Total alkaloids of Fritillaria unibracteata var. wabuensis bulbus ameliorate chronic asthma via the TRPV1/Ca2+/NFAT pathway.

BACKGROUND: Asthma is a chronic inflammatory disease that is challenging to treat. Fritillaria unibracteata var. wabuensis (FUW) is the plant origin for the famous Chinese antitussive medicine Fritillaria Cirrhosae Bulbus. The total alkaloids of Fritillaria unibracteata var. wabuensis bulbus (TAs-FUW) have anti-inflammatory properties and may be used to treat asthma. PURPOSE: To explore whether TAs-FUW have bioactivity against airway inflammation and a therapeutic effect on chronic asthma. METHODS: The alkaloids were extracted via ultrasonication in a cryogenic chloroform-methanol solution after ammonium-hydroxide percolation of the bulbus. UPLC-Q-TOF/MS was used to characterize the composition of TAs-FUW. An ovalbumin (OVA)-induced asthmatic mouse model was established. We used whole-body plethysmography, ELISA, western blotting, RT-qPCR, and histological analyses to assess the pulmonary pathological changes in these mice after TAs-FUW treatment. Additionally, TNF-α/IL-4-induced inflammation in BEAS-2B cells was used as an in vitro model, whereby the effects of various doses of TAs-FUW on the TRPV1/Ca2+-dependent NFAT-induced expression of TSLP were assessed. Stimulation and inhibition of TRPV1 receptors by capsaicin (CAP) and capsazepine (CPZ), respectively, were used to validate the effect of TAs-FUW. RESULTS: The UPLC-Q-TOF/MS analysis revealed that TAs-FUW mainly contain six compounds (peiminine, peimine, edpetiline, khasianine, peimisine, and sipeimine). TAs-FUW improved airway inflammation and obstruction, mucus secretion, collagen deposition, and leukocyte and macrophage infiltration, and downregulated TSLP by inhibiting the TRPV1/NFAT pathway in asthmatic mice. In vitro, the application of CPZ demonstrated that the TRPV1 channel is involved in TNF-α/IL-4-mediated regulation of TSLP. TAs-FUW suppressed TNF-α/IL-4-induced TSLP generation expression by regulating the TRPV1/Ca2+/NFAT pathway. Furthermore, TAs-FUW reduced CAP-induced TSLP release by inhibiting TRPV1 activation. Notably, sipeimine and edpetiline each were sufficient to block the TRPV1-mediated Ca2+ influx. CONCLUSION: Our study is the first to demonstrate that TNF-α/IL-4 can activate the TRPV1 channel. TAs-FUW can alleviate asthmatic inflammation by suppressing the TRPV1 pathway and thereby preventing the increase in cellular Ca2+ influx and the subsequent NFAT activation. The alkaloids in FUW may be used for complementary or alternative therapies in asthma.

Acetaminophen-induced liver injury: Molecular mechanism and treatments from natural products.

Acetaminophen (APAP) is a widely used analgesic and antipyretic over-the-counter medicine worldwide. Hepatotoxicity caused by APAP overdose is one of the leading causes of acute liver failure (ALF) in the US and in some parts of Europe, limiting its clinical application. Excessive APAP metabolism depletes glutathione and increases N-acetyl-p-benzoquinoneimide (NAPQI) levels, leading to oxidative stress, DNA damage, and cell necrosis in the liver, which in turn leads to liver damage. Studies have shown that natural products such as polyphenols, terpenes, anthraquinones, and sulforaphane can activate the hepatocyte antioxidant defense system with Nrf2 as the core player, reduce oxidative stress damage, and protect the liver. As the key enzyme metabolizing APAP into NAPQI, cytochrome P450 enzymes are also considered to be intriguing target for the treatment of APAP-induced liver injury. Here, we systematically review the hepatoprotective activity and molecular mechanisms of the natural products that are found to counteract the hepatotoxicity caused by APAP, providing reference information for future preclinical and clinical trials of such natural products.

Water extract from Herpetospermum pedunculosum attenuates oxidative stress and ferroptosis induced by acetaminophen via regulating Nrf2 and NF-κB pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: The seeds of Herpetospermum pedunculosum seeds is a traditional Tibetan medicine possessing hepatoprotective effect, but their protective effect on APAP-induced liver injury has not yet been explored. AIM OF THE STUDY: This study aimed at exploring the protective effect and mechanism of the water extract from the seeds of Herpetospermum pedunculosum (HPWE) on APAP-induced liver injury in vitro and in vivo. MATERIALS AND METHODS: In vitro and in vivo models of liver injury were established by APAP treatment of BRL-3A cells or mice. The effect and mechanism of action of HPWE were explored by using cell viability assay, ELISA, immunofluorescence assay, RT-qPCR, histological observation and immunohistochemistry staining, western blotting and high-content imaging system. RESULTS: In vitro experiments showed that HPWE treatment significantly promoted the cell viability, decreased ALT/AST level, and inhibited the ROS accumulation induced by APAP. Furthermore, HPWE and Fer-1 alleviated erastin-induced cell ferroptosis, upregulated GPX4 and SLC7A11 expression, and reduced lipid peroxides production. Further study showed that APAP could also downregulate the expression of GPX4 and SLC7A11, causing cell ferroptosis, and HPWE and Fer-1 counteracted this process. Our in vivo experiments showed that pretreatment with HPWE in APAP-treated mice significantly alleviated the serum ALT/AST level, decreased necrotic cells and inflammatory cell infiltration, upregulated the expression of GPX4 and SLC7A11. Further, it was demonstrated that HPWE treatment downregulated Nrf2 and its downstream target genes, i.e. HO-1 and NQO1 expression at the mRNA and protein levels. HPWE treatment also inhibited the activation of NF-κB p65 and downregulated its target genes, i.e. TNF-α and IL-1ß, expression. CONCLUSION: The present study showed that HPWE could relieve oxidative stress and ferroptosis via activating Nrf2 signaling pathway and inhibiting NF-κB mediated pathway.

Integrative analysis of the steroidal alkaloids distribution and biosynthesis of bulbs Fritillariae Cirrhosae through metabolome and transcriptome analyses.

BACKGROUND: Bulbus Fritillariae Cirrhosae (BFC) is an endangered high-altitude medicine and food homology plant with anti-tumor, anti-asthmatic, and antitussive activities as it contains a variety of active ingredients, especially steroidal alkaloids. Bulbus Fritillariae Thunbergia (BFT) is another species of Fritillaria that grows at lower altitude areas. Production of plant-derived active ingredients through a synthetic biology strategy is one of the current hot topics in biological research, which requires a complete understanding of the related molecular pathways. Our knowledge of the steroidal alkaloid biosynthesis in Fritillaria species is still very limited. RESULTS: To promote our understanding of these pathways, we performed non-target metabolomics and transcriptome analysis of BFC and BFT. Metabolomics analysis identified 1288 metabolites in BFC and BFT in total. Steroidal alkaloids, including the proposed active ingredients of Fritillaria species peimine, peimisine, peiminine, etc., were the most abundant alkaloids detected. Our metabolomics data also showed that the contents of the majority of the steroidal alkaloids in BFC were higher than in BFT. Further, our comparative transcriptome analyses between BFC and BFT identified differentially expressed gene sets among these species, which are potentially involved in the alkaloids biosynthesis of BFC. CONCLUSION: These findings promote our understanding of the mechanism of steroidal alkaloids biosynthesis in Fritillaria species.