Synthetic phenolic antioxidant propyl gallate induces male infertility through disruption of calcium homeostasis and mitochondrial function

Ribeiro M.A., Estill M.S., Fernandez G.J., Moraes L.N., Krawetz S.A., Scarano W.R.

Male fertility and spermatogenesis are directly linked to the Sertoli cell's ability to produce factors associated with germ cell development. Sertoli cells express receptors for FSH and testosterone, and are the major regulators of spermatogenesis. Recent studies report that regulatory RNA molecules, such as microRNAs (miRNAs), are able to modulate testicular function during spermatogenesis and that their altered expression may be involved in male infertility. miRNAs may play a role in the response to xenobiotics that have an adverse consequences to health. An important group of xenobiotic organic compounds with toxic potential are dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Experimental models of TCDD exposure in mice demonstrated that TCDD exposure causes low sperm count and delayed puberty. This study below examines the mechanism of TCDD's action in human Sertoli cells, through interrogating the expression profile of miRNAs and mRNAs, that enabled us to identify dysregulated molecular pathawys in Sertoli cell. 78 miRNAs presented altered expression, with positive regulation of 73 and negative regulation of 5 miRNAs when compared to the control group. Regarding gene expression profile, 51 genes were deregulated, of which 46 had positive regulation and 5 genes with negative regulation. Important pathways have been altered by the action of TCDD as AhR pathway, GPR68, FGF2 and LIF. This study has opened the door to new perspectives on the TCDD toxicity pathway as it affects Sertoli cells physiology that can ultimately lead to male infertility.

Tang H., Chen Y., Wang L., Yin Y., Li G., Guo Y., Liu Y., Lin H., Cheng C.H., Liu X.

The pivotal role of androgen receptor (AR) in regulating male fertility has attracted much research attention in the past two decades. Previous studies have shown that total AR knockout would lead to incomplete spermatogenesis and lowered serum testosterone levels in mice, resulting in azoospermia and infertility. However, the precise physiological role of ar in controlling fertility of male fish is still poorly understood. In this study, we have established an ar knockout zebrafish line by transcription activator-like effectors nucleases. Homozygous ar mutant male fish with smaller testis size were found to be infertile when tested by natural mating. Intriguingly, a small amount of mature spermatozoa was observed in the ar mutant fish. These mature spermatozoa could fertilize healthy oocytes, albeit with a lower fertilization rate, by in vitro fertilization. Moreover, the expression levels of most steroidogenic genes in the testes were significantly elevated in the ar mutants. In contrast, the levels of estradiol and 11-ketotestosterone (11-KT) were significantly decreased in the ar mutants, indicating that steroidogenesis was defective in the mutants. Furthermore, the protein level of LHβ in the serum decreased markedly in the ar mutants when compared with wild-type fish, probably due to the positive feedback from the diminished steroid hormone levels.

Yang C., Lim W., Bazer F.W., Song G.

Propyl gallate (PG) is an antioxidant widely used in food additives, cosmetics, adhesives, and lubricants. PG protects the oils in food products from reacting with hydrogen peroxide and oxygen free radicals, thus preventing spoilage. It is known to have both protective and cytotoxic effects on various cells, but its effects on human trophoblasts remain unclear. Therefore, we investigated the effects of PG on proliferation, apoptosis, and invasiveness of human trophoblasts using an immortalized HTR8/SVneo cell line. We found that PG significantly reduced proliferation of and induced apoptosis in HTR8/SVneo cells. In addition, the invasiveness of HTR8/SVneo cells was attenuated in response to PG. Signaling pathways including the PI3K/AKT and MAPK pathways involved in the proliferation and invasiveness of human trophoblasts were regulated by PG treatment in HTR8/SVneo cells. We confirmed that mitochondrial membrane disruption and Ca2+ overload were markedly elevated in response to PG treatment, suggesting that PG-induced apoptosis is closely related to mitochondrial dysfunction and further PG-induced apoptosis in HTR8/SVneo cells is related to endoplasmic reticulum (ER) stress. Collectively, these results indicate that PG exerts harmful effects on human trophoblasts; therefore, exposure to PG in early pregnancy is predicted to cause abnormal implantation and placental development.

Zhu Y., Xu H., Li M., Gao Z., Huang J., Liu L., Huang X., Li Y.

