Plantamajoside inhibits high glucose-induced oxidative stress, inflammation, and extracellular matrix accumulation in rat glomerular mesangial cells through the inactivation of Akt/NF-κB pathway

Plant-derived and dietary phenolic cinnamic acid derivatives: Anti-inflammatory properties

Cinnamic acids are aromatic acids primarily found in plants and plant-derived food. Phenolic cinnamic acids, with one or more hydroxyl groups in the aromatic ring, often contribute to the biological activities attributed to these compounds. The presence of hydroxyl groups and a carboxyl group makes cinnamic acids very hydrophilic, preventing them from crossing biological membranes and exerting their biological activities. To alleviate this condition, a panel of synthetic modifications have been made leading to a diverse set of phenolic cinnamic structures. In this review, an overview of the natural phenolic cinnamic acid derivatives and their plant sources (more than 200) is described. The synthetic approaches to obtain the referred derivatives (more than 200) namely esters and amides are reviewed. Further, their anti-inflammatory activity (more than 70 compounds) is scrutinized. Finally, future directions will be indicated to translate the research on phenolic cinnamic derivatives into potentially effective anti-inflammatory drugs.

Plantamajoside modulates immune dysregulation and hepatic lipid metabolism in rats with nonalcoholic fatty liver disease via AMPK/Nrf2 elevation

Nonalcoholic fatty liver disease (NAFLD) is a hepatic metabolic syndrome with a rapidly increasing prevalence globally. Plantamajoside (PMS), a phenylethanoid glycoside component extracted from Plantago asiatica, has various biological properties. However, its effect on NAFLD remains unknown. The study aimed to explore the effect and mechanism of PMS on NAFLD in the high-fat diet (HFD)-feeding rats. PMS induced a decrease in body and liver weight, and the amelioration in the blood lipid parameters and pathological symptoms in HFD-feeding rats. The increase in the serum concentrations and the relative protein expressions of proinflammatory factors was decreased by the PMS treatment in HFD-induced NAFLD rats. Additionally, PMS reduced the excessive lipid vacuoles, and modified the relative expressions of proteins involved in the fatty acid synthesis and uptake in HFD-feeding rats. Mechanically, the downregulation of AMPK/Nrf2 pathway in HFD-feeding rats was restored by the PMS treatment. Inhibition of AMPK pathway reversed the PMS-induced the increase in the level of inflammatory factors, pathological symptoms, excessive lipid vacuoles, and the relative expression of proteins involved in the fatty acid synthesis and uptake. Collectively, PMS ameliorated immune dysregulation and abnormal hepatic lipid metabolism by activating AMPK/Nrf2 pathway in rats with NAFLD.

Metabolites analysis of plantamajoside based on gut microbiota-drug interaction

BACKGROUND

Plantaginis Herba (Plantago asiatica L.) has the effects of clearing heat and diuresis, oozing wet and drenching. As the main active components of Plantaginis Herba (Plantago asiatica L.), plantamajoside have a wide range of antitumor activities but very low bioavailability. The process of interacting between plantamajoside and gut microbiota remains unclear.

PURPOSE

To illustrate the process of interacting between plantamajoside and gut microbiota based on high-resolution mass spectrometry and targeted metabolomics methods.

STUDY DESIGN AND METHODS

This experiment was divided into two parts. First, metabolites produced from plantamajoside by gut microbiota were identified and quantified based on high-resolution mass spectrometry and LC-MS/MS. Additionally, stimulation of plantamajoside on gut microbiota-derived metabolites was determined by targeted metabolomics and gas chromatography.

RESULTS

We first found that plantamajoside was rapidly metabolized by gut microbiota. Then, we identified metabolites of plantamajoside by high-resolution mass spectrometry and speculated that plantamajoside was metabolized into five metabolites including calceolarioside A, dopaol glucoside, hydroxytyrosol, 3-(3-hydroxyphenyl) propionic acid (3-HPP) and caffeic acid. Among them, we quantitatively analyzed four possible metabolites based on LC‒MS/MS and found that hydroxytyrosol and 3-HPP were final products by the gut microbiota. In addition, we studied whether plantamajoside could affect the short-chain fatty acid (SCFA) and amino acid metabolites. We found that plantamajoside could inhibit the acetic acid, kynurenic acid (KYNA) and kynurenine (KN) produced by intestinal bacteria and promote the indole propionic acid (IPA) and indole formaldehyde (IALD) produced by intestinal bacteria.

