Maackiain suppresses the development of cervical cancer via AMPK priming autophagy.

BACKGROUND: Maackiain (Mac), a flavonoid analog isolated from Sophora flavescens, exhibits neuroprotective, anti-allergic, anti-inflammatory, and pro-apoptotic effects. It is not clear whether Mac has a therapeutic effect on cervical cancer. METHOD: In this work, we used RT-qPCR, western blot, immunofluorescence, and related methods to detect the therapeutic mechanism of Mac for cervical cancer. RESULTS: We demonstrated that Mac significantly inhibited the proliferation, migration, and invasion of human cervical cancer cell lines HeLa and SiHa. And, Mac enhanced the pro-apoptotic effects of cisplatin in treating cervical cancer cells. Mac has shown good efficacy in treating cervical cancer. Furthermore, Mac inhibited the mammalian target of the rapamycin (mTOR) pathway, thereby inducing autophagy in cervical cancer cells. The regulation of mTOR/autophagy pathway by Mac relied on the activation of AMP-activated protein kinase (AMPK), and the inhibition of the AMPK reversed the Mac's anti-cervical cancer activity. In addition, experimental study of Mac in mouse xenograft tumor model further confirmed its good anti-cervical cancer activity. CONCLUSION: Mac inhibits human cervical cancer by activating the AMPK/mTOR/autophagy pathway, indicating that it is a potential natural compound for the treatment of cervical cancer. This study also provides a feasible molecular mechanism for the treatment of cervical cancer.

Maackiain Mimics Caloric Restriction through aak-2-Mediated Lipid Reduction in Caenorhabditis elegans.

Obesity prevalence is becoming a serious global health and economic issue and is a major risk factor for concomitant diseases that worsen the quality and duration of life. Therefore, the urgency of the development of novel therapies is of a particular importance. A previous study of ours revealed that the natural pterocarpan, maackiain (MACK), significantly inhibits adipogenic differentiation in human adipocytes through a peroxisome proliferator-activated receptor gamma (PPARγ)-dependent mechanism. Considering the observed anti-adipogenic potential of MACK, we aimed to further elucidate the molecular mechanisms that drive its biological activity in a Caenorhabditis elegans obesity model. Therefore, in the current study, the anti-obesogenic effect of MACK (25, 50, and 100 µM) was compared to orlistat (ORST, 12 µM) as a reference drug. Additionally, the hybrid combination between the ORST (12 µM) and MACK (100 µM) was assessed for suspected synergistic interaction. Mechanistically, the observed anti-obesogenic effect of MACK was mediated through the upregulation of the key metabolic regulators, namely, the nuclear hormone receptor 49 (nhr-49) that is a functional homologue of the mammalian PPARs and the AMP-activated protein kinase (aak-2/AMPK) in C. elegans. Collectively, our investigation indicates that MACK has the potential to limit lipid accumulation and control obesity that deserves future developments.

Maackiain inhibits proliferation and promotes apoptosis of nasopharyngeal carcinoma cells by inhibiting the MAPK/Ras signaling pathway.

Nasopharyngeal carcinoma (NPC) is the third most common malignancy with a high recurrence and metastasis rate in South China. Natural compounds extracted from traditional Chinese herbal medicines have been developed and utilized for the treatment of a variety of cancers with modest properties and slight side effects. Maackiain (MA) is a type of flavonoid that was first isolated from leguminous plants, and it has been reported to relieve various nervous system disorders and exert anti-allergic as well as anti-inflammatory effects. In this study, we demonstrated that MA inhibited proliferation, arrested cell cycle and induced apoptosis in nasopharyngeal carcinoma CNE1 and CNE2 cells in vitro and in vivo. The expression of the related proteins associated with these processes were consistent with the above effects. Moreover, transcriptome sequencing and subsequent Western blot experiments revealed that inhibition of the MAPK/Ras pathway may be responsible to the anti-tumor effect of MA on NPC cells. Therefore, the effects of MA and an activator of this pathway, tertiary butylhydroquinone (TBHQ), alone or combination, were investigated. The results showed TBHQ neutralized the inhibitory effects of MA. These data suggest that MA exerts its anti-tumor effect by inhibiting the MAPK/Ras signaling pathway and it has the potential to become a treatment for patients with NPC.