Isoflavone is a type of phytoestrogen that exists in soy‑based products. Previous studies have reported that certain foods containing isoflavones, particularly infant formula, may have potential adverse effects on male reproductive function. However, few studies have focused on the effects of isoflavones on testosterone biosynthesis and Sertoli cell function during the neonatal period. The aim of the present study was to investigate the influence of daidzein, a common isoflavone, on testosterone secretion and Sertoli cell function during the neonatal period. The organ culture method was used to assess the effects of daidzein on neonatal mouse testes. Cultured testes were treated with daidzein (0, 0.03, 0.3, 3 or 30 µmol/l) for 72 h. To verify the mechanism of action of daidzein on androgen production, Leydig cells were also treated with daidzein for 24 h. As anticipated, testosterone secretions were suppressed by daidzein (30 µmol/l) in cultured testes and Leydig cells. Further analysis demonstrated that the expression levels of steroidogenic acute regulatory protein (StAR), cholesterol side‑chain cleavage enzyme (P450scc) and 3β‑hydroxysteroid dehydrogenase (3β‑HSD), which are transport proteins and key enzymes in androgen biosynthesis, were suppressed in cultured neonatal mouse testes. In addition, the expression levels of StAR, P450scc, 3β‑HSD and 17α‑hydroxylase/20‑lyase were decreased in Leydig cells. Notably, proliferation of Sertoli cells was also inhibited by daidzein (30 µmol/l). Furthermore, the expression levels of vimentin were significantly suppressed in the testes following treatment with daidzein, whereas inhibin B expression exhibited no change. In conclusion, daidzein may suppress steroidogenic capability and impair Sertoli cell function in the neonatal period in vitro.

Chojnacka K., Zarzycka M., Hejmej A., Mruk D.D., Gorowska E., Kotula-Balak M., Klimek M., Bilinska B.

We investigated the effects of 2-hydroxyflutamide (HF), an active metabolite of the anti-androgen flutamide, on the activation of the phosphoinositide-3 kinase/protein kinase B (PI3K/Akt) in rat Sertoli cells. Sertoli cells, isolated from 20-day-old rat testes, were cultured in vitro and treated with HF, testosterone, or HF+testosterone. Studies by western blotting demonstrated that HF inhibited the testosterone-mediated increase in c-Src activity (p

Aghazadeh Y., Zirkin B.R., Papadopoulos V.

Reduced serum testosterone (T), or hypogonadism, is estimated to affect about 5 million American men, including both aging and young men. Low serum T has been linked to mood changes, worsening cognition, fatigue, depression, decreased lean body mass and bone mineral density, increased visceral fat, metabolic syndrome, decreased libido, and sexual dysfunction. Administering exogenous T, known as T-replacement therapy (TRT), reverses many of the symptoms of low T levels. However, this treatment can result in luteinizing hormone suppression which, in turn, can lead to reduced sperm numbers and infertility, making TRT inappropriate for men who wish to father children. Additionally, TRT may result in supraphysiologic T levels, skin irritation, and T transfer to others upon contact; and there may be increased risk of prostate cancer and cardiovascular disease, particularly in aging men. Therefore, the development of alternate therapies for treating hypogonadism would be highly desirable. To do so requires greater understanding of the series of steps leading to T formation and how they are regulated, and the identification of key steps that are amenable to pharmacological modulation so as to induce T production. We review herein our current understanding of mechanisms underlying the pharmacological induction of T formation in hypogonadal testis.

Ahmed M.A.

The wide abuse of the anabolic steroid nandrolone decanoate by athletes and adolescents for enhancement of sporting performance and physical appearance may be associated with testicular toxicity and infertility. On the other hand, taurine; a free β-amino acid with remarkable antioxidant activity, is used in taurine-enriched beverages to boost the muscular power of athletes. Therefore, the purpose of this study was to investigate the mechanisms of the possible protective effects of taurine on nandrolone decanoate-induced testicular and sperm toxicity in rats. To achieve this aim, male Wistar rats were randomly distributed into four groups and administered either vehicle, nandrolone decanoate (10mg/kg/week, I.M.), taurine (100mg/kg/day, p.o.) or combination of taurine and nandrolone decanoate, for 8 successive weeks. Results of the present study showed that taurine reversed nandrolone decanoate-induced perturbations in sperm characteristics, normalized serum testosterone level, and restored the activities of the key steroidogenic enzymes; 3β-HSD, and 17β-HSD. Moreover, taurine prevented nandrolone decanoate-induced testicular toxicity and DNA damage by virtue of its antioxidant, anti-inflammatory, and anti-apoptotic effects. This was evidenced by taurine-induced modulation of testicular LDH-x activity, redox markers (MDA, NO, GSH contents, and SOD activity), inflammatory indices (TNF-α, ICAM-1 levels, and MMP-9 gene expression), intrinsic apoptotic pathway (cytochrome c gene expression and caspase-3 content), and oxidative DNA damage markers (8-OHdG level and comet assay). In conclusion, at the biochemical and histological levels, taurine attenuated nandrolone decanoate-induced poor sperm quality and testicular toxicity in rats.