CONCLUSION

An interaction between plantamajoside and gut microbiota was revealed in this study. Unlike the traditional metabolic system, the special metabolic characteristics of plantamajoside in gut microbiota was found. Plantamajoside was metabolized into the following active metabolites: calceolarioside A, dopaol glucoside, hydroxytyrosol, caffeic acid and 3-HPP. Besides, plantamajoside could affect SCFA and tryptophan metabolism by gut microbiota. Especially, the exogenous metabolites hydroxytyrosol, caffeic acid and endogenous metabolites IPA may have potential association with the antitumor activity of plantamajoside.

Plantamajoside Alleviates Substantia Nigra Damage in Parkinson's Disease Mice by Inhibiting HDAC2/MAPK Signaling and Reducing Microglia Polarization

Parkinson's disease (PD) is a common neurodegenerative disorder caused by dopaminergic neuron progressive degeneration. Inhibition of microglial activation may contribute to the treatment and prevention of PD. Plantamajoside (PMS) is a natural compound extracted from plantain seeds. It has a wide range of biological activities, including anti-inflammatory, antioxidative, as well as antitumor effects. However, its possible effects on PD are still unclear. In this study, lipopolysaccharide (LPS) was first injected into the right midbrain substantia nigra (SN) of male C57BL/6 mice to establish the PD mouse model. We found that PMS improved LPS-induced behavioral dysfunction in PD mice. PMS attenuated LPS-induced SN injury in PD mice. PMS could suppress LPS-induced microglial overactivation in PD mice. In addition, MS inhibited LPS-induced activation of the HDAC2/MAPK pathway in PD mice and BV-2 cells. It further revealed that PMS alleviated microglia polarization by inhibiting HDAC2. The limitation of this study was the lack of experiments for investigating the further molecular mechanism and in vivo animal validation, which needs to be further confirmed in the future. Collectively, our data suggested that PMS could serve as a promising drug for PD.

Plantamajoside attenuates cardiac fibrosis via inhibiting AGEs activated-RAGE/autophagy/EndMT pathway

Advanced glycation end products (AGEs) have been identified to transduce fibrogenic signals via inducing the activation of their receptor (RAGE)-mediated pathway. Recently, disrupting AGE-RAGE interaction has become a promising therapeutic strategy for chronic heart failure (CHF). Endothelial-to-mesenchymal transition (EndMT) is close to the cardiac fibrosis pathological process. Our previous studies have demonstrated that knockout RAGE suppressed the autophagy-mediated EndMT, and thus alleviated cardiac fibrosis. Plantamajoside (PMS) is the major bioactive compound of Plantago Asiatica, and its activity of anti-fibrosis has been documented in many reports. However, its effect on CHF and the underlying mechanism remains elusive. Thus, we tried to elucidate the protective role of PMS in CHF from the viewpoint of the AGEs/RAGE/autophagy/EndMT axis. Herein, PMS was found to attenuate cardiac fibrosis and dysfunction, suppress EndMT, reduce autophagy levels and serum levels of AGEs, yet did not affect the expression of RAGE in CHF mice. Mechanically, PMS possibly binds to the V-domain of RAGE, which is similar to the interaction between AGEs and RAGE. Importantly, this competitive binding disturbed AGEs-induced the RAGE-autophagy-EndMT pathway in vitro. Collectively, our results indicated that PMS might exert an anti-cardiac fibrosis effect by specifically binding RAGE to suppress the AGEs-activated RAGE/autophagy/EndMT pathway.

Plantamajoside alleviates hypoxia-reoxygenation injury through integrin-linked kinase/c-Src/Akt and the mitochondrial apoptosis signaling pathways in H9c2 myocardial cells