Targeting PI3K/AKT signaling pathway in obesity.

Obesity is a disorder with an increasing prevalence, which impairs the life quality of patients and intensifies societal health care costs. The development of safe and innovative prevention strategies and therapeutic approaches is thus of great importance. The complex pathophysiology of obesity involves multiple signaling pathways that influence energy metabolism in different tissues. The phosphatidylinositol 3-kinases (PI3K)/protein kinase B (AKT) pathway is critical for the metabolic homeostasis and its function in insulin-sensitive tissues is described in the context of health, obesity and obesity-related complications. The PI3K family participates in the regulation of diverse physiological processes including but not limited to cell growth, survival, differentiation, autophagy, chemotaxis, and metabolism depending on the cellular context. AKT is downstream of PI3K in the insulin signaling pathway, and promotes multiple cellular processes by targeting a plethora of regulatory proteins that control glucose and lipid metabolism. Natural products are essential for prevention and treatment of many human diseases, including obesity. Anti-obesity natural compounds effect multiple pathophysiological mechanisms involved in obesity development. Numerous recent preclinical studies reveal the advances in using plant secondary metabolites to target the PI3K/AKT signaling pathway for obesity management. In this paper the druggability of PI3K as a target for compounds with anti-obesity potential is evaluated. Perspectives on the strategies and limitations for clinical implementation of obesity management using natural compounds modulating the PI3K/AKT pathway are suggested.

Maackiain inhibits proliferation and promotes apoptosis of nasopharyngeal carcinoma cells by inhibiting the MAPK/Ras signaling pathway / 中国天然药物

Nasopharyngeal carcinoma (NPC) is the third most common malignancy with a high recurrence and metastasis rate in South China. Natural compounds extracted from traditional Chinese herbal medicines have been developed and utilized for the treatment of a variety of cancers with modest properties and slight side effects. Maackiain (MA) is a type of flavonoid that was first isolated from leguminous plants, and it has been reported to relieve various nervous system disorders and exert anti-allergic as well as anti-inflammatory effects. In this study, we demonstrated that MA inhibited proliferation, arrested cell cycle and induced apoptosis in nasopharyngeal carcinoma CNE1 and CNE2 cells in vitro and in vivo. The expression of the related proteins associated with these processes were consistent with the above effects. Moreover, transcriptome sequencing and subsequent Western blot experiments revealed that inhibition of the MAPK/Ras pathway may be responsible to the anti-tumor effect of MA on NPC cells. Therefore, the effects of MA and an activator of this pathway, tertiary butylhydroquinone (TBHQ), alone or combination, were investigated. The results showed TBHQ neutralized the inhibitory effects of MA. These data suggest that MA exerts its anti-tumor effect by inhibiting the MAPK/Ras signaling pathway and it has the potential to become a treatment for patients with NPC.

A Novel Splice Variant of BCAS1 Inhibits ß-Arrestin 2 to Promote the Proliferation and Migration of Glioblastoma Cells, and This Effect Was Blocked by Maackiain.

Brain-enriched myelin-associated protein 1 (BCAS1) is frequently highly expressed in human cancer, but its detailed function is unclear. Here, we identified a novel splice variant of the BCAS1 gene in glioblastoma multiforme (GBM) named BCAS1-SV1. The expression of BCAS1-SV1 was weak in heathy brain cells but high in GBM cell lines. The overexpression of BCAS1-SV1 significantly increased the proliferation and migration of GBM cells, whereas the RNA-interference-mediated knockdown of BCAS1-SV1 reduced proliferation and migration. Moreover, using a yeast-two hybrid assay, immunoprecipitation, and immunofluorescence staining, we confirmed that ß-arrestin 2 is an interaction partner of BCAS1-SV1 but not BCAS1. The downregulation of ß-arrestin 2 directly enhanced the malignancy of GBM and abrogated the effects of BCAS1-SV1 on GBM cells. Finally, we used a yeast two-hybrid-based growth assay to identify that maackiain (MK) is a potential inhibitor of the interaction between BCAS1-SV1 and ß-arrestin 2. MK treatment lessened the proliferation and migration of GBM cells and prolonged the lifespan of tumor-bearing mice in subcutaneous xenograft and intracranial U87-luc xenograft models. This study provides the first evidence that the gain-of-function BCAS1-SV1 splice variant promotes the development of GBM by suppressing the ß-arrestin 2 pathway and opens up a new therapeutic perspective in GBM.

