Natural products against renin-angiotensin system for antifibrosis therapy

Identification of 18β-glycyrrhetinic acid as an AGT inhibitor against LPS-induced myocardial dysfunction via high throughput screening

Sepsis induced myocardial dysfunction (SIMD) is a serious complication of sepsis. There is increasing evidence that the renin-angiotensin system (RAS) is activated in SIMD. Angiotensinogen (AGT) is a precursor of the RAS, and the inhibition of AGT may have significant cardiovascular benefits. But until now, there have been no reports of small molecule drugs targeting AGT. In this study, we designed a promoter-luciferase based system to screen for novel AGT inhibitors to alleviate SIMD. As a result of high-throughput screening, a total of 5 compounds from 351 medicinal herb-derived natural compounds were found inhibiting AGT. 18β-glycyrrhetinic acid (18βGA) was further identified as a potent suppressor of AGT. In vitro experiments, 18βGA could inhibit the secretion of AGT by HepG2 cells and alleviate the elevated level of mitochondrial oxidative stress in cardiomyocytes co-cultured with HepG2 supernatants. In vivo, 18βGA prolonged the survival rate of SIMD mice, enhanced cardiac function, and inhibited the damage of mitochondrial function and inflammation. In addition, the results showed that 18βGA may reduce AGT transcription by downregulating hepatocyte nuclear factor 4 (HNF4) and that further alleviated SIMD. In conclusion, we provided a more efficient screening strategy for AGT inhibitors and expanded the novel role of 18βGA as a promising lead compound in rescuing cardiovascular disease associated with RAS overactivation.

Natural angiotensin converting enzyme inhibitors: A safeguard against hypertension, respiratory distress syndrome, and chronic kidney diseases

Hypertension is a serious concern as it is one of the causes of kideny failure and pulmonary fibrosis. An important therapeutic strategy for treating chronic hypertension is to inhibit the angiotensin converting enzyme (ACE). ACE inhibition reduces kidney damage, pulmonary artery pressure, and high blood pressure. Due to their high efficacy and low risk of side effects, natural renin-angiotensin system inhibitors have drawn increasing attention over the past decades. Alkaloids, amino acids, anthocyanidins, flavonoids, glucosinolates, isoflavonoids, phenolic acids, polyphenolics, and triterpenoids are among the bioactive metabolites pocessing an impressive ACE inhibitory activity. Many herbs including Rosmarinus officinalis, Hibiscus sabdariffa, Curcuma longa, Rauwolfia serpentina, Emblica officinalis, Cynara scolymus, Punica granatum, Mucuna pruriens, Capsicum annuum, and Moringa olifera were found having ACE inhibitory activities comparable to captopril and enalpril. These enticing natural ACE inhibitors deserve to be a safeguard medicine against hypertension, respiratory distress syndrome, and chronic kidney diseases. More clinical trials are required before new natural compounds and herbs can be used to treat chronic hypertension and its ramifications, such as respiratory distress syndrome and kidney failure.

Antihypertensive effects of Pleurospermum lindleyanum aqueous extract in spontaneously hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pleurospermum lindleyanum (Lipsky) B. Fedtsch is a perennial herb classified in the Apiaceae family, genus Pleurospermum, chiefly native to the Taxkorgan County, Xinjiang, China. In the Xinjiang Province, it is a well-known ethnic traditional herb, often addressed by its tribal name, Kurumuti. It grows in harsh conditions over 4000 m above sea level, such as the Pamirs plateau. It is rich in flavonoids, coumarins, terpenoids, essential oil, substances that have been widely applied in the prevention and treatment of hypertension, diabetes, coronary heart disease, and cerebral thrombosis by local Tajik residents.

AIMS OF THE STUDY

The present study aimed to evaluate the antihypertensive effects of the Pleurospermum Lindleyanum aqueous extract (PLAE) in spontaneously hypertensive rats (SHRs).

MATERIALS AND METHODS

The Pleurospermum lindleyanum was collected from the Taxkorgan Tajik Autonomous County, Xinjiang, China. The main chemical composition of PLAE was identified using the ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). SHRs were treated by gavage with PLAE (equivalent to Pleurospermum lindleyanum 5 or 10 g/kg/day) for 6 weeks, using Captopril (10 mg/kg/day) as positive control. The systolic blood pressure (SBP), renal and cardiac morphology, plasma levels of angiotensin-converting enzyme (ACE), aldosterone (ALD), angiotensinⅡ (AngⅡ), superoxide dismutase (SOD), endothelin-1 (ET-1) and nitric oxide (NO) were measured.

RESULTS

A total of 30 compounds were identified in PLAE. PLAE significantly attenuated the SBP of SHRs. The effects began after 3 weeks of administration and then became steady and long-lasting. Its potential mechanisms may be associated with the protective effects on renal and cardiac injury caused by hypertension, the decrease of plasma vasoconstrictors, such as ACE, ALD, AngⅡ, and ET-1 levels, the maintenance of NO/ET balance, the increase in plasma NO levels and SOD activity, thereby reducing oxidative stress.

CONCLUSION

Pleurospermum lindleyanum can be suggested as a novel antihypertensive ethnic traditional herb, which lays the foundation for researching safe and effective antihypertensive herbal medicines.

