Oral administration of Aristolochia manshuriensis Kom in rats induces tumors in multiple organs

Long-term oral administration of Kelisha capsule does not cause hepatorenal toxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Kelisha capsules (KLS) are often used to treat acute diarrhoea, bacillary dysentery, heat stroke, and other diseases. One of its components, Asarum, contains aristolochic acid I which is both nephrotoxic and carcinogenic. However, the aristolochic acid (AA) content in KLS and its toxicity remain unclear.

AIM OF THE STUDY

The aims of this study were to quantitatively determine the contents of five aristolochic acid analogues (AAAs) in Asarum and KLS, and systematically evaluate the in vivo toxicity of KLS in rats.

MATERIALS AND METHODS

Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to determine the content of the five AAAs in Asarum and KLS. Sprague-Dawley rats were administered KLS at 0, 0.75, 1.5, and 3.0 g/kg respectively, and then sacrificed after 4 weeks of administration or after an additional 2 weeks of recovery. The endpoints assessed included body weight measurements, serum biochemistry and haematology indices, and clinical and histopathological observations.

RESULTS

The AAAs content in Asarum sieboldii Miq. (HB-ESBJ) were much lower than those of the other Asarums. The contents of AA I, AA IVa, and aristolactam I in KLS were in the ranges of 0.03-0.06 μg/g, 1.89-2.16 μg/g, and 0.55-1.60 μg/g, respectively, whereas AA II and AA IIIa were not detected. None of the rats showed symptoms of toxic reactions and KLS was well tolerated throughout the study. Compared to the control group, the activated partial thromboplastin time values of rats in the 1.5 and 3.0 g/kg groups significantly reduced after administration (P < 0.05). In addition, the serum triglycerides of male rats in the 0.75 and 1.5 g/kg groups after administration, and the 0.75, 1.5, 3.0 g/kg groups after recovery were significantly decreased (P < 0.01 or P < 0.001). No significant drug-related toxicological changes were observed in other serum biochemical indices, haematology, or histopathology.

CONCLUSIONS

The AA I content in KLS met the limit requirements (<0.001%) of the Chinese Pharmacopoeia. Therefore, it is safe to use KLS in the short-term. However, for safety considerations, attention should be paid to the effects of long-term KLS administration on coagulation function and triglyceride metabolism.

Long-term toxicity evaluation of aristolochic acid-IIIa in mice

Aristolochic acid (AA)-IIIa is an AA analog present in Aristolochiaceae plants. To evaluate the chronic toxicity of AA-IIIa, mice were intragastrically administered with media control, 1 mg/kg AA-IIIa, and 10 mg/kg AA-IIIa, and designated as the control (CTL), AA-IIIa low dose (AA-IIIa-L), and AA-IIIa high dose (AA-IIIa-H) groups, respectively. AA-IIIa was administered three times a week, every other day, for 24 weeks (24-week time point). Thereafter, some mice were sacrificed immediately, while others were sacrificed 29 or 50 weeks after AA-IIIa withdrawal (53- or 74-week time point). Serum and organs were collected for biochemical and pathological analyses, respectively. Whole-genome sequencing was performed on the kidney, liver, and stomach tissues of AA-IIIa-treated mice for single-nucleotide polymorphism (SNP) detection. AA-IIIa-H mice died at 66 weeks, and the remaining mice showed moribund conditions at the 69 weeks. AA-IIIa induced minor kidney tubule injury, fibroblast hyperplasia, and forestomach carcinoma in mice. Bladder, intestine, liver, heart, spleen, lung, and testis tissues were not pathologically altered by AA-IIIa. In addition, AA-IIIa increased the C:G > A:T mutation in the kidney; however, no SNP mutation changes were observed in the liver and forestomach tissues of AA-IIIa-H mice at the 24-week time point compared with control mice. Therefore, we suspect that AA-IIIa is potentially mutagenic for mice after overdose and long-term administration. On the other hand, the forestomach is a unique organ in mice, but it does not exist in humans; thus, we hypothesize that the stomach toxicity induced by AA-IIIa is not a suitable reference for toxicological evaluation in humans. We recommend that Aristolochiaceae plants containing AA-IIIa should be properly supervised, and overdosing and long-term administration of drugs containing AA-IIIa should be avoided.