Myocardial ischemia-reperfusion injury(MIRI) is one of the common complications after myocardial infarction surgery, Oxidative stress is among the main mechanisms of myocardial ischemia-reperfusion injury. Plantamajoside (PMS), the main effective ingredient in the genus Plantain, has been reported to possess an antioxidation, anti-inflammatory and anti-apoptosis role. However, whether PMS can attenuate myocardial ischemia-reperfusion injury is not yet known. Herein, we explored the effects of PMS on hypoxia-reoxygenation (H/R) injury in H9c2 cardiomyocytes and the underling molecular mechanisms of the treatment. Network pharmacological analysis screened the top 31 key genes in the treatment of MIRI disease treated with PMS, and the result of molecular docking further illustrated the roles that the PMS play in the treatment of MIRI through its interference with integrin-linked kinase (ILK) target protein. PMS was not cytotoxic in the concentration range of 5-40 μM and increased cell survival after H/R injury in a concentration-dependent manner without affecting proliferation or growth. PMS significantly reduced the levels of lactate dehydrogenase, malonic dialdehyde, reactive oxygen species and cell apoptosis, and increased soperoxide dismutase activity compared with those of the H/R injury group. PMS promoted the protein and mRNA expression of ILK and Bcl-2, the protein expression of p-Akt, and reduced the protein and mRNA expression of Bax, Caspase-3, and Cytochrome c, the protein expression of p-c-Src. PMS has protective effects against H/R injury in H9c2 cells, and its protective mechanism may be related to reactive oxygen species clearance, activation of the ILK/c-Src/Akt pathway and inhibition of the mitochondrial apoptosis.

Phytochemicals, Biological Activities, Molecular Mechanisms, and Future Prospects of Plantago asiatica L

Plantago asiatica L. has been used as a vegetable and nutritious food in Asia for thousands of years. According to recent phytochemical and pharmacological research, the active compositions of the plant contribute to various health benefits, such as antioxidant, anti-inflammatory, antibacterial, antiviral, and anticancer. This article reviews the 87 components of the plant and their structures, as well as their biological activities and molecular research progress, in detail. This review provides valuable reference material for further study, production, and application of P. asiatica, as well as its components in functional foods and therapeutic agents.

A natural products solution to diabetic nephropathy therapy

Diabetic nephropathy is one of the most common complications in diabetes. It has been shown to be the leading cause of end-stage renal disease. However, due to their complex pathological mechanisms, effective therapeutic drugs other than angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), which have been used for 20 years, have not been developed so far. Recent studies have shown that diabetic nephropathy is characterized by multiple signalling pathways and multiple targets, including inflammation, apoptosis, pyroptosis, autophagy, oxidative stress, endoplasmic reticulum stress and their interactions. It definitely exacerbates the difficulty of therapy, but at the same time it also brings out the chance for natural products treatment. In the most recent two decades, a large number of natural products have displayed their potential in preclinical studies and a few compounds are under invetigation in clinical trials. Hence, many compounds targeting these singals have been emerged as a comprehensive blueprint for treating strategy of diabetic nephropathy. This review focuses on the cellular and molecular mechanisms of natural prouducts that alleviate this condition, including preclinical studies and clinical trials, which will provide new insights into the treatment of diabetic nephropathy and suggest novel ideas for new drug development.

Fufang Zhenzhu Tiaozhi capsule ameliorates hyperuricemic nephropathy by inhibition of PI3K/AKT/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Excessive serum uric acid (SUA) causes hyperuricemic nephropathy (HN), characterized by inflammatory infiltration and tubulointerstitial fibrosis. Most recently, we demonstrated that Fufang Zhenzhu Tiaozhi (FTZ) capsule attenuated diabetic nephropathy through inhibition of renal inflammation and fibrosis. However, whether FTZ ameliorates HN is still unclear.

AIM OF THE STUDY

To determine the protective roles and mechanism of FTZ in mouse renal injury and fibrosis under hyperuricemic condition.

MATERIALS AND METHODS

HN mice, induced by potassium oxonate and hypoxanthine, were administrated with 600 and 1200 mg/kg FTZ (intragastrically) daily for three weeks. SUA levels, renal functions and histological changes were analyzed. Western blotting, quantitative real-time PCR (q-PCR) and RNA sequencing were used to identify the roles and underlying mechanism of FTZ in HN mice.

RESULTS

We demonstrated that FTZ treatment mitigated renal injury in mice, as evidenced by the decrease in SUA, serum creatinine (SCr) and cystatin C (Cys C) levels, as well as improved renal histology. FTZ markedly attenuates inflammasome activation, collagen deposition and the imbalance of uric acid transporters. RNA-sequencing revealed a key mechanism involved in the protective effects on HN mice was related to PI3K/AKT/NF-κB pathway. Western blot also confirmed that FTZ diminished the phosphorylation of AKT and p65 in HN mice.