Recent Advances in Natural Polyphenol Research

Polyphenols are secondary metabolites produced by plants, which contribute to the plant's defense against abiotic stress conditions (e.g., UV radiation and precipitation), the aggression of herbivores, and plant pathogens. Epidemiological studies suggest that long-term consumption of plant polyphenols protects against cardiovascular disease, cancer, osteoporosis, diabetes, and neurodegenerative diseases. Their structural diversity has fascinated and confronted analytical chemists on how to carry out unambiguous identification, exhaustive recovery from plants and organic waste, and define their nutritional and biological potential. The food, cosmetic, and pharmaceutical industries employ polyphenols from fruits and vegetables to produce additives, additional foods, and supplements. In some cases, nanocarriers have been used to protect polyphenols during food processing, to solve the issues related to low water solubility, to transport them to the site of action, and improve their bioavailability. This review summarizes the structure-bioactivity relationships, processing parameters that impact polyphenol stability and bioavailability, the research progress in nanocarrier delivery, and the most innovative methodologies for the exhaustive recovery of polyphenols from plant and agri-waste materials.

Research and application of herbal medicine in the treatment of chronic kidney disease since the 21st century: A visualized bibliometric analysis

Background: Here, a bibliometric and knowledge-map analysis was used to analyze the research status and application of herbal medicine for the treatment of chronic kidney disease (CKD). By looking for research hotspots and key topics, we provide new clues and research directions for future research.

Methods: Articles and reviews regarding herbal medicine in the treatment of CKD were retrieved from the Web of Science Core Collection on 23 May 2022. The R-bibliometrix, VOSviewer, and CiteSpace software were used to conduct the bibliometric and knowledge-map analysis.

Results: In total, 5,920 authors at 1,330 institutions from 68 countries published 1,602 papers in 355 academic journals. China is the leader and pioneer in the research and application of herbal medicine in the field of CKD treatment. Beijing University of Chinese Medicine contributed the most publications. Ping Li (China-Japan Friendship Hospital) published the most articles, while Yingyong Zhao (Northwest University) had the most cocitations. However, cooperation among countries and the research institutions is not sufficient. Journal of Ethnopharmacology published the most research and application of herbal medicine in the treatment of CKD and was the most commonly co-cited journal. The most influential research hotspots about herbal medicine in the treatment of CKD focused on diabetic nephropathy-related research, Balkan endemic nephropathy, and pharmacokinetic study.

Conclusion: Herbal medicine has a wide range of pharmacological activities and therapeutic value. The research and application of herbal medicine for the treatment of CKD, especially diabetic nephropathy, will remain a hot topic in the future.

Shenkang injection improves chronic kidney disease by inhibiting multiple renin-angiotensin system genes by blocking the Wnt/β-catenin signalling pathway

Chronic kidney disease (CKD) is a major worldwide public health problem. The increase in the number of patients with CKD and end-stage kidney disease requesting renal dialysis or transplantation will progress to epidemic proportions in the next several decades. Although blocking the renin-angiotensin system (RAS) has been used as a first-line standard therapy in patients with hypertension and CKD, patients still progress towards end-stage kidney disease, which might be closely associated with compensatory renin expression subsequent to RAS blockade through a homeostatic mechanism. The Wnt/β-catenin signalling pathway is the master upstream regulator that controls multiple intrarenal RAS genes. As Wnt/β-catenin regulates multiple RAS genes, we inferred that this pathway might also be implicated in blood pressure control. Therefore, discovering new medications to synchronously target multiple RAS genes is necessary and essential for the effective treatment of patients with CKD. We hypothesized that Shenkang injection (SKI), which is widely used to treat CKD patients, might ameliorate CKD by inhibiting the activation of multiple RAS genes via the Wnt/β-catenin signalling pathway. To test this hypothesis, we used adenine-induced CKD rats and angiotensin II (AngII)-induced HK-2 and NRK-49F cells. Treatment with SKI inhibited renal function decline, hypertension and renal fibrosis. Mechanistically, SKI abrogated the increased protein expression of multiple RAS elements, including angiotensin-converting enzyme and angiotensin II type 1 receptor, as well as Wnt1, β-catenin and downstream target genes, including Snail1, Twist, matrix metalloproteinase-7, plasminogen activator inhibitor-1 and fibroblast-specific protein 1, in adenine-induced rats, which was verified in AngII-induced HK-2 and NRK-49F cells. Similarly, our results further indicated that treatment with rhein isolated from SKI attenuated renal function decline and epithelial-to-mesenchymal transition and repressed RAS activation and the hyperactive Wnt/β-catenin signalling pathway in both adenine-induced rats and AngII-induced HK-2 and NRK-49F cells. This study first revealed that SKI repressed epithelial-to-mesenchymal transition by synchronously targeting multiple RAS elements by blocking the hyperactive Wnt/β-catenin signalling pathway.

The Antifungal and Anti-Pneumocystis Activities of the Novel Compound A3IS (Mycosinate)

A3IS (Mycosinate) is a synthetic product which only contains ingredients found naturally within honey. A3IS is a broad-spectrum antimicrobial product which produces a sustained release of hydrogen peroxide at low but therapeutic levels. The product elicits this release through an enzymatic reaction between glucose oxidase and the substrate glucose once the product is hydrated. As medical uses for different honeys are being re-evaluated, the purpose of this study was to evaluate the in vitro effects of A3IS against a comprehensive panel of human pathogens, including Pneumocystis species, providing a unique assessment against a panel of eukaryotic pathogens. Without exception, A3IS exhibited significant efficacy at 50% and 100% inhibitory concentrations against a broad spectrum of human pathogens including yeasts, molds (both hyaline and dematiaceous), and dimorphic fungi. Notably, A3IS was effective against fungal strains with a high level of resistance to fluconazole or voriconazole. The 50% inhibitory concentrations for Pneumocystis carinii and P. murina (surrogates for P. jirovecii) were considered "Marked" and "Moderate" on an established rank scale, and would be considered for in vivo studies, based on an established in vitro-in vivo pipeline. These results indicate that A3IS is a novel anti-fungal agent against an extensive range of human fungal pathogens.