Growing attention on the toxicity of Chinese herbal medicine: a bibliometric analysis from 2013 to 2022

Introduction: Despite the clinical value of Chinese herbal medicine (CHM), restricted comprehension of its toxicity limits the secure and efficacious application. Previous studies primarily focused on exploring specific toxicities within CHM, without providing an overview of CHM's toxicity. The absence of a quantitative assessment of focal points renders the future research trajectory ambiguous. Therefore, this study aimed to reveal research trends and areas of concern for the past decade. Methods: A cross-sectional study was conducted on publications related to CHM and toxicity over the past decade from Web of Science Core Collection database. The characteristics of the publication included publication year, journal, institution, funding, keywords, and citation counts were recorded. Co-occurrence analysis and trend topic analysis based on bibliometric analysis were conducted on keywords and citations. Results: A total of 3,225 publications were analyzed. Number of annal publications increased over the years, with the highest number observed in 2022 (n = 475). The Journal of Ethnopharmacology published the most publications (n = 425). The most frequently used toxicity classifications in keywords were hepatotoxicity (n = 119) or drug-induced liver injury (n = 48), and nephrotoxicity (n = 40). Co-occurrence analysis revealed relatively loose connections between CHM and toxicity, and their derivatives. Keywords emerging from trend topic analysis for the past 3 years (2019-2022) included ferroptosis, NLRP3 inflammasome, machine learning, network pharmacology, traditional uses, and pharmacology. Conclusion: Concerns about the toxicity of CHM have increased in the past decade. However, there remains insufficient studies that directly explore the intersection of CHM and toxicity. Hepatotoxicity and nephrotoxicity, as the most concerned toxicity classifications associated with CHM, warrant more in-depth investigations. Apoptosis was the most concerned toxicological mechanism. As a recent increase in attention, exploring the mechanisms of ferroptosis in nephrotoxicity and NLRP3 inflammasome in hepatotoxicity could provide valuable insights. Machine learning and network pharmacology are potential methods for future studies.

Differences in p38-STAT3-S100A11 signaling after the administration of aristolochic acid I and IVa may account for the disparity in their nephrotoxicity

BACKGROUND

The safety of herbs containing aristolochic acids (AAs) has become a widespread concern. Previous reports indicate that AAs are highly nephrotoxic and carcinogenic, although there are more than 170 analogues of aristolochic acid. Not all AAs have the same degree of nephrotoxicity or carcinogenicity. Previous studies have found that aristolochic acid IVa (AA-IVa), the principal component of AAs within members of the Aristolochiaceae family, especially Asarum, a commonly used herb in China, has essentially no significant nephrotoxicity. However, several studies, including ours, have shown that aristolochic acid I (AA-I) is clearly nephrotoxic.

PURPOSE

The focus of the study was to elucidate the molecular mechanism responsible for the difference in nephrotoxicity between the AA-I and AA-IVa.

STUDY DESIGN/METHOD

Mice were administered with AA-I or AA-IVa for 22 weeks through the oral route, followed by a 50-week recovery time. The kidney tissues of mice were extracted at the end of 22 weeks. Pathological examination and proteomic detection (tandem mass tagging (TMT) and phosphorylated proteomics) were performed on the kidney tissue to investigate the key signaling pathways and targets of AAs-induced renal interstitial fibrosis (RIF). The key signaling pathways and targets were verified by Western blot (WB), siRNA transfection, and luciferase assays.

