In vitro Anti-Inflammatory and Anti-Oxidative Stress Activities of Kushenol C Isolated from the Roots of Sophora flavescens

Prenylated Flavonoids in Sophora flavescens: A Systematic Review of Their Phytochemistry and Pharmacology

Sophora flavescens has been widely used in traditional Chinese medicine for over 1700 years. This plant is known for its heat-clearing, damp-drying, insecticidal, and diuretic properties. Phytochemical research has identified prenylated flavonoids as a unique class of bioactive compounds in S. flavescens. Recent pharmacological studies reveal that the prenylated flavonoids from S. flavescens (PFS) exhibit potent antitumor, anti-inflammatory, and glycolipid metabolism-regulating activities, offering significant therapeutic benefits for various diseases. However, the pharmacokinetics and toxicological profiles of PFS have not been systematically studied. Despite the diverse biological effects of prenylated flavonoid compounds against similar diseases, their structure-activity relationship is not yet fully understood. This review aims to summarize the latest findings regarding the chemical composition, drug metabolism, pharmacological properties, toxicity, and structure-activity relationship of prenylated flavonoids from S. flavescens. It seeks to highlight their potential for clinical use and suggest directions for future related studies.

Phytochemistry and pharmacology of natural prenylated flavonoids

Prenylated flavonoids are a special kind of flavonoid derivative possessing one or more prenyl groups in the parent nucleus of the flavonoid. The presence of the prenyl side chain enriched the structural diversity of flavonoids and increased their bioactivity and bioavailability. Prenylated flavonoids show a wide range of biological activities, such as anti-cancer, anti-inflammatory, neuroprotective, anti-diabetic, anti-obesity, cardioprotective effects, and anti-osteoclastogenic activities. In recent years, many compounds with significant activity have been discovered with the continuous excavation of the medicinal value of prenylated flavonoids, and have attracted the extensive attention of pharmacologists. This review summarizes recent progress on research into natural active prenylated flavonoids to promote new discoveries of their medicinal value.

Polyphenol Supplementation and Antioxidant Status in Athletes: A Narrative Review

Antioxidants in sports exercise training remain a debated research topic. Plant-derived polyphenol supplements are frequently used by athletes to reduce the negative effects of exercise-induced oxidative stress, accelerate the recovery of muscular function, and enhance performance. These processes can be efficiently modulated by antioxidant supplementation. The existing literature has failed to provide unequivocal evidence that dietary polyphenols should be promoted specifically among athletes. This narrative review summarizes the current knowledge regarding polyphenols' bioavailability, their role in exercise-induced oxidative stress, antioxidant status, and supplementation strategies in athletes. Overall, we draw attention to the paucity of available evidence suggesting that most antioxidant substances are beneficial to athletes. Additional research is necessary to reveal more fully their impact on exercise-induced oxidative stress and athletes' antioxidant status, as well as optimal dosing methods.

Piperine ameliorates ischemic stroke-induced brain injury in rats by regulating the PI3K/AKT/mTOR pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Piperine (PIP), a main active component isolated from Piper nigrum L., exerts neuroprotective effects in a rat model of ischemic stroke (IS). However, studies on the effects of PIP on neuroprotection and autophagy after IS are limited.

AIM OF THE STUDY

This study aimed to prove the protective effects of PIP against brain IS and elucidate its underlying mechanisms.

MATERIALS AND METHODS

Specific pathogen-free male Sprague-Dawley rats were selected to establish a permanent middle cerebral artery occlusion model. The experiment was randomly divided into six groups: sham group, model group, PIP intervention group (10, 20, and 30 mg/kg group), and nimodipine group (Nimo group, 12 mg/kg). Neurological function score, postural reflex score, body swing score, balance beam test, and grip strength test were used to detect behavioral changes of rats. The area of cerebral infarction was detected by TTC staining, and the number and morphological changes of neurons were observed by Nissl and HE staining. In addition, the ultrastructure of hippocampal dentate gyrus neurons was observed using a transmission electron microscope. Western blot was used to detect the expression of PI3K/AKT/mTOR signaling pathway proteins and autophagy-related proteins, namely, Beclin1 and LC3, in the hippocampus and cortex. Cell experiments established an in vitro model of oxygen-glucose deprivation (OGD) with the HT22 cell line to verify the mechanism. The experiment was divided into five groups: control group, OGD group, OGD + PIP 20 μg/mL group, OGD + PIP 30 μg/mL group, and OGD + PIP 40 μg/mL group. CCK-8 was used to measure cell activity, and Western blot was used to measure the expression of PI3K/AKT/mTOR signaling pathway proteins and autophagy-related proteins (Beclin1 and LC3).

