Five new bidesmoside triterpenoid saponins from Stauntonia chinensis

Central and peripheral analgesic active components of triterpenoid saponins from Stauntonia chinensis and their action mechanism

Triterpenoid saponins from Stauntonia chinensis have been proven to be a potential candidate for inflammatory pain relief. Our pharmacological studies confirmed that the analgesic role of triterpenoid saponins from S. chinensis occurred via a particular increase in the inhibitory synaptic response in the cortex at resting state and the modulation of the capsaicin receptor. However, its analgesic active components and whether its analgesic mechanism are limited to this are not clear. In order to further determine its active components and analgesic mechanism, we used the patch clamp technique to screen the chemical components that can increase inhibitory synaptic response and antagonize transient receptor potential vanilloid 1, and then used in vivo animal experiments to evaluate the analgesic effect of the selected chemical components. Finally, we used the patch clamp technique and molecular biology technology to study the analgesic mechanism of the selected chemical components. The results showed that triterpenoid saponins from S. chinensis could enhance the inhibitory synaptic effect and antagonize the transient receptor potential vanilloid 1 through different chemical components, and produce central and peripheral analgesic effects. The above results fully reflect that "traditional Chinese medicine has multi-component, multi-target, and multi-channel synergistic regulation".

The complete chloroplast genome of Stauntonia chinensis and compared analysis revealed adaptive evolution of subfamily Lardizabaloideae species in China

BACKGROUND

Stauntonia chinensis DC. belongs to subfamily Lardizabaloideae, which is widely grown throughout southern China. It has been used as a traditional herbal medicinal plant, which could synthesize a number of triterpenoid saponins with anticancer and anti-inflammatory activities. However, the wild resources of this species and its relatives were threatened by over-exploitation before the genetic diversity and evolutionary analysis were uncovered. Thus, the complete chloroplast genome sequences of Stauntonia chinensis and comparative analysis of chloroplast genomes of Lardizabaloideae species are necessary and crucial to understand the plastome evolution of this subfamily.

RESULTS

A series of analyses including genome structure, GC content, repeat structure, SSR component, nucleotide diversity and codon usage were performed by comparing chloroplast genomes of Stauntonia chinensis and its relatives. Although the chloroplast genomes of eight Lardizabaloideae plants were evolutionary conserved, the comparative analysis also showed several variation hotspots, which were considered as highly variable regions. Additionally, pairwise Ka/Ks analysis showed that most of the chloroplast genes of Lardizabaloideae species underwent purifying selection, whereas 25 chloroplast protein coding genes were identified with positive selection in this subfamily species by using branch-site model. Bayesian and ML phylogeny on CCG (complete chloroplast genome) and CDs (coding DNA sequences) produced a well-resolved phylogeny of Lardizabaloideae plastid lineages.

CONCLUSIONS

This study enhanced the understanding of the evolution of Lardizabaloideae and its relatives. All the obtained genetic resources will facilitate future studies in DNA barcode, species discrimination, the intraspecific and interspecific variability and the phylogenetic relationships of subfamily Lardizabaloideae.

Hypoglycemic and hypolipidemic effects of total saponins from Stauntonia chinensis in diabetic db/db mice

Stauntonia chinensis DC. has been utilised as a traditional herbal medicine for its anti‐hyperglycemic characteristic, which has been associated with triterpene saponins. The goal of the current evaluation was to examine hypoglycemic activity and affiliated mechanism of total saponins from S. chinensis. The chemical composition was analysed by HPLC‐ESI‐MS/MS. The fasting blood glucose, oral glucose tolerance test, insulin tolerance test, insulin and glycogen levels of type 2 diabetic db/db mice administered total saponins were quantified to determine the hypoglycemic effects. The serum lipid profiles were assessed to determine the hypolipidemic effects. Western blotting was used to quantify the protein levels of insulin receptor substrates (IRS)‐1/PI3K/AKT, AMPK/ACC and GLUT4. Twenty triterpene saponins were identified from the total saponins, which exhibited hypoglycemic activities and modulated hyperlipidemia that was associated with type 2 diabetes. The hypoglycemic effects were partly due to the activation of GLUT4, which is regulated by IRS‐1/PI3K/AKT. The activation of the AMPK/ACC signalling pathway may be responsible for the hypolipidemic activity. This study revealed that total saponins from S. chinensis have significant hypoglycemic and hypolipidemic activity in diabetic db/db mice, indicating that these may be utilised in the development of saponins based on S. chinensis for the treatment of type 2 diabetes.

Two new noroleanane-type triterpenoid saponins from the stems of Stauntonia chinensis

Two new noroleanane-type triterpenoid saponins, 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-L-fucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside (1) and 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-D-glucopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucopyranoside (2) were isolated from the stems of Stauntonia chinensis DC., together with three known compounds, brachyantheraoside B₂ (3), eupteleasaponin Ⅷ (4) and fargoside B (5). Their structures were elucidated by spectroscopic and chemical methods. The cytotoxic activities of compounds 1 and 2 were evaluated against five human tumor cell lines (HCT-116, HepG2, BGC-823, NCI-H1650, and A2780). Compounds 1 and 2 showed moderate cytotoxic activities toward the tested cell lines with IC₅₀ values ranging from 12.71 to 32.04 μM.

