Aristolochic acid I exposure triggers ovarian dysfunction by activating NLRP3 inflammasome and affecting mitochondrial homeostasis

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.

Treatment of Parkinson's disease model with human umbilical cord mesenchymal stem cell-derived exosomes loaded with BDNF

AIMS

Parkinson's disease (PD) is a common neurodegenerative disease that has received widespread attention; however, current clinical treatments can only relieve its symptoms, and do not effectively protect dopaminergic neurons. The purpose of the present study was to investigate the therapeutic effects of human umbilical cord mesenchymal stem cell-derived exosomes loaded with brain-derived neurotrophic factor (BDNF-EXO) on PD models and to explore the underlying mechanisms of these effects.

MAIN METHODS

6-Hydroxydopamine was used to establish in vivo and in vitro PD models. Western blotting, flow cytometry, and immunofluorescence were used to detect the effects of BDNF-EXO on apoptosis and ferroptosis in SH-SY5Y cells. The in vivo biological distribution of BDNF-EXO was detected using a small animal imaging system, and dopaminergic neuron improvements in brain tissue were detected using western blotting, immunofluorescence, immunohistochemistry, and Nissl and Prussian blue staining.

KEY FINDINGS

BDNF-EXO effectively suppressed 6-hydroxydopamine-induced apoptosis and ferroptosis in SH-SY5Y cells. Following intravenous administration, BDNF-EXO crossed the blood-brain barrier to reach afflicted brain regions in mice, leading to a notable enhancement in neuronal survival. Furthermore, BDNF-EXO modulated microtubule-associated protein 2 and phosphorylated tau expression, thereby promoting neuronal cytoskeletal stability. Additionally, BDNF-EXO bolstered cellular antioxidant defense mechanisms through the activation of the nuclear factor erythroid 2-related factor 2 signaling pathway, thereby conferring neuroprotection against damage.

SIGNIFICANCE

The novel drug delivery system, BDNF-EXO, had substantial therapeutic effects in both in vivo and in vitro PD models, and may represent a new treatment strategy for PD.

Accumulated inflammation and fibrosis participate in atrazine induced ovary toxicity in mice

Atrazine is a widely used herbicide in agricultural production. Previous studies have shown that atrazine affects hormone secretion and oocyte maturation in female reproduction. However, the specific mechanism by which atrazine affects ovarian function remains unclear. In this study, using a mouse gastric lavage model, we report that four weeks of atrazine exposure affects body growth, interferes with the estrous cycle, and increases the number of atretic follicles in mice. The expression levels of follicle development related factors StAR, BMP15, and AMH decreased. Metabolomic analysis revealed that atrazine activates an inflammatory response in ovarian tissue. Further studies confirmed that the expression levels of TNF-α, IL-6, and NF-κB increased in the ovaries of mice exposed to atrazine. Additionally, α-smooth muscle actin (α-SMA) accumulated in ovarian tissue, and transforming growth factor-β (TGF-β) signaling was activated, indicating the occurrence of tissue fibrosis. Moreover, mice exposed to atrazine produced fewer oocytes and exhibited reduced embryonic development. Furthermore, mice exposed to atrazine exhibited altered gut microbiota abundance and a disrupted colon barrier. Collectively, these findings suggest that atrazine exposure induces ovarian inflammation and fibrosis, disrupts ovarian homeostasis, and impairs follicle maturation, ultimately reducing oocyte quality.

Catalpol from Rehmannia glutinosa Targets Nrf2/NF-[Formula: see text]B Signaling Pathway to Improve Renal Anemia and Fibrosis

Rehmannia glutinosa is widely recognized as a prominent medicinal herb employed by practitioners across various generations for the purpose of fortifying kidney yin. Within Rehmannia glutinosa, the compound known as catalpol (CAT) holds significant importance as a bioactive constituent. However, the protective effects of CAT on kidneys, including ameliorative effects on chronic kidney disease - most prominently renal anemia and renal fibrosis - have not been clearly defined. In this study, the kidney injury model of NRK-52E cells and C57BL/6N male mice was prepared by exposure to aristolochic acid I (AA-I), and it was discovered that CAT could ameliorate oxidative stress injury, inflammatory injury, apoptosis, renal anemia, renal fibrosis, and other renal injuries both in vivo and in vitro. Further treatment of NRK-52E cells with Nrf2 inhibitors (ML385) and activators (ML334), as well as NF-[Formula: see text]B inhibitors (PDTC), validated CAT's ability to target Nrf2 activation. Furthermore, the expression of phosphorylated NF-[Formula: see text]B p65, IL-6, and Cleaved-Caspase3 protein was inhibited. CAT also inhibited NF-[Formula: see text]B, and then inhibited the expression of IL-6, p-STAS3, TGF-[Formula: see text]1 protein. Therefore, CAT can regulate Nrf2/NF-[Formula: see text]B signaling pathway, significantly correct renal anemia and renal fibrosis, and is conducive to the preservation of renal structure and function, thus achieving a protective effect on the kidneys.