Anti-adipogenic activity of maackiain and ononin is mediated via inhibition of PPARγ in human adipocytes.

Obesity is a global health burden for which we do not yet have effective treatments for prevention or therapy. Plants are an invaluable source of bioactive leads possessing anti-adipogenic potential. Ethnopharmacological use of Ononis spinosa L. roots (OSR) for treatment of obesity and metabolic disorders requires а scientific rationale. The current study examined the anti-adipogenic capacity of OSR and its secondary metabolites ononin (ONON) and maackiain (MACK) in human adipocytes as an in vitro model of obesity. Both ONON and MACK diminished lipid accumulation during adipocyte differentiation. Molecular docking analysis exposed the potential interactions between MACK or ONON and target regulatory adipogenic proteins. Furthermore, results from an RT-qPCR analysis disclosed significant upregulation of AMPK by MACK and ONON treatment. In addition, ONON increased SIRT1, PI3K and ACC mRNA expression, while MACK notably downregulated CEBPA, AKT, SREBP1, ACC and ADIPOQ. The protein level of PI3K, C/EBPα, PPARγ and adiponectin was reduced upon MACK treatment in a concentration-dependent manner. Similarly, ONON suppressed PI3K, PPARγ and adiponectin protein abundance. Finally, our study provides evidence that ONON exerts anti-adipogenic effect by upregulation of SIRT1 and inhibition of PI3K, PPARγ and adiponectin, while MACK induced strong inhibitory effect on adipogenesis via hampering PI3K, PPARγ/C/EBPα signaling and anti-lipogenic effect through downregulation of SREBP1 and ACC. Even though OSR does not hamper adipogenic differentiation, it could be exploited as a source of natural leads with anti-adipogenic potential. The multidirectional mechanism of action of MACK warrant further validation in the context of in vivo obesity models.

Maackiain Modulates miR-374a/GADD45A Axis to Inhibit Triple-Negative Breast Cancer Initiation and Progression.

Breast cancer ranks as the leading cause of death in lethal malignancies among women worldwide, with a sharp increase of incidence since 2008. Triple negative breast cancer (TNBC) gives rise to the largest proportion in breast cancer-related deaths because of its aggressive growth and rapid metastasis. Hence, searching for promising targets and innovative approaches is indispensable for the TNBC treatment. Maackiain (MA), a natural compound with multiple biological activities, could be isolated from different Chinese herbs, such as Spatholobus suberectus and Sophora flavescens. It was the first time to report the anti-cancer effect of MA in TNBC. MA could suppress TNBC cell proliferation, foci formation, migration, and invasion. MA also exerted a significant inhibitory effect on tumor growth of TNBC. Furthermore, MA could induce apoptosis with an increase of GADD45α and a decrease of miR-374a. In contrast, overexpressing miR-374a would result in at least partly affecting the proapoptotic effect of MA and suppressing GADD45α stimulated by MA. These results reveal the anti-TNBC effect of MA in vitro and in vivo, providing evidence for its potential as a drug candidate utilized in TNBC therapy.

Screening of active components of Euchresta japonica against nasopharyngeal carcinoma / 中国药房

