Co-catalpol alleviates fluoxetine-induced main toxicity: Involvement of ATF3/FSP1 signaling-mediated inhibition of ferroptosis.

BACKGROUND: Fluoxetine is often used as a well-known first-line antidepressant. However, it is accompanied with hepatogenic injury as its main organ toxicity, thereby limiting its application despite its superior efficacy. Fluoxetine is commonly traditionally used combined with some Chinese antidepressant prescriptions containing Rehmannia glutinosa (Dihuang) for depression therapy and hepatoprotection. Our previous experiments showed that co-Dihuang can alleviate fluoxetine-induced liver injury while efficiencies, and catalpol may be the key ingredient to characterize the toxicity-reducing and synergistic effects. However, whether co-catalpol can alleviate fluoxetine-induced liver injury and its toxicity-reducing mechanism remain unclear. PURPOSE: On the basis of the first recognition of the dose and duration at which pre-fluoxetine caused hepatic injury, co-catalpol's alleviation of fluoxetine-induced hepatic injury and its pathway was comprehensively elucidated. METHOD AND RESULTS: The hepatoprotection of co-catalpol was evaluated by serum biochemical indexes sensitive to hepatic injury and multiple staining techniques for hepatic pathologic analysis. Subsequently, the pathway by which catalpol alleviated fluoxetine-induced hepatic injury was predicted by network pharmacology to be predominantly the inhibition of ferroptosis. These were validated and confirmed in subsequent experiments with key technologies and diagnostic reagents related to ferroptosis. Further molecular docking showed that activating transcription factor 3 (ATF3) and ferroptosis suppressor protein 1 (FSP1) were the the most prospective molecules for catalpol and fluoxetine among many ferroptosis-related molecules. The critical role of ATF3/FSP1 signaling was further observed by surface plasmon resonance, diagnostic reagents, transmission electron microscopy, Western blot, real-time PCR, immunofluorescence, and immunohistochemistry. Results showed that fluoxetine directly bound to ATF3 and FSP1; agonisting ATF3 or blocking FSP1 abolished the alleviation of catalpol on fluoxetine-induced liver injury, and both exacerbated ferroptosis. Moreover, co-catalpol significantly enhanced the antidepressant efficacy of fluoxetine against depressive behaviours in mice. CONCLUSION: The hepatic impairment properties of fluoxetine were largely dependent on ATF3/FSP1 target-mediated ferroptosis. Co-catalpol alleviated fluoxetine-induced hepatic injury while enhancing its antidepressant efficacy, and that ATF3/FSP1 signaling-mediated inhibition of ferroptosis was involved in its co-administration detoxification mechanism. This study was the first to reveal the hepatotoxicity characteristics, targets, and mechanisms of fluoxetine; provide a detoxification and efficiency regimen by co-catalpol; and elucidate the detoxification mechanism.

[Preliminary exploration of detoxification mechanism of processing methods on cardiotoxicity induced by radix Tripterygium wilfordii in mice via Nrf2/HO-1 pathway].

This study aims to investigate the detoxification effects of different processing methods on the cardiotoxicity induced by radix Tripterygium wilfordii, and preliminarily explore the detoxification mechanism via the nuclear factor E2-related factor 2(Nrf2)/heme oxygenase 1(HO-1) pathway. The raw and processed products [stir-fried product, product stir-fried with Lysimachiae Herba(JQC), product stir-fried with Phaseoli Radiati Semen(LD), product stir-fried with Paeoniae Radix Alba(BS), product stir-fried with Glycyrrhizae Radix et Rhizoma(GC), and product stir-fried with vinegar(CZ)] of radix T. wilfordii were administrated to mice by gavage at a dose of 2 g·kg~(-1)(based on crude drugs) for 28 days. Twenty-four hours after the last administration, we measured the serum biochemical indexes of mice to evaluate the detoxification effect. Furthermore, we determined the expression of key proteins of Nrf2/HO-1 pathway in mouse heart tissue by Western blot and some oxidation/antioxidation-related indexes by corresponding kits to explore the detoxification mechanism. The administration of the raw product elevated the levels of serum creatine kinase, lactate dehydrogenase, and malondialdehyde, a product of cardiac lipid peroxidation(P<0.01), down-regulated the protein levels of Nrf2 and HO-1(P<0.01), and reduced the levels of total superoxide dismutase, glutathione, glutathione peroxidase, and glutathione S-transferase(P<0.01). However, after the administration of the products stir-fried with JQC, LD, BS, GC, and CZ, the abnormalities of the above indexes induced by the raw product were recovered(P<0.05 or P<0.01). In particular, the product stir-fried with JQC showed the best performance. Taken all together, the cardiotoxicity induced by radix T. wilfordii could be attenuated by stir-frying with JQC, LD, BS, GC, and CZ, and the stir-frying with JQC showed the best detoxification effect. The mechanism might be associated with the cardiac antioxidant defense and oxidative damage mitigation mediated by the up-regulated Nrf2.