Melatonin effect on platelets and coagulation: Implications for a prophylactic indication in COVID-19

Severe COVID-19 is associated with the dynamic changes in coagulation parameters. Coagulopathy is considered as a major extra-pulmonary risk factor for severity and mortality of COVID-19; patients with elevated levels of coagulation biomarkers have poorer in-hospital outcomes. Oxidative stress, alterations in the activity of cytochrome P450 enzymes, development of the cytokine storm and inflammation, endothelial dysfunction, angiotensin-converting enzyme 2 (ACE2) enzyme malfunction and renin–angiotensin system (RAS) imbalance are among other mechanisms suggested to be involved in the coagulopathy induced by severe acute respiratory syndrome coronavirus (SARS-CoV-2). The activity and function of coagulation factors are reported to have a circadian component. Melatonin, a multipotential neurohormone secreted by the pineal gland exclusively at night, regulates the cytokine system and the coagulation cascade in infections such as those caused by coronaviruses. Herein, we review the mechanisms and beneficial effects of melatonin against coagulopathy induced by SARS-CoV-2 infection.

Novel angiotensin-converting enzyme inhibitory peptides from tuna byproducts—milts: Preparation, characterization, molecular docking study, and antioxidant function on H2O2-damaged human umbilical vein endothelial cells

To prepare peptides with high angiotensin-converting enzyme (ACE) inhibitory (ACEi) activity, Alcalase was screened from five proteases and employed to prepare protein hydrolysate (TMH) of skipjack tuna (Katsuwonus pelamis) milts. Subsequently, 10 novel ACEi peptides were isolated from the high-ACEi activity TMH and identified as Tyr-Asp-Asp (YDD), Thr-Arg-Glu (TRE), Arg-Asp-Tyr (RDY), Thr-Glu-Arg-Met (TERM), Asp-Arg-Arg-Tyr-Gly (DRRYG), Ile-Cys-Tyr (ICY), Leu-Ser-Phe-Arg (LSFR), Gly-Val-Arg-Phe (GVRF), Lys-Leu-Tyr-Ala-Leu-Phe (KLYALF), and Ile-Tyr-Ser-Pro (IYSP) with molecular weights of 411.35, 404.41, 452.45, 535.60, 665.69, 397.48, 521.61, 477.55, 753.91, and 478.53 Da, respectively. Among them, the IC₅₀ values of ICY, LSFR, and IYSP on ACE were 0.48, 0.59, and 0.76 mg/mL, respectively. The significant ACEi activity of ICY, LSFR, and IYSP with affinities of −7.0, −8.5, and −8.3 kcal/mol mainly attributed to effectively combining with the ACEi active sites through hydrogen bonding, electrostatic force, and hydrophobic interaction. Moreover, ICY, LSFR, and IYSP could positively influence the production of nitric oxide (NO) and endothelin-1 (ET-1) secretion in human umbilical vein endothelial cells (HUVECs) and weaken the adverse impact of norepinephrine (NE) on the production of NO and ET-1. In addition, ICY, LSFR, and IYSP could provide significant protection to HUVECs against H₂O₂ damage by increasing antioxidase levels to decrease the contents of reactive oxide species and malondialdehyde. Therefore, the ACEi peptides of ICY, LSFR, and IYSP are beneficial functional molecules for healthy foods against hypertension and cardiovascular diseases.

Inhibition of Angiogenesis and Extracellular Matrix Remodeling: Synergistic Effect of Renin-Angiotensin System Inhibitors and Bevacizumab

Bevacizumab (Bev) is a humanized vascular endothelial growth factor monoclonal antibody that is used with chemotherapeutic drugs for the treatment of metastatic colorectal cancer (mCRC). Bev-induced hypertension (HT) is the most common adverse reaction during clinical practice. However, at present, appropriate antihypertensive agents for Bev-induced HT are unavailable. In this study, retrospective analysis of clinical data from mCRC patients who received renin-angiotensin system inhibitors (RASIs) showed significant survival benefits of overall survival (OS) and progression-free survival (PFS) over patients who received calcium channel blockers (CCBs) and patients who received no antihypertensive drug (NO: Y2020046 retrospectively registered). An experiment of HCT116 colon cancer cell xenografts in mice confirmed that combined treatment of Bev and lisinopril (Lis), a RASI, synergistically inhibited subcutaneous tumor growth and enhanced the concentration of 5-fluorouracil (5-Fu) in tumor tissues. Our results showed that the addition of Lis did not interfere with the vascular normalization effect promoted by Bev, but also inhibited collagen and hyaluronic acid (HA) deposition and significantly downregulated the expression of TGF-β1 and downstream SMAD signaling components which were enhanced by Bev, ultimately remodeling primary extracellular matrix components. In conclusion, RASIs and Bev have synergistic effect in the treatment of colorectal cancer and RASIs might be an optimal choice for the treatment of Bev-induced HT.

MicroRNAs in organ fibrosis: From molecular mechanisms to potential therapeutic targets

Fibrosis is caused by chronic tissue injury and characterized by the excessive deposition of extracellular matrix (ECM) that ultimately results in organ failure and death. Owing to lacking of effective treatment against tissue fibrosis, it causes a high morbidity and mortality worldwide. Thus, it is of great importance to find an effective therapy strategy for the treatment of fibrosis. MicroRNAs (miRNAs) play vital roles in many biological processes by targeting downstream genes. Numerous studies demonstrated that miRNAs served as biomarkers of various diseases, suggesting the potential therapeutic targets for diseases. It was recently reported that miRNAs played an important role in the development of organ fibrosis, which showed a promising prospect against fibrosis by targeting intervention. Here, we summarize the roles of miRNAs in the process of organ fibrosis, including liver, lung, heart and kidney, and highlight miRNAs being novel therapeutic targets for organ fibrosis.