RESULTS

Compared with the model group, the neurological function scores, body swing scores, and postural reflex scores of rats in the 10, 20, and 30 mg/kg PIP intervention groups and Nimo groups decreased, whereas the balance beam score and grip test scores increased (all p < 0.05). After 10, 20, and 30 mg/kg PIP and Nimo intervention, the cerebral infarction area of pMCAO rats was reduced (p < 0.01), and Nissl and HE staining results showed that the number of neurons survived in the 30 mg/kg PIP and Nimo intervention groups increased. Cell morphology and structure were significantly improved (p < 0.05). Most of the hippocampal dentate gyrus neurons and their organelles gradually returned to normal in the 30 mg/kg PIP and Nimo intervention groups, with less neuronal damage. The expression levels of p-mTOR, p-AKT, and p-PI3K in the hippocampus and cortex of the 30 mg/kg PIP and Nimo intervention groups decreased, whereas the expression level of PI3K increased (all p < 0.05). In addition, the expression level of autophagy-related proteins, namely, Beclin1 and LC3-II, in the 30 mg/kg PIP and Nimo intervention groups decreased (all p < 0.05). Results of CCK-8 showed that after 1 h of OGD, the 30 and 40 μg/mL PIP intervention groups had higher cell viability than the OGD group (p < 0.01). Western blot results showed that compared with the OGD group, the expression level of p-mTOR, p-AKT, and p-PI3K in the 30 and 40 μg/mL PIP intervention groups decreased, and the expression level of PI3K increased (all p < 0.05). Moreover, the expression level of autophagy-related proteins, namely, Beclin1 and LC3-II, in the 30 and 40 μg/mL PIP intervention groups decreased (all p < 0.05).

CONCLUSIONS

This study shows that PIP is a potential compound with neuroprotective effects. PIP can inhibit the PI3K/AKT/mTOR pathway and autophagy. Its inhibition of autophagy is possibly related to modulating the PI3K/AKT/mTOR pathway. These findings provide new insights into the use of PIP for the treatment of IS and its underlying mechanism.

Chemical diversity, biological activities and Traditional uses of and important Chinese herb Sophora

BACKGROUND

Sophora flavescens Aiton (SF), also known as Kushen (Chinese:), has been an important species in Chinese medicine since the Qin and Han dynasties. It is also recognized as a plant resource suitable for the globalization of Chinese medicine. Traditionally, it has been used in various ethnic medical systems in East Asia, especially in China, to kill insects and dispel dampness. Sophora flavescens is commonly used for clearing heat-clearing, killing worms, and diuretic. Nowdays, accumulating studies demonstrated its anticancer and cardioprotection.

OBJECTIVE OF THE REVIEW

This paper aims to systematically review information on the genus, pharmacological and toxicological significance, chemical composition and biological activity of Sophora flavescens. To promoting its development and application. To summarize recent findings regarding to the metabolism, pharmacological/toxicological effects of Sophora flavescens.

MATERIAL AND METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Sophora flavescens Aiton", "Ku shen", "Pharmacology", "Active ingredient", "Toxicology" and combinations to include published studies of Sophora flavescens Aiton primarily from 1970-2021. Several critical previous studies beyond this period were also included and other related terms.

CONCLUSION

Sophora flavescens has a broad spectrum of biological activities associated with Sophora flavescens has been considered a valuable resource in both traditional and modern medicine. However, there is a lack of in-depth studies on the medicinal uses of Sophora flavescens. Moreover, further studies on single chemical components should be conducted based on the diversity of chemical structures, significant biological activities and clinical applications. The discovery of its bioactive molecules and multi-component interactions would be of great importance for the clinical application of Sophora flavescens spp. Detailed pharmacological and toxicological studies on the classic prescriptions of Sophora flavescens are also needed. It is more beneficial to the wide application of SF plant and facilitates the worldwide promotion of modern Chinese medicine. However, an increasing number of reports indicate that the administration of Sophora flavescens has serious adverse effects. Its main toxic effects are neurotoxicity and acute toxicity, which have caused widespread concern worldwide. In addition, the alkaloids of Sophora flavescens are distributed in the heart, liver, stomach and large intestine. They are excreted from the body through gluconeogenesis, which is the mode of action of certain therapeutic mechanisms of action such as anticancer. The detailed metabolic study of alkaloids and other components of Sophora flavescens in vivo needs to be further investigated. It is important to improve the pharmacological effects and reduce the toxicity of Sophora flavescens. For this purpose, structural modification of active components of Sophora flavescens or combination with other drugs is very essential.