Mitra S., Srivastava A., Khandelwal S.

• Tributyltin chloride induces cytosolic Ca 2+ mediated oxidative damage and cell death in sertoli-germ cell co-culture. • TBTC induces both apoptotic (low dose) and necrotic (high dose) cell death. • TBTC primarily affects sertoli cells which may lead to germ cell damage. • p38 and JNK signaling pathways instigate downstream pathways via mitochondria. • TBTC disrupts blood–testicular barrier (BTB) and spermatogenesis in-vivo upon a single oral dose. The widespread use of tributyltin (TBT) as biocides in antifouling paints and agricultural chemicals has led to environmental and marine pollution. Human exposure occurs mainly through TBT contaminated seafood and drinking water. It is a well known endocrine disruptor in mammals, but its molecular mechanism in testicular damage is largely unexplored. This study was therefore, designed to ascertain effects of tributyltin chloride (TBTC) on sertoli-germ cell co-culture in ex-vivo and in the testicular tissue in-vivo conditions. An initial Ca 2+ rise followed by ROS generation and glutathione depletion resulted in oxidative damage and cell death. We observed p38 and JNK phosphorylation, stress proteins (Nrf2, MT and GST) induction and mitochondrial depolarization leading to caspase-3 activation. Prevention of TBTC reduced cell survival and cell death by Ca 2+ inhibitors and free radical scavengers specify definitive role of Ca 2+ and ROS. Sertoli cells were found to be more severely affected which in turn can hamper germ cells functionality. TBTC exposure in-vivo resulted in increased tin content in the testis with enhanced Evans blue leakage into the testicular tissue indicating blood–testis barrier disruption. Tesmin levels were significantly diminished and histopathological studies revealed marked tissue damage. Our data collectively indicates the toxic manifestations of TBTC on the male reproductive system and the mechanisms involved.

Eler G.J., Santos I.S., de Moraes A.G., Mito M.S., Comar J.F., Peralta R.M., Bracht A.

n-Propyl gallate and its analogs are used in foods and other products to prevent oxidation. In the liver the compound exerts several harmful effects, especially gluconeogenesis inhibition. The mode of transport and distribution of n-propyl gallate and its kinetics of biotransformation have not yet been investigated. To fill this gap the transformation, transport and distribution of n-propyl gallate and two analogs were investigated in the rat liver. Isolated perfused rat liver was used. n-Propyl gallate, methyl gallate, n-octyl gallate and transformation products were quantified by high pressure-liquid chromatography coupled to fluorescence detection. The interactions of n-propyl gallate and analogs with the liver presented three main characteristics: (1) the hydrolytic release of gallic acid from n-propyl gallate and methyl gallate was very fast compared with the subsequent transformations of the gallic acid moiety; (2) transport of the esters was very fast and flow-limited in contrast to the slow and barrier-limited transport of gallic acid; (3) the apparent distribution volume of n-propyl gallate, but probably also of methyl gallate and n-octyl gallate, greatly exceeded the water space in the liver, contrary to the gallic acid space which is smaller than the water space. It can be concluded that at low portal concentrations (

Hamishehkar H., Khani S., Kashanian S., Ezzati Nazhad Dolatabadi J., Eskandani M.

Synthetic phenolic food additives, such as propyl 3,4,5-trihydroxybenzoate (propyl galate; PG), have been used as an antioxidant in the food industry to prevent oils from spoiling. Their toxicity is one of the challengeable issues resulting from the widespread usage of them in food-related industrials. In this study, we investigated the anticell proliferation effects of PG on A549 lung cancer cells. The result showed that PG dose and time dependently decreased the growth of A549 cells with an half-maximal inhibitory concentration of approximately 1 × 10(-3) and 5 × 10(-4)M of PG at 48 and 72 hours, respectively. In addition, DNA strand breaks have been observed through the comet assay technique. Also, morphology of 4',6-diamidino-2-phenylindole (DAPI)-stained cells showed an obvious fragmentation in the chromatin and DNA rings within the nucleus of PG-treated cells, and, finally, flow cytometry analyses of the cells confirmed DAPI staining assay and determined early and late apoptosis in treated cells.