RESULTS

AA-I caused severe nephrotoxicity, high mortality, and extensive RIF. However, the same AA-IVa dosage exhibited almost no nephrotoxicity and does not trigger RIF. The activation of the p38-STAT3-S100A11 signaling pathway and upregulated expression of α smooth muscle actin (α-SMA) and Bcl2-associated agonist of cell death (Bad) proteins could be the molecular mechanism underlying AA-I-induced nephrotoxicity. On the other hand, AA-IVa did not regulate the activation of the p38-STAT3-S100A11 signaling pathway and had relatively little effect on the expression of α-SMA and Bad. Consequently, the difference in the regulation of p38-STAT3-S100A11 pathway, α-SMA, and Bad proteins between AA-I and AA-IVa may be responsible for the divergence in their level of nephrotoxicity.

CONCLUSION

This is the first study to reveal the molecular mechanism underlying the difference in nephrotoxicity between AA-I and AA-IVa. Whether STAT3 is activated or not may be the key factor leading to the difference in nephrotoxicity between AA-I and AA-IVa.

Long-term oral administration of Asarum heterotropoides f. mandshuricum (Maxim.) Kitag. decoction and its aristolochic acid analogs do not cause renal toxicity in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Asarum heterotropoides f. mandshuricum (Maxim.) Kitag. (AH) is widely used to treat influenza, COVID-19, allergic rhinitis, headache, toothache, rheumatoid arthritis, and peptic ulcer. However, its clinical use is controversial due to the concern of aristolochic acid nephropathy (AAN) caused by its component aristolochic acid analogs (AAs).

AIM OF THE STUDY

The chronic toxicity of AH decoction and its main components AA IVa (AA-IVa) and aristolactam I (AL-I) was evaluated in mice.

MATERIALS AND METHODS

AAs contents in AH were quantitated by liquid chromatography-mass spectrometry. A parallel design was employed to examine the potential chronic toxicity of AH decoction at doses equivalent to 0.5, 1.6, and 5.0 g/kg AH (approximately 10-100 times the clinical doses for humans) and its major AA components at doses equivalent to that in 5.0 g/kg AH to mice after consecutive daily oral administration for 12 and 24 weeks, and at 32 weeks after withdrawal for 8 weeks.

RESULTS

AH crude herb contained 2.18 μg/g of AA-I, 48.49 μg/g of AA-IVa, and 14.0 μg/g of AL-I. AH decoction contained 5.45 μg/g of AA-IVa and 2.71 μg/g of AL-I. None of AA-II and AA-IIIa were detected in AH. After long-term administration of AH decoction and its major components AA-IVa and AL-I, mice showed no signs of illness or body weight changes. In addition, biochemical and pathohistological examinations showed that long-term administration of AH decoction and its major components AA-IVa and AL-I did not alter 1) serum levels of glutamic-pyruvic transaminase, glutamic oxalacetic transaminase, alkaline phosphatase, creatinine, and urea nitrogen, 2) renal tissue mRNA expression of kidney injury molecule 1 and neutrophil gelatinase-associated lipocalin, and 3) pathological morphology in the mouse liver, kidney, stomach, and bladder.

CONCLUSIONS

AH has no obvious toxicity to mice and is relatively safe when it is used in the form of decoction. AA-IVa and AL-I, the two major AAs in AH, are not toxic to mice at the dose equivalent to that in the high dose of AH decoction. Considering the limited toxicological data on AH, we recommend that AH decoction medication should not overdose and the duration should not be too long.