CONCLUSIONS

FTZ prevents renal injury, inflammation and fibrosis in HN mice via promoting uric acid excretion and inhibiting PI3K/AKT/NF-κB signaling pathway.

Rhein Inhibits Proliferation, Extracellular Matrix Deposition, and Inflammation in Mesangial Cells via ROS/Akt Signaling Pathway

It has been reported that rhein, a Chinese herbal compound, has a potent anti-inflammatory effect on various diseases. However, it remains elusive whether rhein has a protective effect on chronic kidney disease (CKD) and what its underlying mechanism may be. In the present study, we evaluated whether rhein could prevent lipopolysaccharide (LPS)-induced proliferation, expression of extracellular matrix (ECM) proteins, and inflammation in rat mesangial cells (MCs), and whether these effects were mediated by reactive oxygen species (ROS) and Akt signaling. We also investigated the protective effect of rhein on renal function in a rat CKD model. Results showed that rhein significantly suppressed LPS-initiated proliferation in MCs in a cell counting kit-8 (CCK8) assay. Meanwhile, rhein significantly inhibited LPS-induced expression of ECM proteins and inflammation, as indicated by the decreased expression of fibronectin, α smooth muscle actin (α-SMA), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), and interferon γ (IFN-γ). Of note, rhein significantly enhanced LPS-induced production of reactive oxygen species (ROS) and inhibited LPS-induced Akt phosphorylation. Furthermore, the inhibitory effect of rhein on Akt phosphorylation was inhibited by H2O2 scavenger catalase. Importantly, the protective effect of rhein was almost totally lost in the presence of phosphatidylinositol 3-kinase (PI3K) protagonist insulin-like growth factor 1 (IGF-1). Finally, rhein significantly decreased 24 h urinary protein, serum creatinine (SCr), and blood urea nitrogen (BUN) in CKD rats. Collectively, these results suggested that rhein improved CKD through inhibition of proliferation, ECM synthesis, and inflammation via ROS/Akt signaling in MCs.

Ligament Alteration in Diabetes Mellitus

Connective tissue ageing is accelerated by the progressive accumulation of advanced glycation end products (AGEs). The formation of AGEs is characteristic for diabetes mellitus (DM) progression and affects only specific proteins with relatively long half-lives. This is the case of fibrillar collagens that are highly susceptible to glycation. While collagen provides a framework for plenty of organs, the local homeostasis of specific tissues is indirectly affected by glycation. Among the many age- and diabetes-related morphological changes affecting human connective tissues, there is concurrently reduced healing capacity, flexibility, and quality among ligaments, tendons, bones, and skin. Although DM provokes a wide range of known clinical disorders, the exact mechanisms of connective tissue alteration are still being investigated. Most of them rely on animal models in order to conclude the patterns of damage. Further research and more well-designed large-cohort studies need to be conducted in order to answer the issue concerning the involvement of ligaments in diabetes-related complications. In the following manuscript, we present the results from experiments discovering specific molecules that are engaged in the degenerative process of connective tissue alteration. This review is intended to provide the report and sum up the investigations described in the literature concerning the topic of ligament alteration in DM, which, even though significantly decreasing the quality of life, do not play a major role in research.

Fucoidans from Cucumaria frondosa ameliorate renal interstitial fibrosis via inhibition of the PI3K/Akt/NF-κB signaling pathway

The effects of Cucumaria frondosa polysaccharides (CFPs) on renal interstitial fibrosis by regulating the phosphatidylinositol-3-hydroxykinase/protein kinase-B/nuclear factor-κB (PI3K/AKT/NF-κB) signaling pathway were investigated in vivo and in vitro in this research. The common unilateral urethral obstruction (UUO) model was used to examine the renoprotective effect and its mechanism in vivo. Compared to the UUO group, CFP administration could ameliorate renal function, inhibit inflammation and fibrosis, and reduce the deposition of the extracellular matrix and epithelial-mesenchymal transition. Mechanistic results indicated that CFPs could inhibit the expression of the total protein of PI3K and the conversion of the AKT and NF-κB p65 phosphorylated proteins, thereby inhibiting the transduction of the PI3K/AKT/NF-κB pathway. In addition, CFP treatment could improve inflammation and fibrosis in HK-2 cells induced by TGF-β1, and its in vitro mechanism was also verified to inhibit the PI3K/Akt/NF-κB signaling pathway. Overall, these results showed that CFP could alleviate renal interstitial fibrosis related to the PI3K/AKT/NF-κB signaling pathway.

