Next Article in Journal
InsectFish—The Use of Insect Meal in the Fish Sector in Creating Farm-to-Fork Value: Chemical and Quality Characteristics of Sparus aurata Fillets Fed Hermetia illucens Larvae-Based Feed
Previous Article in Journal
Chemometric Differentiation of Organic Honeys from Southeastern Türkiye Based on Free Amino Acid and Phenolic Profiles
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Foods
Volume 14
Issue 17
10.3390/foods14173106
foods-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Cadmium Toxicity in Caenorhabditis elegans: Mechanisms and Interventions by Vitamin C and Fruit Juices

by
Yanyan Zhao
1,5,
Shan Wang
2,3,
Hongyan Zhang
4,
Xingru Lu
2,
Hengxi Sun
2,
Huiling Hu
3,
Liangbin Hu
4,
Ligong Zhai
1,5,
Wei Zhou
2,* and
Haizhen Mo
4,*
1
School of Food Science and Engineering, Anhui Science and Technology University, Wenhui Road, Chuzhou 239099, China
2
School of Food Science and Technology, Henan Institute of Science and Technology, No. 655 Hualan Street, Xinxiang 453003, China
3
School of Horticulture and Landscape Architecture, Henan Institute of Science and Technology, Xinxiang 453003, China
4
Department of Food and Bioengineering, Shaanxi University of Science and Technology, Weiyang Lake Street, Xi’an 710021, China
5
Anhui Province Key Laboratory of Functional Agriculture and Functional Food, Anhui Science and Technology University, Chuzhou 239000, China
*
Authors to whom correspondence should be addressed.
Foods 2025, 14(17), 3106; https://doi.org/10.3390/foods14173106
Submission received: 25 July 2025 / Revised: 24 August 2025 / Accepted: 2 September 2025 / Published: 5 September 2025
(This article belongs to the Section Nutraceuticals, Functional Foods, and Novel Foods)
Browse Figures
Versions Notes

Abstract

With the rapid development of industry, heavy metal pollution has emerged as a significant threat to food safety and human health. Among these pollutions, cadmium (Cd) pollution has become a global environmental concern. Caenorhabditis elegans, with its short life cycle and evolutionary conservation with humans, serves as an ideal model organism for studying toxicity mechanisms. In this study, we investigated the mechanisms of toxicity induced by Cd in C. elegans and the intervention of ascorbic acid (VC) and fruit juices on toxicity induced by Cd. Using fluorescent probes, we observed that Cd exposure (5 mg/mL and 8 mg/mL of CdCl2) significantly decreased the vitality of C. elegans in a dose-dependent manner within 6 h. Reactive oxygen species (ROS) and nitric oxide (NO) accumulated concurrently. Further exploration revealed that ROS played a crucial role in Cd-induced acute toxicity. The inhibition of ROS by Imidazole (IMZ) and Pyridine (PY) not only reduced NO levels but also restored the vitality of C. elegans. Conversely, the removal of NO by cPTIO [2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide] or L-NMMA (NG-Monomethyl-L-arginine) improved the vitality; however, it still did not affect ROS levels, indicating that ROS accumulation is a primary event in Cd-induced toxicity. We also examined the protective effects of VC and fruit juices. Both VC (0.5 mg/mL, 1 mg/mL) and fruit juices (50% (v/v) of the total volume of the medium) significantly enhanced the vitality of C. elegans under CdCl2 stress and reduced the accumulation of ROS and NO. This suggests that VC-rich materials effectively scavenge ROS and NO, thereby alleviating Cd-induced oxidative stress and toxicity. In summary, our results elucidate that CdCl2 exposure leads to ROS accumulation in C. elegans, which in turn triggers NO production and ultimately reduces nematode activity. VC and VC-rich materials can effectively mitigate CdCl2 toxicity by scavenging ROS and NO, providing a potential strategy for alleviating Cd poisoning.