Maeda N., Okumura K., Tanaka E., Suzuki T., Miyasho T., Haeno S., Ueda H., Hoshi N., Yokota H.

Reproductive toxicities and endocrine disruptions caused by chemicals in adult males are still poorly understood. It is our objectives to understand further details of the initial adverse effects leading severe testicular toxicities of a pharmaceutical endocrine disruptor, diethylstilbestrol (DES). Downregulations of both testicular regulatory proteins, such as the steroidogenic acute regulatory protein (StAR) and the peripheral benzodiazepine receptor (PBR), which play important roles in the transport of cholesterol into the mitochondria, and cytochrome P450 mediating the cholesterol side chain cleavage reaction (P450scc), were observed in the rat orally administered DES (340 μg/kg/2 days) for 2 weeks. We found that after only 1 week treatment with DES, the blood and testicular testosterone (TS) levels were drastically decreased without abnormalities of the StAR and PBR; however, the protein and mRNA levels of P450scc were diminished. Decrease in the conversion rate of cholesterol to pregnenolone was delayed in the in vitro assay using the testicular mitochondrial fraction from the rat treated with DES for 1 week. When the precursors in TS biosynthesis containing the testis were identified and determined by liquid chromatography-mass spectrometry analysis, decreased levels of all precursors except cholesterol were observed. In conclusion, suppressed cytochrome P450scc expression in adult male rat was identified as an initial target of DES in testicular steroidogenesis disorder leading reproductive toxicities.

Shima Y., Miyabayashi K., Haraguchi S., Arakawa T., Otake H., Baba T., Matsuzaki S., Shishido Y., Akiyama H., Tachibana T., Tsutsui K., Morohashi K.

Testosterone is a final product of androgenic hormone biosynthesis, and Leydig cells are known to be the primary source of androgens. In the mammalian testis, two distinct populations of Leydig cells, the fetal and the adult Leydig cells, develop sequentially, and these two cell types differ both morphologically and functionally. It is well known that the adult Leydig cells maintain male reproductive function by producing testosterone. However, it has been controversial whether fetal Leydig cells can produce testosterone, and the synthetic pathway of testosterone in the fetal testis is not fully understood. In the present study, we generated transgenic mice in which enhanced green fluorescence protein was expressed under the control of a fetal Leydig cell-specific enhancer of the Ad4BP/SF-1 (Nr5a1) gene. The transgene construct was prepared by mutating the LIM homeodomain transcription factor (LHX9)-binding sequence in the promoter, which abolished promoter activity in the undifferentiated testicular cells. These transgenic mice were used to collect highly pure fetal Leydig cells. Gene expression and steroidogenic enzyme activities in the fetal Leydig cells as well as in the fetal Sertoli cells and adult Leydig cells were analyzed. Our results revealed that the fetal Leydig cells synthesize only androstenedione because they lack expression of Hsd17b3, and fetal Sertoli cells convert androstenedione to testosterone, whereas adult Leydig cells synthesize testosterone by themselves. The current study demonstrated that both Leydig and Sertoli cells are required for testosterone synthesis in the mouse fetal testis.

Rato L., Alves M.G., Socorro S., Duarte A.I., Cavaco J.E., Oliveira P.F.

Sertoli cells provide nutritional support for germ cells by secreting nutrients or metabolic intermediates, such as amino acids, carbohydrates, lipids, vitamins, and metal ions. Here, the authors discuss the importance of Sertoli cell metabolism in the formation of the mature spermatozoa, and the regulation of this metabolism, which could have a direct influence on male fertility. Male factor infertility is increasing in developed countries, and several factors linked to lifestyle have been shown to negatively affect spermatogenesis. Sertoli cells are pivotal to spermatogenesis, providing nutritional support to germ cells throughout their development. Sertoli cells display atypical features in their cellular metabolism; they can metabolize various substrates, preferentially glucose, the majority of which is converted to lactate and not oxidized via the tricarboxylic acid cycle. Why Sertoli cells preferentially export lactate for germ cells is not entirely understood. However, lactate is utilized as the main energy substrate by developing germ cells and has an antiapoptotic effect on these cells. Several biochemical mechanisms contribute to the modulation of lactate secretion by Sertoli cells. These include the transport of glucose through the plasma membrane, mediated by glucose transporters; the interconversion of pyruvate to lactate by lactate dehydrogenase; and the release of lactate mediated by monocarboxylate transporters. Several factors that modulate Sertoli cell metabolism have been identified, including sex steroid hormones, which are crucial for maintenance of energy homeostasis, influencing the metabolic balance of the whole body. In fact, energy status is essential for normal reproductive function, since the reproductive axis has the capacity to respond to metabolic cues.