The recognition of aristolochic acid I based on fluorescence quenching of bovine serum albumin-stabilized gold nanoclusters

Aristolochic acid I (AAI) is one of the nephrotoxic derivatives present in genera Aristolochia and Asarum. Although some detection strategies for monitoring AAI have been reported, the application of these methods is limited because they involve tedious preparation and require professional operation. In this work, bovine serum albumin (BSA) has been introduced as a reducing agent and stabilizing agent to synthesize gold nanoclusters with strong red fluorescence for the rapid and effective detection of AAI. Under excitation at 328 nm, the fluorescence intensity at the maximum emission wavelength of the bovine serum albumin-stabilized gold nanoclusters (BSA-AuNCs) decreased with the addition of AAI, and the degree of quenching showed a linear relationship with the concentration of AAI from 0.1-12.8 μg mL^-1. The obtained BSA-AuNCs were stable, and quenching in the presence of AAI could be achieved within 10 seconds. Here, we have focused on the application of these gold nanoclusters as an optical sensing material for AAI in rat urine samples, including a discussion on the detection mechanism. The detection result of the fluorescent probe was consistent with that of the HPLC method. In view of this reality, the reported protein-AuNCs sensing platform can serve as a convenient detection strategy in toxicological analyses.

Aristolochic acid and the risk of cancers in patients with type 2 diabetes: Nationwide population-based cohort study

BACKGROUND

Both aristolochic acid (AA) exposure and diabetic can increase risk of certain cancers,whetherAAexposureincreases cancer risk in diabetic patientsisunknown. The purpose of this study was to investigate the association between the use of Chinese herbal products containing AA and the risk of cancer in diabetic patients.

METHODS

A cohort study was conducted using the National Health Insurance Research Database in Taiwan. Patients older than 18 years who were diagnosed with diabetes between 1997 and 2010 were enrolled in our cohort. The use of Chinese herbal products containing AA was recorded from the beginning of 1997 until the ban of herbs containing AA in November 2003. Patients were individually tracked to identify cancer incidence between 1997 and 2013. Only patients who visited traditional Chinese medicine clinics between 1997 and 1 year before the end of follow-up were included in the cohort to ensure comparability. Cox proportional hazards regression was used to calculate the hazard ratio for the association between the use of Chinese herbal products containing AA and the occurrence of cancer.

RESULTS

Among the 430 377 male and 431 956 female patients with diabetes enrolled in our cohort, 37 554 and 31 535 cancer diagnoses were recorded during the study period, respectively. The use of AA-containing herbal products was associated with a significantly higher risk of liver, colorectum, kidney, bladder, prostate, pelvis, and ureter cancer in a dose-dependent manner. An increased risk of extrahepatic bile duct cancer in women was also associated with AA exposure at doses of more than 500 mg.

CONCLUSIONS

Association between AA exposure and the risk of some cancers were found in this study. AA exposure might increase risk of kidney,bladder,pelvis, ureter,liver,colorectum,andprostatecancer in all patientsandextrahepatic bile duct cancerin women.

Study on the potential nephrotoxicity and mutagenicity of aristolochic acid IVa and its mechanism

Previous reports demonstrated that aristolochic acids (AAs) exposure-induced nephrotoxicity, mutations, and tumorigenesis are mainly due to aristolochic acid I (AAI). Notably, the chemical structure of aristolochic acid IVa (AAIVa), which exists at higher levels in many Aristolochiaceae herbs, is extremely similar to AAI. In lack of toxicological data, it is unknown whether AAIVa exposure leads to aristolochic acid nephropathy (AAN), mutations, and tumorigenesis as of AAI. To answer these questions, mice were administered AAIVa by single or repeated long-term gavage, while AAI was used as a positive control. We found that single gavage of 40 mg/kg of AAIVa exhibited no obvious toxicity. Also, there were no tumors or death in mice administrated with 1 and 10 mg/kg of AAIVa for 6 months followed by a 12-month recovery time. There were no noteworthy alterations in gene mutation frequency in the kidney, liver, and stomach between the AAIVa and control mice. Fascinatingly, AA-associated mutational signatures, adenine-to-thymine (A>T) transversions, were absent in AAIVa-treated mice. Nonetheless, 10 mg/kg of AAIVa triggered lymphocytic infiltration and slight fibrous hyperplasia in the kidney at the 6^th month; however, these were alleviated at the 12^th and 18^th months. On the contrary, AAI (positive control) caused severe diffuse fibrosis, tubular atrophy, necrosis, tumors in the forestomach and kidney, and death after the 6^th month. It seems that long-term AAIVa exposure induced mild renal lesions could be due to the activation of the canonical or noncanonical transforming growth factor-β (TGFβ) pathway. Overall, these findings suggest that the mutagenicity and carcinogenic risk of AAIVa are very low.

