New iridoids from Patrinia scabiosaefolia and their hypoglycemic effects by activating PI3K/Akt signaling pathway

Iridoids and lignans from Valeriana officinalis and their bioactivities

Seven undescribed iridoids, identified as valeriridoids A-E (compounds 1, 5, 18, 19a, 19b, 20a, and 20b), were isolated from the roots and rhizomes of Valeriana officinalis L., along with sixteen known iridoids and nine known lignans. The structures were elucidated using NMR and MS spectroscopy, and the absolute configurations of the undescribed iridoids were determined through ECD calculations. Valeriridoids D and E were found to be epimeric and scalemic mixtures, which were successfully resolved through a chiral column. These isolated iridoids were evaluated for their antiproliferative activities, with valeriridoid A, jatamanvaltrates P, and Q showing significant effects against human non-small cell lung cancer cells, with IC50 values of 14.68, 8.77, and 10.07 μM, respectively. Furthermore, the antihyperglycemic properties of the compounds were investigated in insulin-resistant human hepatoblastoma cells induced by palmitic acid treatment, revealing that valeriridoid A, jatamanvaltrates P, and Q at a concentration of 10 μM led to a notable increase in glucose consumption.

Bis-Iridoid Glycosides and Triterpenoids from Kolkwitzia amabilis and Their Potential as Inhibitors of ACC1 and ACL

A comprehensive phytochemical investigation of the twigs/leaves and flower buds of Kolkwitzia amabilis, a rare deciduous shrub native to China, led to the isolation of 39 structurally diverse compounds. These compounds include 11 iridoid glycosides (1-4 and 7-13), 20 triterpenoids (5, 6, and 14-31), and 8 phenylpropanoids (32-39). Among these, amabiliosides A (1) and B (2) represent previously undescribed bis-iridoid glycosides, while amabiliosides C (3) and D (4) feature a unique bis-iridoid-monoterpenoid indole alkaloid scaffold with a tetrahydro-β-carboline-5-carboxylic acid moiety. Amabiliacids A (5) and B (6) are 24-nor-ursane-type triterpenoids characterized by an uncommon ∆11,13(18) transannular double bond. Their chemical structures and absolute configurations were elucidated through spectroscopic data and electronic circular dichroism analyses. Compound 2 exhibited a moderate inhibitory effect against acetyl CoA carboxylase 1 (ACC1), with an IC50 value of 9.6 μM. Lonicejaposide C (8), 3β-O-trans-caffeoyl-olean-12-en-28-oic acid (29), and (23E)-coumaroylhederagenin (31) showed notable inhibitory effects on ATP-citrate lyase (ACL), with IC50 values of 3.6, 1.6, and 4.7 μM, respectively. Additionally, 3β-acetyl-ursolic acid (17) demonstrated dual inhibitory activity against both ACC1 and ACL, with IC50 values of 10.3 and 2.0 μM, respectively. The interactions of the active compounds with ACC1 and ACL enzymes were examined through molecular docking studies. From a chemotaxonomic perspective, the isolation of bis-iridoid glycosides in this study may aid in clarifying the taxonomic relationship between the genera Kolkwitzia and Lonicera within the Caprifoliaceae family. These findings highlight the importance of conserving plant species with unique and diverse secondary metabolites, which could serve as potential sources of new therapeutic agents for treating ACC1/ACL-associated diseases.

Effects of undescribed iridoids in Patrinia punctiflora on insulin resistance in HepG2 cells

Patrinia punctiflora is a medical and edible Chinese herb with high nutritional and medicinal value. The continuing study of its chemical constituents led to the isolation of six iridoids, which were previously unreported compounds, patriscabioins PU (1-6). Their structures were characterized and confirmed with NMR (1D & 2D), HRMS, IR and UV. Among them, compound 5 was screened to evaluate its insulin resistance activity on an IR-HepG-2 cell model. Compound 5 had no cytotoxicity compared with the control group and could promote glucose uptake in IR-HepG-2 cells. Through further mechanism studies, the undescribed compound 5 could increase the expression levels of PI-3 K, p-AKT, GLUT4 and p-GSK3β proteins. Moreover, the expression of PEPCK and G6Pase proteins, which are key gluconeogenic enzymes, was also inhibited. Thus, compound 5 promotes the transfer of GLUT4 to the plasma membrane by activating the PI-3 K/AKT signaling pathway, at the same time, promotes glycogen synthesis and inhibits the onset of gluconeogenesis, which in turn ameliorates insulin resistance.

