Eucommia ulmoides (Tochu) and its extract geniposidic acid reduced blood pressure and improved renal hemodynamics

Study on the substance basis of the efficacy of eucommiae cortex before and after salt processing for the treatment of kidney-yang deficiency syndrome based on the spectrum-effect relationship

ETHNOPHARMACOLOGICAL RELEVANCE

Kidney-Yang deficiency syndrome (KYDS) is one of the common diseases of the elderly and closely related to the ageing of the body, it has a major impact on the quality of life of the patient. Eucommiae Cortex (EC) is the dried bark of Eucommia ulmoides Oliv. Which has the effect of tonifying the liver and kidneys, strengthening the muscles and bones. In Traditional Chinese Medicine clinics, EC is commonly used in the treatment of KYDS, but the material basis for the improvement of its efficacy in treating KYDS after salt processing remains unclear.

AIM OF THE STUDY

This study aimed to find the main active ingredients that could improve the treatment of KYDS efficacy of EC after salt processing.

MATERIALS AND METHODS

Firstly, the fingerprints of raw and salt-processed EC were established to determine the common components by using HPLC, and then an experimental study on the treatment of KYDS efficacy was carried out to compare the difference in the efficacy between raw and salt-processed EC. Thirdly, the spectrum-effect relationship of chemical components and pharmacodynamic indexes was established by using Grey Relational Analysis and Entropy Method. Finally, the network pharmacology and molecular docking technique was used to verify the kidney tonifying effect of the active ingredients of EC.

RESULTS

According to the results of the analysis of hormonal index levels on the hypothalamic-pituitary-target gland axis and the extent of renal lesions, the therapeutic effect of EC on KYDS was mainly reflected in the regulation of the Adrenocorticotropic hormone, Corticosterone in the hypothalamic-pituitary-adrenal axis and Tri-iodothyronine, Tetra-iodothyronine in the hypothalamic-pituitary-thyroid axis, moreover the therapeutic effect of salt-processed EC was stronger than that of raw EC. The pharmacologically active ingredients that improved its treatment of KYDS efficacy after salt processing were peak 1 (geniposidic acid), peak 2 (chlorogenic acid), peak 5 (geniposide), peak 6 (genipin), peak 7 (pinoresinol diglucoside) and peak 11 (hyperoside). Meanwhile, the results of network pharmacology and molecular docking showed that the 6 active ingredients could exert kidney tonic effects through multiple signaling pathways by acting on core targets such as AKT1 and PTGS2.

CONCLUSION

As far as we known, this was the first time to establish and compare the spectrum-effect relationship between raw and salt-processed EC, which laid the foundation for the pharmacokinetics studies of EC and provided a reference for future EC studies.

Effects of lactic acid bacteria on antioxidant activity in vitro and aroma component of Eucommia ulmoides tea

Eucommia ulmoides tea is a popular functional health drink in Asian countries, but its unique herbal aroma is difficult for consumers to accept. The effects of four lactic acid bacteria strains (Lactobacillus plantarium, Lactobacillus bulgaricus, Lactobacillus acidophilus and Streptococcus thermophilus) fermentation on the physicochemical property, antioxidant activity in vitro and aroma component of E. ulmoides leaves were studied. Within the four strains, the sample by L. bulgaricus fermentation showed the higher concentrations of chlorogenic acid, geniposidic acid and stronger antioxidant activity in vitro. Moreover, the sample by L. bulgaricus fermentation produced a stronger fruity and floral flavor. These results suggested that L. bulgaricus was the best strain for fermentation E. ulmoides tea. The differences between different strains should be considered when selecting lactic acid bacteria for raw material fermentation of fruits and vegetables.

Derivation and elimination of uremic toxins from kidney-gut axis

Uremic toxins are chemicals, organic or inorganic, that accumulate in the body fluids of individuals with acute or chronic kidney disease and impaired renal function. More than 130 uremic solutions are included in the most comprehensive reviews to date by the European Uremic Toxins Work Group, and novel investigations are ongoing to increase this number. Although approaches to remove uremic toxins have emerged, recalcitrant toxins that injure the human body remain a difficult problem. Herein, we review the derivation and elimination of uremic toxins, outline kidney-gut axis function and relative toxin removal methods, and elucidate promising approaches to effectively remove toxins.

