Neuroprotective and anti-inflammatory effect of pectolinarigenin, a flavonoid from Amazonian Aegiphila integrifolia (Jacq.), against lipopolysaccharide-induced inflammation in astrocytes via NFκB and MAPK pathways

Pectolinarigenin targeting FGFR3 alleviates osteoarthritis progression by regulating the NF-κB/NLRP3 inflammasome pyroptotic pathway

OBJECTIVE

Osteoarthritis (OA) is a chronic degenerative disease characterized by cartilage degeneration, involving inflammation, pyroptosis, and degeneration of the extracellular matrix (ECM). Pectolinarigenin (PEC) is a natural flavonoid with antioxidant, anti-inflammatory and anti-tumor properties. This study aims to explore the potential of PEC in ameliorating OA progression and its underlying mechanisms.

METHODS

Chondrocytes were exposed to 10 ng/mL IL-1β to simulate OA-like changes. The effect of PEC on IL-1β-treated chondrocytes was assessed using ELISA, western blot, and immunofluorescence. The mRNA sequencing (mRNA-seq) was employed to explore the possible targets of PEC in delaying OA progression. The OA mouse model was induced through anterior cruciate ligament transection (ACLT) and divided into sham, ACLT, ACLT+5 mg/kg PEC, and ACLT+10 mg/kg PEC groups. Micro-computed tomography and histological analysis were conducted to confirm the beneficial effects of PEC on OA in vivo.

RESULTS

PEC mitigated chondrocyte pyroptosis, as evidenced by reduced levels of pyroptosis-related proteins. Additionally, PEC attenuated IL-1β-mediated chondrocyte ECM degradation and inflammation. Mechanistically, mRNA-seq showed that FGFR3 was a downstream target of PEC. FGFR3 silencing reversed the beneficial effects of PEC on IL-1β-exposed chondrocytes. PEC exerted anti-pyroptotic, anti-ECM degradative, and anti-inflammatory effects through upregulating FGFR3 to inhibit the NF-κB/NLRP3 pyroptosis-related pathway. Consistently, in vivo experiments demonstrated the chondroprotective effects of PEC in OA mice.

CONCLUSION

PEC alleviate OA progression by FGFR3/NF-κB/NLRP3 pathway mediated chondrocyte pyroptosis, ECM degradation and inflammation, suggesting the potential of PEC as a therapeutic agent for OA.

Flavonoids as therapeutic agents for epilepsy: unveiling anti-inflammatory and antioxidant pathways for novel treatments

Epilepsy, a chronic neurological disorder affecting millions globally, is often exacerbated by neuroinflammation and oxidative stress. Existing antiepileptic drugs primarily manage symptoms, leaving the disease's progression largely unaddressed. Flavonoids, ubiquitous plant metabolites with potent anti-inflammatory and antioxidant properties, show promise in epilepsy treatment. Unlike conventional therapies, they target multiple pathophysiological processes simultaneously, offering a comprehensive approach to this complex neurological disorder. This review explores the dual role of flavonoids in mitigating neuroinflammation and reducing oxidative stress through various molecular pathways. By inhibiting key inflammatory mediators and pathways such as NF-κB, MAPK, JNK, and JAK, flavonoids offer neuronal protection. They enhance the body's natural antioxidant defenses by modulating enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase. Moreover, flavonoids influence crucial antioxidant response pathways like PI3K/AKT, Nrf2, JNK, and PKA. Despite their therapeutic promise, the low bioavailability of flavonoids poses a considerable challenge. However, cutting-edge strategies, including nanotechnology and chemical modifications, are underway to improve their bioavailability and therapeutic efficacy. These advancements support the potential of flavonoids as a valuable addition to epilepsy treatment strategies.