Traditional Chinese medicine as a therapeutic option for cardiac fibrosis: Pharmacology and mechanisms

Cardiovascular diseases are one of the leading causes of death worldwide and cardiac fibrosis is a common pathological process for cardiac remodeling in cardiovascular diseases. Cardiac fibrosis not only accelerates the deterioration progress of diseases but also becomes a pivotal contributor for futile treatment in clinical cardiovascular trials. Although cardiac fibrosis is common and prevalent, effective medicines to provide sufficient clinical intervention for cardiac fibrosis are still unavailable. Traditional Chinese medicine (TCM) is the natural essence experienced boiling, fry, and other processing methods, including active ingredients, extracts, and herbal formulas, which have been applied to treat human diseases for a long history. Recently, research has increasingly focused on the great potential of TCM for the prevention and treatment of cardiac fibrosis. Here, we aim to clarify the identified pro-fibrotic mechanisms and intensively summarize the application of TCM in improving cardiac fibrosis by working on these mechanisms. Through comprehensively analyzing, TCM mainly regulates the following pathways during ameliorating cardiac fibrosis: attenuation of inflammation and oxidative stress, inhibition of cardiac fibroblasts activation, reduction of extracellular matrix accumulation, modulation of the renin-angiotensin-aldosterone system, modulation of autophagy, regulation of metabolic-dependent mechanisms, and targeting microRNAs. We also discussed the deficiencies and the development direction of anti-fibrotic therapies on cardiac fibrosis. The data reviewed here demonstrates that TCM shows a robust effect on alleviating cardiac fibrosis, which provides us a rich source of new drugs or drug candidates. Besides, we also hope this review may give some enlightenment for treating cardiac fibrosis in clinical practice.

Computer-Aided Drug Design Applied to Secondary Metabolites as Anticancer Agents

Computer-Aided Drug Design (CADD) techniques have garnered a great deal of attention in academia and industry because of their great versatility, low costs, possibilities of cost reduction in in vitro screening and in the development of synthetic steps; these techniques are compared with highthroughput screening, in particular for candidate drugs. The secondary metabolism of plants and other organisms provide substantial amounts of new chemical structures, many of which have numerous biological and pharmacological properties for virtually every existing disease, including cancer. In oncology, compounds such as vimblastine, vincristine, taxol, podophyllotoxin, captothecin and cytarabine are examples of how important natural products enhance the cancer-fighting therapeutic arsenal. In this context, this review presents an update of Ligand-Based Drug Design and Structure-Based Drug Design techniques applied to flavonoids, alkaloids and coumarins in the search of new compounds or fragments that can be used in oncology. A systematical search using various databases was performed. The search was limited to articles published in the last 10 years. The great diversity of chemical structures (coumarin, flavonoids and alkaloids) with cancer properties, associated with infinite synthetic possibilities for obtaining analogous compounds, creates a huge chemical environment with potential to be explored, and creates a major difficulty, for screening studies to select compounds with more promising activity for a selected target. CADD techniques appear to be the least expensive and most efficient alternatives to perform virtual screening studies, aiming to selected compounds with better activity profiles and better "drugability".

Therapeutic options of TCM for organ injuries associated with COVID-19 and the underlying mechanism

BACKGROUND

Coronavirus disease-2019 (COVID-19) caused by infection with severe acute respiratory coronavirus-2 (SARS-CoV-2) has been spreading rapidly throughout China and in other countries since the end of 2019. The World Health Organization (WHO) has declared that the epidemic is a public health emergency of international concerns. The timely and appropriate measures for treating COVID-19 in China, which are inseparable from the contribution of traditional Chinese medicine (TCM), have won much praise of the world.

PURPOSE

This review aimed to summarize and discuss the essential role of TCM in protecting tissues from injuries associated with COVID-19, and accordingly to clarify the possible action mechanisms of TCM from the perspectives of anti-inflammatory, antioxidant and anti-apoptotic effects.

METHODS

Electronic databases such as Pubmed, ResearchGate, Science Direct, Web of Science, medRixv and Wiley were used to search scientific literatures.

RESULTS

The present review found that traditional Chinese herbs commonly used for the clinical treatment of organ damages caused by COVID-19, such as Scutellaria baicalensis, Salvia miltiorrhizaSalvia miltiorrhiza, and ginseng, could act on multiple signaling pathways involved in inflammation, oxidative stress and apoptosis.

CONCLUSION

TCM could protect COVID-19 patients from tissue injuries, a protection that might be, at least partially, attributed to the anti-inflammatory, antioxidant and anti-apoptotic effects of the TCM under investigation. This review provides evidence and support for clinical treatment and novel drug research using TCM.

Chinese herbal medicine: Fighting SARS-CoV-2 infection on all fronts

ETHNOPHARMACOLOGICAL RELEVANCE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), a highly pathogenic virus that has spread rapidly across the entire world. There is a critical need to develop safe and effective drugs, especially broad-spectrum antiviral and organ protection agents in order to treat and prevent this dangerous disease. It is possible that Chinese herbal medicine may play an essential role in the treatment of patients with SARS-CoV-2 infection.