OBJECTIVE To screen t he active component s of Euchresta japonica against nasopharyngeal carcinoma. METHODS Main chemical components of E. japonica were selected ，and their target proteins were predicted in Swiss Target Prediction database. The target proteins of nasopharyngeal cancer were obtained with GeneCards database. Protein-protein interaction（PPI）network was established after the target of chemical components of E. japonica was intersected with the target of nasopharyngeal carcinoma ；PPI network was analyzed by using Cytoscape 3.6.1 software，and the potential active components and key targets of E. japonica against nasopharyngeal carcinoma were screened. The molecular docking technology was used to evaluate binding ability of active component-key target ；active components of E. japonica against nasopharyngeal carcinoma were screened. The anti-nasopharyngeal cancer effect of potential active components of E. japonica was verified by cell proliferation experiment. RESULTS Seven potential active components （tonkinensisol，quercetin，sophoranone，matrine，genistein，coumarin，maackiain） and 10 core targets （SRC，PIK3CA，MAPK1，MAPK3，AKT1，MAPK8，MAP2K1，PTK2，EGFR，JAK3）of E. japonica against nasopharyngeal carcinoma were screened. The molecular docking results showed that above potential active components all possessed certain anti-nasopharyngeal cancer effect. Cell proliferation activity test showed that tonkinensisol ，sophoranone and maackiain had a very significant inhibitory activity on nasopharyngeal carcinoma cells CNE- 1. CONCLUSIONS Tonkinensisol， sophoranone and maackiain might be the main active components of E. japonica against nasopharyngeal carcinoma.

[Metabolites and metabolic pathways of maackiain in rats based on UPLC-Q-TOF-MS].

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was used to investigate the metabolites of maackiain in rats based on the prediction function of UNIFI data processing system and liver microsomal incubation in vitro. Ten metabolites of maackiain after oral absorption were reasonably deduced and characterized. It was found that the biotransformation of maackiain mainly included phase Ⅰ oxidation, dehydrogenation, phase Ⅱ sulfate conjugation, glucosylation conjugation, and glucuronic acid conjugation. Among them, the product of glucosylation conjugation, trifolirhizin, was identified by comparison with the reference for the first time. Liver microsomal incubation in vitro further confirmed the metabolites and metabolic pathways of maackiain in rats. The metabolites in the blood, urine, and feces complemented each other, which revealed the migration, metabolism, and excretion modes of maackiain in rats. This study lays a foundation for the further investigation of the metabolic mechanism of maackiain in vivo and the in-depth research on the mechanism of pharmacodynamics and toxicity.

Metabolites and metabolic pathways of maackiain in rats based on UPLC-Q-TOF-MS / 中国中药杂志

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was used to investigate the metabolites of maackiain in rats based on the prediction function of UNIFI data processing system and liver microsomal incubation in vitro. Ten metabolites of maackiain after oral absorption were reasonably deduced and characterized. It was found that the biotransformation of maackiain mainly included phase Ⅰ oxidation, dehydrogenation, phase Ⅱ sulfate conjugation, glucosylation conjugation, and glucuronic acid conjugation. Among them, the product of glucosylation conjugation, trifolirhizin, was identified by comparison with the reference for the first time. Liver microsomal incubation in vitro further confirmed the metabolites and metabolic pathways of maackiain in rats. The metabolites in the blood, urine, and feces complemented each other, which revealed the migration, metabolism, and excretion modes of maackiain in rats. This study lays a foundation for the further investigation of the metabolic mechanism of maackiain in vivo and the in-depth research on the mechanism of pharmacodynamics and toxicity.

Maackiain dampens osteoclastogenesis via attenuating RANKL-stimulated NF-κB signalling pathway and NFATc1 activity.

Osteolytic diseases are typified by over-enhanced formation and resorbing function of osteoclasts and have a major impact on human health. Inhibition of osteoclastic differentiation and function is a key strategy for clinical therapy of osteolytic conditions. Maackiain is a natural compound extracted from Sophora flavescens, which has been applied to anti-allergic and anti-tumour treatments. The present results showed that Maackiain could restrain receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclast formation and hydroxyapatite resorption dose-dependently, and interrupt the structures of F-actin belts in the mature osteoclasts. It also repressed the expressions of osteoclast-specific genes and proteins. Furthermore, Maackiain could inhibit RANKL-stimulated NF-κB and calcium signalling pathways, and dampen Nuclear factor of activated T cell cytoplasmic 1 activity, protein expression and translocation into the nucleus. These results revealed that Maackiain may have a potential therapeutic effect on osteoclast-related disorders.

The Synergistic Effect of Co-Treatment of Methyl Jasmonate and Cyclodextrins on Pterocarpan Production in Sophora flavescens Cell Cultures.

