Caffeoylquinic acids isolated from Lonicera japonica Thunb. as TAK1 inhibitors protects against LPS plus IFN-γ-stimulated inflammation by interacting with KEAP1-regulated NRF2 activation.

The transforming growth factor-ß-activated kinase 1 (TAK1) phosphorylation promotes inflammation occurrence. Meanwhile, TAK1 directly interacts with KEAP1 and strenghtenes NRF2/HO-1 pathway downregulated-inflammation. Recently, we found that caffeoylquinic acids not only possessed powderful anti-inflammation function, but also attenuated oxidative damage through KEAP1/NRF2 pathway. Whereas it's rarely understood whether the anti-inflammatory activity were regulated by their interaction between TAK1 and NRF2. Herein, 34 caffeoylquinic acids including five new (2, 4-7) were systematically isolated and identified on the basis of spectroscopic evidence from Lonicera japonica Thunb. flower buds. Their inhibitory effects on inflammation induced by LPS plus IFN-γ were exerted substantial NO scavenging activity, and inhibited massive production of inflammatory cytokines and related proteins. Compound 3 (4F5C-QAME) exhibited the best anti-inflammation activity. 4F5C-QAME down-regulated the phosphorylation of TAK1, JNK, and c-JUN, thereby alleviated inflammation stimulated by LPS plus IFN-γ. Meanwhile, 4F5C-QAME could alleviate the interaction between TAK1 and KEAP1, inhibit the ubiquitination degradation of NRF2, activate NRF2/HO-1 signaling pathway, result in the increase in ROS elimination. Furthermore, 4F5C-QAME effectively protected against inflammation through direct inhibition of TAK1 phosphorylation. Based on these findings, 4F5C-QAME directly targeting TAK1 could be represented as a potential drug candidate for preventing/treating inflammatory diseases that regulated NRF2 activation through alleviating the interaction between TAK1 and KEAP1. Moreover, the regulatory mechanism of TAK1 on NRF2 activation under exogenous oxidative stress was revealed for the first time.

JFD, a Novel Natural Inhibitor of Keap1 Alkylation, Suppresses Intracellular Mycobacterium Tuberculosis Growth through Keap1/Nrf2/SOD2-Mediated ROS Accumulation.

It is an effective strategy to treat tuberculosis by enhancing reactive oxygen species- (ROS-) mediated killing of Mycobacterium tuberculosis in macrophages, but there are no current therapeutic agents targeting this pathway. Honeysuckle has been used as the traditional medicine for tuberculosis treatment for 1500 years. Japoflavone D (JFD) is a novel biflavonoid isolated from Honeysuckle promoting ROS accumulation by Nrf2 pathway in hepatocarcinoma cells. However, its activity to kill M. tuberculosis in macrophages and molecular mechanism has not been reported. Our results showed that JFD enhances the M. tuberculosis elimination by boosting ROS levels in THP-1 cells. Moreover, the massive ROS accumulation activates p38 to induce apoptosis. Notably, the mechanism revealed that JFD suppresses the nuclear transport of Nrf2, thereby inhibiting SOD2 transcription, leading to a large ROS accumulation. Further studies showed that JFD disrupts the Keap1 alkylation at specific residues Cys14, Cys257, and Cys319, which is crucial for Nrf2 activation, thereby interrupts the nuclear transport of Nrf2. In pharmacokinetic study, JFD can stay as the prototype for 24 h in mice and can be excreted in feces without any toxicity. Our data reveal for the first time that a novel biflavonoid JFD as a potent inhibitor of Keap1 alkylation can suppress the nuclear transport of Nrf2. And it is the first research of the inhibitor of Keap1 alkylation. Furthermore, JFD robustly promotes M. tuberculosis elimination from macrophages by inhibiting Keap1/Nrf2/SOD2 pathway, resulting in the ROS accumulation. This work identified Keap1 alkylation as a new drug target for tuberculosis and provides a preliminary basis for the development of antituberculosis lead compounds based on JFD.

Isoginkgetin, a potential CDK6 inhibitor, suppresses SLC2A1/GLUT1 enhancer activity to induce AMPK-ULK1-mediated cytotoxic autophagy in hepatocellular carcinoma.