Genome-wide transcriptional analysis of Aristolochia manshuriensis induced gastric carcinoma

Context: Aristolochia manshuriensis Kom (Aristolochiaceae) (AMK) is known for toxicity and mutagenicity.Objective: The tumorigenic role of AMK has yet to be understood.Materials and methods: AMK extracts were extracted from root crude drug. SD (Sprague Dawley) rats underwent gavage with AMK (0.92 g/kg) every other day for 10 (AMK-10) or 20 (AMK-20) weeks. Stomach samples were gathered for histopathological evaluation, microarray and mRNA analysis.Results: The gastric weight to body weight ratio (GW/BW) is 1.7 in the AMK-10 cohort, and 1.8 in AMK-20 cohort compared to control (CTL) cohort. Liver function was damaged in AMK-10 and AMK-20 rats compared to CTL rats. There were no significant changes of CRE (creatinine) in AMK-10 and AMK-20 rats. Histopathological analysis revealed that rats developed dysplasia in the forestomach in AMK-10 rats, and became gastric carcinoma in AMK-20 rats. Genes including Mapk13, Nme1, Gsta4, Gstm1, Jun, Mgst2, Ggt6, Gpx2, Gpx8, Calml3, Rasgrp2, Cd44, Gsr, Dgkb, Rras, and Amt were found to be critical in AMK-10 and AMK-20 rats. Pik3cb, Plcb3, Tp53, Hras, Myc, Src, Akt1, Gnai3, and Fgfr3 worked in AMK-10 rats, and PDE2a and PDE3a played a pivotal role in AMK-20 rats.Discussion and conclusions: AMK induced benign or malignant gastric tumours depends on the period of AMK administration. Genes including Mapk13, Nme1, Gsta4, Gstm1, Jun, Mgst2, Ggt6, Gpx2, Gpx8, Calml3, Rasgrp2, Cd44, Gsr, Dgkb, Rras, Amt, Pik3cb, Plcb3, Tp53, Hras, Myc, Src, Akt1, Gnai3, Fgfr3, PDE2a, and PDE3a were found to be critical in aristolochic acid-induced gastric tumour process.

Nephrotoxicity of Herbal Medicine and Its Prevention

Herbal medicine (HM) has been widely used to treat diseases for thousands of years and has greatly contributed to the health of human beings. Many new drugs have been developed from HM, such as artemisinin. However, artemisinin has adverse effects, such as renal toxicity. In 1993, a study conducted in Belgium reported for the first time that the root extracts of Aristolochia obliqua S. M. Hwang led to progressive interstitial renal fibrosis. The nephrotoxicity of HM has attracted worldwide attention. More than 100 kinds of HM induce renal toxicity, including some herbs, animal HMs, and minerals. This paper aimed to summarize the HM compounds that cause nephrotoxicity, the mechanisms underlying the toxicity of these compounds, biomarkers of renal injury, and prevention strategies. These findings provide a basis for follow-up studies on the prevention and treatment of HM nephrotoxicity.

Evaluation of the toxicity potential of acute and sub-acute exposure to the aqueous root extract of Aristolochia ringens Vahl. (Aristolochiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Aristolochia ringens Vahl. (Aristolochiaceae) is used traditionally in Nigeria for managing a number of ailments including gastrointestinal disturbances, rheumatoid arthritis, pile, insomnia, oedema, and snake bite venom. Some studies in our laboratory have demonstrated a scientific justification for some of such uses. This study aims at investigating the toxicological actions of the aqueous root extract of Aristolochia ringens (AR).