Pterocarpans are derivatives of isoflavonoids, found in many species of the family Fabaceae. Sophora flavescens Aiton is a promising traditional Asian medicinal plant. Plant cell suspension cultures represent an excellent source for the production of valuable secondary metabolites. Herein, we found that methyl jasmonate (MJ) elicited the activation of pterocarpan biosynthetic genes in cell suspension cultures of S. flavescens and enhanced the accumulation of pterocarpans, producing mainly trifolirhizin, trifolirhizin malonate, and maackiain. MJ application stimulated the expression of structural genes (PAL, C4H, 4CL, CHS, CHR, CHI, IFS, I3'H, and IFR) of the pterocarpan biosynthetic pathway. In addition, the co-treatment of MJ and methyl-ß-cyclodextrin (MeßCD) as a solubilizer exhibited a synergistic effect on the activation of the pterocarpan biosynthetic genes. The maximum level of total pterocarpan production (37.2 mg/g dry weight (DW)) was obtained on day 17 after the application of 50 µM MJ on cells. We also found that the combined treatment of cells for seven days with MJ and MeßCD synergistically induced the pterocarpan production (trifolirhizin, trifolirhizin malonate, and maackiain) in the cells (58 mg/g DW) and culture medium (222.7 mg/L). Noteworthy, the co-treatment only stimulated the elevated extracellular production of maackiain in the culture medium, indicating its extracellular secretion; however, its glycosides (trifolirhizin and trifolirhizin malonate) were not detected in any significant amounts in the culture medium. This work provides new strategies for the pterocarpan production in plant cell suspension cultures, and shows MeßCD to be an effective solubilizer for the extracellular production of maackiain in the cell cultures of S. flavescens.

Maackiain Ameliorates 6-Hydroxydopamine and SNCA Pathologies by Modulating the PINK1/Parkin Pathway in Models of Parkinson's Disease in Caenorhabditis elegans and the SH-SY5Y Cell Line.

The movement disorder Parkinson's disease (PD) is the second most frequently diagnosed neurodegenerative disease, and is associated with aging, the environment, and genetic factors. The intracellular aggregation of α-synuclein and the loss of dopaminergic neurons in the substantia nigra pars compacta are the pathological hallmark of PD. At present, there is no successful treatment for PD. Maackiain (MK) is a flavonoid extracted from dried roots of Sophora flavescens Aiton. MK has emerged as a novel agent for PD treatment that acts by inhibiting monoamine oxidase B. In this study, we assessed the neuroprotective potential of MK in Caenorhabditis elegans and investigated possible mechanism of this neuroprotection in the human SH-SY5Y cell line. We found that MK significantly reduced dopaminergic neuron damage in 6-hydroxydopamine (6-OHDA)-exposed worms of the BZ555 strain, with corresponding improvements in food-sensing behavior and life-span. In transgenic worms of strain NL5901 treated with 0.25 mM MK, the accumulation of α-synuclein was diminished by 27% (p < 0.01) compared with that in untreated worms. Moreover, in worms and the SH-SY5Y cell line, we confirmed that the mechanism of MK-mediated protection against PD pathology may include blocking apoptosis, enhancing the ubiquitin-proteasome system, and augmenting autophagy by increasing PINK1/parkin expression. The use of small interfering RNA to downregulate parkin expression in vivo and in vitro could reverse the benefits of MK in PD models. MK may have considerable therapeutic applications in PD.

Maackiain, a compound derived from Sophora flavescens, increases IL-1ß production by amplifying nigericin-mediated inflammasome activation.

Sophora flavescens is used as a traditional herbal medicine to modulate inflammatory responses. However, little is known about the impact of (-)-maackiain, a compound derived from S. flavescens, on the activation of inflammasome/caspase-1, a key factor in interleukin-1ß (IL-1ß) processing. Here, we report that (-)-maackiain potently amplified caspase-1 cleavage in macrophages in response to nigericin (Nig). In macrophages primed with either lipopolysaccharide or monophosphoryl lipid A, Nig-mediated caspase-1 cleavage was also markedly promoted by (-)-maackiain. Notably, (-)-maackiain induced the production of vimentin, an essential mediator for the activation of the NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome, thereby contributing to promotion of the formation of the inflammasome complex to activate caspase-1. Taken together, our data suggest that (-)-maackiain exerts an immunostimulatory effect by promoting IL-1ß production via activation of the inflammasome/caspase-1 pathway. Thus, the potent inflammasome-activating effect of (-)-maackiain may be clinically useful as an acute immune-stimulating agent.

