The action spectrum for folic acid photodegradation in aqueous solutions

Accumulation of 5-methyltetrahydrofolate and other bioactive compounds, in the course of fermentation of green tea (Camellia sinensis) kombucha

Kombucha is a potential probiotic tea-based drink with increasing worldwide consumption. Studies on this probiotic beverage are growing rapidly, especially about micronutrients and microbial population. As such, the present study performed the molecular identification of the microorganism and evaluated 5-methyltetrahydrofolate content by HPLC-DAD, phenolic compounds, flavonoids, carotenoids, antioxidant activity by spectrophotometric methods, and physicochemical composition of green tea kombucha on fermentation days 1, 3, 7, 14, and 21. DNA sequencing identified the Microbacterium genus as predominant. However, was unable to safely determine the species level because of the rRNA 16S gene sequence similarity between four species M. ureisolvens, M. yannicii, M. chocolatum e M. atlanticum. The concentration of 5-methyltetrahydrofolate found on the third day was 39.12 ± 1.32 μg/mL (liquid) and 45.78 ± 8.42 μg/mL (polymeric biofilm); On the twenty-first day it was 50.87 ± 3.56 μg/mL (liquid) and 54.88 ± 3.89 μg/mL (polymeric biofilm). Total phenolic compounds increased with fermentation; however, flavonoids and carotenoids were degraded by the process. The information on 5-methyltetrahydrofolate is unprecedented and highly relevant for food guidelines, since related deficiencies can lead to fetal malformation in the first three months of pregnancy. Lastly, the best fermentation time to obtain 5-methyltetrahydrofolate and others bioactive compounds is between days 7-14. Further analyses are also encouraged to understand the bioavailability of the vitamin.

Folic acid-functionalized L-cys/ZnS:O nanoparticles for homologous targeting and photodynamic therapy of tumor cells

The combination of photodynamic therapy (PDT) and fluorescence imaging provides a promising approach to theranostics. However, traditional photosensitizers (PSs) have low water solubility and lack active targeting ability. Our ingenious design used L-cys/ZnS:O (LZS) nanoparticles (NPs) modified with folic acid (FA), allowing them to easily enter tumor cells and accurately gather around the nucleus of cancer cells. L-Cysteine were used as intermediates, ZnS:O quantum dots and FA could be connected by a solid-state method and a coupling reaction. In doing so, the cytotoxicity of LZS NPs was further reduced, while the hydrophilicity and dispersibility were improved. Moreover, the as-synthesized FA@LZS NPs had a higher generation of reactive oxygen species (ROS) than commercial Ce6, and they killed HepG2 cells specifically in vitro. These findings give a clear way for the development of advanced PSs with homologous labeling functions. A template for NPs or other fluorophores modified by targeting groups is also provided.

Association of sunshine duration with acute myocardial infarction hospital admissions in Beijing, China: A time-series analysis within-summer

BACKGROUND

Over the years, various epidemiological studies found that acute myocardial infarction (AMI) often shows seasonal rhythm patterning, which is usually influenced by the variations of environmental factors, such as air pollution, ambient temperature, solar activity, relative humidity. However, there are few studies on the impact of sunlight-induced AMI especially in developing countries, and they had inconsistent results. This study aimed to examine within-summer variations in the temporal association between sun exposure and AMI.

METHODS

We obtained hospitalization data for AMI of Beijing during 2013-2019. We used a distributed lag non-linear model (DLNM) combined with a quasi-Poisson regression model to estimate the non-linear lag effects of sunshine duration on AMI incidences. We evaluated the overall effect of AMI admissions with exposure to sunshine duration in the lag 0-21 days.

RESULTS

A total of 45,301 AMI cases were enrolled in our study during summer (June-September). The minimum of the morbidity was during days with a sunshine duration of 3.9 h. We found significant and U-shaped associations between sunshine duration and AMI, and the overall estimated relative risk was 1.29 (95% CI: 1.02,1.62) and 1.69 (95% CI: 1.28,2.24) for short (1st percentile) and long (99th percentile) sunshine duration, respectively. The males and younger people (<65 years) were most susceptible to these effects.

CONCLUSION

Our results suggest that both short and long sunshine duration could increase the risk of AMI admissions, especially for males and younger people. We suggest that public health policymakers should fully consider the balance of the pros and cons of solar exposure, and provide appropriate public health recommendations accordingly to gain the greatest benefits from sunlight.

