Assessment toxic effects of exposure to 3-indoleacetic acid via hemato-biochemical, hormonal, and histopathological screening in rats

Plasma and Visceral Organ Kynurenine Metabolites Correlate in the Multiple Sclerosis Cuprizone Animal Model

The cuprizone (CPZ) model of multiple sclerosis (MS) is excellent for studying the molecular differences behind the damage caused by poisoning. Metabolic differences in the kynurenine pathway (KP) of tryptophan (TRP) degradation are observed in both MS and a CPZ mouse model. Our goal was to analyze the kynurenine, serotonin, and indole pathways of TRP degradation on the periphery, in the neurodegenerative processes of inflammation. In our study, mice were fed with 0.2% CPZ toxin for 5 weeks. We examined the metabolites in the three pathways of TRP breakdown in urine, plasma, and relevant visceral organs with bioanalytical measurements. In our analyses, we found a significant increase in plasma TRP, 5-hydroxytryptophan (5-HTP), and indole-3-acetic acid (IAA) levels, while a decrease in the concentrations of 3-hydroxy-L-kynurenine (3-HK), xanthurenic acid (XA), kynurenic acid (KYNA), and quinaldic acid in the plasma of toxin-treated group was found. A marked decrease in the levels of 3-HK, XA, KYNA, quinaldic acid, and indole-3-lactic acid was also observed in the visceral organs by the end of the poisoning. Furthermore, we noticed a decrease in the urinary levels of the TRP, KYNA, and XA metabolites, while an increase in serotonin and 5-hydroxyindoleacetic acid in the CPZ group was noticed. The toxin treatment resulted in elevated tryptamine and indoxyl sulfate levels and reduced IAA concentration. Moreover, the urinary para-cresyl sulfate concentration also increased in the treated group. In the present study, we showed the differences in the three main metabolic pathways of TRP degradation in the CPZ model. We confirmed the relationship and correlation between the content of the kynurenine metabolites in the plasma and the tissues of the visceral organs. We emphasized the suppression of the KP and the activity of the serotonin and indole pathways with a particular regard to the involvement of the microbiome by the indole pathway. Consequently, this is the first study to analyze in detail the distribution of the kynurenine, serotonin, and indole pathways of TRP degradation in the periphery.

Role of Nrf2/HO-1 and cytoglobin signaling in the protective effect of indole-3-acetic acid and chenodeoxycholic acid against kidney injury induced by valproate

Background

Purpose: Valproate (VPA) is an antiepileptic drug widely used to treat various psychiatric and neurological disorders. Although its use is generally considered safe, chronic administration may lead to kidney injury. The mechanisms underlying VPA kidney toxicity are not entirely explored. This has prompted our investigation into a novel molecular signaling pathway involved in VPA-induced kidney injury and the exploration of strategies to ameliorate this toxicity using indole-3-acetic acid (IAA) and chenodeoxycholic acid (CDCA).

Methods

Rats were divided as follows: group I (control); group II (VPA group), where rats were administered VPA (500 mg/kg, i.p.) daily to induce kidney injury for 3 weeks; and groups III and IV, where rats were orally treated with either IAA (40 mg/kg) or CDCA (90 mg/kg), respectively, 1h post-VPA dose, for 3 weeks. The effects of these compounds on kidney tissues were evaluated with a focus on their antioxidant and anti-inflammatory properties using biochemical, histopathological, and immunohistochemical analyses.

Results

VPA caused a significant reduction in renal glutathione (GSH) and heme oxygenase-1 (HO-1) levels, and superoxide dismutase (SOD) activity, along with a significant elevation in malondialdehyde (MDA) levels. Similarly, tumor necrosis factor-α (TNF-α), interleukin-1beta (IL-1β), and interleukin-6 (IL-6) levels were significantly increased. Immunohistochemical analysis demonstrated a significant decline in the immunoreactivity of nuclear factor erythroid 2-related factor (Nrf2) and cytoglobin antigens in renal cells. However, administration of either IAA or CDCA significantly ameliorated these altered parameters, including Nrf2/HO-1 and cytoglobin levels.

Conclusion

IAA and CDCA alleviated the kidney injury induced by VPA via downregulating the inflammatory response and upregulating the antioxidant capacity in renal tissue.

Structure-Activity of Plant Growth Bioregulators and Their Effects on Mammals

In this review, we emphasize structure-activity and the effects on mammals of plant growth bioregulators. plant growth bioregulators can be referred to as "biochemical effectors" since they are substances having biological activity. It is possible to distinguish between "bioregulators" and "regulators" due to the significance of the compounds mentioned above in biochemistry and agrobiology. Thus, "plant growth bioregulators" (PGBRs) are the names given to naturally occurring chemical substances produced by biosynthetic processes. PGBRs affect both plant reign and animal reign. A plethora of plant growth bioregulators were described in the literature, so the structure, activity in plants, and their effects on mammals are presented.

