Screening of the aflatoxin M1 metabolite in urine samples of residents in Terengganu, Malaysia

Impact of Probiotic Lacticaseibacillus paracasei Strain Shirota (LcS) on Aflatoxin Exposure among Healthy Malaysian Adults: A Randomized, Double-Blind, Placebo-Controlled Intervention Study

BACKGROUND

Limited evidence suggests that probiotic Lacticaseibacillus paracasei strain Shirota (LcS) may reduce aflatoxin exposure in Malaysians, though individual factors influencing aflatoxin exposure remain unclear.

OBJECTIVES

This study evaluated the effect of LcS on aflatoxin biomarker concentrations over a 12-wk intervention among healthy Malaysian adults. A secondary objective was to explore the individual factors associated with aflatoxin exposure using baseline data.

METHODS

A randomized, double-blind, placebo-controlled intervention involved healthy Malaysian adults (aged 20-60) of Chinese, Malay, or Indian ethnicities with elevated urinary aflatoxin M1 (AFM1) and serum aflatoxin B1 (AFB1)-albumin concentrations. Hundred and seventy-four (n = 174) subjects were randomly and equally assigned (n = 87/group) to consume either fermented milk with LcS (probiotic) (3 × 1010 CFU/80 mL/bottle) or milk without LcS (placebo) twice/d for 12 wk, with a 4-wk follow-up. Baseline data included sociodemographic characteristics, knowledge, attitude, and practice related to aflatoxin contamination, dietary intake, body weight, and physical activity status. Urine and fasting blood samples were collected every 2 and 4 wk for AFM1 and AFB1-lysine adduct analyses, respectively.

RESULTS

Eighty-five (n = 85) and 82 (n = 82) subjects in the probiotic and placebo groups completed the intervention, respectively. After adjusting for covariates, a significant effect was observed at postintervention in the probiotic group with a 23% reduction in urinary AFM1 concentrations compared with the placebo group (B = -0.26; Exp(B) = 0.77; P = 0.04). Serum AFB1-lysine adduct concentrations remained lower in the probiotic group throughout the study. Both aflatoxin biomarkers significantly differed by ethnicity (AFM1: P = 0.001; AFB1: P = 0.01). Subjects with lower aflatoxin knowledge had significantly higher AFB1-lysine concentrations (mean rank = 95.99) than those with higher knowledge (mean rank = 73.57) (P = 0.04). Urinary AFM1 concentrations were higher with cereal intake (ρ = 0.17, P = 0.03) but lower with protein intake (ρ = -0.18, P = 0.02).

CONCLUSIONS

Ethnicity, knowledge level, and dietary intake influenced aflatoxin exposure. The benefits of consuming LcS to reduce aflatoxin exposure deserve further attention.

TRIAL REGISTRATION NUMBER

This trial is registered in the National Medical Research Register (NMRR-16-2693-3230) and clinicaltrials.gov (NCT03882294).

Assessing aflatoxin exposure in the United Arab Emirates (UAE): Biomonitoring AFM1 levels in urine samples and their association with dietary habits

BACKGROUND

Aflatoxins, known for their carcinoginc properties and produced by Aspergillus fungi, pose a substantial threat to public health, particularly in regions with hot and humid climates, where individuals are exposed to these toxins through contaminated food. The primary objective of this study was to assess the extent of aflatoxin exposure in the Emirate of Sharjah employing Aflatoxin M1 (AFM1) as a biomarker in urine samples from adult participants. Furthermore, this study aimed to explore the relationship between dietary habits and AFM1 levels in order to establish a potential link.

METHODS

In a cross-sectional study design, a total of 144 adults (73 females and 71 males) were recruited for participation. The urine samples obtained from participants were subjected to analysis for AFM1 concentrations utilizing the enzyme-linked immunosorbent assay (ELISA) method. Additionally, structured questionnaires were administered to collect information on the dietary and lifestyle habits of the participants. To explore the relationship between dietary factors and AFM1 levels, various statistical analyses, including linear regression and the Mann-Whitney U test, were performed.