Influence of narrowband ultraviolet B phototherapy on serum folate level in skin of color females: A cross-sectional study

Narrowband ultraviolet B (NB-UVB) (311-312 nm) is widely used for dermatological conditions with a favorable side-effect profile during pregnancy. Recently published data showed that NB-UVB might decrease serum folate level in Fitzpatrick skin phenotype I-III, especially at higher doses; this may predispose newborns to neural tube defects.

Objective

To compare serum folate levels of skin of color females treated with NB-UVB and healthy females of childbearing age, as well as to note whether subsequent complications have been observed, if any.

Methods

Multicenter, cross-sectional study of 30 females (N = 30): 15 female patients undergoing NB-UVB phototherapy as well as 15 age-, gender-, and skin phenotype-matched healthy volunteers who were enrolled into the study after excluding factors known to alter serum folate concentration. NB-UVB exposures were performed 2-3 times a week for at least 8-12 weeks (mean cumulative NB-UVB dose ± standard deviation [SD] was 55 ± 79 J/cm2).

Results

Mean serum folate ± SD in NB-UVB exposed and healthy controls were 10.3 ± 4 and 8.3 ± 3 ng/mL, respectively. This was not a statistically significant difference between the 2 groups (P = .14).

Limitations

Small sample size (N = 30) and a cross-sectional study type.

Conclusion

Cumulative NB-UVB exposure is not associated with a statistically significant difference in serum folate level (P > .05) in skin of color females of childbearing age in comparison to age-, gender-, and skin phenotype-matched healthy females, even with the relatively higher cumulative doses (mean ± SD was 55 ± 79 J/cm2) that have been shown to reduce serum folate level in lighter skin phenotypes.

Age and seasonal variation and establishment of reference intervals for water-soluble vitamins determined by liquid chromatography tandem mass spectrometry

OBJECTIVES

We aimed to establish reference intervals for water-soluble vitamins determined by liquid chromatography tandem mass spectrometry to improve the diagnosis of vitamin deficiency and outcomes of associated conditions.

METHODS

In this retrospective analysis of 24 810 specimens, we aimed to examine sex-, age-, and season-related variations in vitamin levels in different groups, set reference-value intervals for vitamin levels, and evaluate these reference values against those recommended by manufacturers.

RESULTS

Levels of vitamins B₃, B₅, B₆, B₇, and B₁₂ were higher, and those of vitamins B₂, B₉, and C were lower, in men than in women. There were seasonal variations in levels of vitamins B₁, B₃, B₅, B₆, B₉, B₁₂, and C. Levels of vitamins B₁, B₂, B₃, B₅, B₆, B₇, B₉, and C differed across age groups; vitamin B₁ displayed significant differences between ages 0 to 14 years and adults compared with reference change values. The lower limits of vitamins B₁ (ages 15-100 y), B₂, B₃, B₇, and C were lower, and that of vitamin B₅ was higher, than the recommended reference values. Finally, the upper limits of vitamins B₁, B₃, B₅, B₆, and B₇ were lower than the recommended values.

CONCLUSIONS

For values obtained using liquid chromatography tandem mass spectrometry, the lower limits of reference intervals for vitamins B₁ (ages 15-100 y), B₂, B₃, B₇, and C should be lowered, that of vitamin B₅ should be raised, and the upper limits of reference intervals for vitamins B₁, B₃, B₅, B₆, and B₇ should be lowered.

Encapsulation of folic acid (vitamin B9) into sporopollenin microcapsules: Physico-chemical characterisation, in vitro controlled release and photoprotection study

Folic acid (FA) is a crucial vitamin for all living creatures. However, it is susceptible to degradation under pH, heat, ultraviolet (UV) and day sunlight conditions, resulting in lowering its bioavailability. Therefore, a versatile protective encapsulation system for FA is highly required to overcome its inherent instability. We report the use of the robust Lycopodium clavatum sporopollenin (LCS) microcapsules, extracted from their natural micrometer-sized raw spores, for FA microencapsulation. The physico-chemical characterisation of the LCS microcapsules are comprehensively investigated before and after the microencapsulation using SEM, elemental, CLSM, FTIR, TGA/DTG and XRD analyses, revealing a successful FA encapsulation within the LCS in an amorphous form. The phenylpropanoid acids, responsible for the UV protection and the autofluorescence of the LCS, were found in the LCS as evidenced by FTIR analysis. TGA/DTG results revealed that the hemi-cellulose and cellulose are the major component of the LCS. A controlled and sustained release of FA from FA-loaded LCS were achieved where the release profile of FA-loaded LCS was found to be pH-dependent. The percentages of cumulative FA released after 10 h at 37 ± 0.5 °C were 45.5% and 76.1% in pH 1.2 and 7.4, respectively, ensuring controlled and slow release in simulated physiological conditions. The FA release kinetic studies indicated the prevalence of the Fickian diffusion mechanism in pH 1.2, while anomalous non-Fickian transport was ascribed for FA release in pH 7.4. The in vitro cytotoxicity assay revealed that the obtained formulations were biocompatible against the human skin fibroblast (HSF) cell line. The versatile LCS microcapsules exhibited intriguing photostability for FA under UV or sunlight irradiation. Concretely, the obtained FA sustained delivery and photoprotection properties of these LCS microcapsules validate their multifunctional characteristics, opening up intriguing applications in oral and topical drug delivery as well as in food industry.