Targeted HER2-positive cancer therapy using ADAPT6 fused to horseradish peroxidase

Targeted cancer therapy is a promising alternative to the currently established cancer treatments, aiming to selectively kill cancer cells while sparing healthy tissues. Hereby, molecular targeting agents, such as monoclonal antibodies, are used to bind to cancer cell surface markers specifically. Although these agents have shown great clinical success, limitations still remain such as low tumor penetration and off-target effects. To overcome this limitation, novel fusion proteins comprised of the two proteins ADAPT6 and Horseradish Peroxidase (HRP) were engineered. Cancer cell targeting is hereby enabled by the small scaffold protein ADAPT6, engineered to specifically bind to human epidermal growth factor receptor 2 (HER2), a cell surface marker overexpressed in various cancer types, while the enzyme HRP oxidizes the nontoxic prodrug indole-3-acetic acid (IAA) which leads to the formation of free radicals and thereby to cytotoxic effects on cancer cells. The high affinity to HER2, as well as the enzymatic activity of HRP, were still present for the ADAPT6-HRP fusion proteins. Further, in vitro cytotoxicity assay using HER2-positive SKOV-3 cells revealed a clear advantage of the fusion proteins over free HRP by association of the fusion proteins directly to the cancer cells and therefore sustained cell killing. This novel strategy of combining ADAPT6 and HRP represents a promising approach and a viable alternative to antibody conjugation for targeted cancer therapy.

Metabolites derived from gut microbiota mitigate chemoresistance in pancreatic cancer

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is the third-leading cause of tumor-related deaths. The gut microbiota has gained attention in cancer treatment, due to its influence on the immune system and drug activity.

AREAS COVERED

Tintelnot and collaborators highlight distinct gut microbiota composition in metastatic PDAC (mPDAC) patients responding versus non-responding to chemotherapy. In the context of chemotherapy treatment, the gut microbiota of responders can metabolize tryptophan from food into indole-3-acetic acid (3-IAA). The presence of neutrophil-derived myeloperoxidase facilitates the role of 3-IAA in promoting the accumulation of reactive oxygen species in tumor cells. This accumulation, in turn, inducing tumor cell cytotoxicity. Additionally, 3-IAA can inhibit tumor cell autophagy activity, diminishing tumor cells' ability to adapt to cell stress. This manuscript provides a comprehensive analysis of the latest research on microbiota, metabolites, and PDAC, sourced from PubMed, ScienceDirect, and Google Scholar.

EXPERT OPINION

The evaluated study noted an elevation of the bacterial metabolite 3-IAA in responsive PDAC patients' serum, suggesting its potential to enhance chemotherapy sensitivity. Gaining a thorough comprehension of the impact of gut microbiota metabolites on drug activity is beneficial for broadening our strategies to mitigate chemotherapy resistance in tumors and identifying markers that predict chemotherapy outcomes.

Indole-3-acetic acid exposure leads to cardiovascular inflammation and fibrosis in chronic kidney disease rat model

Indole-3-acetic acid (IAA), a protein-bound uremic toxin, has been linked to cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. This study explores the influence of IAA (125 mg/kg) on cardiovascular changes in adenine sulfate-induced CKD rats. HPLC analysis revealed that IAA-exposed CKD rats had lower excretion and increased circulation of IAA compared to both CKD and IAA control groups. Moreover, echocardiography indicated that CKD rats exposed to IAA exhibited heart enlargement, thickening of the myocardium, and cardiac hypertrophy in contrast to CKD or IAA control group. Biochemical analyses supported the finding that IAA-induced CKD rats had elevated serum levels of c-Tn-I, CK-MB, and LDH; there was also evidence of oxidative stress in cardiac tissues, with a significant decrease in SOD and CAT levels, as well as an increase in MDA levels. The gene expression analysis found significant increases in ANP, BNP, β-MHC, TNF-α, IL-1β, and NF-κB levels in IAA-exposed CKD groups in contrast to the CKD or IAA control group. In addition, higher cardiac fibrosis markers, including Col-I and Col-III. The findings of this study indicate that IAA could trigger cardiovascular inflammation and fibrosis in CKD conditions.

Indole-3-acetic acid induced cardiogenesis impairment in in-vivo zebrafish via oxidative stress and downregulation of cardiac morphogenic factors

Plant growth regulators (PGRs) are increasingly used to promote sustainable agriculture, but their unregulated use raises concerns about potential environmental risks. Indole-3-acetic acid (IAA), a commonly used PGR, has been the subject of research on its developmental toxicity in the in-vivo zebrafish model. IAA exposure to zebrafish embryos caused oxidative stress, lipid peroxidation, and cellular apoptosis. The study also revealed that critical antioxidant genes including sod, cat, and bcl2 were downregulated, while pro-apoptotic genes such as bax and p53 were upregulated. IAA exposure also hampered normal cardiogenesis by downregulating myl7, amhc, and vmhc genes and potentially influencing zebrafish neurobehavior. The accumulation of IAA was confirmed by HPLC analysis of IAA-exposed zebrafish tissues. These findings underscore the need for further study on the potential ecological consequences of IAA use and the need for sustainable agricultural practices.