Royer C., Lucas T.F., Lazari M.F., Porto C.S.

The aim of the present study was to investigate the intracellular signaling events downstream of the classical estrogen receptors (ESRs) and G protein-coupled estrogen receptor 1 (GPER) involved in regulation of proliferation and apoptosis of rat Sertoli cells, in which we have previously described ESR1, ESR2, and GPER. ESRs play a role in Sertoli cell proliferation, and GPER, but not ESRs, plays a role modulating gene expression involved with apoptosis. The present study shows that 17beta-estradiol (E2) and the GPER-selective agonist G-1 rapidly activate phosphatidylinositol 3-kinase (PIK3)/serine threonine protein kinase (AKT) and cyclic AMP response element-binding (CREB) phosphorylation. E2 and the ESR1-selective agonist 4,4',4″-(4-propyl-(1H)-pyrazole-1,3,5-triyl)trisphenol (PPT) increase the expression of cyclin D1 (CCND1), whereas the ESR2-selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) and G-1 do not change the expression of this protein, suggesting that ESR1 is the upstream receptor regulating Sertoli cell proliferation. E2- or PPT-ESR1, through activation of epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase 3/1 (MAPK3/1) and PIK3 pathways, induces upregulation of CCND1. KG-501, the compound that disrupts the phospho-CREB/CREB binding protein (CBP) complex, does not change E2- or PPT-ESR1-mediated CCND1 expression, suggesting that phospho-CREB/cyclic AMP response element/CBP is not involved in the expression of this protein. E2- or G-1-GPER, through activation of EGFR/MAPK3/1 and PIK3 pathways, may be involved in the upregulation of antiapoptotic proteins BCL2 and BCL2L2. E2- or G-1-GPER/EGFR/MAPK3/1/phospho-CREB decreases BAX expression. Taken together, these results show a differential effect of E2-GPER on the CREB-mediated transcription of proapoptotic and antiapoptotic genes of the same BCL2 gene family. ESR1 and GPER can mediate the rapid E2 actions in the Sertoli cells, which in turn can modulate nuclear transcriptional events important for Sertoli cell function and maintenance of normal testis development and homeostasis. Our findings are important to clarify the role of estrogen in a critical period of testicular development, and to direct further studies, which may contribute to better understanding of the causes of male infertility.

Frizzell C., Ndossi D., Verhaegen S., Dahl E., Eriksen G., Sørlie M., Ropstad E., Muller M., Elliott C.T., Connolly L.

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays incorporating natural steroid receptors and the H295R steroidogenesis assay have been implemented to assess the endocrine disrupting activity of ZEN and its metabolites α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL). α-ZOL exhibited the strongest estrogenic potency (EC(50) 0.022±0.001 nM), slightly less potent than 17-β estradiol (EC(50) 0.015±0.002 nM). ZEN was ~70 times less potent than α-ZOL and twice as potent as β-ZOL. Binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of ZEN, α-ZOL or β-ZOL. ZEN, α-ZOL or β-ZOL increased production of progesterone, estradiol, testosterone and cortisol hormones in the H295R steroidogenesis assay, with peak productions at 10 μM. At 100 μM, cell viability decreased and levels of hormones were significantly reduced except for progesterone. β-ZOL increased estradiol concentrations more than α-ZOL or ZEN, with a maximum effect at 10 μM, with β-ZOL (562±59 pg/ml)>α-ZOL (494±60 pg/ml)>ZEN (375±43 pg/ml). The results indicate that ZEN and its metabolites can act as potential endocrine disruptors at the level of nuclear receptor signalling and by altering hormone production.

Wen N., Li M., Huo Y., Zhou Y., Ma Y., Gu Q., He M.

Wu S., Gao M., Fang B., Rong L., Ge Z., Chen H., Yao Y., Wang Y., Sun H.