AIM OF THE REVIEW

We aim to review the use of Chinese herbal medicine in the treatment of COVID-19 both in vitro and in clinical practice. Our goal was to provide a better understanding of the potential therapeutic effects of Chinese herbal medicine and to establish a "Chinese protocol" for the treatment of COVID-19.

MATERIALS AND METHODS

We systematically reviewed published research relating to traditional Chinese herbal medicines and the treatment of SARS-CoV-2 from inception to the 6^th January 2021 by screening a range of digital databases (Web of Science, bioRxiv, medRxiv, China National Knowledge Infrastructure, X-MOL, Wanfang Data, Google Scholar, PubMed, Elsevier, and other resources) and public platforms relating to the management of clinical trials. We included the active ingredients of Chinese herbal medicines, monomer preparations, crude extracts, and formulas for the treatment of COVID-19.

RESULTS

In mainland China, a range of Chinese herbal medicines have been recognized as very promising anti-SARS-CoV-2 agents, including active ingredients (quercetagetin, osajin, tetrandrine, proscillaridin A, and dihydromyricetin), monomer preparations (xiyanping injection, matrine-sodium chloride injection, diammonium glycyrrhizinate enteric-coated capsules, and sodium aescinate injection), crude extracts (Scutellariae Radix extract and garlic essential oil), and formulas (Qingfei Paidu decoction, Lianhuaqingwen capsules, and Pudilan Xiaoyan oral liquid). All these agents have potential activity against SARS-CoV-2 and have attracted significant attention due to their activities both in vitro and in clinical practice.

CONCLUSIONS

As a key component of the COVID-19 treatment regimen, Chinese herbal medicines have played an irreplaceable role in the treatment of SARS-CoV-2 infection. The "Chinese protocol" has already demonstrated clear clinical importance. The use of Chinese herbal medicines that are capable of inhibiting SARS-Cov-2 infection may help to address this immediate unmet clinical need and may be attractive to other countries that are also seeking new options for effective COVID-19 treatment. Our analyses suggest that countries outside of China should also consider protocols involving Chinese herbal medicines combat this fast-spreading viral infection.

Flavonoids as potential therapeutics against novel coronavirus disease-2019 (nCOVID-19)

Since time immemorial natural products have been a great source of medicine to mankind. The anti-viral activities from several ayurvedic herbal medicines (in the form of crude extract or fraction or isolated compounds) have been established but their effectiveness against coronavirus still needs to be explored. They can provide a rich resource of anti-SARS-CoV-2 drug candidates. In this paper, in-silico techniques have been used to identify the potential lead molecules against SARS-CoV-2. A list of flavonoids having anti-viral activity was prepared and evaluated against the selected target. Rhoifolin, 5,7-dimethoxyflavanone-4'-O-β-d-glucopyranoside, baicalin, astragalin, luteolin, and kaempferol showed good binding affinity and thus these could be promising compounds. In-silico screening such as ADMET prediction has been performed which predicted that the selected flavonoids have good pharmacokinetics and pharmacodynamics properties. Molecular dynamics simulation studies and MM-PBSA binding free energy calculations showed luteolin to be a more effective candidate against viral protein Mpro. The novelty of the approach mainly rests in the identification of potent anti-viral natural molecules from natural products flavonoid group of molecules to be effective against the latest coronavirus infection.Communicated by Ramaswamy H. Sarma.

Polyporus Umbellatus Protects Against Renal Fibrosis by Regulating Intrarenal Fatty Acyl Metabolites

Background: Chronic renal failure (CRF) results in significant dyslipidemia and profound changes in lipid metabolism. Polyporus umbellatus (PPU) has been shown to prevent kidney injury and subsequent kidney fibrosis.

Methods: Lipidomic analysis was performed to explore the intrarenal profile of lipid metabolites and further investigate the effect of PPU and its main bioactive component, ergone, on disorders of lipid metabolism in rats induced by adenine. Univariate and multivariate statistical analyses were performed for choosing intrarenal differential lipid species in CRF rats and the intervening effect of n-hexane extract of PPU and ergone on CRF rats.

Results: Compared with control group, decreased creatinine clearance rate indicated declining kidney function in CRF group. Based on the lipidomics, we identified 65 lipid species that showed significant differences between CRF and control groups. The levels of 12 lipid species, especially fatty acyl lipids including docosahexaenoic acid, docosapentaenoic acid (22n-3), 10,11-Dihydro-12R-hydroxy-leukotriene C4, 3-hydroxydodecanoyl carnitine, eicosapentaenoic acid, hypogeic acid and 3-hydroxypentadecanoic acid had a strong linear correlation with creatinine clearance rate, which indicated these lipid species were associated with impaired renal function. In addition, receiver operating characteristics analysis showed that 12 lipid species had high area under the curve values with high sensitivity and specificity for differentiating CRF group from control group. These changes are related to the perturbation of fatty acyl metabolism. Treatment with PPU and ergone improved the impaired kidney function and mitigated renal fibrosis. Both chemometrics and cluster analyses showed that rats treated by PPU and ergone could be separated from CRF rats by using 12 lipid species. Intriguingly, PPU treatment could restore the levels of 12 lipid species, while treatment with ergone could only reverse the changes of six fatty acids in CRF rats.

Conclusion: Altered intrarenal fatty acyl metabolites were implicated in pathogenesis of renal fibrosis. PPU and ergone administration alleviated renal fibrosis and partially improved fatty acyl metabolism. These findings suggest that PPU exerted its renoprotective effect by regulating fatty acyl metabolism as a potential biochemical mechanism. Therefore, these findings indicated that fatty acyl metabolism played an important role in renal fibrosis and could be considered as an effective therapeutic avenue against renal fibrosis.

