Identification and functional characterization of three iridoid synthases in Gardenia jasminoides

Neuroprotective role of geniposide-loaded UMSC nanovesicles in depression via P2ry12 downregulation

BACKGROUND

Depression is a prevalent mental disorder characterized by persistent low mood, loss of interest, and cognitive impairment. Oxidative stress and inflammation play crucial roles in its pathogenesis. Novel therapeutic strategies targeting these mechanisms are needed to improve treatment outcomes.

PURPOSE

The purpose of this study is to gauge the therapeutic effectiveness of geniposide (GEN)-loaded umbilical cord-derived mesenchymal stem cell membrane biomimetic nanovesicles (CSPG@UMSC NPs) targeting the P2ry12 factor for depression management, considering its association with oxidative stress and inflammatory pathways.

STUDY DESIGN

A combination of in vitro neuronal cell culture experiments and an in vivo chronic unpredictable mild stress (CUMS) mouse model was used to assess the effects of CSPG@UMSC NPs.

METHODS

In vitro investigations involved culture and characterization of CSPG@UMSC NPs and transcriptome sequencing analysis to identify DEGs in neurons. In vivo experiments utilized a depression mouse model treated with CSPG@UMSC NPs, followed by behavioral tests, biomarker analysis, and histological assessments.

RESULTS

CSPG@UMSC NPs successfully downregulated P2ry12 expression, leading to improved neuronal activity, decreased inflammation, reduced cell apoptosis, and lowered reactive oxygen species levels in both in vitro and in vivo settings.

CONCLUSION

CSPG@UMSC NPs loaded with GEN inhibit oxidative stress and inflammation by downregulating P2ry12. This research unveils, for the initial instance, the vital role of P2ry12 in depression and proposes a novel nano-therapy strategy based on MSCs and GEN, offering new insights and potential clinical applications for the treatment of depression.

Nanocrystalline cellulose-geniposide complex enhances gut-brain axis modulation for depression treatment

Depression, a major global health issue, is closely associated with imbalances in gut microbiota and altered intestinal functions. This study investigates the antidepressant potential of a composite of Geniposide (GP) and Nanocrystalline Cellulose (NCC), focusing on its effects on the gut-brain axis. Utilizing network pharmacology, GP was identified as a key compound targeting the BCL2 gene in depression management. Experimental approaches, including a chronic unpredictable mild stress (CUMS) model in mice, cellular assays, and fecal microbiota transplantation (FMT), were used to evaluate the composite's effectiveness. Results indicate that GP activates the adenosine monophosphate-activated protein kinase (AMPK) pathway by upregulating BCL2, enhancing intestinal barrier integrity, and balancing gut flora. These mechanisms contribute to its positive effects on hippocampal function and depressive-like behaviors in mice, suggesting that the GP-NCC composite could be a promising avenue for developing depression therapies that target gut health.

Phytochemical constitution and pharmacological effects of Genipa americana L. (Rubiaceae): a review

Genipa americana L., popularly known as "jenipapo", is a species easily found, especially in northeastern Brazil. It is remarkable for having iridoids in its composition. Popular for its blue pigment which has been used to manufacture paints and dyes. Furthermore, this plant is utilized for medicinal purposes in addressing a variety of illnesses. This review provide a comprehensive picture of the phytochemical and biological activities characteristics of Genipa americana L. deal with its ethnomedicinal use and botany based on literature reports. These researches pointed out a range of secondary metabolites with iridoids being the most prevalent and abundant. Until now, the biological tests have shown important pharmacological activities, especially the antioxidant, insecticide and antibacterial activities. Besides presenting itself in a very promising way in other areas such as food and cosmetics industry, it is also used in popular medicine to treat several diseases having this potential use disseminated in its various parts. Finally, for a better analysis and validation of its health benefits and properties, extensive research is needed, including clinical trials. The information gathered and approached in this paper might support the planning and discussion of future studies on the topic.

A comprehensive review of ethnopharmacology, chemical constituents, pharmacological effects, pharmacokinetics, toxicology, and quality control of gardeniae fructus

ETHNOPHARMACOLOGICAL RELEVANCE

Gardeniae Fructus (GF), the desiccative mature fruitage of Gardenia jasminoides J. Ellis (G. jasminoides), belongs to the Rubiaceae family. It has abundant medicinal value, such as purging fire and eliminating annoyance, clearing heat and diuresis, cooling blood, and detoxifying. GF is usually used in combination with other drugs to treat diseases such as fever and jaundice in damp heat syndrome in traditional Chinese medicines (TCMs) clinical practice.