Stanley M.M., Sriram B., Wang S., Sherlin V A., Kogularasu S., George M.

Xu Y., Ding T., Zhu Q., Tao L., Liu S., Hu L., Liao C.

Environmental occurrence and risks of novel synthetic phenolic antioxidants (SPAs) remain largely unclear. By using a typical algae (Chlorella pyrenoidosa) as model organism, we evaluated the ecological risks of both traditional and novel SPAs, based on their concentrations in water, sediment, and soil collected from the Yangtze River Delta, China. Detection frequencies (DFs) of 10 novel SPAs were 25-100% in water, 3-100% in sediment, and 0-100% in soil, with geometric means (GMs) of 2700 ng/L, 1270 ng/g, and 2440 ng/g, respectively. For 8 traditional SPAs, DFs were 50-100% (GM: 680 ng/L), 3-100% (534 ng/g), and 47-100% (2240 ng/g) in water, sediment, and soil, respectively. AO3114 was the main pollutant in water, while AO1010 dominated in sediment and soil. Notably, low-molecular-weight SPAs showed migration behavior from sediment to water. Four SPAs (AO626, AO1035, AO1098, and AO1076) showed dose- and time-dependent toxicity on Chlorella pyrenoidosa. As time progressed, sediment-released SPAs became more toxic than those in water. Two SPAs (AO1135 and BHT-Q) posed high risks (RQ

Zahid M., Khalid S., Raana S., Amin S., Javaid H., Arshad R., Jahangeer A., Ahmad S., Hassan S.A.

Edible oils play a vital role in human nutrition, serving as a crucial source of energy, essential fatty acids, and vitamins necessary for bodily functions. However, during handling, cooking, and storage these oils are susceptible to oxidation, resulting in the loss of nutritional value, the development of undesirable flavors, the production of harmful compounds, and a reduction in shelf life. To counteract oxidation and enhance oil stability, synthetic antioxidants have traditionally been employed. However, in recent times, consumer awareness has led to an increased preference for natural antioxidants because of the harmful effects of synthetic antioxidants on human health. This review provides a comprehensive overview of recent research focused on the oxidative stability of various edible vegetable oils through the incorporation of natural antioxidants derived from fruits and vegetable waste. These antioxidants obtained from waste through diverse techniques are blended with different vegetable oils in the form of free extracts, encapsulated extracts, nano-encapsulated extracts, and nano-emulsion oil extracts to assess their antioxidant efficacy. These antioxidant-rich waste extracts efficiently prevented oxidation by scavenging free radicals, chelating metal ions, and delaying the formation of peroxides, offering a safer and more effective alternative to synthetic counterparts. Beyond their antioxidative properties, these extracts contribute to the nutritional enhancement of oils, functioning as nutraceuticals. This approach not only offers a natural means to protect edible oils but also facilitates efficient waste valorization, mitigating potential environmental impacts and making it a sustainable and eco-friendly strategy.

Zhang X., Li N., Zhong W., Lin H., Han S.

Gonçalves-Filho D., De Souza D.

Food additives are chemical compounds intentionally added during foodstuff production to control technological functions, such as pH, viscosity, stability (color, flavor, taste, and odor), homogeneity, and loss of nutritional value. These compounds are fundamental in inhibition the degradation process and prolonging the shelf life of foodstuffs. However, their inadequate employment or overconsumption can adversely affect consumers' health with the development of allergies, hematological, autoimmune, and reproductive disorders, as well as the development of some types of cancer. Thus, the development and application of simple, fast, low-cost, sensitivity, and selectivity analytical methods for identifying and quantifying food additives from various chemical classes and in different foodstuffs are fundamental to quality control and ensuring food safety. This review presents trends in the detection of food additives in foodstuffs using differential pulse voltammetry and square wave voltammetry, the main pulse voltammetric techniques, indicating the advantages, drawbacks, and applicability in food analysis. Are discussed the importance of adequate choices of working electrode materials in the improvements of analytical results, allowing reliable, accurate, and inexpensive voltammetric methods for detecting these compounds in foodstuffs samples.

Amakran A., Hamoudane M., Pagniez F., Lamarti A., Picot C., Figueredo G., Nhiri M., Le Pape P.

