicity induced by aluminum sulphates

Aluminum sulphate has a significant toxic effects for humans. Aluminum is one of the most abundant metal on the Earth crust. The purpose of this study is to evaluate the effects of short term exposure to aluminum sulphate on the bone development of the fetuses in rats, and if folic acid has a protective role upon that effects or not. Forty female rats were used, ten per group, GI served as negative control (receive nothing except normal feeding and water), GII served as positive control (receive water by gastric gavage), GIII treated with aluminum sulphate orally by gastric gavage and GIV treated with aluminum sulphate with folic acid. Mating occurred and known by presence of vaginal plug in the female rats. Rats were killed on day 18 of gestation.

RESULTS

The female rats weight were significantly reduced in the treated group if compared with the control group (p>0.001), all parameters of the fetuses, fetal weight, malformation and the crown rump length reduced significantly p value were <0.000, <0.001, and <0.000 respectively. In histopathological results the aluminum treated group showed severe limited area of preossfication in fetuses vertebrae. Folic acid gave a protective role for all the hazardous effects of aluminum sulphate and prove the diameters measured and also the histopathological effects.

CONCLUSION

Aluminum sulphate can produce hazardous effects on bone of the fetuses, which may affect the life style of these fetuses later on. Folic acid might give a protective role and so should be given to females who tried to conceive.