Bioactive pterocarpans from Trigonella foenum-graecum L.

Trigonella foenum-graecum L. (fenugreek) is used as a leafy vegetable and spice in China and North African countries. However, the biochemical components of its aerial parts were rarely explored. In this study, the bioactivities of the various extract fractions from the aerial parts of this edible plant were assessed, the ethyl acetate extract fraction exhibited strong antioxidant and anti-inflammatory effects. Through bioassay-guided isolation, one new pterocarpan (1), as well as twelve known pterocarpans (2-13) were obtained, nine of them (5-13) were first reported in the fenugreek, four pterocarpans (9, 11-13) had strong antioxidant activity, eleven pterocarpans (1-3, 5-12) possessed obvious anti-inflammatory activity. This study indicates that pterocarpans are main bioactive components of this edible plant. Apart from its nutritional value as food, the aerial parts of this plant can also be further explored as functional foods or antioxidants in food industry.

Antidiabetic activities of chloroform fraction of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes.

ETHNOPHARMACOLOGICAL RELEVANCE: Anthocleista vogelii Planch is a medicinal plant traditionally used in West Africa for the management and treatment of diabetes mellitus. AIM OF THE STUDY: To determine the antidiabetic activities of chloroform fraction (CF) of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes. MATERIALS AND METHODS: Inhibitory activities of CF against α-amylase and α-glucosidase activities were determined in vitro. Three weeks old rats were fed with high-fat diet for 9 weeks to induce obesity prior to further induction of diabetes using alloxan (150 mg/kg body weight, i.p.). Blood glucose levels and body weight were measured every 7 days throughout the experiment. Glucose tolerance was assessed in normal and CF-treated rats on day 21. Terminal blood samples were collected from sacrificed animals for the measurement of serum insulin levels. Pancreases were excised from treated and untreated animals for histopathological examination. RESULTS: LCMS/MS chromatographic profile of CF via positive and negative modes revealed 13 and 23 compounds respectively. Further analysis revealed quebrachitol (QCT), loganin, sweroside, oleoside 11-methyl ester and ferulic acid, which have been previously reported for their antidiabetic activities, as constituents of CF. CF inhibited activities of α-amylase (IC50 = 51.60 ±â€¯0.92 µg/ml) and α-glucosidase (IC50 = 5.86 ±â€¯0.97 µg/ml) in a dose-dependent manner. Treatment of animals with obesity-diabetes with 100 and 200 mg/kg CF significantly improved glucose tolerance (P < 0.001) and enhanced serum insulin levels (P < 0.05) compared to diabetic control rats. CONCLUSIONS: Antidiabetic activities of CF might be mediated via inhibition of α-amylase and α-glucosidase activities, elevation of serum insulin concentration, and enhancement of insulin and leptin sensitivity in obesity-diabetes rats. This study further substantiates the traditional use of A. vogelii in the management and treatment of diabetes in Africa and encourages further studies to investigate its mechanism of action.

SKI3301, a purified herbal extract from Sophora tonkinensis, inhibited airway inflammation and bronchospasm in allergic asthma animal models in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Sophora tonkinensis (Leguminosae, ST) is a traditional herbal plant in Korea and China. Its roots and rhizomes have been used to dissipate heat, to clear toxic material and to treat acute pharyngolaryngeal infections and sore throats. AIM OF STUDY: In this study, we tried to investigate the anti-inflammatory and anti-asthmatic effects of a purified extract (SKI3301) from Sophora tonkinensis using in vitro enzyme assay models and ovalbumin (OVA)-induced asthma animal models. MATERIALS AND METHODS: The effect of SKI3301 on pro-inflammatory enzymes such as 5-lipoxygenase, phosphodiesterase 3 & 4, and thromboxane synthase was assayed in vitro. BALB/c mice were sensitized with OVA/Alum ip injection and nebulized with OVA to induce airway inflammation. Bronchoalveolar lavage (BAL) fluid was collected and analyzed for leukocytes infiltration and IL-5 production along with lung histopathology. Guinea pigs passively sensitized with anti-OVA antiserum were used to investigate the effect of SKI3301 on bronchospasm in vitro and in vivo. RESULTS: SKI3301 potently inhibited the activities of 5-lipoxygenase, phosphodiesterase 3 & 4, and thromboxane synthase. Orally administered SKI3301 attenuated the total leukocytes and eosinophil infiltration and IL-5 level in BAL fluids. Histopathological changes associated with lung inflammation were also reduced by SKI3301. SKI3301 inhibited OVA-induced contraction of isolated trachea from sensitized guinea pigs. SKI3301 also protected OVA-induced bronchoconstriction in the sensitized guinea pigs. Maackiain, one of 3 major components of SKI3301, was effective in inhibiting 5-lipoxygenase and OVA-induced airway inflammation. CONCLUSION: In this study, SKI3301 potently inhibited pro-inflammatory enzymes and attenuated OVA-induced bronchospasm in animal model of allergic asthma. These results suggest that SKI3301 may have therapeutic potential for allergic asthma.