Establishment of enzyme-linked immunosorbent assay for aristolochic acid

In recent years, the nephrotoxicity and carcinogenicity of aristolochic acid have attracted worldwide attention, and the traditional Chinese medicine containing this ingredient has been banned in many places, affecting the TCM industry. To meet this challenge, researchers have developed various detection methods, such as high-performance liquid chromatography, gas chromatography-mass spectrometry and thin-layer chromatography. A rapid detection method must therefore be developed to ensure safety. A polyclonal antibody capable of recognizing aristolochic acid was prepared, and an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established to detect the amount of aristolochic acid in the sample to be measured. Methods Using 1-(4-chlorophenyl) cyclobutylamine as a hapten, immunogens and coating antigens were obtained by coupling with bovine serum albumin (BSA) and chicken ovalbumin (OVA) using the active ester method. UV scanning confirmed the successful coupling of the conjugate, and New Zealand white rabbits were immunized. The obtained antibody serum was screened for the best antibody by ic-ELISA detection. Use the chessboard method to determine three optimal combinations of original coating concentration and antibody dilution ratio, establish a standard curve for each combination to obtain the best combination, and establish a rapid detection method. Finally, the standard aristolochic acid A was added to the purchased apple vinegar and canned coffee for recycling experiments to verify the detection method.By changing the antigen antibody concentration, the antibody showed the highest sensitivity to aristolochic acid standard at the original coating, 1000-fold dilution, IC50 of 24.88 ng/mL, limit of detection IC10 of 3.19 ng/mL, and detection range IC20-IC80 of 6.81-90.91 ng/mL. The recovery experiments under this conditions yielded a recovery rate of 92%-105%, within reasonable limits, indicating the success of the ELISA rapid detection method. Conclusion The enzyme-linked immunoassay method established in this paper can quickly detect the content of aristolochic acid in the sample to be tested, and the antibody prepared by this method has good broad-spectrum and can detect other aristolochic acid, such as aristolochic acid A, aristolochic acid B, aristolochic acid C, and aristolochic acid D.

Histone deacetylase-mediated silencing of PSTPIP2 expression contributes to aristolochic acid nephropathy-induced PANoptosis

BACKGROUND AND PURPOSE

Aristolochic acid nephropathy (AAN) is a progressive kidney disease caused by using herbal medicines. Currently, no therapies are available to treat or prevent aristolochic acid nephropathy. Histone deacetylase (HDAC) plays a crucial role in the development and progression of renal disease. We tested whether HDAC inhibitors could prevent aristolochic acid nephropathy and determined the underlying mechanism.

EXPERIMENTAL APPROACH

HDACs expression in the aristolochic acid nephropathy model was examined. The activation of PANoptosis of mouse kidney and renal tubular epithelial cell were assessed after exposure to HDAC1 and HDAC2 blockade. Kidney-specific knock-in of proline-serine-threonine-phosphatase-interacting protein 2 (PSTPIP2) mice were used to investigate whether PSTPIP2 affected the production of PANoptosome.

KEY RESULTS

Aristolochic acid upregulated the expression of HDAC1 and HDAC2 in the kidneys. Notably, the HDAC1 and HDAC2 specific inhibitor, romidepsin (FK228, depsipeptide), suppressed aristolochic acid-induced kidney injury, epithelial cell pyroptosis, apoptosis and necroptosis (PANoptosis). Moreover, romidepsin upregulated PSTPIP2 in renal tubular epithelial cells, which was enhanced by aristolochic acid treatment. Conditional knock-in of PSTPIP2 in the kidney protected against aristolochic acid nephropathy. In contrast, the knockdown of PSTPIP2 expression in PSTPIP2-knock-in mice restored kidney damage and PANoptosis. PSTPIP2 function was determined in vitro using PSTPIP2 knockdown or overexpression in mouse renal tubular epithelial cells (mTECs). Additionally, PSTPIP2 was found to regulate caspase 8 in aristolochic acid nephropathy.