1. Introduction

With the rapid advancement of industrialization, heavy metal pollution of agricultural land has become an increasingly severe issue, posing a significant threat to food safety and human health. Among these heavy metals, Cd has garnered substantial attention due to its high toxicity, persistence in the environment, and bioaccumulation potential [1]. Cd constitutes a significant risk to human health, inducing both acute and chronic adverse effects on various organs and physiological systems [2]. Cd is introduced into the body through multiple pathways, including bioaccumulation via the food chain, inhalation from environmental sources such as smoking, and dermal contact [3]. Cd is a non-biodegradable heavy metal that can cause toxicity at low concentrations [4]. In addition, it is hard to remove Cd permanently from the environment [5]. As a result, addressing Cd pollution is of urgent importance to protect public health and the environment.
The bioactive compounds in food exhibit a wide range of biological activities, such as anticancer, antioxidant, immune regulation, antimicrobial, cholesterol-lowering, antiaging, and other activities [6]. Thus, bioactive compounds, predominantly found in foods, may serve as a viable therapeutic approach for mitigating Cd-induced renal damage [4]. The potential of these bioactive compounds to ameliorate acute cadmium poisoning warrants further investigation and may represent a valuable approach in the management of cadmium toxicity. VC, as a bioactive compound in food, may be the most important water-soluble antioxidant in human plasma. VC plays an essential role in immune function, collagen, and cortisol synthesis, and it could remove free radical intermediates that initiate damaging reactions [7,8]. Fruit juices contain a variety of bioactive components, such as VC, polysaccharides, and polyphenolic compounds, all of which offer numerous health benefits, including antioxidant properties. Given its antioxidant properties, VC and VC-rich fruit juices may effectively reduce Cd toxicity by scavenging ROS.
Citrus fruits are abundant reservoirs of phytochemicals, including flavonoid glycosides, coumarins, volatile oils, β- and γ-sitosterol, and the rare polyethoxylated flavones. Their dietary matrix is further enriched with polyphenolic compounds, notably ascorbic acid, which effectively prevents VC deficiency [9]. Oranges and lemons both belong to the citrus family. Owing to their elevated Vc content, orange and lemon juices were used as test matrices to quantify their potential protective efficacy against Cd-mediated toxicity in C. elegans.
With a short life cycle, exceptional genetic tractability, and profound evolutionary conservation, C. elegans is an outstanding model for studying toxicity mechanisms [10,11]. This small nematode recapitulates the major organ systems of higher vertebrates, such as nervous, digestive, muscular, hypodermal, and reproductive systems. It displays extensive genetic homology to humans and exhibits sensitivity to environmental toxicants [12]. And its numerous genes and pathways are similar to those responsible for human diseases [13]. These features make C. elegans a valuable tool for studying the toxic effects of Cd and evaluating potential interventions.
The development, reproduction, intestinal ROS production, and locomotion behavior of C. elegans can be used to assess the toxic effects of specific toxicants or stresses [14,15]. Moreover, C. elegans shows the potential for evaluating the ecological risk of specific toxicants at environmentally relevant concentrations [16].
In this study, we aimed to investigate the mechanisms underlying Cd toxicity in C. elegans and explore the potential protective effects of VC and fruit juices. Our findings may provide insights into the role of VC in mitigating heavy metal toxicity and offer a possible strategy for alleviating Cd poisoning.

2. Materials and Methods

2.1. Strains and Culture Conditions

Food medium: Briefly, Escherichia coli OP50 (Caenorhabditis Genetics Center, Minneapolis, MN, USA) stocks were inoculated in liquid broth medium (LB: 10 g/L of NaCl, 10 g/L of peptone, 5 g/L of yeast extract) at 37 °C for 16 h. The bacteria were collected by centrifugation and resuspended in LB medium. Then, 2 mL of the mixture was spread onto the nematode growth medium agar plates. The plates were then exposed to ultraviolet light for 30 min to kill the E. coli OP50. After the plates were dried, they were collected for subsequent use.
The nematode growth medium (NGM: 3 g/L of NaCl, 2.5 g/L of peptone, 17 g/L of agar, 25 mL of KH2PO4-K2HPO4 buffer, 100 μL of 1 mol/L of CaCl2, 1 mL of 5 mg/mL cholesterol, 100 μL of 1 mol/L MgSO4) was prepared.
C. elegans (Caenorhabditis Genetics Center, Minneapolis, MN, USA) were cultured at 20 °C and 70% relative humidity in darkness on NGM agar seeded with E. coli OP50.

2.2. C. elegans Synchronous Cultivation

C. elegans in the adult stage were washed with M9 buffer (2 mM MgSO4, 0.4% glucose, 0.1 mM CaCl2, 1/5 volume of 5*M9 (5*M9 buffer: 17.1 g/L Na2HPO4·12H2O, 3.0 g/L K2H2PO4, 0.5 g/L NaCl, 1.0 g/L NH4Cl)) two to three times. Then, 0.5 M NaOH and 0.5% NaClO were added, and the mixture was shaken slightly. The eggs of C. elegans were washed with M9 buffer more than three times.

2.3. Fruit Juice Preparation

Oranges and lemons were obtained from local markets in China. The oranges and lemons were peeled, and the edible parts were cut into small pieces and homogenized with Ultra-turrax T25 basic (IKA Co., Ltd., Staufen, Germany). The suspension was centrifuged at 8000× g at 4 °C for 5 min. Finally, the supernatant was filtered with a 0.22 μm sterile membrane. Determination of VC was performed by DCPIP (2,6-dichloroindophenol) according to the Association of Official Analytical Chemists (AOAC) method.

2.4. Detection of the Vitality of C. elegans

To study the vitality of C. elegans, SYTOX Green, a nucleic acid-binding fluorescent dye, was used. SYTOX Green was excluded from live cells and entered the permeabilized cells [17]. C. elegans that had grown to the L4 stage were transferred to NGM containing E. coli OP50 and different concentrations of CdCl2 (0, 1, 5, and 8 mg/mL), and then incubated at 20 °C. C. elegans were collected at 0, 0.5, 1, 2, 4, and 6 h, and washed with M9 buffer, respectively. Then, SYTOX Green was added with a final concentration of 1 μM, and the mixtures were incubated at 20 °C for 15 min in the dark. Finally, the nematodes were washed with M9 buffer, and the fluorescence of SYTOX Green was quantified using a microreader with the excitation wavelength 488 nm and emission wavelength 525 nm (Thermol (Waltham, MA, USA), Varioskan Flash).

2.5. Analysis of ROS

DCFH-DA (dichlorodihydrofluorescein diacetate) was used to detect the level of ROS [18]. DCFH-DA (Beyotime Biotechnology Institute, Haimen, China) staining solution was added to the C. elegans at the L4 stage, and the ultimate concentration of the fluorescent probe was 1 μM. Then, different concentrations of CdCl2 (0, 5, and 8 mg/mL) were added to the mixtures, and the mixtures were incubated at 20 °C. The fluorescent intensity of C. elegans was analyzed at 2 h and 6 h using an excitation wavelength of 488 nm and an emission wavelength of 525 nm.