Transcriptome and metabolome analysis reveals mechanism of light intensity modulating iridoid biosynthesis in Gentiana macrophylla Pall

Light intensity is a key factor affecting the synthesis of secondary metabolites in plants. However, the response mechanisms of metabolites and genes in Gentiana macrophylla under different light intensities have not been determined. In the present study, G. macrophylla seedlings were treated with LED light intensities of 15 µmol/m2/s (low light, LL), 90 µmol/m2/s (medium light, ML), and 200 µmol/m2/s (high light, HL), and leaves were collected on the 5th day for further investigation. A total of 2162 metabolites were detected, in which, the most abundant metabolites were identified as flavonoids, carbohydrates, terpenoids and amino acids. A total of 3313 and 613 differentially expressed genes (DEGs) were identified in the LL and HL groups compared with the ML group, respectively, mainly enriched in KEGG pathways such as carotenoid biosynthesis, carbon metabolism, glycolysis/gluconeogenesis, amino acids biosynthesis, plant MAPK pathway and plant hormone signaling. Besides, the transcription factors of GmMYB5 and GmbHLH20 were determined to be significantly correlated with loganic acid biosynthesis; the expression of photosystem-related enzyme genes was altered under different light intensities, regulating the expression of enzyme genes involved in the carotenoid, chlorophyll, glycolysis and amino acids pathway, then affecting their metabolic biosynthesis. As a result, low light inhibited photosynthesis, delayed glycolysis, thus, increased certain amino acids and decreased loganic acid production, while high light got an opposite trend. Our research contributed significantly to understand the molecular mechanism of light intensity in controlling metabolic accumulation in G. macrophylla.

Hepatoprotective activity of Patrinia scabiosaefolia Fisch and quality evaluation based on UPLC fingerprint and multi-component analysis

To establish a quality evaluation method for Patrinia scabiosaefolia Fisch (PS), as well as to study the anti-inflammatory and hepatoprotective effects of the aqueous extract of Patrinia scabiosaefolia Fisch (APS). We used ultra performance liquid chromatography (UPLC) to establish fingerprint and content determination method for PS. The alcoholic liver injury model was prepared by feeding Lieber-DeCarli alcohol liquid feed to mice. We determined the levels of ALT, AST, TC, TG in serum, as well as GSH, MDA in the liver. The mRNA relative expression levels of TNF-α, IL-6, IL-1β, INOS and COX-2 were detected by qRT-PCR, and liver tissues were taken for pathological examination. The fingerprints of 16 batches of PS were established, and 3 component peaks were identified, which were chlorogenic acid (CA), isochlorogenic acid A (ICAA) and isochlorogenic acid C (ICAC). The similarity of the 6 common peaks was between 0.924 and 1.000. A mice model of alcoholic liver injury was successfully made by mixing alcohol liquid feed. The levels of ALT, AST, TC and TG in serum and MDA, TNF-α, IL-1β, LL-6, COX-2 and INOS mRNA in liver were effectively reduced in the drug administration group. The levels of GSH in mouse liver tissue were increased in the drug administration group. The method has good repeatability, stability and feasibility, and it meets the requirements for Quality evaluation. APS exhibits a protective effect against alcoholic liver injury (ALI) in mice.

Advances in Research on Type 2 Diabetes Mellitus Targets and Therapeutic Agents

Diabetes mellitus is a chronic multifaceted disease with multiple potential complications, the treatment of which can only delay and prolong the terminal stage of the disease, i.e., type 2 diabetes mellitus (T2DM). The World Health Organization predicts that diabetes will be the seventh leading cause of death by 2030. Although many antidiabetic medicines have been successfully developed in recent years, such as GLP-1 receptor agonists and SGLT-2 inhibitors, single-target drugs are gradually failing to meet the therapeutic requirements owing to the individual variability, diversity of pathogenesis, and organismal resistance. Therefore, there remains a need to investigate the pathogenesis of T2DM in more depth, identify multiple therapeutic targets, and provide improved glycemic control solutions. This review presents an overview of the mechanisms of action and the development of the latest therapeutic agents targeting T2DM in recent years. It also discusses emerging target-based therapies and new potential therapeutic targets that have emerged within the last three years. The aim of our review is to provide a theoretical basis for further advancement in targeted therapies for T2DM.