Sophoraflavanone G from Sophora flavescens Ameliorates Allergic Airway Inflammation by Suppressing Th2 Response and Oxidative Stress in a Murine Asthma Model

Sophoraflavanone G (SG), isolated from Sophora flavescens, has anti-inflammatory and anti-tumor bioactive properties. We previously showed that SG promotes apoptosis in human breast cancer cells and leukemia cells and reduces the inflammatory response in lipopolysaccharide-stimulated macrophages. We investigated whether SG attenuates airway hyper-responsiveness (AHR) and airway inflammation in asthmatic mice. We also assessed its effects on the anti-inflammatory response in human tracheal epithelial cells. Female BALB/c mice were sensitized with ovalbumin, and asthmatic mice were treated with SG by intraperitoneal injection. We also exposed human bronchial epithelial BEAS-2B cells to different concentrations of SG to evaluate its effects on inflammatory cytokine levels. SG treatment significantly reduced AHR, eosinophil infiltration, goblet cell hyperplasia, and airway inflammation in the lungs of asthmatic mice. In the lungs of ovalbumin-sensitized mice, SG significantly promoted superoxide dismutase and glutathione expression and attenuated malondialdehyde levels. SG also suppressed levels of Th2 cytokines and chemokines in lung and bronchoalveolar lavage samples. In addition, we confirmed that SG decreased pro-inflammatory cytokine, chemokine, and eotaxin expression in inflammatory BEAS-2B cells. Taken together, our data demonstrate that SG shows potential as an immunomodulator that can improve asthma symptoms by decreasing airway-inflammation-related oxidative stress.

Daurisoline alleviated experimental colitis in vivo and in vitro: Involvement of NF-κB and Wnt/β-Catenin pathway

Daurisoline (DS) is one of the most abundant alkaloids extracted from the rhizome of Menispermum Dauricum DC, which is traditionally used to treat inflammatory diseases, especially intestinal inflammation. In this study, we established lipopolysaccharide (LPS)-induced RAW 264.7 macrophages in vitro and Dextran sulfate sodium (DSS)-induced colitis mice model in vivo to investigate the anti-inflammatory effect of DS and its underlying mechanisms. Disease activity index (DAI) was detected during drug intervention. The colon length, macroscopic changes and histopathological scores were adopted to observe the physiological status and the colon injury. The apoptosis of intestinal mucosa was detected using TUNEL. In addition, involved molecular indicators were measured by ELISA kits, RT-qPCR, immunofluorescence (IF), immunohistochemistry (IHC) and western blotting. The vitro experiments indicated that DS significantly suppressed the production of Nitric oxide (NO), reactive oxygen species (ROS) and glutathione (GSH), as well as inhibited the expression of NF-κB signaling pathway in RAW 264.7 cells induced by LPS. Consistent with the vitro experimental results, different doses of DS significantly reduced the incidence of diarrhea, DAI, shortening of the colon, visible damage and histological damage in DSS-induced colitis mice. Moreover, DS treatment decreased the levels of pro-inflammatory mediators cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and interleukin (IL)-1β, and increased the anti-inflammatory cytokines IL-4 and IL-10 in colon tissues. RT-qPCR, western blotting and immunofluorescence analyses further demonstrated that DS inhibits the expression of Wnt/β-Catenin pathway. We reported for the first time that DS may be an active ingredient in treating ulcerative colitis. Its mechanism might be related to the regulation of the NF-κB and Wnt/β-Catenin signaling pathway.

Genus Sophora: a comprehensive review on secondary chemical metabolites and their biological aspects from past achievements to future perspectives

Sophora is deemed as one of the most remarkable genera of Fabaceae, and the third largest family of flowering plants. The genus Sophora comprises approximately 52 species, 19 varieties, and 7 forms that are widely distributed in Asia and mildly in Africa. Sophora species are recognized to be substantial sources of broad spectrum biopertinent secondary metabolites namely flavonoids, isoflavonoids, chalcones, chromones, pterocarpans, coumarins, benzofuran derivatives, sterols, saponins (mainly triterpene glycosides), oligostilbenes, and mainly alkaloids. Meanwhile, extracts and isolated compounds from Sophora have been identified to possess several health-promising effects including anti-inflammatory, anti-arthritic, antiplatelets, antipyretic, anticancer, antiviral, antimicrobial, antioxidant, anti-osteoporosis, anti-ulcerative colitis, antidiabetic, anti-obesity, antidiarrheal, and insecticidal activities. Herein, the present review aims to provide comprehensive details about the phytochemicals and biological effects of Sophora species. The review spotlighted on the promising phytonutrients extracted from Sophora and their plethora of bioactivities. The review also clarifies the remaining gaps and thus qualifies and supplies a platform for further investigations of these compounds.

