Protective effect of iridoid glycosides from Paederia scandens (LOUR.) MERRILL (Rubiaceae) on uric acid nephropathy rats induced by yeast and potassium oxonate

Cytotoxic iridoid glycosides from the leaves of Paederia scandens

A phytochemical investigation on the 80% EtOH extract of the leaves of Paederia scandens (Lour.) Merr. resulted into the isolation of three undescribed iridoid glycosides, 10-O-trans-p-coumaroyl-(4R,6R)-3,4-dihydro-3α-methylthiopaederoside (1), 10-O-trans-feruloyl-(4S,6R)-3,4-dihydro-2'-O-3α-paederoside (2), and 10-O-trans-caffeoyl-paederosidic acid ethyl ester (3). The structures of the new compounds were elucidated by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy, as well as high resolution mass spectrometry. The isolated compounds were tested in vitro for cytotoxic activity against five endocrine tumor cell lines. As a result, compound 1 exhibited some cytotoxicities against all the tested tumor cell lines with IC50 value less than 20.0 μM.

Biomedicine and pharmacotherapeutic effectiveness of combinatorial atorvastatin and quercetin on diabetic nephropathy: An in vitro study

INTRODUCTION

Diabetic nephropathy is a type of kidney disorder that develops as a complication of multifactorial diabetes. Diabetic nephropathy is characterized by microangiopathy, resulting from glucose metabolism, oxidative stress, and changes in renal hemodynamics. This study strived to evaluate the in vitro cytoprotective activity of atorvastatin (ATR), and quercetin (QCT) alone and in combination against diabetic nephropathy.

METHODS

The MTT assay was utilized to analyze the effects of the test compounds on NRK-52E rat kidney epithelial cells. The detection of apoptosis and ability to scavenge free radicals was assessed via acridine orange-ethidium bromide (AO-EB) dual fluorescence staining, and 2,2-diphenyl-1-picrylhydrazyfree assay (DPPH), respectively. The ability of anti-inflammatory effect of the test compounds and western blot analysis against TGF-β, TNF-α, and IL-6 further assessed to determine the combinatorial efficacy.

RESULTS

Atorvastatin and quercetin treatment significantly lowered the expression of TGF-β, TNF-α, and IL-6 indicating the protective role in Streptozotocin-induced nephrotoxicity. The kidney cells treated with a combination of atorvastatin and quercetin showed green fluorescing nuclei in the AO-EB staining assay, indicating that the combination treatment restored cell viability. Quercetin, both alone and in combination with atorvastatin, demonstrated strong DPPH free radical scavenging activity and further encountered an anti-oxidant and anti-inflammatory effect on the combination of these drugs.

CONCLUSION

Nevertheless, there is currently no existing literature that reports on the role of QCT as a combination renoprotective drug with statins in the context of diabetic nephropathy. Hence, these findings suggest that atorvastatin and quercetin may have clinical potential in treating diabetic nephropathy.

Therapeutic potentials of iridoids derived from Rubiaceae against in vitro and in vivo inflammation: A scoping review