Antiangiogenic potential of phytochemicals from Clerodendrum inerme (L.) Gaertn investigated through in silico and quantum computational methods

Suppressing vascular endothelial growth factor (VEGF), its receptor (VEGFR2), and the VEGF/VEGFR2 signaling cascade system to inhibit angiogenesis has emerged as a possible cancer therapeutic target. The present work was designed to discover and evaluate bioactive phytochemicals from the Clerodendrum inerme (L.) Gaertn plant for their anti-angiogenic potential. Molecular docking of twenty-one phytochemicals against the VEGFR-2 (PDB ID: 3VHE) protein was performed, followed by ADMET profiling and molecular docking simulations. These investigations unveiled two hit compounds, cirsimaritin (- 12.29 kcal/mol) and salvigenin (- 12.14 kcal/mol), with the highest binding energy values when compared to the reference drug, Sorafenib (- 15.14 kcal/mol). Furthermore, only nine phytochemicals (cirsimaritin and salvigenin included) obeyed Lipinski's rule of five and passed ADMET filters. Molecular dynamics simulations run over 100 ns revealed that the protein-ligand complexes remained stable with minimal backbone fluctuations. The binding free energy values of cirsimaritin (- 52.35 kcal/mol) and salvigenin (- 55.89 kcal/mol), deciphered by MM-GBSA analyses, further corroborated the docking interactions. The HOMO-LUMO band energy gap (ΔE) was calculated using density-functional theory (DFT) and substantiated using density of state (DOS) spectra. The chemical reactivity analyses revealed that salvigenin exhibited the highest chemical softness value (6.384 eV), the lowest hardness value (0.07831 eV), and the lowest ΔE value (0.1566 eV), which implies salvigenin was less stable and chemically more reactive than cirsimaritin and sorafenib. These findings provide further evidence that cirsimaritin and salvigenin have the ability to prevent angiogenesis and the development of cancer. Nevertheless, more in vitro and in vivo confirmation is necessary.

Pro-inflammatory enzyme inhibition of lipoxygenases by flavonoid rich extract from Artemisia vulgaris

The peroxyl radicals generated by the activity of lipoxygenases (LOX) are mediators to trigger inflammatory diseases. Therefore, it is important to investigate potent LOX inhibitor for modulating the occurrence and resolving inflammatory processes. Artemisa vulgaris, is a herbal plant that is known for flavonoids, potentially inhibiting lipid peroxidation and scavenging radicals. The objectives of the present study were to obtain flavonoids rich extract from A. vulgaris, and determine the inhibitory mode of the extract against LOX. The flavonoids rich extract was optimized in an ultrasound assisted extraction using ionic liquids as extraction solvent. The results found that the optimum conditions; ratio of solid-to-liquid (1:10) and 30 min of extraction time could produce the high yield (10.14 %) and flavonoid content (5.30 mg QE/g). The LOX activity was demonstrated to follow a mixed mode of inhibition in the presence of the flavonoid rich extract as an inhibitor. The Michaelis-Menten constant (Km) was increased from 0.283 µM to 0.435 µM, whereas the maximum velocity was reduced from 0.22 µM/min to 0.058 µM/min in the inhibition. The flavonoids rich extract is likely to be a natural potent non-competitive inhibitor which may bind to free LOX or substrate-bound LOX.

Characterization of the glucuronidating pathway of pectolinarigenin, the major active constituent of the Chinese medicine Daji, in humans and its influence on biological activities

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese medicine Daji (the aerial part of Cirsium japonicum DC.) and its charred product (Cirsii Japonici Herba Carbonisata) have been widely used as hemostatic agents or diuretic agents to prepare a variety of Chinese herbal formula. Pectolinarigenin (PEC), one of the most abundant constituents in both Daji and its charred product, has been considered as the key effective substance responsible for the major pharmacological activities of Daji, including hemostasis, hepatoprotective, anti-tumor and anti-osteoporosis effects. However, the major metabolic pathways of PEC in humans and the influence of PEC metabolism on its biological activities are poorly understood.

AIM OF THE STUDY

To characterize the main metabolic pathway(s) and key enzymes of PEC in human biological systems, as well as to reveal the influence of PEC metabolism on its biological activities.

MATERIALS AND METHODS

The metabolic stability assays of PEC were investigated in human liver microsomes (HLM). The O-glucuronide of PEC was biosynthesized and characterized by nuclear magnetic resonance (NMR) spectroscopy. The key enzymes responsible for O-glucuronidation of PEC in humans were assigned by performing UGT reaction phenotyping, chemical inhibition and enzymatic kinetic assays. The agonist effects of PEC and its O-glucuronide on nuclear factor erythroid2-related factor 2 (Nrf2), Peroxisome proliferator activated receptors (PPARα and PPARβ) were tested at the cellular level.