Potent selective monoamine oxidase B inhibition by maackiain, a pterocarpan from the roots of Sophora flavescens.

Monoamine oxidase (MAO) catalyzes the oxidation of monoamines and its two isoforms, MAO-A and MAO-B, break down neurotransmitter amines. Of the compounds isolated from the roots of Sophora flavescens, (-)-maackiain (4), a pterocarpan, was found to potently and selectively inhibit human MAO-B, with an IC50 of 0.68µM, and to have a selectivity index of 126.2 for MAO-B. As compared with other herbal natural products, the IC50 value of 4 for MAO-B is one of the lowest reported to date. Genistein (1) highly, effectively and non-selectively inhibited MAO-A and MAO-B with IC50 values of 3.9µM and 4.1µM, respectively. (-)-4-Hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (2) effectively and non-selectively inhibited MAO-A and MAO-B with IC50 values of 20.3µM and 10.3µM, respectively. In addition, compound 4 reversibly and competitively inhibited MAO-B with a Ki value of 0.054µM. Molecular docking simulation revealed that the binding affinity of 4 for MAO-B (-26.6kcal/mol) was greater than its affinity for MAO-A (-8.3kcal/mol), which was in-line with our inhibitory activity findings. Furthermore, Cys172 of MAO-B was found to be a key residue for hydrogen bonding with compound 4. The findings of this study suggest compound 4 be viewed as a new potent, selective, and reversible MAO-B inhibitor, and that compounds 1 and 2 be considered useful lead compounds for the developments of nonselective and reversible MAO inhibitors for the treatment of disorders like Parkinson's disease, Alzheimer disease, and depression.

Maackiain is a novel antiallergic compound that suppresses transcriptional upregulation of the histamine H1 receptor and interleukin-4 genes.

Kujin contains antiallergic compounds that inhibit upregulation of histamine H1 receptor (H1R) and interleukin (IL)-4 gene expression. However, the underlying mechanism remains unknown. We sought to identify a Kujin-derived antiallergic compound and investigate its mechanism of action. The H1R and IL-4 mRNA levels were determined by real-time quantitative RT-PCR. To investigate the effects of maackiain in vivo, toluene-2,4-diisocyanate (TDI)-sensitized rats were used as a nasal hypersensitivity animal model. We identified (-)-maackiain as the responsible component. Synthetic maackiain showed stereoselectivity for the suppression of IL-4 gene expression but not for H1R gene expression, suggesting distinct target proteins for transcriptional signaling. (-)-Maackiain inhibited of PKCδ translocation to the Golgi and phosphorylation of Tyr(311) on PKCδ, which led to the suppression of H1R gene transcription. However, (-)-maackiain did not show any antioxidant activity or inhibition of PKCδ enzymatic activity per se. Pretreatment with maackiain alleviated nasal symptoms and suppressed TDI-induced upregulations of H1R and IL-4 gene expressions in TDI-sensitized rats. These data suggest that (-)-maackiain is a novel antiallergic compound that alleviates nasal symptoms in TDI-sensitized allergy model rats through the inhibition of H1R and IL-4 gene expression. The molecular mechanism underlying its suppressive effect for H1R gene expression is mediated by the inhibition of PKCδ activation.