2.6. Analysis of NO

DAF-FM DA (4-amino-5-methylamino-2′,7′-difluorescein diacetate) was used to determine the level of NO [19]. When at the L4 stage, C. elegans were mixed with DAF-FM-DA (Beyotime Biotechnology Institute, Haimen, China), and the final concentration of DAF-FM-DA was 5 μM. Then, different concentrations of CdCl2 (0, 5, and 8 mg/mL) were added to the mixtures, and the mixtures were cultured at 20 °C. Subsequently, the fluorescent intensity of C. elegans was analyzed at 2 h and 6 h, respectively (excitation 490 nm and emission 525 nm).

2.7. Analysis of the Roles of ROS and NO in Cadmium Toxicity

IMZ and PY were used as ROS inhibitors to study the role of ROS in cadmium toxicity in C. elegans. C. elegans were exposed to 5 mg/mL of CdCl2 and incubated with 2.4 mM of IME and 10 mM of PY for 6 h at 20 °C. C. elegans were treated without CdCl2 or ROS inhibitor as the control. The vitality of C. elegans and the levels of ROS and NO in C. elegans were determined as described above.
L-NMMA is the inhibitor of NO synthase, and cPTIO is a NO scavenger [20]. L-NMMA and cPTIO were used to study the role of NO in Cd toxicity in C. elegans. C. elegans were exposed to 5 mg/mL of CdCl2 and incubated with 0.4 mM of L-NMMA and 0.2 mM of cPTIO for 6 h at 20 °C. C. elegans were treated without CdCl2, L-NMMA, or cPTIO as the control. Then, the vitality of C. elegans and the levels of ROS and NO in C. elegans were determined as described above.

2.8. The Intervention of VC on Cadmium Toxicity

The protective role of VC against CdCl2 in C. elegans was assessed. To observe these specific characteristics, pre-experiments were carried out. The VC concentrations (0.5 and 1 mg/mL) were selected based on the results of the pre-experiments. C. elegans were exposed to 5 mg/mL of CdCl2 supplemented with VC at various concentrations. The mixtures were incubated at 20 °C for 6 h, and C. elegans were treated without CdCl2 or VC as the control. Finally, the vitality of C. elegans and the levels of ROS and NO in C. elegans were determined as described above.

2.9. The Intervention of Fruit Juices on Cadmium Toxicity

The protective role of fruit juices against CdCl2 in C. elegans was performed as follows. The concentrations of fruit juices were determined based on the results of the pre-experiments. C. elegans were exposed to 5 mg/mL of CdCl2 supplemented with fruit juices (50% (v/v) of the total volume of the medium). C. elegans were treated without CdCl2 or fruit juices as the control. The vitality of C. elegans and the levels of ROS and NO in C. elegans were determined as described above.

2.10. Statistical Analysis

Three biological replicates were performed for each experiment, and the results were presented as mean ± standard deviation. Significance of difference was analyzed by one-way analysis of variance and considered significant at p < 0.05.

3. Results

3.1. The Vitality of C. elegans Decreased Under CdCl2 Stress

SYTOX Green was used to study the vitality of C. elegans under Cd stress. The results (Figure 1) showed that the vitality of C. elegans decreased gradually with the increase of CdCl2 concentration and treatment time. There was no significant difference (p < 0.05) in fluorescence intensity between the group treated with 1 mg/mL of CdCl2 and the control group within 6 h, indicating that 1 mg/mL of CdCl2 had little effect on the vitality of C. elegans. The fluorescence intensity increased significantly after 6 h of treatment with 5 mg/mL of CdCl2 or 4 h of treatment with 8 mg/mL of CdCl2, indicating that a high concentration of CdCl2 would induce a decrease in the vitality of C. elegans.

3.2. The Accumulation of ROS and NO Under CdCl2 Stress

Cd stress usually leads to intracellular oxidative stress, which will promote cell death [21]. To determine whether CdCl2 induces oxidative stress in nematodes, ROS and NO were detected by DCFH-DA and DAF-FM-DA, respectively. C. elegans were treated with different concentrations (5 mg/mL and 8 mg/mL) of CdCl2 for different times (2 h and 6 h); then, the intensities of fluorescence were detected, respectively. The results are shown in Figure 2. The vitality of C. elegans was inhibited with the increase of CdCl2 treatment times at concentrations of 8 mg/mL and had no significant difference at the concentrations of 5 mg/mL (Figure 2A). At the same time, with the increase of CdCl2 concentration, the accumulations of ROS and NO were increased (Figure 2B,C). The accumulation of ROS in nematodes increased significantly after being exposed to CdCl2 for 2 h, and nematodes showed a fluorescence intensity about 3.5-fold higher than the control after being exposed to 8 mg/mL of CdCl2 for 6 h. The accumulation of NO in nematodes did not significantly increase after being exposed to CdCl2 for 2 h. In comparison, the accumulation of NO in nematodes increased sharply after being exposed to CdCl2 for 6 h, and the fluorescence intensity was about 6.5-fold higher than that of the control group. The changing trend followed the change in the vitality of C. elegans under CdCl2 stress.