RESULTS

PEC could be readily metabolized to form a mono-O-glucuronide in both human liver microsome (HLM) and human intestinal microsome (HIM). The mono-O-glucuronide was bio-synthesized by mouse liver S9 and its structure was fully characterized as PEC-7-O-β-D-glucuronide (PEC-O-7-G). UGT1A1, UGT1A3 and UGT1A9 are key enzymes responsible for PEC-7-O-glucuronidation in HLM, while UGT1A1, UGT1A9 and 1A10 may play key roles in this reaction in HIM. Biological tests revealed that PEC displayed strong agonist effects on Nrf2, PPARα and PPARβ, whereas PEC-7-O-glucuronide showed relatively weak Nrf2 agonist effect and very weak PPAR agonist effects, indicating that PEC-7-O-glucuronidation strongly weaken its agonist effects on Nrf2 and PPAR.

CONCLUSIONS

Our results demonstrate that 7-O-glucuronidation is the major metabolic pathway of PEC in human tissues, while UGT1A1, 1A3 and 1A9 are key contributing enzymes responsible for PEC-7-O-glucuronidation in human liver. It is also found that PEC 7-O-glucuronidation significantly weakens the Nrf2 and PPAR agonist effects. All these findings are very helpful for the pharmacologists to deep understand the metabolic rates of PEC in humans.

Pectolinarigenin attenuates hepatic ischemia/reperfusion injury via activation of the PI3K/AKT/Nrf2 signaling pathway

Hepatic ischemia/reperfusion (I/R) injury is an unavoidable complication of liver hepatectomy, transplantation, and systemic shock. Pectolinarigenin (Pec) is a flavonoid with many biological activities, which include anti-inflammatory, anti-apoptotic, and antioxidant stress. This study explored whether Pec pretreatment could reduce hepatic I/R injury and the potential mechanisms at play. After pretreatment of mice and AML12 cells with Pec, I/R and hypoxia/reoxygenation (H/R) models were established. By examining markers related to liver injury, cell viability, oxidative stress, inflammatory response, and apoptosis, the effect of Pec on important processes involved in hepatic I/R injury was assessed. Protein levels associated with the PI3K/AKT/Nrf2 pathway were analyzed by relative quantification to investigate possible pathways through which Pec plays a role in the I/R process. Pec treatment corrected abnormal transaminase levels resulting from I/R injury, improved liver injury, and increased AML12 cell viability. Moreover, Pec treatment inhibited oxidative stress, inflammation and apoptosis and could activate the PI3K/AKT/Nrf2 pathway during I/R and H/R. Further studies found that LY294002 (PI3K inhibitor) suppressed the protective effect of Pec on hepatic I/R injury. In summary, our results show that Pec inhibits oxidative stress, inflammatory responses, and apoptosis, thereby attenuating I/R-induced liver injury and H/R-induced cell damage via activation of the PI3K/AKT/Nrf2 pathway.

Pectolinarigenin Improves Oxidative Stress and Apoptosis in Mouse NSC-34 Motor Neuron Cell Lines Induced by C9-ALS-Associated Proline-Arginine Dipeptide Repeat Proteins by Enhancing Mitochondrial Fusion Mediated via the SIRT3/OPA1 Axis