Isoginkgetin (ISO), a natural biflavonoid, exhibited cytotoxic activity against several types of cancer cells. However, its effects on hepatocellular carcinoma (HCC) cells and mechanism remain unclear. Here, we revealed that ISO effectively inhibited HCC cell proliferation and migration in vitro. LC3-II expression and autophagosomes were increased under ISO treatment. In addition, ISO-induced cell death was attenuated by treatment with chloroquine or knockdown of autophagy-related genes (ATG5 or ULK1). ISO significantly suppressed SLC2A1/GLUT1 (solute carrier family 2 member 1) expression and glucose uptake, leading to activation of the AMPK-ULK1 axis in HepG2 cells. Overexpression of SLC2A1/GLUT1 abrogated ISO-induced autophagy. Combining molecular docking with thermal shift analysis, we confirmed that ISO directly bound to the N terminus of CDK6 (cyclin-dependent kinase 6) and promoted its degradation. Overexpression of CDK6 abrogated ISO-induced inhibition of SLC2A1/GLUT1 transcription and induction of autophagy. Furthermore, ISO treatment significantly decreased the H3K27ac, H4K8ac and H3K4me1 levels on the SLC2A1/GLUT1 enhancer in HepG2 cells. Finally, ISO suppressed the hepatocarcinogenesis in the HepG2 xenograft mice and the diethylnitrosamine+carbon tetrachloride (DEN+CCl4)-induced primary HCC mice and we confirmed SLC2A1/GLUT1 and CDK6 as promising oncogenes in HCC by analysis of TCGA data and human HCC tissues. Our results provide a new molecular mechanism by which ISO treatment or CDK6 deletion promotes autophagy; that is, ISO targeting the N terminus of CDK6 for degradation inhibits the expression of SLC2A1/GLUT1 by decreasing the enhancer activity of SLC2A1/GLUT1, resulting in decreased glucose levels and inducing the AMPK-ULK1 pathway.

Quassinoids from Eurycoma longifolia and their bone formation evaluation in zebrafish, C3H10 cells and silico.

Phytochemicals with bone formation potential in traditional medicines captured more and more attentions due to their advantages to bone loss and fewer side effects. As a famous aphrodisiac phytomedicine, Eurycoma longifolia (EL) has acquired general recognition in improving male sexual health, and thus been considered as traditional medicine for the treatment of androgen-deficient osteoporosis. Although the aqueous extract of EL had been proved to be beneficial to bone loss, the active constituents and the mechanisms underlying the effects are still obscure. The current study performed a chemical investigation on the roots of EL, which resulted in the isolation and identification of ten quassinoids (EL-1-EL-10), and then conducted their osteogenic activity evaluations in vivo zebrafish model with or without dexamethasone (Dex) and in vitro C3H10 cell model. The result displayed that most tested concentrations of EL-1-EL-5 could significantly increase the mineralization areas and integrated optical densities (IODs) of skull in both zebrafish model. The majority tested concentrations of EL-1-EL-5 could also improve the mRNA expression of early osteogenic associated genes ALPL, Runx2a, Sp7 in zebrafish model without Dex, but only a few could accelerate the mRNA expression of late osteogenic associated genes OCN. These results suggested the ability of EL-1-EL-5 to increase bone formation mainly by accelerating osteogenic differentiation at the early stage. The structure-based virtual screening based on the pharmacophores in ePharmaLib, as well as the molecular docking study, implied that the effects of the quassinoids (EL-1-EL-5) on the enhancement of bone formation might be related with improving the content and the activity of androgen through binding with CYP19A, SHBG and AKR1C2, and activating bone metabolism-related ANDR target genes and signal pathways by combining with ANDR directly. Although the assumptions are in silico model-based and further in vitro and in vivo validations are still necessary, we provided a new perspective to explore the potential of EL to be used as an alternative treatment for not only androgen-deficient osteoporosis, but also estrogen-deficient bone loss, by combining with SHBG.

Genus Lonicera: New drug discovery from traditional usage to modern chemical and pharmacological research.

BACKGROUND: Lonicera Linn. belonging to the family Caprifoliaceae, the largest genus in the plant family, includes about more than 200 species, which are mainly distributed in northern Africa, North America, Europe and Asia. Some species of this genus have been usually used in traditional Chinese medicine as well as functional foods, cosmetics and other applications, such as L. japonica Thunb. Bioactive components and pharmacological activities of the genus Lonicera plants have received an increasing interest from the scientific community. Thus, a comprehensive and systematic review on their traditional usage in China, chemical components, and their pharmacological properties of their whole plants, bioactive extracts, and bioactive isolates including partial structure-activity relationships from the genus is indispensable. METHODS: Information on genus Lonicera of this systematic electronic literature search was gathered via the published articles, patents, clinical trials website (https://clinicaltrials.gov/) and several online bibliographic databases (PubMed, Sci Finder, Research Gate, Science Direct, CNKI, Web of Science and Google Scholar). The following keywords were used for the online search: Lonicera, phytochemical composition, Lonicerae japonica, Lonicera review articles, bioactivities of Lonicera, anti-inflammatory, antiviral, antimicrobial, anticancer, hepatoprotective, antioxidant, neuroprotective, anti-diabetic, and clinical trials. This review paper consists of a total of 225 papers covering the Lonicera genus from 1800 to 2021, including research articles, reviews, patents, and book chapters. RESULTS: In this review (1800s-2021), about 420 components from the genus of Lonicera Linn. including 87 flavonoids, 222 terpenoids, 51 organic acids, and other compounds, together with their pharmacological activities including anti-inflammatory, antiviral, antimicrobial, anticancer, hepatoprotective, antioxidant, neuroprotective, antidiabetic, anti-allergic, immunomodulatory effects, and toxicity were summarized. CONCLUSION: The relationship is discussed among their traditional usage, their pharmacological properties, and their chemical components, which indicate the genus Lonicera have a large prospect in terms of new drug exploitation, especially in COVID-19 treatment.