RESULTS

AFM1 was detected in 69 % of the samples under invstigation, wherein males exhibited a higher mean level (0.912 ng/mg creatinine) in comparison to females (0.676 ng/mg creatinine). The overall mean concentration of AFM1 was determined to be 0.792 ng/mg creatinine. It is worth noting that there was a significant correlation between rice consumption and heightened AFM1 exposure among males, while no such correlation was observed among females.

CONCLUSION

This study conducted in the UAE provides novel perspectives on aflatoxin exposure, shedding light on the gender-specific correlation between rice consumption and aflatoxin levels among males. These findings hold significant implications for guiding public health interventions and underscore the pivotal role of ongoing surveillance and stringent food safety regulations in mitigating the hazards associated with aflatoxin contamination.

Aflatoxin M1 levels in urine and breast milk of lactating mothers in Kuala Lumpur, Malaysia

Aflatoxins are carcinogens that can contaminate food and affect various body organs especially liver and kidney. When consumed, aflatoxin B1 (AFB1) is partially metabolised into aflatoxin M1 (AFM1), which is excreted in the urine. Breast milk may also contain AFM1 due to maternal dietary intake from contaminated food. This cross-sectional study aimed to determine the levels of AFM1 in both urine and breast milk among breastfeeding mothers (n = 256). The mother's demographic information was collected during recruitment. Mothers were then scheduled for an appointment to provide a morning urine sample along with five to ten mL samples of breast milk. AFM1 levels in both samples were analysed using an enzyme-linked immunosorbent assay (ELISA). Spearman's rho and Chi-square were used to determine the associations between mean levels of AFM1 in urine and breast milk. Findings show 68.0% of urine samples were contaminated with AFM1 (mean levels = 0.08 ± 0.04 ng/mL), while 14.8% of breast milk samples had AFM1 (mean levels = 5.94 ± 1.81 ng/kg). Urine AFM1 levels were not significantly associated with AFM1 levels in breast milk (p > 0.05). This study can act as a baseline for future research examining long-term aflatoxin exposure among both mothers and infants.

FOXM1 Aptamer-Polyethylenimine Nanoplatform Coated With Hyaluronic Acid And AS1411 Aptamer For Dual-Targeted Delivery of Doxorubicin And Synergistic Treatment of Tumor Cells

The objective of this investigation was to develop a self-assembled, dual-functionalized delivery system that could effectively transport doxorubicin (DOX) to cancer cells through the use of AS1411 aptamer and hyaluronic acid polymer (HA). The ultimate goal is an improved targeting approach for more efficient treatment. The core of this system comprised polyethylenimine (PEI) and FOXM1 aptamer, which was coated by HA. Next, nucleolin targeting aptamers (AS1411) were loaded onto the nanocomplex. Afterward, DOX was added to Aptamers (Apts)-HA-PEI-FOXM1 NPs to create the DOX-AS1411-HA-PEI-FOXM1 NPs for better treatment of cancer cells. The cytotoxic effect of the nanocomplex on L929, 4T1, and A549 cells showed that cell mortality in target cancer cells (4T1 and A549) was considerably enhanced compared to nontarget cells (L929, normal cells). The findings from the flow cytometry analysis and fluorescence imaging demonstrated the cellular absorption of DOX-Apts-HA-PEI-FOXM1 NPs in target cells was significantly enhanced when compared to L929 cells. Furthermore, in vivo antitumor study exhibited that DOX-Apts-HA-PEI-FOXM1 NPs rendered specific tumor accumulation and increasing of the anti-tumor effects.