Mechanism of herbal medicine on hypertensive nephropathy (Review)

Hypertensive nephropathy is the most common complication of hypertension, and is one of the main causes of end-stage renal disease (ESRD) in numerous countries. The basic pathological feature of hypertensive nephropathy is arteriolosclerosis followed by renal parenchymal damage. The etiology of this disease is complex, and its pathogenesis is mainly associated with renal hemodynamic changes and vascular remodeling. Despite the increased knowledge on the pathogenesis of hypertensive nephropathy, the current clinical treatment methods are still not effective in preventing the development of the disease to ESRD. Herbal medicine, which is used to relieve symptoms, can improve hypertensive nephropathy through multiple targets. Since there are few clinical studies on the treatment of hypertensive nephropathy with herbal medicine, this article aims to review the progress on the basic research on the treatment of hypertensive nephropathy with herbal medicine, including regulation of the renin angiotensin system, inhibition of sympathetic excitation, antioxidant stress and anti-inflammatory protection of endothelial cells, and improvement of obesity-associated factors. Herbal medicine with different components plays a synergistic and multi-target role in the treatment of hypertensive nephropathy. The description of the mechanism of herbal medicine in the treatment of hypertensive nephropathy will contribute towards the progress of modern medicine.

Investigation of inhibition effect of butanol and water extracts of Matricaria chamomilla L. on angiotensin-converting enzyme purified from human plasma

Angiotensin-converting enzyme (ACE) liable for the regulation of blood pressure was purified from human plasma by affinity chromatography. Impact of water and butanol extracts of Matricaria chamomilla L. on purity ACE was examined. ACE was purified using the affinity chromatography method. The enzyme activity was evaluated at 345 nm by a spectrophotometer. Extracts of M. chamomilla plant with butanol and water were prepared. Lisinopril was utilized as a specific inhibitor. ACE was purified 3,659-fold from human plasma and the specific activity was 1,350 EU/mg protein. The molecular weight and purity of ACE were found by SDS-PAGE and two bands of 60 and 70 kDa on the gel were detected. Water and butanol extracts of M. chamomilla demonstrated inhibitor impact on ACE activity. IC₅₀ constants for water and butanol extracts of M. chamomilla were computed to be 1.292 and 0.353 mg/mL, respectively. The type of inhibition for whole inhibitors was identified as noncompetitive. IC₅₀ and K_i constants for lisinopril were calculated to be 0.781 and 0.662 nM, respectively. These results indicate that butanol and water extracts of M. chamomilla may have an ACE inhibitor potential.

Beneficial Effects of Spirulina Aqueous Extract on Vasodilator Function of Arteries from Hypertensive Rats

Hypertension is a multifactorial disorder considered one of the major causes of premature death worldwide. This pathology is associated with vascular functional/structural alterations in which nitric oxide (NO) and oxygen reactive species participate. On the other hand, the use of microalgae extracts in the treatment of cardiovascular diseases is increasing. Based on the antioxidant and antihypertensive properties of Spirulina, this study aims to investigate the effect of an aqueous extract of Spirulina on the vasodilator function of the aorta from spontaneously hypertensive rats (SHR), analyzing the functional role of NO. For this, aortic segments from male SHR were divided into two groups, one control and the other exposed to an Spirulina aqueous extract (0.1% w/v, for 3 hours), to analyze (i) the production of NO, superoxide anion, and hydrogen peroxide; (ii) the vasodilator response induced by acetylcholine (ACh), by the NO donor and sodium nitroprusside (SNP), and by the KATP channel opener and pinacidil; and (iii) the expression of the p-Akt, p-eNOS, and HO-1 proteins. The results showed that the aqueous Spirulina extract (i) increased the production of NO, did not significantly modify that of superoxide, while decreased that of hydrogen peroxide; (ii) increased the vasodilatory responses induced by ACh, NPS, and pinacidil; and (iii) increased the expression of p-Akt and HO-1. These results suggest that incubation with the aqueous Spirulina extract improves the vascular function of arteries from SHR by increasing the release/bioavailability/function of NO. Increased KATP channel activation and expression of pAkt and HO-1 appear to be participating in these actions.

Deciphering the cellular mechanisms underlying fibrosis-associated diseases and therapeutic avenues

Fibrosis is the excessive deposition of extracellular matrix components, which results in disruption of tissue architecture and loss of organ function. Fibrosis leads to high morbidity and mortality worldwide, mainly due to the lack of effective therapeutic strategies against fibrosis. It is generally accepted that fibrosis occurs during an aberrant wound healing process and shares a common pathogenesis across different organs such as the heart, liver, kidney, and lung. A better understanding of the fibrosis-related cellular and molecular mechanisms will be helpful for development of targeted drug therapies. Extensive studies revealed that numerous mediators contributed to fibrogenesis, suggesting that targeting these mediators may be an effective therapeutic strategy for antifibrosis. In this review, we describe a number of mediators involved in tissue fibrosis, including aryl hydrocarbon receptor, Yes-associated protein, cannabinoid receptors, angiopoietin-like protein 2, high mobility group box 1, angiotensin-converting enzyme 2, sphingosine 1-phosphate receptor-1, SH2 domain-containing phosphatase-2, and long non-coding RNAs, with the goal that drugs targeting these important mediators might exhibit a beneficial effect on antifibrosis. In addition, these mediators show profibrotic effects on multiple tissues, suggesting that targeting these mediators will exert antifibrotic effects on different organs. Furthermore, we present a variety of compounds that exhibit therapeutic effects against fibrosis. This review suggests therapeutic avenues for targeting organ fibrosis and concurrently identifies challenges and opportunities for designing new therapeutic strategies against fibrosis.

