Bruceine B Displays Potent Antimyeloma Activity by Inducing the Degradation of the Transcription Factor c-Maf.

The oncogenic transcription factor c-Maf has been proposed as an ideal therapeutic target for multiple myeloma (MM), a not-yet-curable malignancy of plasma cells. In the present study, we establish a c-Maf-based luciferase screen system and apply it to screen a homemade library composed of natural products from which bruceine B (BB) is identified to display potent antimyeloma activity. BB is a key ingredient isolated from the Chinese traditional medicinal plant Brucea javanica (L.) Merr. (Simaroubaceae). BB inhibits MM cell proliferation and induces MM cell apoptosis in a caspase-3-dependent manner. The mechanism studies showed that BB inhibits c-Maf transcriptional activity and downregulates the expression of CCND2 and ITGB7, the downstream genes typically modulated by c-Maf. Moreover, BB induces c-Maf degradation via proteasomes by inducing c-Maf for K48-linked polyubiquitination in association with downregulated Otub1 and USP5, two proven deubiquitinases of c-Maf. We also found that c-Maf activates STAT3 and BB suppresses the STAT3 signaling. In the in vivo study, BB displays potent antimyeloma activity and almost suppresses the growth of myeloma xenografts in 7 days but shows no overt toxicity to mice. In conclusion, this study identifies BB as a novel inhibitor of c-Maf by promoting its degradation via the ubiquitin-proteasomal pathway. Given the safety and the successful clinical application of bruceine products in traditional medicine, BB is ensured for further investigation for the treatment of patients with MM.

Melatonin Suppresses Cyclic GMP-AMP Synthase-Stimulator of Interferon Genes Signaling and Delays the Development of Hearing Loss in the C57BL/6J Presbycusis Mouse Model.

Melatonin supplementation has been shown to delay age-related hearing loss (ARHL) progression. Previously, melatonin was found to inhibit neuronal mitochondrial DNA (mtDNA) release, as well as inhibit cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling, thereby delaying the onset of central nervous system diseases. Therefore, we hypothesized that melatonin may delay the progression of hearing loss in the C57BL/6J presbycusis mouse model by inhibiting cGAS-STING signaling in the auditory pathway. Oral melatonin at 10 mg/kg/d was administered to 3-month-old C57BL/6J mice until 12 months of age. The auditory brainstem response (ABR) threshold was used to assess their hearing ability. By real-time polymerase chain reaction and Western blot analysis, the levels of cytosolic mtDNA, cGAS/STING, and cytokines were examined in the mouse cochlea, inferior colliculus, and auditory cortex. We found that the 12-month-old control mice exhibited significant hearing loss, increased cytosolic mtDNA, increased expression of inflammatory factors TNF-α, IL-6, IFN-ß, Cxcl10, and Ifit3, up-regulated cGAS and STING expression, and enhanced interferon regulatory factor 3 (IRF3) phosphorylation in the C57BL/6J mouse cochlea, inferior colliculus, and auditory cortex. Melatonin treatment significantly improved hearing, decreased cytosolic mtDNA, suppressed the expression of inflammatory cytokines TNF-α, IL-6, IFN-ß, Ifit3, and Cxcl10, down-regulated cGAS and STING expression, and attenuated IRF3 phosphorylation in the C57BL/6J mouse cochlea, inferior colliculus, and auditory cortex. This study suggested that melatonin had a protective effect on auditory function in the C57BL/6J presbycusis mouse model, which may be mediated through reducing mtDNA release, inhibiting the cGAS-STING signaling pathway in the auditory pathway.

Jiedu-Yizhi Formula Alleviates Neuroinflammation in AD Rats by Modulating the Gut Microbiota.