Acute inflammation may develop into chronic, life-threatening inflammation-related diseases if left untreated or if there are persistent triggering factors. Cancer, diabetes mellitus, stroke, cardiovascular diseases, and neurodegenerative disorders are some of the inflammation-related diseases affecting millions of people worldwide. Despite that, conventional medical therapy such as non-steroidal anti-inflammatory drugs (NSAIDs) is associated with serious adverse effects; hence, there is an urgent need for a newer and safer therapeutic alternative from natural sources. Iridoids are naturally occurring heterocyclic monoterpenoids commonly found in Rubiaceae plants. Plant extracts from the Rubiaceae family were demonstrated to have medicinal benefits against neurodegeneration, inflammation, oxidative stress, hyperglycaemia, and cancer. However, the therapeutic effects of natural iridoids derived from Rubiaceae as well as their prospective impacts on inflammation in vitro and in vivo have not been thoroughly explored. The databases of PubMed, Scopus, and Web of Science were searched for pertinent articles in accordance with PRISMA-ScR guidelines. A total of 31 pertinent articles from in vitro and in vivo studies on the anti-inflammatory potentials of iridoids from Rubiaceae were identified. According to current research, genipin, geniposide, and monotropein are the most researched iridoids from Rubiaceae that reduce inflammation. These iridoids primarily act by attenuating inflammatory cytokines and mediators via inhibition of the NF-κB signalling pathway in various disease models. A comprehensive overview of the current research on the anti-inflammatory properties of iridoids from the Rubiaceae family is presented in this review, highlighting the characteristics of the experimental models used as well as the mechanisms of action of these iridoids. To develop an alternative therapeutic agent from iridoids, more studies are needed to elucidate the effects and mechanism of action of iridoids in a wide variety of experimental models as well as in clinical studies pertaining to inflammation-related diseases.

Determination and Mechanism of Antidiarrheal Chemical Constituents of Paederia scandens Determined by HPLC-ESI-MS Integrated with Network Pharmacology

Paederia scandens is a natural medicinal plant that is widely used for its various pharmacological effects including antiviral, antitumor, anti-inflammatory, and antibacterial activities. However, there is no scientific evidence to support its antidiarrheal effect. In this study, the antidiarrheal activity of P. scandens was evaluated using several validated models. By using HPLC-ESI-MS in conjunction with a network pharmacology approach, the possible antidiarrheal mechanisms of P. scandens active fragments were studied, and they were subsequently verified in a mouse model of diarrhea. Finally, utilizing molecular docking, active compounds that might have antidiarrheal properties were hypothesized. The results show that the main antidiarrheal part of P. scandens has 10 chemical components in the n-butanol fraction (PSNB). The key targets of PSNB and diarrhea, EGFR, AKT1, and PIK3CA, were screened by network pharmacology analysis. And the mechanism of PSNB in the treatment of diarrhea may be highly related to the EGFR tyrosine kinase inhibitor resistance and PI3K/AKT signaling pathway. Besides, through the qRT-PCR and western-blot experiments, it was found that PSNB could inhibit the gene expression of proinflammatory factors by reducing the protein expression of AKT1 and PI3K and regulating the NF-κB signaling pathway in mice. In addition, asperuloside, paederosidic acid, paederoside, paederosidic acid methyl ester, and 6'-O-E-feruloylmonotropein have better docking energies than other chemical components in PSNB with EGFR, AKT1, and PIK3CA. In conclusion, the main antidiarrheal active site of P. scandens is the n-butanol site. PSNB may exert an antidiarrheal effect by regulating the PI3K/Akt/NF-κB signaling pathway. Among them, asperuloside, paederosidic acid, paederoside, paederosidic acid methyl ester, and 6'-O-E-feruloylmonotropein may be the active ingredients that exert an antidiarrheal effect.

Anti-inflammatory iridoid glycosides from Paederia scandens (Lour.) Merrill

Eight previously undescribed iridoid glycosides together with 20 known congeners were isolated from the aerial parts of Paederia scandens (Lour.) Merrill (Rubiaceae). Their structures incorporating absolute configurations were elucidated based on the comprehensive analyses of NMR data, HR-ESI-MS spectrometry, and ECD data. The potential anti-inflammatory activities of the isolated iridoids were evaluated in lipopolysaccharide-stimulated RAW 264.7 macrophages. Compound 6 significantly inhibited the production of nitric oxide (NO) with an IC₅₀ value of 15.30 μM. The results of immunoblotting, qPCR, and immunofluorescence staining assays revealed that compound 6 exhibited anti-inflammatory activity by suppressing nuclear translocation of NF-κB and reducing the expression of COX-2, iNOS, IL-1β, and IL-6. These results provide a basis for further development and utilization of P. scandens as a natural source of potential anti-inflammatory agents.