3.3. Reducing ROS and NO Levels in C. elegans Alleviates CdCl2 Toxicity

To detect the role of ROS in the toxicity of CdCl2 to nematodes, IMZ and PY were used as ROS inhibitors [22]. As shown in Figure 3A, IMZ and PY could significantly reduce the fluorescence of DCF in C. elegans, which means that the accumulation of ROS was reduced. The results also indicated that 10 mM of PY and 2.4 mM of IMZ could alleviate the vitality stress (Figure 3B).
To further ascertain the role of NO under CdCl2 stress, the inhibitor and scavenger of NO were used. The accumulation of NO in C. elegans under CdCl2 stress was inhibited by L-NMMA and cPTIO (Figure 4A). At the same time, L-NMMA and cPTIO could moderate the vitality stress in C. elegans under CdCl2 stress (Figure 4B). These data suggested that the mechanism underlying acute CdCl2 poisoning in C. elegans was related to the accumulation of ROS and NO.

3.4. ROS Accumulation Drives NO Build-Up and Compromises Nematode Vitality

To clarify how ROS and NO interact during acute CdCl2 toxicity in C. elegans, we examined whether suppressing ROS affects NO levels and whether blocking NO influences ROS accumulation. We found that treatment with 10 mM PY or 2.4 mM IMZ, two ROS inhibitors reduced ROS accumulation, concurrently suppressed NO levels, and alleviated CdCl2-induced vitality loss in C. elegans (Figure 3). L-NMMA, as a NO inhibitor, and cPTIO, as a NO scavenger, attenuated both NO accumulation and the associated vitality decline, yet left the ROS levels unchanged (Figure 4). According to the above results, ROS plays a vital role in CdCl2 toxicity to C. elegans. We infer that CdCl2 could cause the accumulation of ROS in nematodes, further induce the outbreak of NO, and, finally, lead to a decrease in nematode activity and the death of nematodes.

3.5. Vitamin C and Fruit Juices Alleviate CdCl2 Poisoning

To evaluate the effect of VC on CdCl2 poisoning, C. elegans were treated with 5 mg/mL of CdCl2 and different concentrations of VC for 6 h. As shown in Figure 5A, C. elegans treated with CdCl2 and VC showed a weaker fluorescence intensity of SYTOX Green than C. elegans under Cd stress, indicating that VC could alleviate Cd poisoning in C. elegans, and the vitality of C. elegans under Cd stress increased gradually with the increase of VC concentration. The simultaneous quantification of ROS and NO revealed that VC markedly suppresses their accumulation in C. elegans under Cd stress (Figure 5B,C). These findings indicate that VC confers Cd tolerance by attenuating ROS and NO accumulation, revealing a key protective mechanism.
The protective role of fruit juices against Cd in C. elegans was performed. The results are shown in Figure 6. It is determined that C. elegans treated with CdCl2 and juices showed higher vitality than C. elegans under CdCl2 stress, indicating that orange juice and lemon juice could ameliorate CdCl2 toxicity in C. elegans. The VC content in orange juice was determined to be 52.36 mg/100 mL, whereas that in lemon juice was 51.55 mg/100 mL. Orange juice and lemon juice could also reduce the accumulation of ROS and NO in C. elegans under CdCl2 stress. Our results supported the hypothesis that VC and fruit juices could alleviate CdCl2 poisoning.

4. Discussion

Cd pollution, one of the most critical environmental problems, poses a threat to food safety and human health. Microbial toxicity assays constitute an indispensable pillar within the environmental risk-assessment framework for chemical contaminants [23]. Compared with microorganisms, C. elegans exhibit many responses similar to those observed in vertebrate systems. C. elegans, a model organism, has been widely used to analyze the harm of the heavy metal [24].
In this study, C. elegans was used as an in vivo model. We delineated a sequential toxicity pathway for CdCl2: CdCl2 exposure → ROS burst → NO generation → vitality decline. ROS was identified as the primary trigger, whereas NO acted as a downstream amplifier. Both VC and VC-rich natural juices effectively scavenged ROS and NO, fully restoring the vitality of C. elegans. These results provide direct evidence that dietary antioxidants can antagonize acute Cd toxicity.
The inhibition of ROS simultaneously reduced NO levels and rescued vitality, whereas NO scavengers improved vitality without altering ROS, confirming the upstream position of ROS. In general, heavy metals could lead to oxidative damage, and the damages are mediated by the production of ROS [25,26]. It has been reported that Cd could deplete glutathione and protein-bound sulfhydryl groups, resulting in the production of ROS [25]. Free radicals play several beneficial roles for the organism when they are maintained at low or moderate concentrations. However, when the concentration is higher than the normal state, oxidative stress will induce a variety of diseases, accelerating the process of body aging and leading to acute allergic reactions [27]. The production of ROS could also result in enhanced lipid peroxidation, DNA damage, and the disruption of sulfhydryl homeostasis. Subsequent investigations are warranted to track temporal variations in these indicators quantitatively.
It was discovered that C. elegans under CdCl2 stress were also accompanied by the accumulation of NO, and the level of NO was also related to the vitality of nematodes. Several studies indicate that endogenous NO can contribute to Cd toxicity in plants [28,29]. The endogenous NO has been considered a signaling molecule triggering cell death in mammals. Therefore, it is attractive to study the level of NO in animal models exposed to Cd. Other than amplifying oxidative damage, NO can form peroxynitrite (ONOO−) with O2•−. Future work should employ ONOO−-specific fluorescent probes to quantify the production of ONOO−.
VC shows excellent potential to protect against Cd-induced damage in rats [30]. VC-rich fruit juices may pose detoxifying potential. Our study provides compelling evidence that both VC and VC-rich fruit juices restore C. elegans vitality and markedly suppress CdCl2-elicited ROS and NO accumulation. VC is a nutritional supplement, yet excessive intake can be toxic. The acute toxic dose low (TDLo) in humans is 900 mg/kg (https://pubchem.ncbi.nlm.nih.gov/compound/54670067#section=Adverse-Effects, accessed on 16 August 2025). The highest concentration used in this study to antagonize acute Cd toxicity was only 1 mg/mL, which is far below that limit. ADI of VC is not specified, as intake from food is not considered a health hazard (https://pubchem.ncbi.nlm.nih.gov/compound/54670067#section=Exposure-Control-and-Personal-Protection, accessed on 16 August 2025). Oranges and lemons are characterized by a rich array of natural compounds, including ascorbic acid, citric acid, polyphenols, essential oils, and notably abundant flavonoids [31]. It has been reported that citric acid exerts a protective effect against oxidative damage triggered by heavy metal exposure in C. elegans [32], and polyphenols exhibit remarkable antioxidant activity. An amount of 0.5 mg/mL VC significantly restored vitality, and juices applied at half volume delivered about 0.26 mg/mL VC yet performed comparably. The results suggest that VC synergizes with natural compounds such as citric acid and polyphenols. This synergistic effect points to a critical direction for further investigation.
This study examined cadmium toxicity induced by high-dose exposure and employed a single animal model. It lacks validation in mammals or at the cellular level. Because C. elegans possesses neither livers nor kidneys, the primary organs for cadmium accumulation, which are toxicokinetic, differ markedly from those in humans. The mechanistic analysis relied solely on ROS/NO fluorescent probes and ROS/NO inhibitors, without a systematic dissection of downstream signaling pathways. Therefore, future research should focus on exploring the detailed molecular pathways involved in Cd-induced ROS and NO production, as well as investigating the long-term protective effects of VC and fruit juices in more complex biological models. Specifically, transgenic lines can be employed to determine whether VC exerts its protective effects via defined signaling cascades. At the same time, RNA-seq-based profiling of differentially expressed genes can further validate the ROS/NO molecular network. Moreover, the investigation should be extended to higher animal models, such as mice, to compare the cadmium-toxicity-mitigating efficacy of VC and fruit juices, as well as VC-deficient diets, thereby providing robust evidence for population-level nutritional interventions.