Properties and reactivity of the folic acid and folate photoproduct 6-formylpterin

Folates (vitamin B9) are essential components of our diet and our gut microbiota. They are omnipresent in our cells and blood. Folates are necessary for DNA synthesis, methylation, and other vital bioprocesses. Folic acid (FA), as the synthetic form of folates, is largely found in supplements and fortified foods. FA and folate drugs are also extensively used as therapeutics. Therefore, we are continuously exposed to the pterin derivatives, and their photo-degradation products, such as 6-formylpterin (6-FPT) and pterin-6-carboxylic acid. During ultraviolet radiation, these two photolytic products generate reactive oxygen species (ROS) responsible for the cellular oxidative stress. 6-FPT can exhibit variable pro/anti-oxidative roles depending on the cell type and its environment (acting as a cell protector in normal cells, or as an enhancer of drug-induced cell death in cancer cells). The ROS-modulating capacity of 6-FPT is well-known, whereas its intrinsic reactivity has been much less investigated. Here, we have reviewed the properties of 6-FPT and highlighted its capacity to form covalent adducts with the ROS-scavenging drug edaravone (used to treat stroke and amyotrophic lateral sclerosis) as well as its implication in immune surveillance. 6-FPT and its analogue acetyl-6-FPT function as small molecule antigens, recognized by the major histocompatibility complex-related class I-like molecule, MR1, for presentation to mucosal-associated invariant T (MAIT) cells. As modulators of the MR1/MAIT machinery, 6-FPT derivatives could play a significant immuno-regulatory role in different diseases. This brief review shed light on the multiple properties and cellular activities of 6-FPT, well beyond its primary ROS-generating activity.

A nanocellulose-based platform towards targeted chemo-photodynamic/photothermal cancer therapy

Cellulose nanocrystals (CNCs) have advantages as drug delivery carriers because of their biocompatibility and the presence of hydroxyl groups which favor chemical modification and drug binding. The present study describes the development of novel multifunctional rod-like CNCs-based carriers as therapeutic platforms: CNCs were hybridized with folic acid for actively targeting tumor cells, carbon dots (Cdots) for both imaging and photodynamic/photothermal treatments and doxorubicin (DOX) as an anticancer drug. Hybridized carriers displayed excellent drug-loading capacity. Moreover, Cdots-containing hybrids showed fluorescence and photosensitized singlet oxygen generation and photothermal behavior. Carriers exhibited pH-sensitive drug release because of changing interactions with DOX, and this release proved to be effective against in vitro cervical cancer cells, as evidenced by dose-dependent reduced cellular viabilities. Additionally, DOX release was promoted by light irradiation and the photodynamic behavior by reactive oxygen species was confirmed. These results demonstrate the potential of multifunctional CNCs-based carriers as platforms for multimodal photodynamic/photothermal-chemotherapy.

Folic acid retention evaluation in preparations with wheat flour and corn submitted to different cooking methods by HPLC/DAD

Folic acid content was evaluated in food preparations containing wheat and corn flour submitted to baking, deep-frying, and steaming. Commercially fortified flours showed the absence of folic acid. Flours with laboratory folic acid fortification showed 487 and 474 μg of folic acid in 100 g of wheat and corn flours, respectively. In the corn flour preparations, the cake had the highest retention (99%) when compared to couscous (97%). Besides, the cake showed higher retention when compared to the wheat flour preparations due to the interactions of the folic acid with the hydrophobic amino acids of the Zein, a protein found in corn. In wheat flour preparations, vitamin retention was 87%, 80% and 57% in bread, cake, and White sauce respectively. These findings relate to the change of the physicochemical properties of food components that occurs during mixing and cooking of the ingredients.