An integration of UPLC-Q-TOF/MS and chemometrics analysis for the holistic quality evaluation of different geographical Paederia scandens

RATIONALE

Due to the special geographical location and climate of China, there are large differences in the chemical composition and content of Paederia scandens (PS) from different origins, which will have a large impact on its efficacy.

METHODS

An efficient quality control method for PS was established by combining ultra-high-performance liquid chromatography (UPLC) and electrospray ionization mass spectrometry analyses. First, a UPLC-quadrupole time-of-flight mass spectrometry system was employed to identify the chemical composition of PS from seven different origins. Then, the chemical variation in 73 batches of PS samples was subsequently investigated by quantitation of four marker compounds.

RESULTS

A total of 15 common compounds were identified in the samples of PS from seven origins. And four of the marker compounds were chosen based on VIP values to characterize the differences between PS samples of different origins. The linearity ranged between 0.005 and 2.500 mg/mL; the correlation coefficients (r² ) ranged from 0.999 to 1; the limits of detection ranged from 0.013 to 0.033 μg/mL; and the relative standard deviations for repeatability, precisions, and stabilities were below 0.2%, 1.6%, and 0.6%, respectively.

CONCLUSION

The results show that the method can be effective and comprehensive in evaluating the quality of PS from different origins. And this comprehensive strategy proved to be a powerful technique used to differentiate between different geographical herbs.

Ultrasonic-assisted extraction of polyphenolic compounds from Paederia scandens (Lour.) Merr. Using deep eutectic solvent: optimization, identification, and comparison with traditional methods

Ultrasonic-assisted extraction (UAE) coupled with deep eutectic solvent (DES) is a novel, efficient and green extraction method for phytochemicals. In this study, the effects of 16 DESs coupled with UAE on the extraction rate of polyphenols from Paederia scandens (Lour.) Merr. (P. scandens), an edible and medicinal herb, were investigated. DES synthesised with choline chloride and ethylene glycol at a 1:2 M ratio resulted in the highest extractability. Moreover, the effects of extraction parameters were investigated by using a two-level factorial experiment followed by response surface methodology The optimal parameters (water content in DES of 49.2%, the actual ultrasonic power of 72.4 W, and ultrasonic time of 9.7 min) resulted in the optimal total flavonoid content (TFC) (27.04 mg CE/g DW), ferric-reducing antioxidant power (FRAP) value (373.27 μmol Fe(Ⅱ)E/g DW) and 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid radical (ABTS⁺) value (48.64 μmol TE/g DW), closely matching the experimental results. Furthermore, a comparison study demonstrated that DES-UAE afforded the higher TFC and FRAP value than traditional extraction methods. 36 individual polyphenolic compounds were identified and quantified by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) in P. scandens extracts, and of which 30 were found in the extracts obtained by DES-UAE. Additionally, DES-UAE afforded the highest sum of individual polyphenolic compound content. These results revealed that DES-UAE enhanced the extraction efficiency for polyphenols and provided a scientific basis for further processing and utilization of P. scandens.

The Complex Interplay between Autophagy and NLRP3 Inflammasome in Renal Diseases

Autophagy is a highly conserved process of the eukaryotic cell cycle. It plays an important role in the survival and maintenance of cells by degrading organelles, proteins, and macromolecules in the cytoplasm and the circulation of degraded products. The dysfunction of autophagy can lead to the pathology of many human diseases. The nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome belongs to the family of nucleotide-binding and oligomerization domain-like receptors (NLRs) and can induce caspase-1 activation, thus leading to the maturation and secretion of interleukin-1beta (IL-1β) and IL-18. It has been reported that the interplay between autophagy and NLRP3 inflammasome is involved in many diseases, including renal diseases. In this review, the interplay between autophagy and the NLRP3 inflammasome and the mechanisms in renal diseases are explored to provide ideas for relevant basic research in the future.