Poricoic acid A as a modulator of TPH-1 expression inhibits renal fibrosis via modulating protein stability of β-catenin and β-catenin-mediated transcription

Background

Renal fibrosis is the common feature of chronic kidney disease (CKD). However, few drugs specifically target fibrogenesis due to the lack of an effective therapeutic target. Hence, it is urgent to find a therapeutic strategy that inhibits renal fibrosis. Here, we identified that poricoic acid A (PAA) as the modulator of tryptophan hydroxylase-1 (TPH-1), the key enzyme in tryptophan metabolism, exerted potent anti-fibrotic effects in the kidney.

Methods

Lentiviral vector, luciferase reporter activity assay and co-immunoprecipitation were used. The animal model of unilateral ureteral obstruction and adenine-induced chronic renal failure as well as transforming growth factor (TGF)-β1-treated epithelial cells NRK-52E and fibroblasts NRK-49F were used.

Results

TPH-1 was gradually decreased during CKD progression, while PAA treatment significantly increased TPH-1 expression to suppress renal fibrosis. Pharmacological overexpression of TPH-1 by PAA treatment exhibited anti-fibrosis and was linked to Wnt/β-catenin signaling activity. TPH-1 exhibited anti-fibrotic effects by suppressing epithelial cell injury and fibroblast activation, and PAA promoted TPH-1 expression and then suppressed the Wnt/β-catenin signaling pathway via regulating the protein stability of β-catenin and β-catenin-mediated transcription. TPH-1 overexpression enhanced the anti-fibrotic effects of PAA, while TPH-1 deficiency weakened the anti-fibrotic effects of PAA, indicating that TPH-1 was required for the anti-fibrotic effects of PAA.

Conclusion

PAA as a modulator of TPH-1 expression attenuated renal fibrosis through regulating the Wnt/β-catenin signaling pathway by acting on the protein stability of β-catenin and β-catenin-mediated transcription. TPH-1 was required for PAA to exert anti-fibrosis.

Alleviation by Mahuang Fuzi and Shenzhuo Decoction in High Glucose-Induced Podocyte Injury by Inhibiting the Activation of Wnt/β-Catenin Signaling Pathway, Resulting in Activation of Podocyte Autophagy

Background

Organ fibrosis is a common endpoint of a variety of diseases. Many studies have shown that the pathogenesis of diabetic kidney disease (DKD) is related to the excessive activation of the Wnt/β-catenin signaling pathway on podocytes, so the treatment of DKD starts from this signaling pathway. At the same time, DKD, as a metabolic disease, has many connections related to podocyte autophagy.

Objectives

We experimented the effects of Mahuang Fuzi and Shenzhuo decoction (MFSD) which is the combination of Mahuang Fuzi decoction and Shenzhuo decoction in traditional Chinese medicine compounds used "The Golden Chamber" in high glucose-induced podocytes, determined whether this effect was related to Wnt/β-catenin signaling pathway, and further investigated the relationship between this effect and autophagy.

Methods

The mice podocytes were stimulated by using 30 mmol/L of high glucose and serum containing MFSD or Wnt/β-catenin signaling pathway inhibitor DKK1 (100 ng/ml) was used to intervene podocytes before high glucose stimulation. Podocyte injury-related proteins, Wnt/β-catenin signaling pathway-related proteins, and autophagy-related proteins were detected by using western blotting and immunofluorescence analysis.

Results

Our results showed that DKK1 and MFSD treatment significantly upregulated the protein expressions of nephrin, podocin, podocalyxin, and podoplanin in high glucose-induced podocytes and downregulated the β-catenin protein expression. Furthermore, the protein expressions of beclin1, LC3B, and P62 were also significantly increased in high glucose-induced podocytes.

Conclusion

Our experiments confirmed that the destruction of podocytes in DKD is related to the excessive activation of Wnt/β-catenin signaling pathway and the inhibition of autophagy after activation. MFSD treatment can inhibit the activation of Wnt/β-catenin signaling pathway in podocytes stimulated by high glucose and helpful in reducing the podocyte injury. This protective mechanism can be related to the enhancement of podocyte autophagy by MFSD treatment.

Angiotensin-converting enzyme inhibitor and angiotensin II type 1 receptor blocker: Potential agents to reduce post-surgical scar formation in humans

Studies on the effectiveness and mechanisms of reducing scar formation by interfering with the renin-angiotensin-aldosterone-system (RAAS) have been demonstrated in animals, but not in humans due to the lack of clinical support. Our aim was to investigate whether angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II type 1 receptor blocker (ARB) could inhibit scar formation in humans. Thus, an observational and hypothesis-generating study using a designed questionnaire was carried out. A total of 347 patients with postoperative scars secondary to thyroid tumours were enrolled. They were divided into four groups: ACEI group, ARB group, other antihypertensive drugs control group and blank control group according to the administration of antihypertensive drugs. The width of scar was measured, and the Scar Cosmesis Assessment and Rating (SCAR) Scale was filled out. Results showed that patients of ACEI group (mean scar width 1.60 mm) and ARB group (mean scar width 1.57 mm) formed smaller scars than those of other antihypertensive drugs control group (mean scar width 2.09 mm) and blank control group (mean scar width 2.0 mm). Oral administration of ACEI and ARB may be associated with better post-surgical scar formation in humans. These two kinds of antihypertensive drugs may be active components of anti-scar medicine.

