Indole diterpenes are a large class of secondary metabolites produced by fungi, possessing a cyclic diterpenoid backbone and an indole moiety. Novel structures and important biological activity have made indole diterpenes one of the focuses of synthetic chemists. Although the discovery, identification, structural diversity, biological activity and especially structure–activity relationship of indole diterpenes have been reported in some papers in recent years, they are absent of a systematic and comprehensive analysis, and there is no elucidation of enzymes related to this kind of natural product. Therefore, it is necessary to summarize the relevant reports to provide new perspectives for the following research. In this review, for the first time, the function of related synthases and the structure–activity relationship of indole diterpenes are expounded, and the recent research advances of them are emphasized.

Dragon’s blood (DB) is a traditional Chinese medicine (TCM) with hemostatic effects and antibacterial properties. However, it is still challenging to use for rapid hemostasis because of its insolubility. In this study, different amounts of DB were loaded on mesoporous silica nanoparticles (MSNs) to prepare a series of DB-MSN composites (5DB-MSN, 10DB-MSN, and 20DB-MSN). DB-MSN could quickly release DB and activate the intrinsic blood coagulation cascade simultaneously by DB and MSN. Hemostasis tests demonstrated that DB-MSN showed superior hemostatic effects than either DB or MSNs alone, and 10DB-MSN exhibited the best hemostatic effect. In addition, the antibacterial activities of DB-MSN against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) improved with the increase in DB. Furthermore, the hemolysis assay and cytocompatibility assay demonstrated that all DB-MSNs exhibited excellent biocompatibility. Based on these results, 10DB-MSN is expected to have potential applications for emergency hemostatic and antibacterial treatment in pre-hospital trauma.

Obcordata A (OA) is a polyoxypregnane glycoside derived from the Dai medicine Aspidopterys obcordata vines. This study aims to investigate the efficacy of OA on renal tubular epithelial cells exposed to calcium oxalate crystals. We incubated renal tubular cells with 28 μg·cm² calcium oxalate crystals for 24 h with and without OA, GKT137831, phorbol-12-myristate-13-acetate (PMA), and tocopherol. The MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, microscopic examination, flow cytometry, and immunofluorescence staining revealed that calcium oxalate crystals decreased cell viability and elevated reactive oxygen species (ROS) levels. OA, GKT137831, and tocopherol protected cells and decreased ROS levels. However, OA did not exhibit direct DPPH scavenging ability. In addition, immunoblotting illustrated that OA inhibited the NOX4 (nicotinamide adenine dinucleotide phosphate oxidases 4) expression and downregulated the protein expression in the NOX4/ROS/p38 MAPK (p38 mitogen-activated protein kinase) pathway. The findings suggest that the cytoprotective and antioxidant effects of OA can be blocked by the NOX4 agonist PMA. In conclusion, OA could be used as a NOX4 inhibitor to prevent kidney stones.

ABSTACT A chemical investigation of the endophyte Penicillium sp. Nb 19, isolated from leaves of the traditionally medical plant Baphicacanthus cusia (Nees) Bremek., yielded one new indole diterpenoid, 7-methoxy-13-dehydroxypaxilline (1) together with seven known metabolites (2-8). The obtained structure of compound 1 was elucidated by its spectroscopic data. In addition, the absolute configuration of compound 6 was confirmed by ECD for the first time. Compounds 1-6 were evaluated for antitumor activity against MCF-7, HepG2, and HCCC-9810 cell lines. Graphical Abstract

This study investigated the protective effect of Dai Bai Jie (DBJ) extract against acute alcoholic liver injury (AALI) and elucidated its potential mechanism. The total saponin level in the DBJ extracts was measured using vanillin–chloroform acid colorimetry. To observe the preventive and protective effects of DBJ on AML-12 cells in an ethanol environment, the effective components of DBJ were identified. An alcohol-induced AALI mouse model was used to evaluate the efficacy of DBJ against AALI. For this purpose, alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) levels were assessed, liver function indices and oxidative and inflammatory markers were determined, and histopathological examinations were performed. Mechanistic investigations were conducted using RT-qPCR assays and immunohistochemical analysis to determine the protective effects of DBJ. The samples (DBJ-1, DBJ-2, and DBJ-3) were obtained by extracting DBJ with water, 50% ethanol, and 95% ethanol, yielding total saponin contents of 5.35%, 6.64%, and 11.83%, respectively. DBJ-3 was isolated and purified, and its components were identified by Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS). DBJ-3 had the greatest effect on cell viability in an ethanol environment. Moreover, DBJ-3 reduced inflammatory infiltration, liver cell degeneration, and hemorrhage, while increasing ADH and ALDH levels in liver tissues. Additionally, DBJ-3 considerably decreased the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), and triglyceride (TG) levels. DBJ-3 reduced malondialdehyde (MDA), reactive oxygen species (ROS), and inflammatory factors, such as tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and interleukin 6 (IL-6), while increasing superoxide dismutase (SOD) and glutathione S-transferase (GST) activities. Furthermore, DBJ-3 significantly increased alcohol dehydrogenase 1b (ADH1B) and aldehyde dehydrogenase 2 (ALDH2) expression at the gene and protein levels within alcohol metabolism pathways and reduced the nuclear factor kappa-B (NF-κB) gene and protein levels. These findings suggest that DBJ-3 can prevent AALI by enhancing alcohol metabolism via the regulation of ADH1B and ALDH2 and the modulation of the NF-κB pathway to improve antioxidant and anti-inflammatory effects.

Liver fibrosis (LF) is a liver condition that represents a serious health risk to humans, and effective therapeutic options are limited. Polygonatum sibiricum polysaccharide (PSP), derived from the roots of P. sibiricum Red, has been demonstrated to exert anti‑inflammatory, antioxidant and antibacterial effects. However, its potential therapeutic impact on LF remains unexplored. In the present study, LF model rats were established through subcutaneous injection of carbon tetrachloride combined with a high‑fat diet and alcohol administration. Following the induction of fibrosis, rats in the PSP and Biejia ruangan (BJRG) treatment groups received daily intragastric doses of PSP and BJRG, respectively, for a duration of 4 weeks. The control and model groups were administered an equivalent volume of water. Liver function was evaluated through biochemical analyses, whereas hepatopathological alterations were assessed using hematoxylin and eosin and Masson's trichrome staining. Levels of inflammatory and oxidative stress markers were quantified using ELISA. Hepatic collagen synthesis and degradation were examined using ELISA and immunohistochemistry. Furthermore, the expression of genes and proteins associated with the TGF‑β/Smad signaling pathway were analyzed by reverse transcription‑quantitative PCR and western blotting. The results indicated that PSP exerts anti‑fibrotic effects, primarily through anti‑inflammatory and antioxidant mechanisms. Moreover, PSP appeared to promote the degradation and inhibit the synthesis of hepatic collagen fibers, potentially through modulation of the TGF‑β/Smad signaling pathway.