Scutellaria baicalensis Extract-phospholipid Complex: Preparation and Initial Pharmacodynamics Research in Rats.

BACKGROUND: Baicalin, a flavonoid glycoside compound present in Scutellaria baicalensis, has shown a wide spectrum of biological activities, but its liposolubility, water-solubility and mucosal permeability are all very poor, which leads to the low concentration in brain and poor bioavailability by oral or intravenous injective administration. OBJECTIVE: The primary objective of this study was to formulate the Scutellaria baicalensis extract (SBE) with phospholipid to yield Scutellaria baicalensis extract-phospholipid complex (SBEPC) , and to evaluate its pharmacodynamics in the middle cerebral artery occlusion (MCAO). METHODS: The optimal preparation technology of SBEPC was obtained through single-factor test and central composite design-response surface methodology (CCD-RSM), and was characterized with various analytical techniques including SEM, FT-IR and NMR. The storage conditions of SBEPC were established through stability study and the MCAO rat model was investigated through conducting pharmacodynamic studies to screen the appropriate administration and dose of SBEPC as well as to verify the neuroprotective effect of SBEPC on cerebral ischemia-reperfusion injury. RESULTS: The optimized preparation conditions of SBEPC were summarized as follows: the ratio of phospholipids to drug was 2:1, the drug concentration was 3.5 mg/ml, the reaction temperature was 50 °C, and the entrapment efficiency was over 93.00%. Stability studies have demonstrated that SBEPC should be stored under 40 °C in a dry and ventilated place away from light and below 37% humidity. Furthermore, pharmacodynamic studies have found that, compared with SBE, SBEPC could introduce drugs into the brain and better exert the neuroprotective effect on MCAO rats, and the optimal administration and dose concentration of SBEPC were nasal administration and 40 mg/ml, respectively. CONCLUSION: These findings demonstrate that SBEPC is successfully prepared by CCD-RSM. SBEPC can enhance drugs' ability to enter the brain and improve the bioavailability of drugs in brain, and can effectively exert the neuroprotective effect on cerebral ischemia-reperfusion injury as compared with SBE.

Alkaloid constituents from the fruits of Flueggea virosa.

Three new indole alkaloids, flueindolines A-C (1-3), along with nine known alkaloids (4-12), were isolated from the fruits of Flueggea virosa (Roxb. ex Willd.) Voigt. Compounds 1 and 2 are two new fused tricyclic indole alkaloids possessing an unusual pyrido[1, 2-a]indole framework, and 3 presents a rare spiro (pyrrolizidinyl-oxindole) backbone. Their structures with absolute configurations were elucidated by means of comprehensive spectroscopic analysis, chemical calculation, as well as X-ray crystallography. Chiral resolution and absolute configuration determination of the known compounds 4, 10, and 11 were reported for the first time. The hypothetical biogenetical pathways of 1-3 were herein also proposed.

Absolute Configurations and Stereochemical Inversion Mechanism of Epimeric Securinega Alkaloids from Flueggea suffruticosa.

Three pairs of Securinega alkaloid epimers with a piperidin-2-yl moiety (1-6) were isolated from Flueggea suffruticosa, and their structures including absolute configurations were definitely characterized. An interconvertible C-2' epimerization process within each pair of epimers was observed. The following comprehensive experimental and theoretical investigations demonstrated an unusual stereochemical inversion mechanism of an N-substituted carbon stereogenic center, which was evidenced to be a protic solvent mediated process involving a tandem 1,4-elimination/1,4-addition as the key step.

[A new flavonostilbene glycoside from roots of Polygonum multiflorum].

Polygonflavanol B(1), a new flavonostilbene glycoside, was isolated from the roots of Polygonum multiforum(Polygonaceae) by various column chromatography methods including macroporous resin HP-20, silica gel, Sephadex LH-20, and preparative HPLC. The structure with absolute configuration of the new compound was identified by its physicochemical properties, spectroscopic data, ECD calculation, and chemical method.