Dysfunctional Coagulation in COVID-19: From Cell to Bedside

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which can induce multisystem disease. Human angiotensin-converting enzyme 2 (ACE2) widely expressing in arterial and venous endothelial cells and arterial smooth muscle cells has been identified as a functional receptor for SARS-CoV-2. Dysfunction of ACE2 leads to abnormal activation of the renin-angiotensin system and a systemic endotheliitis that may relate to abnormal coagulation and sepsis. Meanwhile, innate immune response and inflammation activation participate in dysfunctional coagulation. Previous research indicated that dysfunctional coagulation was one of the important risk factors accountable for a high risk of severe disease and death in patients with COVID-19. Understanding the possible mechanisms of dysfunctional coagulation and appropriate anticoagulation therapeutic strategies are important to prevent disease deterioration and reduce fatality rates during the ongoing COVID-19 pandemic.

Alisol B 23-acetate attenuates CKD progression by regulating the renin-angiotensin system and gut-kidney axis

Background:

Increasing evidence suggests a link between the gut microbiome and various diseases including hypertension and chronic kidney disease (CKD). However, studies examining the efficacy of controlling blood pressure and inhibiting the renin–angiotensin system (RAS) in preventing CKD progression are limited.

Methods:

In the present study, we used 5/6 nephrectomised (NX) and unilateral ureteral obstructed (UUO) rat models and cultured renal tubular epithelial cells and fibroblasts to test whether alisol B 23-acetate (ABA) can attenuate renal fibrogenesis by regulating blood pressure and inhibiting RAS.

Results:

ABA treatment re-established dysbiosis of the gut microbiome, lowered blood pressure, reduced serum creatinine and proteinuria, suppressed expression of RAS constituents and inhibited the epithelial-to-mesenchymal transition in NX rats. Similarly, ABA treatment inhibited expression of collagen I, fibronectin, vimentin, α-smooth muscle actin and fibroblast-specific protein 1 at both mRNA and protein levels in UUO rats. ABA was also effective in suppressing activation of the transforming growth factor-β (TGF-β)/Smad3 and preserving Smad7 expression in both NX and UUO rats. In vitro experiments demonstrated that ABA treatment inhibited the Wnt/β-catenin and mitochondrial-associated caspase pathways.

Conclusion:

These data suggest that ABA attenuated renal fibrosis through a mechanism associated with re-establishing dysbiosis of the gut microbiome and regulating blood pressure, and Smad7-mediated inhibition of Smad3 phosphorylation. Thus, we demonstrate ABA as a promising candidate for treatment of CKD by improving the gut microbiome and regulating blood pressure.

Aryl hydrocarbon receptor activation mediates kidney disease and renal cell carcinoma

The aryl hydrocarbon receptor (AhR) is a well-known ligand-activated cytoplasmic transcription factor that contributes to cellular responses against environmental toxins and carcinogens. AhR is activated by a range of structurally diverse compounds from the environment, microbiome, natural products, and host metabolism, suggesting that AhR possesses a rather promiscuous ligand binding site. Increasing studies have indicated that AhR can be activated by a variety of endogenous ligands and induce the expression of a battery of genes. AhR regulates a variety of physiopathological events, including cell proliferation, differentiation, apoptosis, adhesion and migration. These new roles have expanded our understanding of the AhR signalling pathways and endogenous metabolites interacting with AhR under homeostatic and pathological conditions. Recent studies have demonstrated that AhR is linked to cardiovascular disease (CVD), chronic kidney disease (CKD) and renal cell carcinoma (RCC). In this review, we summarize gut microbiota-derived ligands inducing AhR activity in patients with CKD, CVD, diabetic nephropathy and RCC that may provide a new diagnostic and prognostic approach for complex renal damage. We further highlight polyphenols from natural products as AhR agonists or antagonists that regulate AhR activity. A better understanding of structurally diverse polyphenols and AhR biological activities would allow us to illuminate their molecular mechanism and discover potential therapeutic strategies targeting AhR activation.

Discrimination of Different Parts of Saffron by Metabolomic-Based Ultra-Performance Liquid Chromatography Coupled with High-Definition Mass Spectrometry

In this study, the metabolite profiling of three different parts of Crocus sativus L. was measured by using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTof-MS/MS). Multivariate statistical analysis was used to distinguish among the samples from different parts. A total of 54 compounds were identified in tepals, stigmas and stamens by UPLC-QTof-MS/MS. The results stated that chemical characteristics of saffron were obviously diverse in terms of the parts of flower. Through analysis, coniferin and crocin-2 were special components in stigmas when compared to tepals and stamens. The content of flavonoids was high in tepals when compared with the stigmas. The tepal of saffron may processed as a source of flavonoids in the future. The research provided the basis for the theory that only the stigma can be used as medicine.

Chronic kidney disease: Biomarker diagnosis to therapeutic targets

Chronic kidney disease (CKD), characterized as renal dysfunction, is recognized as a major public health problem with high morbidity and mortality worldwide. Unfortunately, there are no obvious clinical symptoms in early stage disease until severe damage has occurred. Further complicating early diagnosis and treatment is the lack of sensitive and specific biomarkers. As such, novel biomarkers are urgently needed. Metabolomics has shown an increasing potential for identifying underlying disease mechanisms, facilitating clinical diagnosis and developing pharmaceutical treatments for CKD. Recent advances in metabolomics revealed that CKD was closely associated with the dysregulation of numerous metabolites, such as amino acids, lipids, nucleotides and glycoses, that might be exploited as potential biomarkers. In this review, we summarize recent metabolomic applications based on animal model studies and in patients with CKD and highlight several biomarkers that may play important roles in diagnosis, intervention and development of new therapeutic strategies.