Inhibition of epidermal growth factor receptor signaling by Saussurea involucrata, a rare traditional Chinese medicinal herb, in human hormone-resistant prostate cancer PC-3 cells

Integration of bioassay and non-target metabolite analysis of tomato reveals that β-carotene and lycopene activate the adiponectin signaling pathway, including AMPK phosphorylation

Adiponectin, an adipokine, regulates glucose metabolism and insulin sensitivity through the adiponectin receptor (AdipoR). In this study, we searched for metabolites that activate the adiponectin signaling pathway from tomato (Solanum lycopersicu). Metabolites of mature tomato were separated into 55 fractions by liquid chromatography, and then each fraction was examined using the phosphorylation assay of AMP-protein kinase (AMPK) in C2C12 myotubes and in AdipoR-knockdown cells by small interfering RNA (siRNA). Several fractions showed AMPK phosphorylation in C2C12 myotubes and siRNA-mediated abrogation of the effect. Non-targeted metabolite analysis revealed the presence of 721 diverse metabolites in tomato. By integrating the activity of fractions on AMPK phosphorylation and the 721 metabolites based on their retention times of liquid chromatography, we performed a comprehensive screen for metabolites that possess adiponectin-like activity. As the screening suggested that the active fractions contained four carotenoids, we further analyzed β-carotene and lycopene, the major carotenoids of food. They induced AMPK phosphorylation via the AdipoR, Ca²⁺/calmodulin-dependent protein kinase kinase and Ca²⁺ influx, in addition to activating glucose uptake via AdipoR in C2C12 myotubes. All these events were characteristic adiponectin actions. These results indicated that the food-derived carotenoids, β-carotene and lycopene, activate the adiponectin signaling pathway, including AMPK phosphorylation.

Component Identification of Phenolic Acids in Cell Suspension Cultures of Saussureainvolucrata and Its Mechanism of Anti-Hepatoma Revealed by TMT Quantitative Proteomics

Saussurea involucrata (S. involucrata) had been reported to have anti-hepatoma function. However, the mechanism is complex and unclear. To evaluate the anti-hepatoma mechanism of S. involucrata comprehensively and make a theoretical basis for the mechanical verification of later research, we carried out this work. In this study, the total phenolic acids from S. involucrata determined by a cell suspension culture (ESPI) was mainly composed of 4,5-dicaffeoylquinic acid, according to the LC-MS analysis. BALB/c nude female mice were injected with HepG2 cells to establish an animal model of liver tumor before being divided into a control group, a low-dose group, a middle-dose group, a high-dose group, and a DDP group. Subsequently, EPSI was used as the intervention drug for mice. Biochemical indicators and differences in protein expression determined by TMT quantitative proteomics were used to resolve the mechanism after the low- (100 mg/kg), middle- (200 mg/kg), and high-dose (400 mg/kg) interventions for 24 days. The results showed that EPSI can not only limit the growth of HepG2 cells in vitro, but also can inhibit liver tumors significantly with no toxicity at high doses in vivo. Proteomics analysis revealed that the upregulated differentially expressed proteins (DE proteins) in the high-dose group were over three times that in the control group. ESPI affected the pathways significantly associated with the protein metabolic process, metabolic process, catalytic activity, hydrolase activity, proteolysis, endopeptidase activity, serine-type endopeptidase activity, etc. The treatment group showed significant differences in the pathways associated with the renin-angiotensin system, hematopoietic cell lineage, etc. In conclusion, ESPI has a significant anti-hepatoma effect and the potential mechanism was revealed.

Prostate cancer: Therapeutic prospect with herbal medicine

Prostate cancer (PCa) is a major cause of morbidity and mortality in men worldwide. A geographic variation on the burden of the disease suggested that the environment, genetic makeup, lifestyle, and food habits modulate one's susceptibility to the disease. Although it has been generally thought to be an older age disease, and awareness and timely execution of screening programs have managed to contain the disease in the older population over the last decades, the incidence is still increasing in the population younger than 50. Existing treatment is efficient for PCa that is localized and responsive to androgen. However, the androgen resistant and metastatic PCa are challenging to treat. Conventional radiation and chemotherapies are associated with severe side effects in addition to being exorbitantly expensive. Many isolated phytochemicals and extracts of plants used in traditional medicine are known for their safety and diverse healing properties, including many with varying levels of anti-PCa activities. Many of the phytochemicals discussed here, as shown by many laboratories, inhibit tumor cell growth and proliferation by interfering with the components in the pathways responsible for the enhanced proliferation, metabolism, angiogenesis, invasion, and metastasis in the prostate cells while upregulating the mechanisms of cell death and cell cycle arrest. Notably, many of these agents simultaneously target multiple cellular pathways. We analyzed the available literature and provided an update on this issue in this review article.