5. Conclusions

This study provides comprehensive insights into the mechanisms underlying Cd-induced toxicity in C. elegans and explores the protective effects of VC and fruit juices against Cd-induced oxidative stress and toxicity. Our results demonstrate that Cd exposure (5 mg/mL and 8 mg/mL of CdCl2) significantly impairs the vitality of C. elegans within a short period (6 h), primarily through the accumulation of ROS and NO. The findings that the inhibition of ROS not only reduces NO levels but also restores the vitality of C. elegans—whereas the removal of NO only improves vitality without affecting ROS levels—strongly suggest that ROS accumulation is the primary event in Cd-induced toxicity, while NO acts as a secondary contributor to the overall toxic response. Moreover, our study highlights the potential of VC and VC-rich fruit juices as effective interventions against Cd-induced toxicity. Both VC and fruit juices significantly enhance the vitality of C. elegans under CdCl2 stress by effectively scavenging ROS and NO. This indicates that the antioxidant properties of VC-rich materials play a crucial role in mitigating Cd-induced oxidative stress and toxicity.

Author Contributions

Y.Z., S.W. and W.Z. wrote the main manuscript text. H.Z. prepared Figure 1, Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6. S.W., H.Z., X.L. and H.S. performed the experiment. L.Z. reviewed the manuscript. H.H., L.H. and H.M. conceived the study. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by Colleges and Universities Key Scientific Research projects of Henan Province (Grant No. 24A550008), the Talent Introduction Program of Anhui Science and Technology University (Grant No. SPYJ202403), and the Youth Backbone Teachers Foundation of Henan Province (Grant No. 2020GGJS167).

Data Availability Statement

The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.

Conflicts of Interest

The authors declare noconflicts of interest.