Amyotrophic lateral sclerosis (ALS) is considered a fatal progressive degeneration of motor neurons (MN) caused by oxidative stress and mitochondrial dysfunction. There are currently no treatments available. The most common inherited form of ALS is the C9orf72 mutation (C9-ALS). The proline-arginine dipeptide repeat protein (PR-DPR) produced by C9-ALS has been confirmed to be a functionally acquired pathogenic factor that can cause increased ROS, mitochondrial defects, and apoptosis in motor neurons. Pectolinarigenin (PLG) from the traditional medicinal herb Linaria vulgaris has antioxidant and anti-apoptotic properties. I established a mouse NSC-34 motor neuron cell line model expressing PR-DPR and confirmed the neuroprotective effect of PLG. The results showed that ROS production and apoptosis caused by PR-DPR could be improved by PLG treatment. In terms of mechanism research, PR-DPR inhibited the activity of the mitochondrial fusion proteins OPA1 and mitofusin 2. Conversely, the expression of fission protein fission 1 and dynamin-related protein 1 (DRP1) increased. However, PLG treatment reversed these effects. Furthermore, I found that PLG increased the expression and deacetylation of OPA1. Deacetylation of OPA1 enhances mitochondrial fusion and resistance to apoptosis. Finally, transfection with Sirt3 small interfering RNA abolished the neuroprotective effects of PLG. In summary, the mechanism by which PLG alleviates PR-DPR toxicity is mainly achieved by activating the SIRT3/OPA1 axis to regulate the balance of mitochondrial dynamics. Taken together, the potential of PLG in preclinical studies for C9-ALS drug development deserves further evaluation.

Therapeutic targeting of Ras/Raf/MAPK pathway by natural products: A systematic and mechanistic approach for neurodegeneration

BACKGROUND

Multiple dysregulated pathways are behind the pathogenesis of neurodegenerative diseases (NDDs); however, the crucial targets are still unknown. Oxidative stress, apoptosis, autophagy, and inflammation are the most dominant pathways that strongly influence neurodegeneration. In this way, targeting the Ras/Raf/mitogen-activated protein kinases (MAPKs) pathway appears to be a developing strategy for combating NDDs like Parkinson's disease, Alzheimer's disease, stroke, aging, and other NDDs. Accordingly, plant secondary metabolites have shown promising potentials for the simultaneous modulation of the Ras/Raf/MAPKs pathway and play an essential role in NDDs. MAPKs include p38 MAPK, extracellular signal-regulated kinase 1/2 (ERK 1/2), and c-Jun N-terminal kinase (JNK), which are important molecular players in neurodegeneration. Ras/Raf, which is located the upstream of MAPK pathway influences the initiation and progression of neurodegeneration and is regulated by natural products.

PURPOSE

Thus, the present study aimed to investigate the neuroprotective roles of plant- and marine-derived secondary metabolites against several NDDs through the modulation of the Ras/Raf/MAPK signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was performed to highlight the modulatory roles of natural products on the Ras/Raf/MAPK signaling pathway in NDDs, according to the PRISMA guideline, using scholarly electronic databases, including PubMed, Scopus, and Web of Sciences. Associated reference lists were also searched for the literature review.

RESULTS

From a total of 1495 results, finally 107 articles were included in the present study. The results show that several natural compounds such as alkaloid, phenolic, terpenoids, and nanoformulation were shown to have modulatory effects on the Ras/Raf/MAPKs pathway.

CONCLUSION

Natural products are promising multi-targeted agents with on NDDs through Ras/Raf/MAPKs pathway. Nevertheless, additional and complementary studies are necessary to check its efficacy and potential side effects.

Apoptosis induction in cancer cell lines and anti-inflammatory and anti-pathogenic properties of proteinaceous metabolites secreted from potential probiotic Enterococcus faecalis KUMS-T48

Potential probiotic Enterococcus faecalis KUMS-T48, isolated from a kind of Iranian traditional dairy product (Tarkhineh), was assessed for its anti-pathogenic, anti-inflammatory and anti-proliferative properties against HT-29 and AGS cancer cell lines. This strain showed strong effects on Bacillus subtilis and Listeria monocytogenes and moderate effect on Yersinia enterocolitica, while indicated weak effect on Klebsiella pneumoniae and Escherichia coli. Also, neutralizing the cell-free supernatant and treating it with catalase and proteinase K enzymes reduced the antibacterial effects. Similar to Taxol, the cell-free supernatant of E. faecalis KUMS-T48 inhibited the in vitro proliferation of both cancer cells in a dose-dependent manner, but unlike Taxol, they had no activity against normal cell line (FHs-74). Pronase-treatment of the CFS of E. faecalis KUMS-T48 abrogated its anti-proliferative capacity, thereby showing the proteinaceous nature of the cell-free supernatant. Further, induction of apoptosis-based cytotoxic mechanism by E. faecalis KUMS-T48 cell-free supernatant is related to anti-apoptotic genes ErbB-2 and ErbB-3, which is different from Taxol's apoptosis induction (intrinsic mitochondria apoptosis pathway). Also, as evidenced by a decline in interleukin 1β inflammation-promoting gene expression and a rise in the anti-inflammatory interleukin-10 gene expression in the HT-29 cell line, probiotic E. faecalis KUMS-T48 cell-free supernatant demonstrated a significant anti-inflammatory impact.