The Role of the Interplay Between Autophagy and NLRP3 Inflammasome in Metabolic Disorders

Autophagy is an important and conserved cellular pathway in which cells transmit cytoplasmic contents to lysosomes for degradation. It plays an important role in maintaining the balance of cell composition synthesis, decomposition and reuse, and participates in a variety of physiological and pathological processes. The nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome can induce the maturation and secretion of Interleukin-1 beta (IL-1β) and IL-18 by activating caspase-1. It is involved in many diseases. In recent years, the interplay between autophagy and NLRP3 inflammasome has been reported to contribute to many diseases including metabolic disorders related diseases. In this review, we summarized the recent studies on the interplay between autophagy and NLRP3 inflammasome in metabolic disorders to provide ideas for the relevant basic research in the future.

Plantaginis Semen polysaccharides ameliorate renal damage through regulating NLRP3 inflammasome in gouty nephropathy rats

Gouty nephropathy (GN) is considered to be a prevalent renal disease and is an inflammatory event mainly induced by MSU crystals. Plantaginis Semen is a traditional Chinese herb that has been used in the treatment of gout, gouty arthritis and GN, but the mechanism and ingredients have been unclear. In this study, we explored and evaluated the preliminary structural characterizations of Plantaginis Semen polysaccharides (PSPs) and the activity of protecting against renal damage in GN rats. Three polysaccharide fractions, PSP-D, PSP-H and PSP-S, were sequentially extracted by different processes from the seed of Plantago asiatica L. The Fourier transform infrared spectral (FTIR) results showed that there were significant differences between PSP-S and the other two polysaccharides (PSP-D and PSP-H). PSP-D and PSP-H have pyrene monomers and linkages of β-glycosides in their structures, and PSP-S has furanoside in the molecular structure. The scanning electron microscope (SEM) images of three polysaccharides showed that PSP-D has a smooth surface and a small curve, PSP-H is block-like and uneven in magnitude, whereas PSP-S is sea-tent-like and its surface is very distinct from the others. Main components and molar ratios are also different. Rats were randomly divided into six groups (n^1/6 8 per group): the control group, model group, positive group, and three treatment groups (PSP-D, PSP-H and PSP-S). For all groups except the control group, rats were intragastrically administered the adenine suspension (50 mg kg^-1 d^-1) and fed with a high-yeast diet (15 g kg^-1 d^-1) for 28 days. On the 9th day, the control group and the model group were administered normal saline at the same time. Treatment groups were individually given corresponding drugs for 20 days. We found that PSPs could prevent renal damage, including decreasing the inflammatory response and regulating the (NOD)-like receptor protein 3 (NLRP3) protein in renal tissue. The underlying mechanism was related to NLRP3 inflammasome signal pathways, and it could take effect through the down-regulation of the protein expression levels of NLRP3, ASC and caspase-1 and inhibit the release of downstream inflammatory factors. PSPs are promising polysaccharides that could protect against renal injury through ameliorating renal inflammation in GN rats. Plantaginis Semen polysaccharides are potential functional food ingredients or pharmacological agents for treating GN in clinical practice.

Functional crosstalk between Long non-coding RNAs and the NLRP3 inflammasome in the regulation of diseases

Emerging evidence has indicated that long noncoding RNAs (lncRNAs) are involved in various pathophysiological processes of disease, such as cancer occurrence, viral invasion, and inflammatory damage. The main inflammatory body component, nod-like receptor protein 3 (NLRP3), is the trigger point of inflammatory reactions and inflammation-related diseases and coordinates the body's response to inflammation. At present, increasing evidence shows that the interaction of lncRNAs and the NLRP3 inflammasome plays an important role in the inflammatory response and different diseases. This may be involved in the development and progression of various diseases by activating signalling pathways and a variety of molecular regulatory mechanisms-this article reviews progress in research on the relationship between lncRNAs and the NLRP3 inflammasome under different conditions.