References

  1. Nordberg, M.; Nordberg, G.F. Metallothionein and cadmium toxicology-historical review and commentary. Biomolecules 2022, 12, 360. [Google Scholar] [CrossRef]
  2. Urbano, T.; Filippini, T.; Wise, L.A.; Lasagni, D.; De Luca, T.; Sucato, S.; Polledri, E.; Malavolti, M.; Rigon, C.; Santachiara, A.; et al. Associations of urinary and dietary cadmium with urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine and blood biochemical parameters. Environ. Res. 2022, 210, 112912. [Google Scholar] [CrossRef]
  3. Gattea, A.Z.; Abbas, A.H.; Kadhum, O.H.; Sajer, N.H.; Ali, S.A. Histopathological study of liver and kidney tissues in C57 mice via chronic exposure to Cadmium and Zinc. Arch. Razi Inst. 2021, 76, 1501–1508. [Google Scholar] [CrossRef]
  4. Marini, H.R.; Bellone, F.; Catalano, A.; Squadrito, G.; Micali, A.; Puzzolo, D.; Freni, D.; Pallio, G.; Minutoli, L. Nutraceuticals as alternative approach against cadmium-induced kidney damage: A narrative review. Metabolites 2023, 13, 722. [Google Scholar] [CrossRef] [PubMed]
  5. Wang, T.; Shi, Z.Q.; Hu, L.; Xu, X.; Han, F.X.; Zhou, L.; Chen, J. Thymol ameliorates cadmium-induced phytotoxicity in the root of rice (Oryza sativa) seedling by decreasing endogenous nitric oxide generation. J. Agric. Food Chem. 2017, 65, 7396–7405. [Google Scholar] [CrossRef] [PubMed]
  6. Yaermaimaiti, S.; Wu, T.; Aisa, H.A. Bioassay-guided isolation of antioxidant, antimicrobial, and antiviral constituents of cordia dichotoma fruits. Ind. Crops Prod. 2021, 172, 113977. [Google Scholar] [CrossRef]
  7. Calder, P.C.; Kreider, R.B.; McKay, D.L. Enhanced Vitamin C delivery: A systematic literature review assessing the efficacy and safety of alternative supplement forms in healthy adults. Nutrients 2025, 17, 279. [Google Scholar] [CrossRef]
  8. Block, G.; Jensen, C.D.; Morrow, J.D.; Holland, N.; Norkus, E.P.; Milne, G.L.; Hudes, M.; Dalvi, T.B.; Crawford, P.B.; Fung, E.B. The effect of vitamins C and E on biomarkers of oxidative stress depends on baseline level. Free Radic. Biol. Med. 2008, 45, 377–384. [Google Scholar] [CrossRef]
  9. Rafique, S.; Hassan, S.M.; Mughal, S.S.; Hassan, S.K.; Shabbir, N.; Perveiz, S.; Mushtaq, M.; Farman, M. Biological attributes of lemon: A review. J. Addict. Med. Ther. Sci. 2020, 6, 030–034. [Google Scholar] [CrossRef]
  10. Bai, X.; Wang, M.; Xu, T.; Zhou, S.; Chu, W. Antioxidant and anti-aging activities of Acanthopanax senticosus polysaccharide CQ-1 in nematode Caenorhabditis elegans. Int. J. Biol. Macromol. 2025, 297, 139925. [Google Scholar] [CrossRef]
  11. Gonzalez-Moragas, L.; Roig, A.; Laromaine, A. C. elegans as a tool for in vivo nanoparticle assessment. Adv. Colloid Interface 2015, 219, 10–36. [Google Scholar] [CrossRef] [PubMed]
  12. Qu, M.; Xu, K.; Li, Y.; Wong, G.; Wang, D. Using acs-22 mutant Caenorhabditis elegans to detect the toxicity of nanopolystyrene particles. Sci. Total Environ. 2018, 643, 119–126. [Google Scholar] [CrossRef] [PubMed]
  13. Li, J.; Le, W. Modeling neurodegenerative diseases in Caenorhabditis elegans. Exp. Neurol. 2013, 250, 94–103. [Google Scholar] [CrossRef]
  14. Liu, J.L.; Zhang, X.P.; Peng, C.W.; Luo, H.Y.; Liu, A.L. Effect of haloacetic acid water disinfection byproducts on intestinal barrier function in nematode Caenorhabditis elegans. Environ. Toxicol. Chem. 2025, 44, 2233–2243. [Google Scholar] [CrossRef] [PubMed]
  15. Xiao, G.; Chen, H.; Krasteva, N.; Liu, Q.; Wang, D. Identification of interneurons required for the aversive response of Caenorhabditis elegans to graphene oxide. J. Nanobiotechnol. 2018, 16, 45. [Google Scholar] [CrossRef]
  16. Dong, S.; Qu, M.; Rui, Q.; Wang, D. Combinational effect of titanium dioxide nanoparticles and nanopolystyrene particles at environmentally relevant concentrations on nematode Caenorhabditis elegans. Ecotoxicol. Environ. Saf. 2018, 165, 444–450. [Google Scholar] [CrossRef]
  17. Roth, B.L.; Poot, M.; Yue, S.T.; Millard, P.J. Bacterial viability and antibiotic susceptibility testing with SYTOX Green nucleic acid stain. Appl. Environ. Microbiol. 1997, 63, 2421–2431. [Google Scholar] [CrossRef]
  18. Shen, Q.S.; Zhou, W.; Li, H.B.; Hu, L.B.; Mo, H.Z. ROS involves the fungicidal actions of thymol against spores of Aspergillus flavus via the induction of nitric oxide. PLoS ONE 2016, 11, e0155647. [Google Scholar] [CrossRef]
  19. Kojima, H.; Urano, Y.; Kikuchi, K.; Higuchi, T.; Hirata, Y.; Nagano, T. Fluorescent indicators for imaging nitric oxide production. Angew. Chem. Int. Ed. 1999, 21, 3209–3212. [Google Scholar] [CrossRef]
  20. Chen, J.; Zhang, H.; Hu, L.; Shi, Z. Microcystin-LR-induced phytotoxicity in rice crown root is associated with the cross-talk between auxin and nitric oxide. Chemosphere 2013, 93, 283–293. [Google Scholar] [CrossRef]