Geniposidic acid attenuates DSS-induced colitis through inhibiting inflammation and regulating gut microbiota

Geniposidic acid (GPA) is a bioactive compound isolated from Gardenia jasminoides Ellis (Rubiaceae) that has long been used to treat arthritis, jaundice, and hypertension. However, the therapeutic effects of GPA against colitis remain underexplored. This study aimed to investigate the effect of GPA on the remission of colitis and the underlying mechanisms. A DSS-induced colitis mouse model was used to evaluate the influence of GPA on the modulation of gut microbiota and intestinal epithelial barrier function. Our results indicated that GPA improved DSS-induced mouse colitis, including loss of body weight, disease activity index (DAI), colon length, and colonic pathological damage. DSS-induced destruction of the intestinal barrier was also significantly repaired by GPA treatment. In addition, the relative levels of pro-inflammatory cytokines, such as IL-1β and TNF-α, were markedly alleviated by GPA. Furthermore, western blot analysis revealed that GPA downregulated the protein expression of the nuclear transcription factor NF-κB. Finally, we first demonstrated that GPA could alleviate gut microbiota dysbiosis in mice with colitis by bacterial 16S rRNA sequencing. In conclusion, our study demonstrates the therapeutic and protective effects of GPA on IBD and provides novel insights into the prevention of colitis by targeting gut microbiota metabolism using natural products.

Quality Marker Discovery and Quality Evaluation of Eucommia ulmoides Pollen Using UPLC-QTOF-MS Combined with a DPPH-HPLC Antioxidant Activity Screening Method

Pollen, as an important component of Eucommia ulmoides (EUP), is rich in nutrients and is receiving increasing attention. At present, there are no reports on research related to the chemical composition and quality standards of EUP, and there are significant quality differences and counterfeit phenomena in the market. This study used a UPLC-QTOF-MS system to identify 49 chemical components in EUP for the first time. In the second step, 2,2-diphenyl-1-picrylhydrazyl (DPPH)-HPLC antioxidant activity screening technology was used to identify the main active components of EUP, quercetin-3-O-sophoroside (QSH), quercetin-3-O-sambubioside (QSB), and quercetin 3-O-neohesperidoside (QNH), and their purification, preparation, and structure identification were carried out. Third, molecular docking was used to predict the activity of these components. Fourth, the intracellular ROS generation model of RAW264.7 induced by H₂O₂ was used to verify and evaluate the activity of candidate active ingredients to determine their feasibility as Q-markers. Finally, a quality control method for EUP was constructed using the three selected components as Q-markers. The identification of chemical components and the discovery, prediction, and confirmation of characteristic Q-markers in EUP provide important references for better research on EUP and the effective evaluation and control of its quality. This approach provides a new model for the quality control of novel foods or dietary supplements.

Moshen granule ameliorates membranous nephropathy by blocking intrarenal renin-angiotensin system signalling via the Wnt1/β-catenin pathway

BACKGROUND

Membranous nephropathy (MN) is one of the cardinal causes of nephrotic syndrome in adults, but an adequate treatment regimen is lacking.

PURPOSE

We assessed the effect of Moshen granule (MSG) on patients with MN and cationic bovine serum albumin (CBSA)-induced rats. We further identified the bioactive components of MSG and revealed the underlying molecular mechanism of its renoprotective effects.

METHODS

We determined the effect of MSG on patients with MN and CBSA-induced rats and its components on podocyte injury in zymosan-activated serum (ZAS)-elicited podocytes and revealed their regulatory mechanism on the Wnt/β-catenin/renin-angiotensin system (RAS) signalling axis.