Chemical Components and Pharmacological Activities of Terpene Natural Products from the Genus Paeonia

Paeonia is the single genus of ca. 33 known species in the family Paeoniaceae, found in Asia, Europe and Western North America. Up to now, more than 180 compounds have been isolated from nine species of the genus Paeonia, including terpenes, phenols, flavonoids, essential oil and tannins. Terpenes, the most abundant naturally occurring compounds, which accounted for about 57% and occurred in almost every species, are responsible for the observed in vivo and in vitro biological activities. This paper aims to give a comprehensive overview of the recent phytochemical and pharmacological knowledge of the terpenes from Paeonia plants, and enlighten further drug discovery research.

Triterpenoid saponins from Stauntonia chinensis ameliorate insulin resistance via the AMP-activated protein kinase and IR/IRS-1/PI3K/Akt pathways in insulin-resistant HepG2 cells

Inflammation and oxidative stress play crucial roles in the etiology of type 2 diabetes mellitus. In this study, we examined the anti-diabetic effects of triterpenoid saponins extracted from Stauntonia chinensis on stimulating glucose uptake by insulin-resistant human HepG2 cells. The results showed that saponin 6 significantly increased glucose uptake and glucose catabolism. Saponin 6 also enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and activated the insulin receptor (IR)/insulin receptor substrate-1 (IRS-1)/phosphoinositide 3-kinase (PI3K)/Akt pathway. Therefore, our results suggest that saponins from S. chinensis improve glucose uptake and catabolism in hepatic cells by stimulating the AMPK and the IR/IRS-1/PI3K/Akt signaling pathways. The results also imply that saponins from S. chinensis can enhance glucose uptake and insulin sensitivity, representing a promising treatment for type 2 diabetes mellitus.

Triterpenoid glycosides from Stauntonia chinensis

A new bidesmoside triterpenoid saponin, named stauntoside C1 (1), along with three known saponins (2-4) was isolated from Stauntonia chinensis DC. (Lardizabalaceae). Their structures were established by means of spectral and chemical methods as 3-O-beta-D-xylopyranosyl-(1 --> 2)-O-beta-D-xylopyranosyl-(1 --> 3)-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), scabiosaponin E (2), sieboldianoside B (3), and kizutasaponin K(12) (4).

Bioactive iridoid glucosides from the fruit of Gardenia jasminoides

Seven new iridoid glucosides, 6''-O-trans-sinapoylgenipin gentiobioside (1), 6''-O-trans-p-coumaroylgenipin gentiobioside (2), 6''-O-trans-cinnamoylgenipin gentiobioside (3), 6'-O-trans-p-coumaroylgeniposide (4), 6'-O-trans-p-coumaroylgeniposidic acid (5), 10-O-succinoylgeniposide (6), and 6'-O-acetylgeniposide (7), two new monoterpenoids, 11-(6-O-trans-sinapoylglucopyranosyl)gardendiol (8) and 10-(6-O-trans-sinapoylglucopyranosyl)gardendiol (9), and three known ones, 6'-O-trans-sinapoylgeniposide (10), geniposide (11), and 10-O-acetylgeniposide (12), were isolated from the fruit of Gardenia jasminoides. The structures of these compounds were elucidated on the basis of 1D and 2D NMR spectra analyses. Furthermore, short-term memory assays on an Abeta transgenic drosophila model showed that compounds 4 and 6-12 can improve the short-term memory capacity to varying degrees, with compounds 4 and 7 being the most active ones, suggesting that these compounds may have a potential antagonism effect against Alzheimer's disease.

Bidesmoside triterpenoid glycosides from Stauntonia chinensis and relationship to anti-inflammation

Ten triterpenoid glycosides, yemuoside YM(26-35) (1-9 and 12), were isolated from a traditional Chinese medicine known as "Ye Mu Gua" (Stauntonia chinensis DC.) along with two known ones, kalopanax saponin C (10) and sieboldianoside A (11). Their structures, as elucidated by spectroscopic analyses and chemical methods, were either penta-saccharidic or hexa-saccharidic bidesmoside triterpenoid glycosides. To help explain the clinical applications of "Ye Mu Gua" for its anti-inflammatory effects, the inhibitory activity on the release of inflammatory mediators (nitric oxide, TNF-alpha and IL-6) of 1-12 and the related aglycone, hederagenin (13), was evaluated in vitro. It was found that compound 13, but not 1-12, exhibited significant inhibitory activity. The abundant triterpenoid glycosides in "Ye Mu Gua" might therefore be transformed into their respective aglycones, and thus inhibit the release of inflammatory factors in vivo. This could then account for the clinical value of "Ye Mu Gua" as regards anti-inflammatory effects. This proposed explanation of how "Ye Mu Gua" may have an effect is similar to the concept of prodrugs for chemical drugs which could be extended to some traditional medicines. That is, the major components might be biologically active not directly, but via biochemical transformation in vivo. Hence, we propose a "traditional medicine's prodrug characteristic" concept.