Riboflavin Plays a Pivotal Role in the UVA-Induced Cytotoxicity of Fibroblasts as a Key Molecule in the Production of H2O2 by UVA Radiation in Collaboration with Amino Acids and Vitamins

To investigate environmental factors that contribute to ultraviolet A (UVA)-induced oxidative stress, which accelerates the senescence and toxicity of skin cells, we irradiated human fibroblasts cultured in commonly used essential media with UVA and evaluated their viability and production of reactive oxygen species. The viability of fibroblasts exposed to a single dose of 3.6 J/cm² UVA was not reduced when cultured in Hanks balanced salt solution, but it was significantly decreased when cultured in Dulbecco’s modified Eagle’s medium (DMEM), which contains various amino acids and vitamins. Furthermore, cell viability was not reduced when fibroblasts were cultured in DMEM and treated with a hydrogen peroxide (H₂O₂) scavenger such as glutathione or catalase added after UVA irradiation. In addition, we confirmed that the production of H₂O₂ was dramatically increased by UVA photosensitization when riboflavin (R) coexisted with amino acids such as tryptophan (T), and found that R with folic acid (F) produced high levels of H₂O₂ after UVA irradiation. Furthermore, we noticed that R and F or R and T have different photosensitization mechanisms since NaN₃, which is a singlet oxygen quencher, suppressed only R and T photosensitization. Lastly, we examined the effects of antioxidants (L-ascorbic acid, trolox, L-cysteine, and L-histidine), which are singlet oxygen or superoxide or H₂O₂ scavengers, on R and F or on R and T photosensitization, and found that 1 mM ascorbic acid, Trolox, and L-histidine were strongly photosensitized with R, and produced significant levels of H₂O₂ during UVA exposure. However, 1 mM L-cysteine dramatically suppressed H₂O₂ production by UVA photosensitization. These data suggest that a low concentration of R-derived photosensitization is elicited by different mechanisms depending on the coexisting vitamins and amino acids, and regulates cellular oxidative stress by producing H₂O₂ during UVA exposure.

By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans

Pigmentation evolved in ancestral humans to protect against toxic, ultraviolet B irradiation, but the question remains: "what is being protected?" Because humans with dark pigmentation display a suite of superior epidermal functions in comparison with their more lightly pigmented counterparts, we hypothesized and provided evidence that dark pigmentation evolved in Africa to support cutaneous function. Because our prior clinical studies also showed that a restoration of a competent barrier dampens cutaneous inflammation, we hypothesized that resistance to inflammation could have provided pigmented hominins with yet another, important evolutionary benefit. We addressed this issue here in two closely related strains of hairless mice, endowed with either moderate (Skh2/J) or absent (Skh1) pigmentation. In these models, we showed that (a) pigmented mice display a markedly reduced propensity to develop inflammation after challenges with either a topical irritant or allergen in comparison with their nonpigmented counterparts; (b) visible and histologic evidence of inflammation was paralleled by reduced levels of pro-inflammatory cytokines (i.e., IL-1α and INFα); (c) because depigmentation of Skh2/J mouse skin enhanced both visible inflammation and pro-inflammatory cytokine levels after comparable pro-inflammatory challenges, the reduced propensity to develop inflammation was directly linked to the presence of pigmentation; and (d) furthermore, in accordance with our prior work showing that pigment production endows benefits by reducing the surface pH of skin, acidification of albino (Skh1) mouse skin also protected against inflammation, and equalized cytokine levels to those found in pigmented skin. In summary, pigmentation yields a reduced propensity to develop inflammation, consistent with our hypothesis that dark pigmentation evolved in ancestral humans to provide a suite of barrier-linked benefits that now include resistance to inflammation.

Optical properties of folic acid in phosphate buffer solutions: the influence of pH and UV irradiation on the UV-VIS absorption spectra and photoluminescence

Using UV-VIS absorption spectroscopy, photoluminescence (PL) and photoluminescence excitation (PLE), the photodegradation reactions of folic acid (FA) in phosphate buffer (PB) solutions were studied. Regardless of the PB solution's pH, the UV-VIS spectra showed a gradual decrease in absorbance at 284 nm simultaneous with an increase in the absorbance of another band in the spectral range of 320-380 nm, which was downshifted under UV irradiation. The relative intensity of the FA PL band, situated in the spectral range 375-600 nm, was dependent on the pH of the PB solution. The FA PL intensity increased as increasing UV irradiation time up to 281 min. in PB solutions with pH values of 6.4 and 5.4. Under an emission wavelength of 500 nm, the position of the FA PLE spectrum changed as the PB solution pH varied from 7 to 5.4 and the irradiation time increased to 317 min. These changes were correlated with the formation of two photodegradation products, namely, pterine-6-carboxylic acid and p-amino-benzoyl-L-glutamic acid. According to UV-VIS spectroscopy and PL and PLE studies, the presence of various excipients in commercial pharmaceutical tablets does not affect the photodegradation of FA in PB solutions. Using IR spectroscopy, new evidences for the formation of the two photodegradation products of FA in PB solutions are shown.