Resveratrol ameliorates atrazine-induced caspase-dependent apoptosis and fibrosis in the testis of adult albino rats

Pesticides like atrazine which are frequently present in everyday surroundings, have adverse impacts on human health and may contribute to male infertility. The work aimed to analyze the histological and biochemical effects of atrazine on the testis in adult albino rats and whether co-administration with resveratrol could reverse the effect of atrazine. Forty adult male albino rats in good health participated in this study. They were categorized at random into four groups: the Group Ӏ received water through a gastric tube for two months every day, the Group ӀӀ received resveratrol (20 mg/kg body weight (b.w.)) through a gastric tube for two months every day, the Group ӀӀӀ received atrazine (50 mg/kg bw) through a gastric tube for two months every day, the Group ӀV received concomitant doses of atrazine and resveratrol for two months every day. The testes of the animals were then carefully removed and prepared for biochemical, immunohistochemical, light, and electron microscopic studies. Atrazine exposure led to a significant decrease in serum testosterone hormone level, upregulation of caspase 3 and iNOS mRNA levels, destructed seminiferous tubules with few sperms in their lumens, many collagen fibres accumulation in the tunica albuginea and the interstitium, abnormal morphology of some sperms as well as many vacuolations, and damaged mitochondria in the cytoplasm of many germ cells. Concomitant administration of resveratrol can improve these adverse effects. It was concluded that atrazine exposure is toxic to the testis and impairs male fertility in adult rat and coadministration of resveratrol guards against this toxicity.

Indole-3 acetic acid induced cardiac hypertrophy in Wistar albino rats

Indole-3-acetic acid (IAA) is the most widely utilized plant growth regulator. Despite its extensive usage, IAA is often overlooked as an environmental pollutant. Due to its protein-binding nature, it also functions as a uremic toxin, contributing to its association with chronic kidney disease (CKD). While in vitro and epidemiological research have demonstrated this association, the precise impact of IAA on cardiovascular disease in animal models is unknown. The main objective of this study is to conduct a mechanistic analysis of the cardiotoxic effects caused by IAA using male Wistar albino rats as the experimental model. Three different concentrations of IAA (125, 250, 500 mg/kg) were administered for 28 days. The circulating IAA concentration mimicked previously observed levels in CKD patients. The administration of IAA led to a notable augmentation in heart size and heart-to-body weight ratio, indicating cardiac hypertrophy. Echocardiographic assessments supported these observations, revealing myocardial thickening. Biochemical and gene expression analyses further corroborated the cardiotoxic effects of IAA. Dyslipidemia, increased serum c-Troponin-I levels, decreased SOD and CAT levels, and elevated lipid peroxidation in cardiac tissue were identified. Moreover, increased expression of cardiac inflammatory biomarkers, including ANP, BNP, β-MHC, Col-III, TNF-α, and NF-κB, was also found in the IAA-treated animals. Histopathological analysis confirmed the cardiotoxic nature of IAA, providing additional evidence of its adverse effects on cardiovascular health. These results offer insights into the potential negative impact of IAA on cardiovascular function, and elucidating the underlying mechanisms of its cardiotoxicity.

Saikosaponin A protects against uremic toxin indole‑3 acetic acid‑induced damage to the myocardium

Chronic kidney disease (CKD)‑associated cardiac injury is a common complication in patients with CKD. Indole‑3 acetic acid (IAA) is a uremic toxin that injures the cardiovascular system. Saikosaponin A (SSA) protects against pressure overload‑induced cardiac fibrosis. However, the role and molecular mechanisms of IAA and SSA in CKD‑associated cardiac injury remain unclear. The present study investigated the effects of IAA and SSA on CKD‑associated cardiac injury in neonatal mouse cardiomyocytes and a mouse model of CKD. The expression of tripartite motif‑containing protein 16 (Trim16), receptor interacting protein kinase 2 (RIP2) and phosphorylated‑p38 were assessed using western blotting. The ubiquitination of RIP2 was measured by coimmunoprecipitation, and mouse cardiac structure and function were evaluated using hematoxylin and eosin staining and echocardiography. The results demonstrated that, SSA inhibited IAA‑induced cardiomyocyte hypertrophy, upregulated Trim16 expression, downregulated RIP2 expression and decreased p38 phosphorylation. Furthermore, Trim16 mediated SSA‑induced degradation of RIP2 by ubiquitination. In a mouse model of IAA‑induced CKD‑associated cardiac injury, SSA upregulated the protein expression levels of Trim16 and downregulated those of RIP2. Moreover, SSA alleviated heart hypertrophy and diastolic dysfunction in IAA‑treated mice. Taken together, these results suggest that SSA is a protective agent against IAA‑induced CKD‑associated cardiac injury and that Trim16‑mediated ubiquitination‑related degradation of RIP2 and p38 phosphorylation may contribute to the development of CKD‑associated cardiac injury.