THE AIM OF THE REVIEW

This review comprehensively summarizes the research progress in botany, traditional medical use, processing method, phytochemistry, pharmacological activity, quality control, pharmacokinetics, and toxicology, which aims to provide a scientific basis for the rational application and future research of GF.

MATERIALS AND METHODS

ScienceDirect, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Embase, Scopus etc. databases were retrieved to gain the comprehensive information of GF.

RESULTS

At present, more than 215 compounds were isolated and identified from GF, including iridoids, diterpenes, triterpenoids, flavonoids, organic esters, and so on. The traditional application of GF mainly focused on clearing heat and detoxification. Pharmacological studies proved that GF had anti-inflammatory, antioxidation, antifatigue, antithrombotic, liver and gallbladder protection, and other pharmacological effects. In addition, many improved processing methods can alleviate the side effects and toxic reactions caused by long-term use of GF, so controlling its quality through multi-component content measurement has become an important means of research.

CONCLUSION

GF has a wide range of applications, the mechanisms by which some effective substances exert their pharmacological effects have not been clearly explained due to the complexity and diversity of its components. This review systematically elaborates on the traditional medical use, processing method, phytochemistry, pharmacological activity, quality control, and toxicology of GF, and it is expected to become a candidate drug for treating diseases, such as depression, pancreatitis, alcoholic or non-alcoholic fatty liver.

A fused hybrid enzyme of 8-hydroxygeraniol oxidoreductase (8HGO) from Gardenia jasminoides and iridoid synthase (ISY) from Catharanthus roseus significantly enhances nepetalactol and iridoid production

MAIN CONCLUSION

The operation of 8HGO-ISY fusion enzymes can increase nepetalactol flux to iridoid biosynthesis, and the Gj8HGO-CrISY expression in Gardenia jasminoides indicates that seco-iridoids and closed-ring iridoids share a nepetalactol pool. Nepetalactol is a common precursor of (seco)iridoids and their derivatives, which are a group of noncanonical monoterpenes. Functional characterization of an 8HGO (8-hydroxygeraniol oxidoreductase) from Catharanthus roseus, a seco-iridoids producing plant, has been reported; however, the 8HGO from G. jasminoides with plenty of closed-ring iridoids remains uninvestigated. In this work, a Gj8HGO was cloned and biochemically characterized. In addition, the relatively low production of nepetalactol in plants and engineered microbial host is likely to be attributed to the fact that Cr8HGO and CrISY (iridoid synthase) are substrate-promiscuous enzymes catalyzing unexpected substrates to the undesired products. Herein, a bifunctional enzyme consisting of an 8HGO fused to an ISY was designed for the proximity to the substrate and recycling of NADP+ and NADPH cofactor to reduce the undesired intermediate in the synthesis of nepetalactol. Of four fusion enzymes (i.e., Gj8HGO-GjISY, Gj8HGO-GjISY2, Gj8HGO-GjISY4, and Gj8HGO-CrISY), interestingly, only the last one can enable cascade reaction to form cis-trans-nepetalactol. Furthermore, we establish a reliable Agrobacterium-mediated transformation system. The expression of Gj8HGO-CrISY in G. jasminoides led to a significant enhancement of nepetalactol production, about 19-fold higher than that in wild-type plants, which further resulted in the twofold to fivefold increase of total iridoids and representative iridoid such as geniposide, indicating that seco-iridoids in C. roseus and closed-ring iridoids in G. jasminoides share a nepetalactol pool. All results suggest that 8HGO and ISY can be manipulated to maximize metabolic flux for nepetalactol and iridoid production.