Serum levels of folate, 25-hydroxyvitamin D3 and cobalamin during UVB phototherapy: findings in a large prospective trial

Background

Narrowband UVB phototherapy (NB‐UVB) is a mainstay in the treatment of numerous inflammatory dermatoses. Whereas, a wealth of studies has shown that NB‐UVB treatment increases 25‐hydroxyvitamin D3 (25(OH)D) levels, only sparse and controversial data exist on its effect on serum folate and cobalamin.

Objectives

To determine whether exposure to NB‐UVB alters serum folate or cobalamin levels.

Methods

A single‐centre, prospective, open observational study on 101 patients subjected to NB‐UVB phototherapy between late fall and early spring. Serum folate, 25(OH)D and cobalamin levels were measured after 0, 12, 24 and 36 NB‐UVB exposures.

Results

After 12 NB‐UVB exposures a significant decrease of mean serum folate (−1.0 nmol/L; P = 0.03) and cobalamin (−14.5 pmol/L, P = 0.03) levels was observed whereas serum levels of 25(OH)D showed a significant increase (35.4 nmol/L, P < 0.0001).

Conclusions

A standard course of NB‐UVB induces a small but significant decrease of serum folate and cobalamin levels.

Improved water dispersibility and photostability in folic acid nanoparticles with transglycosylated naringin using combined processes of wet-milling and freeze-drying

We successfully prepared folic acid (FA) nanoparticles with excellent dispersibility and photostability using a combination of bead milling and freeze-drying with transglycosylated naringin (Naringin-G), a newly developed transglycosylated food additive. Poly-vinyl pyrrolidon (PVP) was used for comparison with Naringin-G. Water dispersibility and photostability of the freeze-dried formulations were assessed. The dispersibility and physicochemical properties of nanoparticle formulations were evaluated using dynamic light scattering, powder X-ray diffraction (PXRD), and small-angle X-ray scattering (SAXS). Results indicated that the median particle size of FA in the slurry bead milled with Naringin-G decreased notably with time and fell below 100 nm after milling for 300 min. Further, FA nanoparticles with Naringin-G were stable without aggregation following re-dispersion of freeze-dried FA formulations in water. Contrarily, the addition of PVP did not prevent the aggregation of FA nanoparticles following re-dispersion of freeze-dried FA formulations. Solid structures of freeze-dried FA formulations with Naringin-G or PVP were assessed using PXRD and SAXS. PXRD patterns of all freeze-dried formulations highlighted broadening and weakening of peaks, indicating a decrease in FA crystallinity following bead milling, regardless of the additive concentration of Naringin-G and PVP. The scattering intensity profiles of FA formulations with PVP dramatically decreased after milling, whereas FA formulations with Naringin-G did not exhibit changes in SAXS patterns. FA formulations with Naringin-G registered faster enhancement in release rate than PVP in pH 1.2 buffer solutions. The release rate of freeze-dried FA formulation with Naringin-G exhibited at least five-fold enhancement when compared to untreated FA. FA formulation with Naringin-G was stable to photodegradation under fluorescent light. Naringin-G prevented photodegradation of FA due to its antioxidant effect and scavenged radicals. These findings indicated that freeze-dried FA formulation with Naringin-G can improve its water-dispersibility and photodegradation due to the effectiveness of Naringin-G as a dispersant and cryoprotectant.

Inhibition of Photodegradation of Highly Dispersed Folic Acid Nanoparticles by the Antioxidant Effect of Transglycosylated Rutin

We developed highly dispersible and photostable nanoparticles of vitamin, folic acid (FA). FA was wet bead milled with milling and dispersing adjuvants and transglycosylated compounds such as α-glucosyl hesperidin (Hesperidin-G) and rutin (Rutin-G), which solubilized FA. The milled slurries of FA particles with transglycosylated compounds consisted of nanosized particles with a median diameter of <100 nm. The lyophilized formulations of these slurries retained their nanometer size after resuspension in water with no aggregation. The apparent solubility of FA in these formulations was 100-fold higher than that of untreated FA. The solubilizing effect of Rutin-G may affect the particle size reduction and dispersibility of FA. The photostability results showed that the strong antioxidant activity of Rutin-G substantially increased the photostability of FA solution. On the basis of these results, bead milling of FA with Rutin-G is a promising technique for developing highly dispersible, photostable nanoparticle FA formulations.