CONCLUSION AND IMPLICATIONS

HDAC-mediated silencing of PSTPIP2 may contribute to aristolochic acid nephropathy. Hence, HDAC1 and HDAC2 specific inhibitors or PSTPIP2 could be valuable therapeutic agents for preventing aristolochic acid nephropathy.

Comprehensive HRMS Screening and Risk Assessments of Aristolochic Acid Analogues in Asari Radix et Rhizoma and Related Commercial Health Products

Aristolochic acid analogues (AAAs) are well-known toxins. We performed the first comprehensive screening on AAAs in Asari Radix et Rhizoma (underground part of Asarum heterotropoides Schmidt), the only Aristolochiaceae plant widely used in clinical practice. LC-HRMS revealed 70 trace AAAs using polygonal mass defect filtering and precursor ion list strategies, 38 of which were newly discovered in A. heterotropoides. UHPLC-QTrap-MS/MS was then utilized for quantitative/semiquantitative analysis of 26 abundant compounds. Seventeen AAAs were detected from 91 batches of A. heterotropoides and 20 AAAs from 166 consumable products. For 141 Asari-containing proprietary products, aristolactam I and aristolactam II-glucoside exhibited the widest distribution, present in 98% products. AA IVa was the most abundant, detected in 91%. Notably, 60% of the products contained AA I (0.03-0.79 ppm). The safety was assessed using linear extrapolation, permitted daily exposure, cumulative amount, and the margin of exposure. It is recommended that AA I content be limited to 3 ppm.

Rosmarinic acid mitigates acrylamide induced neurotoxicity via suppressing endoplasmic reticulum stress and inflammation in mouse hippocampus

BACKGROUND

Acrylamide (ACR) is a widely used compound that is known to be neurotoxic to both experimental animals and humans, causing nerve damage. The widespread presence of ACR in the environment and food means that the toxic risk to human health can no longer be ignored. Rosmarinic acid (RA), a natural polyphenolic compound extracted from the perilla plant, exhibits anti-inflammatory, antioxidant, and other properties. It has also been demon strated to possess promising potential in neuroprotection. However, its role and potential mechanism in treating ACR induced neurotoxicity are still elusive.

PURPOSE

This study explores whether RA can improve ACR induced neurotoxicity and its possible mechanism.

METHODS

The behavioral method was used to study RA effect on ACR exposed mice's neurological function. We studied its potential mechanism through metabolomics, Nissl staining, HE staining, immunohistochemical analysis, and Western blot.

RESULTS

RA pretreatment reversed the increase in mouse landing foot splay and decrease in spontaneous activity caused by 3 weeks of exposure to 50 mg/kg/d ACR. Further experiments demonstrated that RA could prevent ACR induced neuronal apoptosis, significantly downregulate nuclear factor-κB and tumor necrosis factor-α expression, and inhibit NOD-like receptor protein 3 inflammasome activation, thereby reducing inflammation as confirmed by metabolomics results. Additionally, RA treatment prevented endoplasmic reticulum stress (ERS) caused by ACR exposure, as evidenced by the reversal of significant P-IRE1α,TRAF2,CHOP expression increase.

CONCLUSION

RA alleviates ACR induced neurotoxicity by inhibiting ERS and inflammation. These results provide a deeper understanding of the mechanism of ACR induced neurotoxicity and propose a potential new treatment method.

Quantum Dot-Based Immunoassays: Unraveling Sensitivity Discrepancies and Charting Future Frontiers

The 2023 Nobel Prize in Chemistry honors the groundbreaking contributions of Alexei Ekimov, Louis Brus, and Moungi Bawendi to the field of quantum dots (QDs). In this spirit, we developed a direct competitive QD fluorescence immunoassay (dc-QD-FLISA) to detect aristolochic acid type I (AAI), a potent carcinogen found in herbal remedies. Unexpectedly, the dc-QD-FLISA exhibited lower sensitivity than that of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), contrary to our initial expectations. This discrepancy in the sensitivity prompted a comprehensive analysis of the entire experimental process. We propose that steric hindrance between QDs and antigen-binding sites on antibodies may significantly diminish the binding efficiency, reducing sensitivity within the dc-QD-FLISA method. Furthermore, issues such as buffer conditions, antibody handling, and separation methods are also contributing factors. We recommend site-directed QD modification and stringent consideration of the experimental conditions. This study not only provides insights into QD-based immunoassays but also highlights the need for future advancements in immunoassay technology in terms of augmenting sensitivity and specificity, potentially revolutionizing disease diagnosis, biomarker discovery, and biomedical research.