Pectolinarigenin shows lipid-lowering effects by inhibiting fatty acid biosynthesis in vitro and in vivo

Pectolinarigenin is the main flavonoid compound and presents in Linaria vulgaris and Cirsium chanroenicum. In this study, RNA sequencing (RNA-seq) was applied to dissect the effect of pectolinarigenin on the transcriptome changes in the high lipid Huh-7 cells induced by oleic acid. RNA-seq results revealed that 15 pathways enriched by downregulated genes are associated with cell metabolism including cholesterol metabolism, glycerophospholipid metabolism, steroid biosynthesis, steroid hormone biosynthesis, fatty acid biosynthesis, etc. Moreover, 13 key genes related to lipid metabolism were selected. Among them, PPARG coactivator 1 beta (PPARGC1B) and carnitine palmitoyltransferase 1A (CPT1A) were found to be upregulated, solute carrier family 27 member 1(SLC27A1), acetyl-CoA carboxylase alpha (ACACA), fatty-acid synthase (FASN), 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCR), etc. were found to be downregulated. Glycolysis/gluconeogenesis, steroid hormone biosynthesis, and fatty acid biosynthesis were all significantly downregulated, according to gene set variation analysis and gene set enrichment analysis. Besides, protein levels of FASN, ACACA, and SLC27A1 were all decreased, whereas PPARγ and CPT1A were increased. Docking models showed that PPARγ may be a target for pectolinarigenin. Furthermore, pectolinarigenin reduced serum TG and hepatic TG, and improved insulin sensitivity in vivo. Our findings suggest that pectolinarigenin may target PPARγ and prevent fatty acid biosynthesis.

Investigation of the chemical profile and anti-inflammatory mechanisms of flavonoids from Artemisia vestita Wall. ex Besser via targeted metabolomics, zebrafish model, and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia vestita Wall. ex Besser is wildly distributed in the western high-altitude area of China and has been used as a Tibetan medicine to treat inflammatory diseases. We previously demonstrated the total flavonoids of Artemisia vestita Wall. ex Besser (TFA) showed obvious anti-inflammatory effects and its content was 276.62 mg/g. However, the chemical profile, active ingredients, and anti-inflammatory mechanisms of TFA are not clear.

AIM OF THE STUDY

This study aimed to study the components of TFA, evaluate the anti-inflammatory effects of TFA, and preliminarily predict the anti-inflammatory mechanism of TFA.

MATERIALS AND METHODS

TFA was prepared by the semi-biomimetic extraction method and purified by macroporous resin. The components of TFA were analyzed based on LC-MS combined with the targeted metabolomics method. The anti-inflammatory activity of TFA was evaluated using CuSO₄-induced and tail cutting-induced zebrafish inflammation models. Based on the network pharmacology method, the anti-inflammatory mechanism of the main components of TFA was preliminarily predicted.

RESULTS

A total of 185 components were identified in TFA. TFA showed significant anti-inflammatory effects on CuSO₄-induced and tail cutting-induced zebrafish inflammation models. According to network pharmacology prediction and experimental verification, 10 compounds were identified as the main active ingredients, including 3,7-di-O-methylquercetin, Hesperetin 5-O-glucoside, Myricitrin, et al. Twenty key targets were recognized, such as TNF, AKT1, VEGFA, MMP9, EGFR, PTGS2 et al. Moreover, the TNF signaling pathway and NOD-like receptor signaling pathway were identified to play vital roles in the anti-inflammatory effects of TFA.