  21. Bertin, G.; Averbeck, D. Cadmium: Cellular effects, modifications of biomolecules, modulation of dna repair and genotoxic consequences (A review). Biochimie 2006, 88, 1549–1559. [Google Scholar] [CrossRef] [PubMed]
  22. Jiang, M.; Zhang, J. Cross-talk between calcium and reactive oxygen species originated from NADPH oxidase in abscisic acid-induced antioxidant defense in leaves of maize seedlings. Plant Cell Environ. 2003, 26, 929–939. [Google Scholar] [CrossRef] [PubMed]
  23. Strotmann, U.; Durand, M.J.; Thouand, G.; Eberlein, C.; Heipieper, H.J.; Gartiser, S.; Pagga, U. Microbiological toxicity tests using standardized ISO/OECD methods-current state and outlook. Appl. Microbiol. Biotechnol. 2024, 108, 454. [Google Scholar] [CrossRef]
  24. Höss, S.; Schlottmann, K.; Traunspurger, W. Toxicity of ingested cadmium to the nematode Caenorhabditis elegans. Environ. Sci. Technol. 2011, 45, 10219–10225. [Google Scholar] [CrossRef] [PubMed]
  25. Mahmud, J.A.; Hasanuzzaman, M.; Nahar, K.; Bhuyan, M.H.M.B.; Fujita, M. Insights into citric acid-induced cadmium tolerance and phytoremediation in Brassica juncea L.: Coordinated functions of metal chelation, antioxidant defense and glyoxalase systems. Ecotoxicol. Environ. Saf. 2018, 147, 990–1001. [Google Scholar] [CrossRef]
  26. Fu, Z.; Xi, S. The effects of heavy metals on human metabolism. Toxicol. Mech. Methods 2020, 30, 167–176. [Google Scholar] [CrossRef]
  27. Pizzino, G.; Irrera, N.; Cucinotta, M.; Pallio, G.; Mannino, F.; Arcoraci, V.; Squadrito, F.; Altavilla, D.; Bitto, A. Oxidative stress: Harms and benefits for human health. Oxidative Med. Cell. Longev. 2017, 2017, 8416763. [Google Scholar] [CrossRef]
  28. Arasimowicz-Jelonek, M.; Floryszak-Wieczorek, J.; Gwóźdź, E.A. The message of nitric oxide in cadmium challenged plants. Plant Sci. 2011, 181, 612–620. [Google Scholar] [CrossRef]
  29. Ma, W.; Xu, W.; Xu, H.; Chen, Y.; He, Z. Nitric oxide modulates cadmium influx during cadmium-induced programmed cell death in tobacco BY-2 cells. Planta 2010, 232, 325–335. [Google Scholar] [CrossRef]
  30. Bolkent, S.; Sacan, O.; Yanardag, R.; Bolkent, S. Effects of vitamin E, vitamin C, and selenium on gastric fundus in cadmium toxicity in male rats. Int. J. Toxicol. 2008, 27, 217–222. [Google Scholar] [CrossRef]
  31. Zacarías-García, J.; Pérez-Través, L.; Gil, J.-V.; Rodrigo, M.-J.; Zacarías, L. Bioactive compounds, nutritional quality and antioxidant capacity of the red-fleshed Kirkwood Navel and Ruby Valencia oranges. Antioxidants 2022, 11, 1905. [Google Scholar] [CrossRef] [PubMed]
  32. Song, S.; Han, Y.; Zhang, Y.; Ma, H.; Zhang, L.; Huo, J.; Wang, P.; Liang, M.; Gao, M. Protective role of citric acid against oxidative stress induced by heavy metals in Caenorhabditis elegans. Environ. Sci. Pollut. Res. 2019, 26, 36820–36831. [Google Scholar] [CrossRef] [PubMed]
Foods 14 03106 g001
Figure 1. Vitality of C. elegans under the different concentrations of CdCl2. The stronger fluorescence intensity indicated the weaker vitality of nematodes.
Figure 1. Vitality of C. elegans under the different concentrations of CdCl2. The stronger fluorescence intensity indicated the weaker vitality of nematodes.
Foods 14 03106 g001
Foods 14 03106 g002
Figure 2. Effect of different concentrations of CdCl2 and different treatment times on C. elegans. (A) The vitality of C. elegans under CdCl2 stress. (B) The accumulation of ROS in C. elegans under CdCl2 stress. (C) The accumulation of NO in C. elegans under CdCl2 stress. The different letters indicate significant differences (p < 0.05).
Figure 2. Effect of different concentrations of CdCl2 and different treatment times on C. elegans. (A) The vitality of C. elegans under CdCl2 stress. (B) The accumulation of ROS in C. elegans under CdCl2 stress. (C) The accumulation of NO in C. elegans under CdCl2 stress. The different letters indicate significant differences (p < 0.05).
Foods 14 03106 g002
Foods 14 03106 g003
Figure 3. Effect of PY and IMZ on C. elegans under CdCl2 stress. (A) Effect of PY and IMZ on ROS accumulation in C. elegans under CdCl2 stress. (B) Vitality of C. elegans exposed to CdCl2 with the removal of ROS. (C) Effects of removal of ROS on NO production in C. elegans under CdCl2 stress. Control: C. elegans were treated with distilled water for 6 h; Cd: C. elegans were treated with 5 mg/mL of CdCl2 for 6 h; Cd + PY: C. elegans were treated with 5 mg/mL of CdCl2 and 10 mM of PY for 6 h; Cd + IMZ: C. elegans were treated with 5 mg/mL of CdCl2 and 2.4 mM of IMZ for 6 h. The different letters indicate significant differences (p < 0.05).