AbstractThis study aimed to define the chemical composition of Moroccan Thymus capitatus essential oil, and to investigate its in vitro antioxidant and antifungal activities against human pathogenic fungi. Chemical analysis using GC‐FID and GC‐MS system revealed 28 constituents, representing 99 % of total compounds. Oxygenated monoterpenes represented the highest proportion (79.79 %), among which carvacrol (75.73 %) was the predominant compound, followed by linalol (2.26 %). Monoterpene hydrocarbons represented the second major fraction (16.29 %): within them, the predominant constituents were γ‐terpinene (5,55 %), ρ‐cymene (5,50 %), and β‐caryophyllene (2.73 %). Antioxidant activity was performed by DPPH scavenging, β‐carotene bleaching inhibition, and ferric reducing power. T. capitatus revealed pronounced DPPH radical scavenging activity (IC50=110.53 μg mL−1), strong ferric reducing ability (EC50=644.4 μg mL−1), and a remarkable degree of protection against lipid peroxidation during β‐carotene bleaching inhibition (IC50=251.76 μg mL−1). Antifungal activity was carried out against Candida, Aspergillus, and Rhizopus species by microdilution method. T. capitatus exhibited potent anticandidal activity (MIC=125–500 μg mL−1) and strong inhibition against filamentous fungi (MIC=250‐500 μg mL−1). Its hemolytic activity against human erythrocytes had a low toxic effect at concentrations lower than 1250 μg mL−1. The useful antioxidant properties and broad antifungal effect of T. capitatus EO confirm its considerable potential for the food industry and for phytopharmaceutical production.

Tekіn M., Kuru İ.S.

Abstract The study investigated total phenolic-flavonoid content, antioxidant activity, and phytochemical compounds across various parts (bulb, stem, leaf, and flower) of the endemic Bellevalia sasonii, commonly known as hyacinth, belonging to the Asparagaceae family. Phenolic content was highest in bulb extracts (117.28 μg GAE) and lowest in stems (45.11 μg GAE). Conversely, leaf extracts exhibited the highest flavonoid content (79.44 μg QEs), while stems showed the lowest (22.77 μg QEs). When the antioxidant activities were compared, by DPPH method leaf = flower > bulb > stem; in ABTS and CUPRAC methods bulb > flower > leaf > stem, respectively. Considering the results in general, it was revealed that bulbs and flowers displayed higher activity, while stem exhibited lower activity compared to other parts. The phytochemical analysis identified 53 active substances, with 27 absent in any extract and 15 detected across all extracts. The distribution of phytochemicals varied among parts, with bulbs, stems, flowers, and leaves also different numbers. The LC-MS/MS analysis revealed prominent metabolites including fumaric acid in leaves, caffeic acid in bulbs, and cosmosiin and quinic acid in flowers. This study provides foundational insights into B. sasonii, an important endemic plant in Türkiye, laying the groundwork for future research on its medicinal and ecological roles.

Feng J., Tian W., Liu D., Wang H., Liu W., Lin X.

Propyl gallate (PG), a commonly used oil-soluble antioxidant, exhibits remarkable antioxidative properties, so it is extensively employed in vegetable oils, lard, poultry fats and oil-rich food products. However, prolonged excessive consumption of PG may pose health risks to humans such as kidney damage or contact dermatitis. Herein, a novel economically sensitive sensor for PG was constructed based on cerium-cobalt bimetallic organic framework (CeCo-BMOF) materials. The morphology and composition of the materials were characterized by scanning electron microscope (SEM), element mapping, X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), and Raman spectrum (RS). The construction process of the sensor was characterized by electrochemical impedance spectroscopy (EIS), chronocoulometry method (Q-t1/2) and cyclic voltammetry (CV). The sensor not only demonstrates a wide linear range (1.5 μM – 17.6 μM and 11.5 μM – 458 μM) and a low limit of detection (LOD = 0.49 μM; S/N = 3) for the determination of PG, but also exhibits excellent anti-interference capability, stability, and repeatability. Above all, the recommended method can be successfully employed for the detection of PG in peanut oil and corn oil.

Lei X., Wang H., Bai Z., Zhang X., Lin H., Han S.

