Comparative analyses of complete chloroplast genomes reveal interspecific difference and intraspecific variation of Tripterygium genus

The genus Tripterygium was of great medicinal value and attracted much attention on the taxonomic study using morphological and molecular methods. In this study, we assembled 12 chloroplast genomes of Tripterygium to reveal interspecific difference and intraspecific variation. The sequence length (156,692-157,061 bp) and structure of Tripterygium were conserved. Comparative analyses presented abundant variable regions for further study. Meanwhile, we determined the ndhB gene under positive selection through adaptive evolution analysis. And the phylogenetic analyses based on 15 chloroplast genomes supported the monophyly of Tripterygium hypoglaucum and the potential sister relationship between Tripterygium wilfordii and Tripterygium regelii. Molecular dating analysis indicated that the divergence time within Tripterygium was approximately 5.99 Ma (95% HPD = 3.11-8.68 Ma). The results in our study provided new insights into the taxonomy, evolution process, and phylogenetic construction of Tripterygium using complete plastid genomes.

Tripterygium hypoglaucum extract ameliorates adjuvant-induced arthritis in mice through the gut microbiota

Traditionally, Tripterygium hypoglaucum (Levl.) Hutch (THH) are widely used in Chinese folk to treat rheumatoid arthritis (RA). This study aimed to investigate whether the anti-RA effect of THH is related with the gut microbiota. The main components of prepared THH extract were identified by HPLC-MS. C57BL/6 mice with adjuvant-induced arthritis (AIA) were treated with THH extract by gavage for one month. THH extract significantly alleviated swollen ankle, joint cavity exudation, and articular cartilage destruction in AIA mice. The mRNA and protein levels of inflammatory mediators in muscles and plasma indicated that THH extract attenuated inflammatory responses in the joint by blocking TLR4/MyD88/MAPK signaling pathways. THH extract remarkably restored the dysbiosis of the gut microbiota in AIA mice, featuring the increases of Bifidobacterium, Akkermansia, and Lactobacillus and the decreases of Butyricimonas, Parabacteroides, and Anaeroplasma. Furthermore, the altered bacteria were closely correlated with physiological indices and drove metabolic changes of the intestinal microbiota. In addition, antibiotic-induced pseudo germ-free mice were employed to verify the role of the intestinal flora. Strikingly, THH treatment failed to ameliorate the arthritis symptoms and signaling pathways in pseudo germ-free mice, which validates the indispensable role of the intestinal flora. For the first time, we demonstrated that THH extract protects joint inflammation by manipulating the intestinal flora and regulating the TLR4/MyD88/MAPK signaling pathway. Therefore, THH extract may serve as a microbial modulator to recover RA in clincial practice.ver RA in clincial practice.

[Qualitative and quantitative analyses of Tripterygium hypoglaucum in Yinning Tablets, a compound traditional Chinese herbal preparation]

OBJECTIVE

To conduct qualitative and quantitative analyses of Tripterygium hypoglaucum in Yinning Tablets, a compound preparation of traditional Chinese herbal medicine.

METHODS

Thin-layer chromatography (TLC) was used for qualitative analysis of Tripterygium hypoglaucum in Yining Tablets and the analytical protocols were optimized. High-performance liquid chromatography (HPLC) was used to quantitatively analyze the content of triptolide (the main active ingredient of Tripterygium hypoglaucum) in Yinning Tablets.

RESULTS

The results of TLC analysis showed that the test sample of Yinning Tablets and the positive control samples both produced clear, well separated spots without obvious interference in the blank samples. Assessment of the influences of the thin-layer plates from different manufacturers, temperature and humidity on the test results demonstrated good durability of the test. HPLC analysis of triptolide showed a good linear relationship within the concentration range of 1-100 μg/mL (regression equation: A=22.219C-19.165, r=0.9999); the contents of triptolide in 3 batches of Yinning tablets were 0.34, 0.34, and 0.28 μg per tablet, all within the range of 0.28-0.34 μg per tablet. It was finally determined that each Yinning tablet should not contain more than 0.6 μg of triptolide.

CONCLUSION

TLC and HPLC are simple, accurate, durable and specific for qualitative and quantitative analyses of Tripterygium hypoglaucum in Yinning Tablets.

Effects of honeybee (Apis cerana) visiting behaviour on toxic plant (Tripterygium hypoglaucum) reproduction

Honeybees play a significant role in the plant-pollinator interactions of many flowering plants. The ecological and evolutionary consequences of plant-pollinator interactions vary by geographic region, and the effects of honeybees on the reproduction of toxic plants have not been well studied. We measured the florescence of toxic plants, the flower-visiting behaviour of honeybees and the effects of pollination on the fertility, weight and moisture content of seeds. The effects of climatic factors on the number of flowers, and the spatial and temporal variation in pollinator visits were evaluated, and the effects of pollinator visits on seed quality were evaluated. Flower visitors were diverse, climatic factors had a great impact on spatio-temporal flowering variation and the number of bee visits was strongly correlated with the spatio-temporal variation in the number of flowers. Honeybees strongly increase the fullness and weight of seeds. Our study demonstrated a good ecological fit between the spatio-temporal variation in the flowering of toxic plants and the general validity of honeybee pollination syndrome in the south of Hengduan Mountains in East Asia. A linear relationship between honeybee visitation and plant reproduction can benefit the stabilization of plant reproduction.

Cytotoxic terpenoids from Tripterygium hypoglaucum against human pancreatic cancer cells SW1990 by increasing the expression of Bax protein

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium hypoglaucum (Kunmingshanhaitang in Chinese) is a plant of the genus Tripterygium which have been used as anti-tumor folk medicines in Yi and Bai ethnic groups in Yunnan province, China for hundreds of years. Terpenoids from T. hypoglaucum presented therapeutic effects on multiple tumors. But there were few studies about pancreatic cancer treatment of these terpenoids. Pancreatic cancer is an aggressive malignancy and lacked of specific drugs. Currently, anti-tumor drugs have poor therapeutic effect and prognosis for pancreatic cancer.

AIM OF THE STUDY

This study aimed to elucidate the terpenoids from T. hypoglaucum and illuminate their anti-pancreatic cancer bioactivities.

MATERIAL AND METHODS

Terpenoids were obtained through sequential chromatographic methods including silica gel, MCI gel, Sephadex LH-20, and preparative HPLC. Their structures were determined by HRESIMS, 1D and 2D NMR spectroscopic analysis. The absolute configurations of some new diterpenoids were assigned through comparison of experimental and calculated circular dichroism spectra. The cytotoxicity of isolates was measured using the MTT method on human pancreatic cancer cells SW1990. The effects on expressions of AKT, Erk1/2, p-AKT, p-Erk1/2, and Bax proteins in human pancreatic cancer cells SW1990 of these compounds were determined by western blotting assays.

RESULTS

Eleven new (compounds 1∼11) and fourteen known terpenoids (compounds 12∼25) were isolated from the underground parts of T. hypoglaucum. These compounds were belonged to abietane diterpenoids, isoprimara diterpenoids, ent-kaurane diterpenoids, oleanane triterpenoids, and friedelane triterpenoids. Compounds 5, 7, 8, 9, 16, 18, 22, 24, and 25 possessed significant cytotoxicity against SW1990 cells with IC₅₀ values of 19.28 ± 4.39, 9.91 ± 2.23, 27.32 ± 5.89, 56.43 ± 6.92, 0.16 ± 0.05, 0.58 ± 0.15, 0.81 ± 0.04, 0.48 ± 0.11, and 10.01 ± 1.39 μM respectively. After compounds 16, 22, and 24 been treated with the pancreatic cancer cells in medium and high doses, the protein expressions of AKT, p-AKT, Erk, and p-Erk were not remarkably reduced and the expressions of Bax protein were significantly increased.

CONCLUSION

This study indicated that terpenoids from T. hypoglaucum could inhibit human pancreatic cancer cells SW1990. Especially, compounds 16, 22, and 24 possessed significant cytotoxicity against SW1990 cells with low IC₅₀ values and could increase the expressions of Bax protein. These compounds shared a wide variety of structural characteristics which provided us more candidate molecules for the development of anti-pancreatic cancer drugs and further prompted us to investigate their anti-pancreatic mechanisms.

Higher toxin tolerance to triptolide, a terpenoid foraged by a sympatric honeybee

The thunder god vine, Tripterygium hypoglaucum, is a toxic nectar plant distributed across China. A terpenoid, called triptolide (TRP), found in nectar can impair honeybees' foraging responses, dance communication, and olfactory learning. In the present study, we tested the tolerances of the native honeybee Apis cerana and the introduced honeybee A. mellifera to short-term and long-term exposure to TRP. The results showed that introduced A. mellifera is more vulnerable in fatality to high concentrations of TRP sucrose solution (5 and 10 µg TRP mL^-1) than A. cerana. We also compared the short-term and long-term exposure effects of TRP on olfactory learning and memory between the two honeybee species, and the olfactory learning and memory of both honey bee species showed impaired performance after both 2 h or 7 days of being fed with TRP sucrose solution. However, A. cerana showed a higher tolerance and resistance to TRP toxin than A. mellifera. Our results support a coevolution hypothesis in that the native species A. cerana has higher toxin tolerance than the introduced species A. mellifera.

[Dynamics of seed rain of Tripterygium hypoglaucum and soil seed bank]

Tripterygium hypoglaucum is an endangered species in arid areas of Xiannvshan Chongqing, China. The dynamic characteristics of seed rain and soil seed bank of T. hypoglaucum were studied in this paper．Results showed that T. hypoglaucum years of mature seeds distribution number up to October; the seed rain occurred from the last ten-day of September to in the first ten-day of November and the peak of scattered seed rain concentrated in the October．The numbers of soil seed bank at 2-5 cm soil layer,mainly concentrated in the 1.5-3.5 m range. T. hypoglaucum seeds to the wind as a force for transmission, the transmission ability is strong, but in the process of natural reproduction, full mature seed rate is low, the soil seed bank seeds seed short-lived factors these were unfavorable for the natural reproduction of T. hypoglaucum population.

Terpenoids from Tripterygium hypoglaucum and their inhibition of LPS-induced NO production

One new (1) and three known (2-4) sesquiterpenes and four known diterpenes (5-8) were isolated from the root bark of Tripterygium hypoglaucum. Their structures were elucidated on the basis of extensive spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D-NMR, and 2D-NMR). The inhibitory activity toward LPS-induced NO production of these terpenoids was evaluated, all the compounds showing inhibitory effects.

Chemical comparison of Tripterygium wilfordii and Tripterygium hypoglaucum based on quantitative analysis and chemometrics methods

Tripterygium wilfordii (T. wilfordii) and Tripterygium hypoglaucum (T. hypoglaucum), two commonly used Chinese herbal medicines derived from Tripterygium genus, have been widely used for the treatment of rheumatoid arthritis and other related inflammatory diseases in clinical therapy. In the present study, a rapid resolution liquid chromatography/electrospray ionization tandem mass spectrometry (RRLC-ESI-MS(n)) method has been developed and validated for simultaneous determination of 19 bioactive compounds including four catechins, three sesquiterpene alkaloids, four diterpenoids, and eight triterpenoids in these two similar herbs. The method validation results indicated that the developed method had desirable specificity, linearity, precision and accuracy. Quantitative analysis results showed that there were significant differences in the content of different types of compounds in T. wilfordii and T. hypoglaucum. Moreover, chemometrics methods such as one-way ANOVA, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the two Tripterygium herbs based on the quantitative data of analytes, and it was proven straightforward and reliable to differentiate T. wilfordii and T. hypoglaucum samples from different origins. In conclusion, simultaneous quantification of multiple-active component by RRLC-ESI-MS(n) coupled with chemometrics analysis could be a well-acceptable strategy to compare and evaluate the quality of T. wilfordii and T. hypoglaucum.