Background: The Jiedu-Yizhi formula (JDYZF) is a Chinese herbal prescription used to treat Alzheimer's disease (AD). It was previously confirmed that JDYZF can inhibit the expression of pyroptosis-related proteins in the hippocampus of AD rats and inhibit gut inflammation in AD rats. Therefore, it is hypothesized that JDYZF has a regulatory effect on the gut microbiota. Methods: In this study, an AD rat model was prepared by bilateral hippocampal injection of Aß 25-35 and AD rats received high, medium, and low doses of JDYZF orally for 8 weeks. The body weights of the AD rats were observed to assess the effect of JDYZF. The 16S rRNA sequencing technique was used to study the regulation of the gut microbiota by JDYZF in AD rats. Immunohistochemical staining was used to observe the expression levels of Caspase-1 and Caspase-11 in the hippocampus. Results: JDYZF reduced body weight in AD rats, and this effect may be related to JDYZF regulating body-weight-related gut microbes. The 16S rRNA analysis showed that JDYZF increased the diversity of the gut microbiota in AD rats. At the phylum level, JDYZF increased the abundances of Bacteroidota and Actinobacteriota and decreased the abundances of Firmicutes, Campilobacterota, and Desulfobacterota. At the genus level, the abundances of Lactobacillus, Prevotella, Bacteroides, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, and Blautia were increased and the abundances of Lachnospiraceae-NK4A136-group, Anaerobiospirillum, Turicibacter, Oscillibacter, Desulfovibrio, Helicobacter, and Intestinimonas were decreased. At the species level, the abundances of Lactobacillus johnsonii, Lactobacillus reuteri, and Lactobacillus faecis were increased and the abundances of Helicobacter rodentium and Ruminococcus_sp_N15.MGS-57 were decreased. Immunohistochemistry showed that JDYZF reduced the levels of Caspase-1- and Caspase-11-positive staining. Conclusion: JDYZF has a regulatory effect on the gut microbiota of AD rats, which may represent the basis for the anti-inflammatory effect of JDYZF.

Jiedu-Yizhi Formula Improves Cognitive Impairment in an Aß 25-35-Induced Rat Model of Alzheimer's Disease by Inhibiting Pyroptosis.

Jiedu-Yizhi formula (JDYZF) is prescribed for the treatment of Alzheimer's disease (AD) and was created by Jixue Ren, a master of traditional Chinese medicine, based on the "marrow deficiency and toxin damage" theory. In our clinic, this formula has been used for the treatment of AD for many years and has achieved good results. However, the mechanism by which JDYZF improves cognitive impairment has not been determined. In this study, we confirmed that orally administered JDYZF reversed the cognitive deficits in an Aß 25-35-induced rat model, increased the number of neurons in the hippocampal CA1 area, improved their structure, decreased the deposition of ß-amyloid (Aß), reduced the expression of proteins related to the NLRP3/Caspase-1/GSDMD and LPS/Caspase-11/GSDMD pyroptosis pathways, and reduced the levels of interleukin 1ß (IL-1ß) and IL-18, thereby inhibiting the inflammatory response. In addition, JDYZF exerted no hepatotoxicity in rats. In short, these results provide scientific support for the clinical use of JDYZF to improve the cognitive function of patients with AD.

Capparis spinosa Alleviates DSS-Induced Ulcerative Colitis via Regulation of the Gut Microbiota and Oxidative Stress.

Ulcerative colitis (UC) is a chronic inflammatory disease. Here, the potential effects of Capparis spinosa water extract (CSWE) on colonic histopathology, inflammation, and gut microbiota composition in dextran sulfate sodium (DSS) induced UC mice were evaluated. Our results showed that CSWE treatment improved the colonic histopathology of UC mice, increased the levels of tight junction protein gene ZO-1 and Occludin in intestinal epithelial cells, and inhibited the expression of proinflammatory cytokines (IL-1ß, IL-6, and TNF-α). Furthermore, CSWE administration alleviated oxidative stress in the colon of UC mice. The effects of CSWE on the compositions and metabolomic profiles of the gut microbiota in UC mice were investigated. It was found that CSWE could enhance the diversity of gut microbes and the abundance of probiotics and metabonomics had the strongest association with Firmicutes. Our results indicated that CSWE might be an ideal candidate as a potential therapeutic natural product for the treatment of UC.