The enhancement of cold flow properties (CFPs) and oxidative stability (OS) in biodiesel-diesel blends typically involves the use of pour point depressants and antioxidants. However, a scant number of additives are capable of manifesting both pour point depression and antioxidant functionalities concurrently. This study explored the grafting of syringic acid (SA), 3,5-di-tert-butyl-4-hydroxybenzoic acid (DTBHA), and gallic acid (GA) onto polymethacrylate (PMA) type copolymers, culminating efficacious copolymers, namely PTG-SA, PTG-DTBHA and PTG-GA. The findings reveal that with the addition of 1500 ppm of PTG-GA, the CFPP and PP of B20 (20 vol% soybean biodiesel+80 vol% diesel) decrease by 10 and 18 °C respectively, and with the addition of 2000 ppm, the induction period (IP) of B20 can be extended from 1.34 to 8.69 h. In contrast, the application of PTG-SA and PTG-DTBHA to B20 led to inferior OS and CFPs as compared to PTG-GA. The inherent scientific mechanism that underlies this performance discrepancy was thoroughly investigated, scrutinizing it through the lens of co-crystallization and nucleation processes. This research underscores the potential of post-modification of PMA type pour point depressants with antioxidants, a strategy that not only bolsters the CFPs of B20 but also confers antioxidant attributes to the pour point depressants.

Park W.H.

AbstractPropyl gallate (PG) exhibits an anti-growth effect on various cell types. The present study investigated the impact of PG on the levels of reactive oxygen species (ROS) and glutathione (GSH) in primary human pulmonary fibroblast (HPF) cells. Moreover, the effects of N-acetyl cysteine (NAC, an antioxidant), l-buthionine sulfoximine (BSO, a GSH synthesis inhibitor), and small interfering RNA (siRNAs) against various antioxidant genes on ROS and GSH levels and cell death were examined in PG-treated HPF cells. PG (100–800 μM) increased the levels of total ROS and O2·− at early time points of 30–180 min and 24 h, whereas PG (800–1600 μM) increased GSH-depleted cell number at 24 h and reduced GSH levels at 30–180 min. PG downregulated the activity of superoxide dismutase (SOD) and upregulated the activity of catalase in HPF cells. Treatment with 800 μM PG increased the number of apoptotic cells and cells that lost mitochondrial membrane potential (MMP; ΔΨm). NAC treatment attenuated HPF cell death and MMP (ΔΨm) loss induced by PG, accompanied by a decrease in GSH depletion, whereas BSO exacerbated the cell death and MMP (ΔΨm) loss without altering ROS and GSH depletion levels. Furthermore, siRNA against SOD1, SOD2, or catalase attenuated cell death in PG-treated HPF cells, whereas siRNA against GSH peroxidase enhanced cell death. In conclusion, PG induced cell death in HPF cells by increasing ROS levels and depleting GSH. NAC was found to decrease HPF cell death induced by PG, while BSO enhanced cell death. The findings shed light on how manipulating the antioxidant system influence the cytotoxic effects of PG in HPF cells.

Yang S., Yang F., Zou Y., Wang Y., Ding Z., Zhang L., Zhou X., Liu M., Duan Z., Huo L.

Propyl gallate (PG), owing to its exceptional antioxidant properties, is extensively used in industries such as food processing. The potential harmful impacts of PG have sparked concern among people. It has been reported that exposure of PG has certain reproductive toxicity, which can affect the maturation of mouse oocytes and induce testicular dysfunction. However, its impact on early embryonic development is still unclear. In this study, we explored the toxic effects and potential mechanisms of PG on mouse 2-cell stage embryonic development. The results showed that exposure of PG can decrease the development of 2-cell stage embryos and repress the development of 4-cell stage embryos. Further study found that PG could induce intracellular oxidative stress and the accumulation of DNA damage in 2-cell stage embryos. Moreover, exposure of PG impaired the function of mitochondria and lysosomes in 2-cell stage embryos, thereby triggering the occurrence of autophagy. In addition, exposure of PG altered the epigenetic modification of 2-cell stage embryos, displaying a decreased level of DNA methylation and an increased level of H3K4me3. In summary, our results indicated that exposure of PG can damage the development of mouse 2-cell stage embryos by inducing oxidative stress, DNA damage, and autophagy, and altering epigenetic modification.

Park W.H.

Ziegler‐Skylakakis K.

Abstract This chapter deals with esters of monocarboxylic acids as well as with monoalcohols, di‐, tri‐, or polyalcohols, such as glycerol esters, resorcinol esters, and gallates. The esters of aromatic monocarboxylic acids are benzoates, salicylates, parabens, cinnamates, p ‐aminobenzoates, and o ‐aminobenzoates. The chemical structures and the physicochemical properties of these chemicals vary considerably. Accordingly, they are widely used in different industrial settings and consumer products. Some of these compounds occur naturally. They exhibit in general a low toxicity.