Mechanistic Insights of Soluble Uric Acid-related Kidney Disease

Hyperuricemia, defined as the presence of elevated serum uric acid (sUA), could lead to urate deposit in joints, tendons, kidney and other tissues. Hyperuricemia as an independent risk factor was common in patients during the causation and progression of kidney disease. Uric acid is a soluble final product of endogenous and dietary purine metabolism, which is freely filtered in kidney glomeruli where approximately 90% of filtered uric acid is reabsorbed. Considerable studies have demonstrated that soluble uric acid was involved in the pathophysiology of renal arteriolopathy, tubule injury, tubulointerstitial fibrosis, as well as glomerular hypertrophy and glomerulosclerosis. In the review, we summarized the mechanistic insights of soluble uric acid related renal diseases.

Molecular mechanistic insight into the anti-hyperuricemic effect of Eucommia ulmoides in mice and rats

CONTEXT

Eucommia ulmoides Oliver (Eucommiaceae) has various medicinal properties. Our previous studies revealed that Eucommia ulmoides has a protective effect on hyperuricaemia.

OBJECTIVE

This study investigates the effect of Eucommia ulmoides cortex ethanol extract (EU) on hyperuricaemia and explores the underlying mechanism in Kunming mice and Sprague-Dawley rats.

MATERIAL AND METHODS

Sixty mice and sixty rats were divided into normal control, hyperuricaemia, allopurinol (10 mg/kg) and three EU groups. The EU groups received intragastric EU at 80, 160, 320 mg/kg in mice and 100, 200, 400 mg/kg in rats for 7 days. Serum uric acid (SUA) was measured using a kit. mRNA and proteins were quantified by RT-qPCR and immunohistochemical assays (IHC), respectively.

RESULTS

The Maximal Tolerable Dose (MTD) of EU administered intragastrically was 18 g/kg in mice. The intermediate (160 mg/kg) and high (320 mg/kg) EU treatment significantly reduced (p < 0.05) SUA levels to 130.16 μmol/L and 109.29 μmol/L, respectively, and markedly elevated the mRNA expression of organic anion transporters 1 (OAT1) and organic anion transporters 3 (OAT3), while significantly deceasing the mRNA levels of glucose transporter 9 (GLUT9) and uric acid transporter 1 (URAT1) in the mouse kidney (p < 0.05). In hyperuricemic rats, high EU (400 mg/kg) significantly reduced SUA levels to 253.85 μmol/L, and increased OAT1 and OAT3 levels, but decreased URAT1 and GLUT9, compared to the hyperuricaemia group (p < 0.05).

DISCUSSION AND CONCLUSIONS

This study demonstrated the potential hyperuricaemia ameliorating effect of EU. Specific active ingredients in EU should be evaluated. These results are valuable for the development of antihyperuritic agents from EU.

Characterization of the complete chloroplast genome of Paederia scandens (Rubiaceae): a Chinese folk medicinal plant

Paederia scandens has been used as a traditional medicine in Asian countries to treat jaundice, dysentery, and the pain of rheumatism. The complete chloroplast (cp) genome sequence of P. scandens was reported and characterized in this study. The cp genome is 153,626 bp in length, composed of a pair of 26,513 bp inverted repeat (IR) regions separated by a large single-copy (LSC) region of 83,712 bp and a small single-copy (SSC) region of 16,888 bp. There were 131 predicted genes (86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes) in the genome, and the overall GC content of the genome is 37.7%. Phylogenetic analysis based on the cp genome data showed that P. scandens was sister to the clade formed by Galium mollugo and G. aparine.