CONCLUSIONS

This study revealed the chemical profile of TFA and identified the main active ingredients, key targets, and pathways of TFA in anti-inflammatory effects, which is helpful to elucidate the pharmacodynamic substances and action mechanisms of Artemisia vestita Wall. ex Besser, to promote its clinical rational application.

A Comprehensive Review on Anti-Inflammatory Response of Flavonoids in Experimentally-Induced Epileptic Seizures

Flavonoids, a group of natural compounds with phenolic structure, are becoming popular as alternative medicines obtained from plants. These compounds are reported to have various pharmacological properties, including attenuation of inflammatory responses in multiple health issues. Epilepsy is a disorder of the central nervous system implicated with the activation of the inflammatory cascade in the brain. The aim of the present study was to summarize the role of various neuroinflammatory mediators in the onset and progression of epilepsy, and, thereafter, to discuss the flavonoids and their classes, including their biological properties. Further, we highlighted the modulation of anti-inflammatory responses achieved by these substances in different forms of epilepsy, as evident from preclinical studies executed on multiple epilepsy models. Overall, the review summarizes the available evidence of the anti-inflammatory potential of various flavonoids in epilepsy.

Comparison of protective effects of hesperetin and pectolinarigenin on high-fat diet-induced hyperlipidemia and hepatic steatosis in Golden Syrian hamsters

A comparative study was conducted to determine whether hesperetin and pectolinarigenin could lower total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL), and high-density lipoprotein cholesterol (HDL) in a high-fat diet (HFD)-induced high lipid model in Golden Syrian hamsters. 48 Golden Syrian hamsters (8 weeks old) were fed with a HFD for 15 days. HFD induced significant increases in plasma TC, TG, LDL, and HDL. Then, these high lipid hamsters were divided into four groups and were administered with 0.5% sodium carboxymethyl cellulose (CMC-Na), hesperetin (100 mg/kg/day), pectolinarigenin (100 mg/kg/day) or atorvastatin (1.0 mg/kg/day), for 7 weeks. It was found that pectolinarigenin treatment resulted in significant reductions in body weight, adiposity index, serum levels of TC, TG and hepatic TC, TG and free fatty acid compared to those in control hamsters with hyperlipidemia (P<0.05). However, hesperetin treatment only caused reductions in plasma TC and hepatic TG levels. Besides, the hamsters treated with pectolinarigenin showed a relatively normal hepatic architecture compared to the hepatic steatosis shown in the control group. Moreover, the expressions of fatty-acid synthase (Fasn) and solute carrier family 27 member 1 (Slc27a1) involved in lipid biosynthesis, were suppressed in the pectolinarigenin-treated groups, and the expression of carnitine palmitoyltransferase 1A (Cpt1a) involved in fatty acid oxidation was increased in the pectolinarigenin-treated group. Taken together, these results suggest pectolinarigenin exerts stronger protective effects against hyperlipidemia and hepatic steatosis than hesperetin, which may involve the inhibition of lipid uptake and biosynthesis.

Flavonoids and saponins: What have we got or missed?

BACKGROUND

Flavonoids and saponins are important bioactive compounds that have attracted wide research interests. This review aims to summarise the state of the art of the pharmacology, toxicology and clinical efficacy of these compounds.

METHODS

Data were retrieved from PubMed, Cochrane Library, Web of Science, Proquest, CNKI, Chongqing VIP, Wanfang, NPASS and HIT 2.0 databases. Meta-analysis and systematic reviews were evaluated following the PRISMA guideline. Statistical analyses were conducted using SPSS23.0.