RESULTS

MSG treatment improved renal function and reduced proteinuria in MN patients and significantly reduced proteinuria and preserved the protein expression of podocin, nephrin, podocalyxin and synaptopodin in CBSA-induced MN rats. Mechanistically, MSG treatment significantly inhibited the protein expression of angiotensinogen, angiotensin converting enzyme and angiotensin II type 1 receptor, which was accompanied by inhibition of the protein expression of Wnt1 and β-catenin and its downstream gene products, including Snail1, Twist, matrix metalloproteinase-7, plasminogen activator inhibitor-1 and fibroblast-specific protein 1, in CBSA-induced MN rats. We further identified 81 compounds, including astragaloside IV (AGS), calycosin, barleriside A and geniposidic acid, that preserve the podocyte-specific protein expression in ZAS-induced podocytes. Among these four compounds, AGS exhibited the strongest inhibitory effects on podocyte protein expression. AGS treatment significantly inhibited the protein expression of RAS components and Wnt1 and β-catenin and its downstream gene products in ZAS-induced podocytes. In contrast, the inhibitory effect of AGS on podocyte-specific proteins, β-catenin downstream gene products and RAS components was partially abolished in ZAS-induced podocytes treated with ICG-001 and β-catenin siRNA.

CONCLUSION

This study first demonstrates that AGS mitigates podocyte injury by inhibiting the activation of RAS signalling via the Wnt1/β-catenin pathway by both pharmacological and genetic methods. Therefore, AGS might be considered a new β-catenin inhibitor that inhibits the Wnt1/β-catenin pathway to retard MN in patients.

Characteristics of endophytic bacteria and active ingredients in the Eucommiae cortex from different origins

Objective

This study aimed to explore the differences between Eucommiae cortex (EC) endophytic bacteria from different origins and their effects on the active ingredients of EC.

Methods

A total of 10 samples of Eucommia ulmoides Oliv. (E. ulmoides) bark were collected from each of the following four regions, namely, Zunyi in Guizhou (GZ), Baokang in Hubei (HUB), Cili in Hunan (HUN), and Loyang in Shaanxi (SX). Subsequently, the contents of the main active ingredients of EC were determined by ultra-performance liquid chromatography (UPLC), and the endophytic bacteria of EC were detected by 16S rRNA sequencing. The relationship between the dominant endophytic bacteria and the active ingredients was investigated by correlation analysis.

Results

A total of 4,551 different operational taxonomic units (OTUs) were delineated in the four groups of samples, of which 585, 439, 957, and 684 genera were annotated from GZ, HUB, HUN, and SX, respectively. The richness and diversity of endophytic bacteria from different origins were ranked as HUN > SX > GZ or HUB. The analysis demonstrated that there was no significant correlation between the diversity and richness of endophytic bacteria in EC and its active ingredients. Nevertheless, notable variations in the community structures of endophytic bacteria were observed across different origins, and they had a considerable impact on certain active ingredients in EC. Comamonas and Cedecea were the dominant genera. Characteristic bacteria of different origins could be clearly distinguished. Simultaneous, significant correlations had been identified between some characteristic endophytic bacteria derived from different origins and active ingredients of EC. For example, Delftia, a characteristic bacterium from GZ, showed a significant positive correlation with pinoresinol diglucoside. Paenibacillus and Klebsiella, two characteristic bacteria from HUB, exhibited significant positive correlations with geniposidic acid. Thauera, a characteristic bacterium from HUN, demonstrated a significant positive correlation with geniposide. Brevundimonas, a characteristic bacterium from SX, displayed a significant positive correlation with pinoresinol diglucoside.

Conclusion

There was a complex correlation between EC endophytic bacteria and active ingredient content, while EC endophytic bacteria from different origins had significant differences at the genus level.