Genotoxic properties of Betonica officinalis, Gratiola officinalis, Vincetoxicum luteum and Vincetoxicum hirundinaria extracts

Genotoxicity of B. officinalis, G. officinalis, V. luteum and V. hirundinaria extracts, which demonstrated strong antioxidant capacity, was tested using chromosome aberration, sister chromatid exchange (SCE), cytokinesis-block micronucleus and alkaline single-cell gel electrophoresis (comet) assays in human lymphocytes in vitro and Ames Salmonella/microsome test. All tested extracts were not mutagenic in S. typhimurium strains TA98 and TA100 with and without metabolic activation and did not induce chromosome aberrations in human lymphocytes in vitro. Extract from G. officinalis was the only one, which induced significant increase in micronuclei, indicating possible aneugenic effect. All investigated plant extracts induced DNA damage evaluated by the comet assay, while B. officinalis and V. luteum extracts induced slight increase in SCE values. The determined variation in response might be due to the plant extract tested and donor susceptibility.

Long non-coding RNA ANRIL-mediated inflammation response is involved in protective effect of rhein in uric acid nephropathy rats

Background

The aim of this study was to investigate the role of long non-coding RNAs (LncRNAs) antisense non-coding RNA in the INK4 locus (ANRIL) in anti-inflammation of rhein in uric acid nephropathy (UAN) rats.

Methods

Rat models of UAN were induced by adenine and potassium oxonate. Enzyme-linked immunosorbent assay (ELISA) was performed to assess inflammation factor in serum and supernatant. ANRIL mRNA level was detected using real-time reverse transcription PCR (qRT-PCR). Immunostaining was used to observe pathological changes of renal tissues in rats.

Results

ANRIL and inflammatory factor levels were highly expressed in patient with UAN. Furthermore, rhein showed an observable effect on anti-inflammatory and renal protection in UAN rats, rhein inhibited expressions of ANRIL in vivo or in vitro. Besides, ANRIL-mediated inflammatory response attenuated protective effect of rhein.

Conclusions

ANRIL-mediated inflammatory response attenuated the protective effect of rhein in UAN rats. This study showed an understanding of the role and mechanism of ANRIL in UAN, which provides a new target and therapy for the prevention and treatment of UAN.

Protective effects of Paederia scandens extract on rheumatoid arthritis mouse model by modulating gut microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Paederia scandens (Lour.) Merr. (P. scandens) has been traditionally used to treat the pain of rheumatism.

AIM OF THE STUDY

The purpose of this study was to investigate the possible influences of P. scandens on the progression of rheumatoid arthritis (RA), inflammatory responses and gut bacterial communities in RA mouse model.

MATERIALS AND METHODS

collagen-induced arthritis (CIA) mice were orally administered with P. scandens extract (PSE) for 24 days. Then, pro-inflammatory cytokine levels in the serum were measured, and gut microbiota was examined with Illumina HiSeq.

RESULTS

Compared with the vehicle group, PSE significantly inhibited paw swelling and reduced arthritis score. Histological examination of ankle soft tissue of demonstrated PSE effectively inhibited the tissue fibrosis and inflammatory cell infiltration. The increased serum levels of TNF-α, IL-1β, IL-6, IL-7, and IL-23 in RA mice were significantly suppressed by PSE. Moreover, PSE treatment help restore gut microbial ecosystem altered in RA mice including decreasing relative abundance of inflammatory related microorganisms, Desulfovibrio, Mucispirillum, Helicobacter, and Lachnospiraceae.

CONCLUSION

These results suggest that PSE has therapeutic effects in RA mice with CIA, showing the potential as anti-arthritis reagent.