Transcriptome Analysis Provides Insights into Catalpol Biosynthesis in the Medicinal Plant Rehmannia glutinosa and the Functional Characterization of RgGES Genes

Rehmannia glutinosa, a member of the Scrophulariaceae family, has been widely used in traditional Chinese medicine since ancient times. The main bioactive component of R. glutinosa is catalpol. However, the biogenesis of catalpol, especially its downstream pathway, remains unclear. To identify candidate genes involved in the biosynthesis of catalpol, transcriptomes were constructed from R. glutinosa using the young leaves of three cultivars, Beijing No. 3, Huaifeng, and Jin No. 9, as well as the tuberous roots and adventitious roots of the Jin No. 9 cultivar. As a result, 71,142 unigenes with functional annotations were generated. A comparative analysis of the R. glutinosa transcriptomes identified over 200 unigenes of 13 enzymes potentially involved in the downstream steps of catalpol formation, including 9 genes encoding UGTs, 13 for aldehyde dehydrogenases, 70 for oxidoreductases, 44 for CYP450s, 22 for dehydratases, 30 for decarboxylases, 19 for hydroxylases, and 10 for epoxidases. Moreover, two novel genes encoding geraniol synthase (RgGES), which is the first committed enzyme in catalpol production, were cloned from R. glutinosa. The purified recombinant proteins of RgGESs effectively converted GPP to geraniol. This study is the first to discover putative genes coding the tailoring enzymes mentioned above in catalpol biosynthesis, and functionally characterize the enzyme-coding gene in this pathway in R. glutinosa. The results enrich genetic resources for engineering the biosynthetic pathway of catalpol and iridoids.

Transcriptome and metabolome analysis revealed the changes of Geniposide and Crocin content in Gardenia jasminoides fruit

BACKGROUND

Gardenia jasminoides Ellis is a perennial evergreen shrub of G. jasminoides of Rubiaceae. Geniposide and Crocin are important components in the fruit of G. jasminoides. In addition to being used as medicinal materials, they are also widely used in food, medicine, cosmetics, and other fields. They have high medicinal value, economic value, and ornamental value. However, at present, the utilization rate of G. jasminoides resources is low, mainly focused on germplasm cultivation, primary processing, and clinical pharmacology, and there are few studies on the quality of Gardenia fruit.

METHODS AND RESULTS

Based on transcriptome sequencing and metabolic group analysis, the morphological and structural changes of Gardenia fruit with young fruit, middle fruit, and ripe fruit were analyzed, and the formation mechanism and content changes of Geniposide and Crocin in Gardenia fruit were studied. The content of Geniposide decreased with the development of fruit, so did the expression of the main structural gene GES, G10H, and IS in its synthesis pathway, while the content of Crocin increased with the development of fruit, and the expression of the main structural gene CCD, ALDH, and UGT in its synthesis pathway also increased. The relationship between the morphological structure of G. jasminoides and the accumulation of Geniposide and Crocin was summarized.

CONCLUSIONS

This study not only provides a theoretical basis for the mining and utilization of Geniposide and Crocin, but also provides a theoretical basis for genetic background for the identification and cloning of bioactive substances in gardenia fruit in future. At the same time, it provides support for increasing the dual-use value of G. jasminoides and breeding excellent germplasm resources.

Elucidation of Geniposide and Crocin Accumulation and Their Biosysnthsis-Related Key Enzymes during Gardenia jasminoides Fruit Growth

Gardenia jasminoides fruits are extensively grown worldwide, with a large harvest, and its major medicinal ingredients are geniposide and crocins. Research on their accumulation and biosynthsis-related enzymes is rare. In this study, the accumulation of geniposide and crocin of G. jasminoides fruits at different developmental stages were clarified by HPLC. The highest cumulative amount of geniposide was 2.035% during the unripe-fruit period, and the highest content of crocin was 1.098% during the mature-fruit period. Furthermore, transcriptome sequencing was performed. A total of 50 unigenes encoding 4 key enzymes related in geniposide biosynthsis pathways were screened, and 41 unigenes encoding 7 key enzymes in the pathways of crocin were elucidated. It was found that the expression levels of differentially expressed genes of DN67890_c0_g1_i2-encoding GGPS, which is highly related to geniposide biosynthesis, and DN81253_c0_g1_i1-encoding lcyB, DN79477_c0_g1_i2-encoding lcyE, and DN84975_c1_g7_i11-encoding CCD, which are highly related to crocin biosynthesis, were consistent with the accumulation of geniposide and crocin content, respectively. The qRT-PCR results showed that the trends of relative expression were consistent with transcribed genes. This study provides insights for understanding the geniposide and crocin accumulation and biosynthsis during fruit development in G. jasminoides.