RESULTS

Rising research trends on flavonoids and saponins were observed since the 1990s and the 2000s, respectively. Studies on pharmacological targets and activities of flavonoids and saponins represent an important area of research advances over the past decade, and these important resources have been documented in open-access specialised databases and can be retrieved with ease. The rising research on flavonoids and saponins can be attributed, at least in part, to their links with some highly investigated fields of research, e.g., oxidative stress, inflammation and cancer; i.e., 6.88% and 3.03% of publications on oxidative stress cited by PubMed in 1990 - 2021 involved flavonoids and saponins, respectively, significantly higher than the percentage involving alkaloids (1.88%). The effects of flavonoids concern chronic venous insufficiency, cervical lesions, diabetes, rhinitis, dermatopathy, prostatitis, menopausal symptoms, angina pectoris, male pattern hair loss, lymphocytic leukaemia, gastrointestinal diseases and traumatic cerebral infarction, etc, while those of saponins may have impact on venous oedema in chronic deep vein incompetence, erectile dysfunction, acute impact injuries and systemic lupus erythematosus, etc. The volume of in vitro research appears way higher than in vivo and clinical studies, with only 10 meta-analyses and systematic reviews (involving 290 interventional and observational studies), and 36 clinical studies on flavonoids and saponins. Data are sorely needed on pharmacokinetics, in vitro pan-assay interferences, purity of tested compounds, interactions in complex herbal extracts, real impact of anti-oxidative strategies, and mid- and long-term toxicities. To fill these important gaps, further investigations are warranted. On the other hand, drug interactions may cause adverse effects but might also be useful for synergism, with the goals of enhancing effects or of detoxifying. Furthermore, the interactions between phytochemicals and the intestinal microbiota are worth investigating as the field may present a promising potential for novel drug development.

An ethnopharmacological review on the therapeutical properties of flavonoids and their mechanisms of actions: A comprehensive review based on up to date knowledge

Flavonoids -a class of low molecular weight secondary metabolites- are ubiquitous and cornucopia throughout the plant kingdom. Structurally, the main structure consists of C6-C3-C6 rings with different substitution patterns so that many sub-classes are obtained, for example: flavonols, flavonolignans, flavonoid glycosides, flavans, anthocyanidins, aurones, anthocyanidins, flavones, neoflavonoids, chalcones, isoflavones, flavones and flavanones. Flavonoids are evaluated to have drug like nature since they possess different therapeutic activities, and can act as cardioprotective, antiviral, antidiabetic, anti-inflammatory, antibacterial, anticancer, and also work against Alzheimer's disease and others. However, information on the relationship between their structure and biological activity is scarce. Therefore, the present review tries to summarize all the therapeutic activities of flavonoids, their mechanisms of action and the structure activity relationship.

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Latest updated ethnopharmacological review of the therapeutic effects of flavonoids.

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Flavonoids are attracting attention because of their therapeutic properties.

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Flavonoids are valuable candidates for drug development against many dangerous diseases.

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This overview summarizes the most important therapeutic effect and mechanism of action of flavonoids.

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General knowledge about the structure activity relationship of flavonoids is summarized.

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Substitution of chemical groups in the structure of flavonoids can significantly change their biological and chemical properties.

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The chemical properties of the basic flavonoid structure should be considered in a drug-based structural program.

Natural Flavonoid Pectolinarigenin Alleviated Hyperuricemic Nephropathy via Suppressing TGFβ/SMAD3 and JAK2/STAT3 Signaling Pathways

Natural flavonoid pectolinarigenin (PEC) was reported to alleviate tubulointerstitial fibrosis of unilateral ureteral obstruction (UUO) mice in our previous study. To further investigate nephroprotective effects of PEC in hyperuricemic nephropathy (HN), adenine and potassium oxonate induced HN mice and uric acid-treated mouse kidney epithelial (TCMK-1) cells were employed in the study. As a result, PEC significantly lowered serum uric acid level and restored hyperuricemia-related kidney injury in HN mice. Meanwhile, PEC alleviated inflammation, fibrosis, and reduced adipokine FABP4 content in the kidneys of HN mice and uric acid-treated TCMK-1 cells. Mechanistically, PEC inhibited the TGF-β1 expression as well as the phosphorylation of transcription factor SMAD3 and STAT3 to regulate the corresponding inflammatory and fibrotic gene expression in kidney tissues. In conclusion, our results suggested that PEC could inhibit the activation of SMAD3 and STAT3 signaling to suppress inflammation and fibrosis, and thereby alleviate HN in mice.

Dual quinoline-hybrid compounds with antimalarial activity against Plasmodium falciparum parasites

Although we have at our disposal relatively low-cost drugs that can be prescribed for the treatment of malaria, the prevalence of resistant strains of the causative parasite has required the development of new drugs.