Assessment of aflatoxin M1 exposure and associated determinants in children from Lahore, Pakistan

Aflatoxins are potent carcinogenic and immunomodulatory mycotoxins, and exposure may lead to deleterious effects on human health. This study aimed to detect aflatoxin M₁ (AFM₁) as biomarker of exposure and determine associated risk factors in children attending a specialized-childcare hospital in Lahore. Urine samples collected from 238 children (1-11 years) during winter (January-mid-March 2020) and hot-humid summer (August-September 2020) were tested for AFM₁ presence using ELISA. Data on potential risk factors were also collected. Of 238 samples, 156 (65.5%) were positive for urinary AFM₁. Season was significantly associated (OR = 2.64; 95% CI = 1.49-4.79; p = 0.001) with AFM₁ positivity; prevalence was higher in hot-humid months (74.6%) than winter (57.3%). The place of living was also significantly associated (OR = 2.21; 95% CI = 1.25-3.97; p = 0.007), and urinary AFM₁ positivity was higher in urban children (71.1%) compared to rural (58.3%). Median value for creatinine-adjusted AFM₁ was 1.9 ng/mg creatinine (Q1-Q3 = 0.82-6.0 ng/mg creatinine), while non-creatinine-adjusted AFM₁ was 0.57 ng/mL (Q1-Q3 = 0.23-1.4 ng/mL). Significantly higher urinary AFM₁ levels were detected in children; age ≤2 years (p = 0.037), who consumed more milk (p = 0.048), and who presented to the nutrition clinic (p = 0.003). These findings highlight the need for an effective control program to reduce the AFM₁ burden in children.

A preliminary study on aflatoxin exposure by urine biomonitoring in Chile

We assessed the occurrence of aflatoxin M₁ (AFM₁) in urine in a sample of the MAUCO population-based cohort (n = 120) using an enzyme-linked immune sorbent assay (ELISA) kit specially designed for the analysis of AFM₁ in urine. We found AFM₁ in the urine of 59% of the participants (> limit of detection), with 12% of the samples being over the limit of quantification. The mean of the quantifiable samples was 0.66 (± 0.35) ng/mg adjusted creatinine, ranging from 0.31 to 1.39 ng/mg creatinine. The mean probable daily intake (PDI) of AFB₁ was 0.23 (± 0.37) ng/kg bw according to the upper bound (UB), being significantly higher in women and 0.14 (± 0.23) ng/kg bw in the modified lower bound (mLB) approach, ranging from 0.01 to 1.98 ng/kg bw. The risk of AFB₁ was assessed with the margin of exposure (MOE) approach estimated at 2800 in the mean mLB and 1733 in the mean UB. According to the MOE values obtained in this study, aflatoxin B₁ exposure must be considered a public health concern and must be taken as a priority for food risk management.

A novel colorimetric aptasensor for ultrasensitive detection of aflatoxin M1 based on the combination of CRISPR-Cas12a, rolling circle amplification and catalytic activity of gold nanoparticles

Colorimetric approaches have received noticeable attention among sensing methods in view of simplicity and watching the color change of sample by the naked eyes. However, developing colorimetric sensing methods which show high sensitivity is still problematic. Herein, based on CRISPR-Cas12a, rolling circle amplification (RCA) and catalytic activity of gold nanoparticles (AuNPs), a colorimetric aptasensor was introduced for highly sensitive detection of aflatoxin M₁ (AFM₁). In the presence of AFM₁, the CRISPR-Cas12a is inactivated and large single-stranded DNA (ssDNA) structures are formed on the surface of AuNPs following the addition of T4 DNA ligase and phi29 DNA polymerase. So, the sample color remains yellow after addition of 4-nitrophenol. However, no huge DNA structure is observed on the surface of AuNPs in the absence of target because of activation of CRISPR-Cas12a and digestion of primer. So, the color of sample switches to colorless. The results indicated that the biosensor had high selectivity toward AFM₁ and the approach achieved a detection limit as low as 0.05 ng/L. In addition, it could sensitively identify AFM₁ in the spiked milk samples. Overall, this approach is highly sensitive and does not require sophisticated equipment. Therefore, it maintains promising potential for other mycotoxins detection in real samples by simply replacing the applied sequences.