LncRNA ANRIL promotes NLRP3 inflammasome activation in uric acid nephropathy through miR-122-5p/BRCC3 axis

This study is designed to explore the mechanism by which long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) plays a pathogenic role in uric acid nephropathy (UAN). The expressions of ANRIL, miR-122-5p, BRCA1-BRCA2-containing complex subunit 3 (BRCC3) and NOD-like receptor protein 3 (NLRP3) were determined in UAN patients and uric acid-treated HK-2 cells by qRT-PCR. Protein levels of BRCC3 and NLRP3 were examined by western blot. The levels of inflammatory cytokines were quantified by ELISA. CCK-8 assay was used to assess cell viability. Apoptosis was detected by Annexin V-FITC/PI double-labeled flow cytometry and TUNEL assay. The interaction between ANRIL, miR-122-5p and BRCC3 were studied using luciferase reporter assay. The role of ANRIL in renal injury was evaluated in experimental rats. ANRIL and BRCC3 were highly expressed while miR-122-5p was down-regulated in serum of UAN patients and uric acid-treated tubular epithelial cells. Luciferase reporter assay and in vitro rescue experiment confirmed that ANRIL promoted NLRP3 inflammasome activation by up-regulating BRCC3 expression via sponging miR-122-5p. Furthermore, in vivo experiment validated that knockdown of ANRIL alleviated renal injury of UAN rats. ANRIL exerted pathogenic effect in UAN to promote NLRP3 inflammasome activation via miR-122-5p/BRCC3 axis.

CXCR1/CXCR2 antagonist G31P inhibits nephritis in a mouse model of uric acid nephropathy

The prevalence of gout is relatively high worldwide, and many gout patients suffer from uric acid nephropathy (UAN) concomitantly. ELR-CXC chemokines such as CXCL8 and CXCL1 have a elevated expression in UAN. In this research, a mouse UAN model was established for a 12 week duration, and uric acid-related crystals were observed. CXCL8(3-72)K11R/G31P (G31P) is a mutant protein of CXCL8/interleukin 8 (IL-8), which has been reported to have therapeutic efficacy in both inflammatory diseases and malignancies for it acts as a selective antagonist towards CXCR1/CXCR2. In this study, G31P-treated mice showed declined production of the blood urea nitrogen (BUN) level and urine volume in UAN mice compared with G31P-untreated UAN counterparts. In addition, G31P effectively improved renal fibrosis, and reduced uric acid accumulation and leukocyte infiltration in UAN kidneys. Furthermore, the expressions of CXCL1 and CXCL2 were reduced and the activation of NOD-like receptors protein 3 (NLRP3) was inhibited by G31P treatment. This study has demonstrated that G31P attenuates inflammatory progression in chronic UAN, and plays a renoprotective function.

Weicao capsule ameliorates renal injury through increasing autophagy and NLRP3 degradation in UAN rats

Uric acid nephropathy (UAN) is one of the most common metabolic diseases and leads to kidney damage. This study aimed to evaluate the effect of Weicao capsule on renal injury of UAN rats and to examine whether the mechanism was associated with induction of autophagy and degradation of nucleotide binding oligomerization domain (Nod)-like receptor (NLR) protein 3 (NLRP3) inflammasome. Sixty Sprague-Dawley rats were randomly allocated into 6 groups: Control, Model, Allopurinol, and Weicao (0.55/1.1/2.2 g/kg) group. The data showed activation of renal NLRP3 inflammasome in UAN rats, with elevation in serum levels of interleukin (IL)-1β and IL-18, and subsequent deterioration of renal injury. Fortunately, Weicao had a markedly therapeutic effect on UAN rats, including improving renal function-related indexes, ameliorating hyperuricemia-related inflammation, decreasing crystals in renal tissue and alleviating renal interstitial fibrosis. Additionally, Weicao exerted anti-proliferative and anti-apoptosis effects on rat renal tubular epithelial cell NRK-52E in macrophages from UAN rats. Our investigation into the mechanism revealed that Weicao suppressed the activated NLRP3 inflammasome. Furthermore, Weicao induced autophagy, as evidenced by a dose-dependent increase in levels of renal autophagy-related proteins in UAN rats. Moreover, autophagy inhibitor 3-MA and NLRP3 activator ATP blocked the effect of Weicao on autophagy induction and NLRP3 inflammasome degradation. In conclusion, Weicao had similar effects as allopurinol and exerted anti-inflammatory and renal-protective effect in a concentration-dependent manner in UAN rats, most likely through increasing autophagy and NLRP3 degradation. Our study provides new insight into the underlying mechanism of Weicao in the treatment of UAN.