MATERIALS AND METHODS

Brine shrimp lethality assay was carried out using 10, 100 and 1000 μg/ml of the extract. Oral and intraperitoneal acute toxicity tests were carried out using mice. The effect of sub-acute (30 days) repeated oral exposure to the extract at 10, 50 and 250 mg/kg in rats was also evaluated via weekly assessments of body weights and general observations as well as end of exposure haematological, biochemical and histological examinations of blood and tissue samples of treated rats. Phytochemical analyses to determine the presence of aristolochic acid I in the extract was also carried out using high performance liquid chromatography (HPLC).

RESULTS

The aqueous root extract of A. ringens showed potential for biological activity and cytotoxicity with an LC₅₀ of 175 μg/ml in brine shrimps. AR was found to be relatively safe on acute oral exposure with LD₅₀ estimated to be greater than 10 g/kg, while its LD₅₀ on intraperitoneal administration was 407.38 mg/kg. Upon 30 days sub-chronic exposure, AR induced significant weight loss in female rats, enlargement of male rats' stomach, oxidative stress in male and female rats' kidney and liver tissues and disruption of leukocytes level in female rats. It also showed evidence of kidney and liver injuries inducible by oxidative damage and the potential to cause male sterility. HPLC revealed the presence of 0.003 mg/1 g of aristolochic acid in AR.

CONCLUSION

These results show that AR contains detectible aristolochic acid I and has potential to induce toxic responses. Caution must therefore be exercised in its medicinal application especially when required for a prolonged use.

Systematic Overview of Aristolochic Acids: Nephrotoxicity, Carcinogenicity, and Underlying Mechanisms

Aristolochic acids (AAs) are a group of toxins commonly present in the plants of genus Aristolochia and Asarum, which are spread all over the world. Since the 1990s, AA-induced nephropathy (AAN) and upper tract urothelial carcinoma (UTUC) have been reported in many countries. The underlying mechanisms of AAN and AA-induced UTUC have been extensively investigated. AA-derived DNA adducts are recognized as specific biomarkers of AA exposure, and a mutational signature predominantly characterized by A→T transversions has been detected in AA-induced UTUC tumor tissues. In addition, various enzymes and organic anion transporters are involved in AA-induced adverse reactions. The progressive lesions and mutational events initiated by AAs are irreversible, and no effective therapeutic regimen for AAN and AA-induced UTUC has been established until now. Because of several warnings on the toxic effects of AAs by the US Food and Drug Administration and the regulatory authorities of some other countries, the sale and use of AA-containing products have been banned or restricted in most countries. However, AA-related adverse events still occur, especially in the Asian and Balkan regions. Therefore, the use of AA-containing herbal remedies and the consumption of food contaminated by AAs still carry high risk. More strict precautions should be taken to protect the public from AA exposure.

Aristolochic acid I aggravates renal injury by activating the C3a/C3aR complement system

Previous studies have reported that the complement system is unconventionally activated in many kinds of glomerulonephritis. Multiple complement components participate in the pathogenic process by triggering immune response or other intracellular signaling pathways. Here, we have investigated the role of C3a and its receptor C3aR in aristolochic acid nephropathy (AAN), which, is featured with progressive interstitial fibrosis. Over release of C3a and increased expression of C3aR parallels to the up-regulation of α-SMA and TGF-β1 in AAN, which appeared to promote epithelial-mesenchymal-transition (EMT). To identify the role of complement activation in AAN, we used an inhibitor of C3aR (C3aRA) to block the coupling of C3a to its receptor. Our results confirmed from decreased EMT, the protective effect of C3aRA in cell apoptosis and inflammatory response induced by aristolochic acid I. These results showed that C3a and its receptor C3aR played pathogenic roles in AAN, and renal tubular epithelial cells were potentially pivotal targets of complement activation that could cause pro-fibrotic effects.