Catalpol Weakens Depressive-like Behavior in Mice with Streptozotocin-induced Hyperglycemia via PI3K/AKT/Nrf2/HO-1 Signaling Pathway.

Depression has huge social risks of high incidence, disability, and suicide. Its prevalence and harm in people with hyperglycemia are 2-3 times higher than in normal people. However, antidepressants with precise curative effects and clear mechanisms for patients with hyperglycemia are currently lacking. Prescriptions containing Radix Rehmannia glutinosa Libosch., a traditional medicinal herb with a wide range of nutritional and medicinal values, are often used as antidepressants in Chinese clinical medicine. Catalpol is one of the main effective compounds of Radix R. glutinosa, with multiple biological activities such as hypoglycemia. Here, the antidepressant effect of catalpol on the pathological state of streptozotocin (STZ)-induced hyperglycemia and the underlying molecular mechanisms were analyzed. Results showed that administering catalpol orally to hyperglycemic mice for 21 consecutive days significantly reversed the abnormalities in tail suspension, forced swimming, and open field tests. Catalpol also reversed the abnormal phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) and the abnormal levels of nuclear factor erythroid 2-related factor 2 (Nrf2) protein, heme oxygenase-1 (HO-1), and antioxidants, including superoxide dismutase, glutathione peroxidase, glutathione-s transferase, reduced glutathione, and malondialdehyde in the hippocampus and frontal cortex of STZ-induced hyperglycemic mice. Thus, catalpol attenuates depressive-like behavior in pathological hyperglycemic state, and the antidepressant mechanism could at least be partly attributed to the upregulation of the PI3K/AKT/Nrf2/HO-1 signaling pathway in both brain regions, thus restoring the balance between oxidative and antioxidant damage. These data expanded the scientific understanding of catalpol and provided preclinical experimental evidence for its application.

[Processing technology for reducing toxicity of fried Tripterygium wilfordii in Lysimachia christinae decoction].

On the basis of the previous work of the research group, the orthogonal design method was further used to optimize the processing technology for reducing toxicity of fried Tripterygium wilfordii in Lysimachia christinae Decoction. A total of 9 processed products of T.wilfordii in L.christinae decoction were prepared by four factors and three levels orthogonal design table. The contents of triptolide in T.wilfordii were determined by high performance liquid chromatography(HPLC) before and after processing: 4.27, 3.92, 3.57, 2.75, 2.42, 2.66, 3.51, 1.87, 1.75, 2.03 µg·g~(-1). On this basis, the above processed products were orally given to mice for 28 days. 12 hours after the last administration, food fasting except water was provided, and 24 hours later, the eyeballs were taken for blood and liver tissue. Serum biochemical indexes, liver lipid peroxidation and antioxidant related indexes were detected by kit method. Twenty-eight days after oral administration of raw T.wilfordii, the levels of serum alanine aminotransferase(AST), alanine aminotransferase(ALT), alkaline phosphatase(ALP) and liver malondialdehyde(MDA) in mice increased by 91%(P<0.01), 46%(P<0.05), 73%(P<0.01) and 99%(P<0.01), while the liver antioxidant indexes such as superoxide dismutase(SOD), glutathione(GSH), glutathione peroxidase(GPX) and glutathione-S transferase(GST) significantly decreased(P<0.01). After administration of the processed products, the above indexes were significantly reversed(P<0.01 or P<0.05). Especially, the processing conditions of A_3B_2C_1D_3 had the best detoxification effect on T.wilfordii, which decreased the high levels of AST, ALT, ALP and MDA by 49%(P<0.01), 32%(P<0.01), 42%(P<0.01), and 17%(P<0.05). Therefore, the best processing conditions for T.wilfordii in L.christinae decoction were A_3B_2C_1D_3, namely "15% mass fraction of L.christinae, 1 h moistening time, 160 ℃ frying temperature, and 9 min frying time".