Anti-hyperuricemic and nephroprotective effects of extracts from Chaenomeles sinensis (Thouin) Koehne in hyperuricemic mice

CSF-E possesses potent anti-hyperuricemic through inhibiting XOD activity.

Potassium oxonate induces acute hyperuricemia in the tree shrew (tupaia belangeri chinensis)

Potassium oxonate, a selectively competitive uricase inhibitor, produced hyperuricemia (HUA) in rodents in a previous study. In this study, we employed the tree shrew as an animal model to study potassium oxonate-induced HUA. The effect of allopurinol (ALLO), a uric acid reducer, was also examined in this model. Potassium oxonate at doses of 5, 20, 40, 60, 80, 100, and 1,000 mg/kg was given intraperitoneally to tree shrews. The results showed that potassium oxonate can effectively increase the levels of uric acid in tree shrews at doses ranging from 40 to 100 mg/kg. Semiquantitative RT-PCR showed that the xanthine dehydrogenase/oxidase (XDH/XO) mRNA expression level was significantly higher in the liver tissue of tree shrews with high levels of uric acid. There were no changes in serum urea nitrogen, or serum creatinine values. ALLO can significantly decrease serum uric acid levels (P<0.01) and raise XDH/XO mRNA expression levels in the liver tissue of tree shrews with HUA. XDH/XO mRNA expression levels did not change in untreated tree shrews. Studies on acute toxicity in the tree shrew did not show any significantly abnormal signs. There were no adverse effects at the macroscopic level up to doses ≤100 mg/kg. Potassium oxonate induced acute HUA in tree shrews at lower doses compared with other animal models. Potassium oxonate-treated tree shrews may be a potential animal model for studying pathogenic mechanism and evaluating a new therapeutic agent for treatment of HUA in humans.

Chemical Profiles and Protective Effect of Hedyotis diffusa Willd in Lipopolysaccharide-Induced Renal Inflammation Mice

Protective effect of Hedyotis diffusa (H. diffusa) Willd against lipopolysaccharide (LPS)-induced renal inflammation was evaluated by the productions of cytokines and chemokine, and the bioactive constituents of H. diffusa were detected by the ultra-fast liquid chromatography-diode array detector-quadrupole-time of flight mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) method. As the results showed, water extract of H. diffusa (equal to 5.0 g/kg body weight) obviously protected renal tissues, significantly suppressed the productions of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein (MCP)-1, as well as significantly promoted the production of IL-10 in serum and renal tissues. According the chemical profiles of H. diffusa, flavonoids, iridoid glycosides and anthraquinones were greatly detected in serum from H. diffusa extract treatment mice. Two main chemotypes, including eight flavonoids and four iridoid glycosides were found in renal tissues from H. diffusa extract treatment mice. The results demonstrated that water extract of H. diffusa had protective effect on renal inflammation, which possibly resulted from the bioactive constituents consisting of flavonoids, iridoids and anthraquinones.

Secondary metabolites from Rubiaceae species

This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psychotria, Hedyotis, Ophiorrhiza and Morinda. The occurrence and distribution of iridoids, alkaloids and anthraquinones point out their chemotaxonomic correlation among tribes and subfamilies. From an evolutionary point of view, Rubioideae is the most ancient subfamily, followed by Ixoroideae and finally Cinchonoideae. The chemical biosynthetic pathway, which is not so specific in Rubioideae, can explain this and large amounts of both iridoids and indole alkaloids are produced. In Ixoroideae, the most active biosysthetic pathway is the one that produces iridoids; while in Cinchonoideae, it produces indole alkaloids together with other alkaloids. The chemical biosynthetic pathway now supports this botanical conclusion.