α‑rhamnrtin‑3‑α‑rhamnoside exerts anti‑inflammatory effects on lipopolysaccharide‑stimulated RAW264.7 cells by abrogating NF‑κB and activating the Nrf2 signaling pathway

α-rhamnrtin-3-α-rhamnoside (ARR) is the principal compound extracted from Loranthus tanakae Franch. & Sav. However, its underlying pharmacological properties remain undetermined. Inflammation is a defense mechanism of the body; however, the excessive activation of the inflammatory response can result in physical injury. The present study aimed to investigate the effects of ARR on lipopolysaccharide (LPS)-induced RAW264.7 macrophages and to determine the underlying molecular mechanism. A Cell Counting Kit-8 assay was performed to assess cytotoxicity. Nitric oxide (NO) production was measured via a NO colorimetric kit. Levels of prostaglandin E2 (PGE₂) and proinflammatory cytokines, IL-1β and IL-6, were detected using ELISAs. Reverse transcription-quantitative (RT-q)PCR analysis was performed to detect the mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and IL-1β in LPS-induced RAW246.7 cells. Western blotting, immunofluorescence and immunohistochemistry analyses were performed to measure the expression levels of NF-κB and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins to elucidate the molecular mechanisms of the inflammatory response. The results of the cytotoxicity assay revealed that doses of ARR ≤200 µg/ml exhibited no significant effect on the viability of RAW264.7 cells. The results of the Griess assay demonstrated that ARR inhibited the production of NO. In addition, the results of the ELISAs and RT-qPCR analysis discovered that ARR reduced the production of the proinflammatory cytokines, IL-1β and IL-6, as well as the proinflammatory mediators, PGE₂, iNOS and COX-2, in LPS-induced RAW264.7 cells. Immunohistochemical analysis demonstrated that ARR inhibited LPS-induced activation of TNF-associated factor 6 (TRAF6) and NF-κB p65 signaling molecules, while reversing the downregulation of the NOD-like receptor family CARD domain containing 3 (NLRC3) signaling molecule, which was consistent with the results of the western blotting analysis. Immunofluorescence results indicated that ARR reduced the increase of NF-κB p65 nuclear expression induced by LPS. Furthermore, the results of the western blotting experiments also revealed that ARR upregulated heme oxygenase-1, NAD(P)H quinone dehydrogenase 1 and Nrf2 pathway molecules. In conclusion, the results of the present study suggested that ARR may exert anti-inflammatory effects by downregulating NF-κB and activating Nrf2-mediated inflammatory responses, suggesting that ARR may be an attractive anti-inflammatory candidate drug.

Sophoraflavanone M, a prenylated flavonoid from Sophora flavescens Ait., suppresses pro-inflammatory mediators through both NF-κB and JNK/AP-1 signaling pathways in LPS-primed macrophages

(2R)-3α,7,4'-trihydroxy-5-methoxy-8-(γ,γ-dimethylallyl)-flavanone is a prenylated flavonoid isolated from the anti-inflammatory herb Sophora flavescens Ait. We firstly named it sophoraflavanone M (SFM) in accordance with trivial names of related constitutes from this plant. Although various studies investigated the anti-inflammatory properties of prenylated flavonoids from Sophora flavescens Ait., that of SFM remains unclear and is yet to be determined. In the current study, we assessed the anti-inflammatory effects of SFM in LPS-induced in vivo and in vitro models. In the serum of endotoxemia mice, SFM significantly suppressed LPS-elevated inflammatory cytokines. Furthermore, at nontoxic concentrations, SFM reduced LPS-induced production of inflammatory mediators NO, IL-6, TNF-α, and MCP-1 in mouse primary peritoneal macrophages. Accordingly, in LPS-primed RAW264.7 cell line, it also inhibited these mediators' expression at both transcriptional and translational levels without cytotoxicity. Mechanistically, SFM is found to concurrently inhibit two important inflammatory signaling pathways, NF-κB and JNK/AP-1. SFM restrained phosphorylation and degradation of IκBα as well as the subsequent p65 translocation to dampen NF-κB activity. Meanwhile, it also suppressed JNK phosphorylation to inhibit the transcriptional activity of AP-1. These results provide material basis for traditional application of the anti-inflammatory herb Sophora flavescens Ait. and suggest SFM is a promising natural candidate for alleviating inflammatory conditions.