[The improvement effects of Yiqi Huashi Tongluo Formula on oxidative stress and renal fibrosis of experimental CRF rats].

OBJECTIVE: Effects of Yiqi Huashi Tongluo Formula on oxidative stress and renal fibrosis of residual kidney were investigated in five/sixth nephrectomy rats. METHODS: The rat model of chronic renal failure after nephrectomy was established by Platt method. Two weeks after the operation, the rats were randomly divided into model group, Yiqi Huashi Tongluo Formula (YHT) group, benazepril online (BH) group and sham group, with 8 rats in each group. Treatment was initiated once a day for 12 weeks after successful modeling. Animals were treated once a day with intragastric administration for 12 weeks. (Aqueous solution of free decoction granules in YHT group was 0.276 g/100 g·d. BH group benazepril hydrochloride tablet aqueous solution 0.09 mg/100 g·d gavage; sham group and model group were gavage with 1 ml/100 g normal saline). Urine was collected with a metabolic cage at the end of the 12th week, and urine protein content was detected for 24 hours. The rats were then anesthetized to extract blood from the abdominal aorta and the kidneys. The pathological changes of left kidney were observed by HE staining and Masson staining. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in kidney homogenate were determined by colorimetry. Western blot assay was used to detect the expressions of nuclear factor-erythroid 2-related factor 2 (Nrf2), kelch-like ech-associated protein-1 (Keap1), NADPH oxidase 4 (Nox4), transforming growth factor-binding 1(TGF-ß1), type I collagen (Collagen1) and Nrf2 in the nucleus in renal tissue. RESULTS: Compared with sham group, model group rats had severe glomerular injury and obvious fibrosis. Levels of Scr, BUN, MDA and 24-hour urine protein excretion, protein expressions of Keap1, Nox4, TGF-ß1 and Collagen1 were significantly increased (P＜0.01), while SOD activity and Nrf2 expression were significantly decreased (P＜0.01).Compared with the model group, the degree of glomerular lesion was reduced and fibrosis was less after YHT or BH intervention, and the levels of Scr, BUN, MDA, 24-hour urine protein excretion, protein expressions of Keap1, Nox4, TGF-ß1 and Collagen1 were significantly decreased (P＜0.01), while SOD activity and Nrf2 expression were significantly increased (P＜0.01). CONCLUSION: Through affecting the Nrf2/Keap1 signaling pathway and down-regulating the expression of TGF-ß1 protein, Yiqi Huashi Tongluo Formula improved the oxidative stress damage and fibrosis degree of residual kidney in the model rats with renal failure.

Inhibiting c-Jun N-terminal kinase (JNK)-mediated apoptotic signaling pathway in PC12 cells by a polysaccharide (CCP) from Coptis chinensis against Amyloid-ß (Aß)-induced neurotoxicity.

In this study, we investigated the protective effect and possible mechanism of a polysaccharide (CCP) from Coptis chinensis against Amyloid-ß protein (Aß)-induced toxicity in PC12 cells. The results showed pretreatment with CCP significantly protected PC12 cells from Aß25-35 induced cell death, lactate dehydrogenase (LDH) release, nuclear fragmentation, mitochondrial dysfunction and cytochrome c release from mitochondria. Furthermore, CCP (100 µg/ml) significantly inhibited Aß25-35 induced c-Jun N-terminal kinase (JNK) phosphorylation, but not influence signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (p38MAPK) pathway, and interestingly, the promoting effect of CCP on PC12 cell survival was only blocked by pre-treatment with a SP600125 (JNK inhibitor). In addition, Aß25-35-induced increase of Bax and cleaved caspase-3, as well as decrease of Bcl-2 protein expression was markedly reversed by CCP or SP600125. Thus, our results indicate that the neuroprotective effect of CCP is associated with JNK-dependent apoptotic pathway.