Figure 3. Effect of PY and IMZ on C. elegans under CdCl2 stress. (A) Effect of PY and IMZ on ROS accumulation in C. elegans under CdCl2 stress. (B) Vitality of C. elegans exposed to CdCl2 with the removal of ROS. (C) Effects of removal of ROS on NO production in C. elegans under CdCl2 stress. Control: C. elegans were treated with distilled water for 6 h; Cd: C. elegans were treated with 5 mg/mL of CdCl2 for 6 h; Cd + PY: C. elegans were treated with 5 mg/mL of CdCl2 and 10 mM of PY for 6 h; Cd + IMZ: C. elegans were treated with 5 mg/mL of CdCl2 and 2.4 mM of IMZ for 6 h. The different letters indicate significant differences (p < 0.05).
Foods 14 03106 g003
Foods 14 03106 g004
Figure 4. Effect of L-NMMA and cPTIO on C. elegans under CdCl2 stress. (A) Effects of L-NMMA and cPTIO on the accumulation of NO in C. elegans under CdCl2 stress. (B) Effects of L-NMMA and cPTIO on SYTOX Green fluorescence intensity in C. elegans under CdCl2 stress. (C) Effects of L-NMMA and cPTIO on the accumulation of ROS under CdCl2 stress. Control: C. elegans were treated with distilled water for 6 h; Cd: C. elegans were treated with 5 mg/mL of CdCl2 for 6 h; Cd + L-NMMA: C. elegans were treated with 5 mg/mL of CdCl2 and 0.4 mM of L-NMMA for 6 h; Cd + cPTIO: C. elegans were treated with 5 mg/mL of CdCl2 and 0.2 mM of cPTIO for 6 h. The different letters indicate significant differences (p < 0.05).
Figure 4. Effect of L-NMMA and cPTIO on C. elegans under CdCl2 stress. (A) Effects of L-NMMA and cPTIO on the accumulation of NO in C. elegans under CdCl2 stress. (B) Effects of L-NMMA and cPTIO on SYTOX Green fluorescence intensity in C. elegans under CdCl2 stress. (C) Effects of L-NMMA and cPTIO on the accumulation of ROS under CdCl2 stress. Control: C. elegans were treated with distilled water for 6 h; Cd: C. elegans were treated with 5 mg/mL of CdCl2 for 6 h; Cd + L-NMMA: C. elegans were treated with 5 mg/mL of CdCl2 and 0.4 mM of L-NMMA for 6 h; Cd + cPTIO: C. elegans were treated with 5 mg/mL of CdCl2 and 0.2 mM of cPTIO for 6 h. The different letters indicate significant differences (p < 0.05).
Foods 14 03106 g004
Foods 14 03106 g005
Figure 5. Effect of VC on CdCl2 poisoning in C. elegans. (A) Effect of VC on the vitality of C. elegans under CdCl2 stress. (B) Effect of VC on the accumulation of ROS in C. elegans under CdCl2 stress. (C) Effect of VC on the accumulation of NO in C. elegans under Cd stress. The different letters indicate significant differences (p < 0.05).
Figure 5. Effect of VC on CdCl2 poisoning in C. elegans. (A) Effect of VC on the vitality of C. elegans under CdCl2 stress. (B) Effect of VC on the accumulation of ROS in C. elegans under CdCl2 stress. (C) Effect of VC on the accumulation of NO in C. elegans under Cd stress. The different letters indicate significant differences (p < 0.05).
Foods 14 03106 g005
Foods 14 03106 g006
Figure 6. Effect of fruit juices on CdCl2 poisoning in C. elegans. (A) Effect of fruit juices on the vitality of C. elegans under CdCl2 stress. (B) Effect of fruit juices on the accumulation of ROS in C. elegans under CdCl2 stress. (C) Effect of fruit juices on the accumulation of NO in C. elegans under CdCl2 stress. The different letters indicate significant differences (p < 0.05).
Figure 6. Effect of fruit juices on CdCl2 poisoning in C. elegans. (A) Effect of fruit juices on the vitality of C. elegans under CdCl2 stress. (B) Effect of fruit juices on the accumulation of ROS in C. elegans under CdCl2 stress. (C) Effect of fruit juices on the accumulation of NO in C. elegans under CdCl2 stress. The different letters indicate significant differences (p < 0.05).
Foods 14 03106 g006
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Zhao, Y.; Wang, S.; Zhang, H.; Lu, X.; Sun, H.; Hu, H.; Hu, L.; Zhai, L.; Zhou, W.; Mo, H. Cadmium Toxicity in Caenorhabditis elegans: Mechanisms and Interventions by Vitamin C and Fruit Juices. Foods 2025, 14, 3106. https://doi.org/10.3390/foods14173106

AMA Style

Zhao Y, Wang S, Zhang H, Lu X, Sun H, Hu H, Hu L, Zhai L, Zhou W, Mo H. Cadmium Toxicity in Caenorhabditis elegans: Mechanisms and Interventions by Vitamin C and Fruit Juices. Foods. 2025; 14(17):3106. https://doi.org/10.3390/foods14173106

Chicago/Turabian Style

Zhao, Yanyan, Shan Wang, Hongyan Zhang, Xingru Lu, Hengxi Sun, Huiling Hu, Liangbin Hu, Ligong Zhai, Wei Zhou, and Haizhen Mo. 2025. "Cadmium Toxicity in Caenorhabditis elegans: Mechanisms and Interventions by Vitamin C and Fruit Juices" Foods 14, no. 17: 3106. https://doi.org/10.3390/foods14173106

APA Style

Zhao, Y., Wang, S., Zhang, H., Lu, X., Sun, H., Hu, H., Hu, L., Zhai, L., Zhou, W., & Mo, H. (2025). Cadmium Toxicity in Caenorhabditis elegans: Mechanisms and Interventions by Vitamin C and Fruit Juices. Foods, 14(17), 3106. https://doi.org/10.3390/foods14173106

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop