Comparative transcriptome analysis of rhizome nodes and internodes in Panax. japonicus var. major reveals candidate genes involved in the biosynthesis of triterpenoid saponins

Mass spectrometry-based ginsenoside profiling: Recent applications, limitations, and perspectives

Ginseng, the roots of Panax species, is an important medicinal herb used as a tonic. As ginsenosides are key bioactive components of ginseng, holistic chemical profiling of them has provided many insights into understanding ginseng. Mass spectrometry has been a major methodology for profiling, which has been applied to realize numerous goals in ginseng research, such as the discrimination of different species, geographical origins, and ages, and the monitoring of processing and biotransformation. This review summarizes the various applications of ginsenoside profiling in ginseng research over the last three decades that have contributed to expanding our understanding of ginseng. However, we also note that most of the studies overlooked a crucial factor that influences the levels of ginsenosides: genetic variation. To highlight the effects of genetic variation on the chemical contents, we present our results of untargeted and targeted ginsenoside profiling of different genotypes cultivated under identical conditions, in addition to data regarding genome-level genetic diversity. Additionally, we analyze the other limitations of previous studies, such as imperfect variable control, deficient metadata, and lack of additional effort to validate causation. We conclude that the values of ginsenoside profiling studies can be enhanced by overcoming such limitations, as well as by integrating with other -omics techniques.

Full-length transcriptome and metabolite analysis reveal reticuline epimerase-independent pathways for benzylisoquinoline alkaloids biosynthesis in Sinomenium acutum

Benzylisoquinoline alkaloids (BIAs) are a large family of plant natural products with important pharmaceutical applications. Sinomenium acutum is a medicinal plant from the Menispermaceae family and has been used to treat rheumatoid arthritis for hundreds of years. Sinomenium acutum contains more than 50 BIAs, and sinomenine is a representative BIA from this plant. Sinomenine was found to have preventive and curative effects on opioid dependence. Despite the broad applications of S. acutum, investigation on the biosynthetic pathways of BIAs from S. acutum is limited. In this study, we comprehensively analyzed the transcriptome data and BIAs in the root, stem, leaf, and seed of S. acutum. Metabolic analysis showed a noticeable difference in BIA contents in different tissues. Based on the study of the full-length transcriptome, differentially expressed genes, and weighted gene co-expression network, we proposed the biosynthetic pathways for a few BIAs from S. acutum, such as sinomenine, magnoflorine, and tetrahydropalmatine, and screened candidate genes involved in these biosynthesis processes. Notably, the reticuline epimerase (REPI/STORR), which converts (S)-reticuline to (R)-reticuline and plays an essential role in morphine and codeine biosynthesis, was not found in the transcriptome data of S. acutum. Our results shed light on the biogenesis of the BIAs in S. acutum and may pave the way for the future development of this important medicinal plant.

Anti-inflammatory and osteoprotective effects of Chikusetsusaponin Ⅳa on rheumatoid arthritis via the JAK/STAT signaling pathway

BACKGROUND

Rheumatoid arthritis (RA) is a common autoimmune disease, for which no economical and safe target drug treatment is available. Chikusetsusaponin Ⅳa (CS-IVa), an active compound in Panax japonicus C.A. Mey, has a good anti-inflammatory effect, but whether this compound can serve as a targeted drug for RA and the corresponding therapeutic mechanism remain unclear.

PURPOSE

To investigate the anti-inflammatory and bone-protecting effects of CS-IVa on RA and the possible corresponding mechanisms of action.

METHODS

Biomarkers and underlying pathological mechanisms were examined by performing a bioinformatics analysis of RA synovial gene expression data profiles, and the feasibility of CS-IVa treatment for RA was predicted using molecular docking and molecular dynamics simulation techniques. Histomorphological and molecular biology techniques were used to verify the feasibility and molecular mechanism of CS-IVa treatment for RA in vivo using a collagen-induced arthritis (CIA) model.

RESULTS

CS-IVa alleviated symptoms and reduced the immune organ index, arthritis index, hind paw thickness, and number of swollen joints in the foot for CIA mice. Bioinformatics analysis suggested that interferon-gamma (IFN-γ), interleukin-1 β (IL-1β), and the Janus kinase/signal transduction and activator of transcription (JAK/STAT) pathway played important roles in the pathogenesis of RA. The results of molecular docking and molecular dynamics simulations showed that CS-IVa bound effectively to IFN-γ and IL-1β and that the combined pose has good stability and flexibility. The histomorphological results showed that CS-IVa reduced joint histopathology scores, OARSI scores, and TRAP-positive cell counts. Molecular biology analysis indicated that CS-IVa reduced the concentration of inflammatory factors in the peripheral serum of CIA mice and suppressed the mRNA expression of these factors in the spleen in a dose-dependent manner. The protein expression level of the JAK/STAT pathway was also inhibited by CS-IVa.

CONCLUSION

The results of the current study demonstrate a novel inhibitory effect of CS-IVa on inflammation and bone destruction in CIA mice, and the mechanism may be related to the JAK/STAT signaling pathway, which provides new insights into the development of CS-IVa as a therapeutic agent for RA.

Advance in glycosyltransferases, the important bioparts for production of diversified ginsenosides

Ginsenosides are a series of glycosylated triterpenoids predominantly originated from Panax species with multiple pharmacological activities such as anti-aging, mediatory effect on the immune system and the nervous system. During the biosynthesis of ginsenosides, glycosyltransferases play essential roles by transferring various sugar moieties to the sapogenins in contributing to form structure and bioactivity diversified ginsenosides, which makes them important bioparts for synthetic biology-based production of these valuable ginsenosides. In this review, we summarized the functional elucidated glycosyltransferases responsible for ginsenoside biosynthesis, the advance in the protein engineering of UDP-glycosyltransferases (UGTs) and their application with the aim to provide in-depth understanding on ginsenoside-related UGTs for the production of rare ginsenosides applying synthetic biology-based microbial cell factories in the future.

Identification of two UDP-glycosyltransferases involved in the main oleanane-type ginsenosides in Panax japonicus var. major

Two UDP-glycosyltransferases from Panax japonicus var. major were identified, and the biosynthetic pathways of three oleanane-type ginsenosides (chikusetsusaponin IVa, ginsenoside Ro, zingibroside R₁) were elucidated. Chikusetsusaponin IVa and ginsenoside Ro are primary active components formed by stepwise glycosylation of oleanolic acid in five medicinal plants of the genus Panax. However, the key UDP-glycosyltransferases (UGTs) in the biosynthetic pathway of chikusetsusaponin IVa and ginsenoside Ro are still unclear. In this study, two UGTs (PjmUGT1 and PjmUGT2) from Panax japonicus var. major involved in the biosynthesis of chikusetsusaponin IVa and ginsenoside Ro were identified based on bioinformatics analysis, heterologous expression and enzyme assays. The results show that PjmUGT1 can transfer a glucose moiety to the C-28 carboxyl groups of oleanolic acid 3-O-β-D-glucuronide and zingibroside R₁ to form chikusetsusaponin IVa and ginsenoside Ro, respectively. Meanwhile, PjmUGT2 can transfer a glucose moiety to oleanolic acid 3-O-β-D-glucuronide and chikusetsusaponin IVa to form zingibroside R₁ and ginsenoside Ro. This work uncovered the biosynthetic mechanism of chikusetsusaponin IVa and ginsenoside Ro, providing the rational production of valuable saponins through synthetic biology strategy.

Insight to nitrification during cattle manure-maize straw and biochar composting in terms of multi-variable interaction

This study investigated nitrification process during cattle manure-maize straw (CM) and biochar (CMB) composting in terms of multi-variable interaction (MVI) among environmental parameters, ammonia-oxidizing archaea (AOA) and bacteria (AOB) community structure, nitrogen-related enzymes as well as substrates using structural equation model (SEM). Results showed that adding biochar significantly reduced potential ammonia oxidation rates. SEM analysis revealed that AOB was affected by temperature and pH, which stimulated the release of urease, increased NH₄⁺-N concentration and finally exerted influence on nitrification in CM. Temperature (0.755) and NO₂^--N (-0.994) were identified as the main factors mediating nitrification in CM and CMB, respectively. Moreover, MVI analysis indicated that nitrification and denitrification occurred simultaneously. Mutual verification of SEM and quantitative analyses (RNA level) confirmed that AOB predominated nitrification. The above results indicated that nitrification could be better explained by MVI using SEM during composting.