Plantamajoside promotes metformin-induced apoptosis, autophagy and proliferation arrest of liver cancer cells via suppressing Akt/GSK3β signaling

Metformin, a well-known antidiabetic drug, exhibits anticancer effect in a variety of cancers, including liver cancer. Plantamajoside (PMS), a phenylethanoid glycoside compound isolated from Plantago asiatica, is proved to possess anticancer effects, too. In our study, we hypothesized that PMS might promote metformin mediated anticancer effects on liver cancer. The half maximal inhibitory concentration (IC₅₀) of metformin was evaluated by cell viability assay. The influence of PMS on proliferation, migration, invasion and apoptosis of metformin-treated cells was evaluated by BrdU incorporation assay, flow cytometry, western blot, wound scratch healing assay, transwell cell migration assay and immunofluorescence. A fasting/feeding mouse model was built to evaluate the influence of PMS on metformin sensitivity in vivo. PMS (2.5, 10 or 40 μg/mL) treatment reduced the IC₅₀ of metformin under different glucose concentrations. PMS (10 μg/mL) promoted metformin (5 mm) induced apoptosis and autophagy, and inhibition on proliferation, migration and invasion of HepG2 and HuH-7 cells. In the fasting/feeding mouse model, PMS (50 mg/kg) promoted metformin (200 mg/kg) induced proliferation arrest and apoptosis in vivo. Meanwhile, PMS reduced the level of pAkt^(ser473) and GSK3β^(ser9) in HepG2 and HuH-7 cells. Restoration of Akt/GSK3β signaling by a constitutively activated myr-Akt1 abrogated the effects of PMS on metformin-treated liver cancer cells. Our results demonstrated that PMS promoted the anticancer effects of metformin on liver cancer in vitro and in vivo.

Overview of key molecular and pharmacological targets for diabetes and associated diseases

Diabetes epidemiological quantities are demonstrating one of the most important communities' health worries. The essential diabetic difficulties are including cardiomyopathy, nephropathy, inflammation, and retinopathy. Despite developments in glucose decreasing treatments and drugs, these diabetic complications are still ineffectively reversed or prohibited. Several signaling and molecular pathways are vital targets in the new therapies of diabetes. This review assesses the newest researches about the key molecules and signaling pathways as targets of molecular pharmacology in diabetes and diseases related to it for better treatment based on molecular sciences. The disease is not cured by current pharmacological strategies for type 2 diabetes. While several drug combinations are accessible that can efficiently modulate glycemia and mitigate long-term complications, these agents do not reverse pathogenesis, and in practice, they are not established to modify the patient's specific molecular profiling. Therapeutic companies have benefited from human genetics. Genome exploration, which is agnostic to the information that exists, has revealed tens of loci that impact glycemic modulation. The physiological report has begun to examine subtypes of diseases, illustrate heterogeneity and propose biochemical therapeutic pathways.

The protective mechanism of action of plantamajoside on a rat model of acute spinal cord injury

Acute spinal cord injury (ASCI) is a severe traumatic disease of the central nervous system, characterized by a high incidence and high morbidity, for which there are no effective drug therapies in the clinic. A rat model of ASCI was established to study the effects of plantamajoside (PMS) treatment on the expression of apoptotic factors, including caspase-3, caspase-9, poly (ADP-ribose) polymerase (PARP), Bax and Bcl-2. The Allen's weight hit rat ASCI model was used for the present study, and the rats were treated with various concentrations of PMS. The behavior of rats was assessed using the Basso-Beattle-Bresnahan locomotor rating scale (BBB), the histopathologic changes of spinal cord tissue were observed by hematoxylin and eosin staining, the survival of neurons was assessed by TUNEL staining and the expression levels of apoptotic proteins such as caspase-3, caspase-9, PARP, Bcl-2 and Bax was measured using western blot assays and RT-qPCR. It was observed that PMS could reverse the decrease in the BBB score after ASCI, improve the morphological characteristics of the spinal cord, reduce the degree apoptosis and affect the expression of caspase-3, caspase-9, PARP, Bax and Bcl-2 in a concentration dependent manner. In conclusion, PMS protected ASCI rats by inhibiting apoptosis; therefore PMS may be a potential candidate for ASCI therapy.