Kushenol C Prevents Tert-Butyl Hydroperoxide and Acetaminophen-Induced Liver Injury

Sophora flavescens, also known as Kushen, has traditionally been used as a herbal medicine. In the present study we evaluated the ameliorative effects of kushenol C (KC) from S. flavescens against tBHP (tert-Butyl hydroperoxide)-induced oxidative stress in hepatocellular carcinoma (HEPG2) cells and acetaminophen (APAP)-induced hepatotoxicity in mice. KC pretreatment protected the HEPG2 cells against oxidative stress by reducing cell death, apoptosis and reactive oxygen species (ROS) generation. KC pretreatment also upregulated pro-caspase 3 and GSH (glutathione) as well as expression of 8-Oxoguanine DNA Glycosylase (OGG1) in the HEPG2 cells. The mechanism of action was partly related by KC's activation of Akt (Protein kinase B (PKB)) and Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) in the HepG2 cells. In in vivo investigations, coadministration of mice with KC and APAP significantly attenuated APAP-induced hepatotoxicity and liver damage, as the serum enzymatic activity of aspartate aminotransferase and alanine aminotransferase, as well as liver lipid peroxidation and cleaved caspase 3 expression, were reduced in APAP-treated mice. Coadministration with KC also up-regulated antioxidant enzyme expression and prevented the production of proinflammatory mediators in APAP-treated mice. Taken together, these results showed that KC treatment has potential as a therapeutic agent against liver injury through the suppression of oxidative stress.

Comparation of Anti-Inflammatory and Antioxidantactivities of Curcumin, Tetrahydrocurcuminand Octahydrocurcuminin LPS-Stimulated RAW264.7 Macrophages

Curcumin (CUR) possesses pronounced anti-inflammatory and antioxidant activities. Generally, the clinical application of CUR is restricted due to its apparent unstability and poor absorption, and the biological activities of CUR may be closely associated with its metabolites. Tetrahydrocurcumin (THC) and octahydrocurcumin (OHC) are two major hydrogenated metabolites of CUR with appreciable biological potentials. Here, we comparatively explored the anti-inflammatory and antioxidant activities of CUR, THC, and OHC in lipopolysaccharide- (LPS-) induced RAW264.7 macrophages. The results revealed that CUR, THC, and OHC dose-dependently inhibited the generation of NO and MCP-1 as well as the gene expression of MCP-1 and iNOS. Additionally, CUR, THC, and OHC significantly inhibited NF-κB activation and p38MAPK and ERK phosphorylation, while substantially upregulated the Nrf2 target gene expression (HO-1, NQO-1, GCLC, and GCLM). Nevertheless, zinc protoporphyrin (ZnPP), a typical HO-1 inhibitor, significantly reversed the alleviative effect of CUR, THC, and OHC on LPS-stimulated ROS generation. These results demonstrated that CUR, THC, and OHC exerted beneficial effect on LPS-stimulated inflammatory and oxidative responses, at least partially, through inhibiting the NF-κB and MAPKs pathways and activating Nrf2-regulated antioxidant gene expression. Particularly, THC and OHC might exert superior antioxidant and anti-inflammatory activities to CUR in LPS-stimulated RAW264.7 cells, which can be further explored to be a promising novel effective agent for inflammatory treatment.

Discovery and Development of Inflammatory Inhibitors from 2-Phenylchromonone (Flavone) Scaffolds

Flavonoids are compounds based on a 2-phenylchromonone scaffold. Flavonoids can be divided into flavonoids, flavonols, dihydroflavones, anthocyanins, chalcones and diflavones according to the oxidation degree of the central tricarbonyl chain, the connection position of B-ring (2-or 3-position), and whether the tricarbonyl chain forms a ring or not. There are a variety of biological activities about flavonoids, such as anti-inflammatory activity, anti-oxidation and anti-tumor activity, and the antiinflammatory activity is apparent. This paper reviews the anti-inflammatory activities and mechanisms of flavonoids and their derivatives reported in China and abroad from 2011 till date (2011-2020), in order to find a good drug scaffold for the study of anti-inflammatory activities.