The Differences of Mechanisms in Antihypertensive and Anti-Obesity Effects of Eucommia Leaf Extract between Rodents and Humans

In the 1970s, Eucommia leaf tea, known as Tochu-cha in Japanese, was developed from roasted Eucommia leaves in Japan and is considered as a healthy tea. The antihypertensive, diuretic, anti-stress, insulin resistance improving, and anti-obesity effects of Eucommia leaf extract have been reported. However, the identification and properties of the active components as well as the underlying mechanism of action are largely unknown. In this review, we summarize studies involving the oral administration of geniposidic acid, a major iridoid component of Eucommia leaf extract which increases plasma atrial natriuretic peptide (ANP) on the atria of spontaneously hypertensive rats (SHR) by activating the glucagon-like peptide-1 receptor (GLP-1R). To achieve the antihypertensive effects of the Eucommia leaf extract through ANP secretion in humans, combining a potent cyclic adenosine monophosphate phosphodiesterase (cAMP-PDE) inhibitor, such as pinoresinol di-β-d-glucoside, with geniposidic acid may be necessary. Changes in the gut microbiota are an important aspect involved in the efficacy of asperuloside, another component of the Eucommia leaf extract, which improves obesity and related sequelae, such as insulin resistance and glucose intolerance. There are species differences of mechanisms associated with the antihypertensive and anti-obesity effects between rodents and humans, and not all animal test results are consistent with that of human studies. This review is focused on the mechanisms in antihypertensive and anti-obesity effects of the Eucommia leaf extract and summarizes the differences of mechanisms in their effects on rodents and humans based on our studies and those of others.

Eucommia Ulmoides Extracts Exert Protective Effect on Osteoporosis in Rats

Our study proposed to probe the therapeutic effect of Eucommia ulmoides extracts (EUE) on osteoporosis in rats and the potential mechanism. Castrated osteoporosis model was constructed in rats, followed by orally administrated with 50, 100, and 200 mg/kg EUE per day for one and half months, with sham animals as the negative control. The pathological conditions of femur were detected by HE staining, while the apoptotic state was evaluated by TUNEL. ELISA was utilized to measure the serum level of IL-6, calcium, and phosphorus. Significantly damaged bone trabecular structure and aggravated apoptosis were observed in castrated osteoporosis model rats, which were markedly alleviated by the administration of EUE. Furthermore, compared to control, the serum level of phosphorus was greatly declined and the IL-6 level was dramatically increased in castrated osteoporosis model rats, which were reversed by the administration of EUE. Taken together, EUE improved the pathological state of the femur tissue in osteoporosis rats by regulating the levels of phosphorus and IL-6 in serum and inhibited the apoptosis of the femur tissue cells, which effectively alleviated the osteoporosis induced by estrogen deficiency.

Eucommia ulmoides bark extract reduces blood pressure and inflammation by regulating the gut microbiota and enriching the Parabacteroides strain in high-salt diet and N(omega)-nitro-L-arginine methyl ester induced mice

Hypertension is a major threat to human health. Eucommia ulmoides Oliv. (EU) is a small tree and EU extract is widely used to improve hypertension in East Asia. However, its major constituents have poor absorption and stay in the gut for a long time. The role of the gut microbiota in the anti-hypertensive effects of EU is unclear. Here, we examined the anti-hypertensive effects of EU in high-salt diet and N(omega)-nitro-L-arginine methyl ester (L-NAME) induced mice. After receiving EU for 6 weeks, the blood pressure was significantly reduced and the kidney injury was improved. Additionally, EU restored the levels of inflammatory cytokines, such as serum interleukin (IL)-6 and IL-17A, and renal IL-17A. The diversity and composition of the gut microbiota were influenced by administration of EU; 40 significantly upregulated and 107 significantly downregulated amplicon sequence variants (ASVs) were identified after administration of EU. ASV403 (Parabacteroides) was selected as a potential anti-hypertensive ASV. Its closest strain XGB65 was isolated. Furthermore, animal studies confirmed that Parabacteroides strain XGB65 exerted anti-hypertensive effects, possibly by reducing levels of inflammatory cytokines, such as renal IL-17A. Our study is the first to report that EU reduces blood pressure by regulating the gut microbiota, and it enriches the Parabacteroides strain, which exerts anti-hypertensive effects. These findings provide directions for developing novel anti-hypertensive treatments by combining probiotics and prebiotics.