Toxicological evaluation of S. involucrata culture: Acute, 90-day subchronic and genotoxicity studies

Saussurea involucrata is an endangered plant that is used in traditional Chinese medicine. Through the use of plant cell culture techniques, preparations of Saussurea involucrata (S. involucrata) cell cultures have been developed and used to generate medicinal preparations. There have been few evidence-based analyses of the toxicological effects of S. involucrata culture conducted to date. Here, we conducted the experiments designed to assess the acute, subchronic, and genotoxic toxicological effects of S. involucrata culture. The genotoxic study was assessed through Ames, marrow micronucleus, and sperm malformation assays. The acute toxicity was assessed by orally administering in rats and mice at dose of 7500 mg/kg. Subchronic toxicity studies were then conducted by administering rats at doses of 500, 1000, or 1500 mg/kg for 90 days. No genotoxicity was observed at any tested dose levels, nor was any evidence of acute toxicity detected in treated mice or rats. Similarly, subchronic study of S. involucrata culture administration was not associated with any changes in rat food intake, weight, hematological parameters, organ weight, or organ histology. Then, we determined that the no observed adverse effect level of S. involucrata culture was greater than 1500 mg/kg in our 90-day toxicity study.

Chemical Fingerprint Analysis for Discovering Markers and Identifying Saussurea involucrata by HPLC Coupled with OPLS-DA

The quality control of Saussurea involucrata has been greatly improved by macroscopic and microscopic identification and chemical profiling described in Chinese Pharmacopoeia since 2005. However, these methods have their own limitations, e.g., their dependence on personal experience and expertise, and it is a huge challenge to identify closely related species that share similar or identical morphological characteristics and chemical profiles. A novel and generally accepted identification strategy is urgently needed as a complement to regulations for protecting the public health interests. In this work, a comprehensive chromatographic fingerprint method was developed and tested on 43 samples from four haplotypes of S. involucrata according to DNA barcoding. Three common patterns consisting of 20, 14, and 7 common peaks were generated by frequency filters of median, upper quartile, and 100%, respectively. Based on two formerly screened patterns, S. involucrata can be effectively identified from its five easily confused snow lotus species, including the most closely related plant (S. orgaadayi) in the orthogonal partial least-squares discriminant analysis (OPLS-DA) models. The model is supported by good R and Q coefficients. In addition, different haplotypes of S. involucrata can be discriminated in the OPLS-DA model using the 20 common peaks. Among them, peaks 9, 11, 16 (zaluzanin C), and 18 (dehydrocostus lactone) have been identified as fingerprint markers of S. involucrata via S-plots and VIP values (>1). Additionally, peaks 19 and 20 were identified as linolenic acid and linoleic acid with anti-inflammatory activity, and they were isolated from the herb for the first time. Collectively, the chromatographic fingerprint of S. involucrata can be an effective and integrated method for the identification of authentic herbs from adulterant species or related plants, and discrimination of its different haplotypes provides an objective and reliable tool for quality control.

Cannabinoids and Prostate Cancer: A Systematic Review of Animal Studies

Prostate cancer is a major cause of death among men worldwide. Recent preclinical evidence implicates cannabinoids as powerful regulators of cell growth and differentiation, as well as potential anti-cancer agents. The aim of this review was to evaluate the effect of cannabinoids on in vivo prostate cancer models. The databases searched included PubMed, Embase, Scopus, and Web of Science from inception to August 2020. Articles reporting on the effect of cannabinoids on prostate cancer were deemed eligible. We identified six studies that were all found to be based on in vivo/xenograft animal models. Results: In PC3 and DU145 xenografts, WIN55,212-2 reduced cell proliferation in a dose-dependent manner. Furthermore, in LNCaP xenografts, WIN55,212-2 reduced cell proliferation by 66-69%. PM49, which is a synthetic cannabinoid quinone, was also found to result in a significant inhibition of tumor growth of up to 90% in xenograft models of LNCaP and 40% in xenograft models of PC3 cells, respectively. All studies have reported that the treatment of prostate cancers in in vivo/xenograft models with various cannabinoids decreased the size of the tumor, the outcomes of which depended on the dose and length of treatment. Within the limitation of these identified studies, cannabinoids were shown to reduce the size of prostate cancer tumors in animal models. However, further well-designed and controlled animal studies are warranted to confirm these findings.

Saussureae Involucratae Herba (Snow Lotus): Review of Chemical Compositions and Pharmacological Properties

Saussureae Involucratae Herba is the dried ground part of Saussurea involucrata (Kar. et Kir.) Sch.-Bip, which is also named as “Snow lotus” and being used in traditional Uyghur and/or Chinese medicine. This rare herb can be found at 4,000 m elevation in western part of Tianshan Mountain, Xinjiang China. According to China Pharmacopoeia (2015), the major pharmaceutical values of “Snow lotus” (Xuě liánhuā in Chinese) are alleviating rheumatoid arthritis, accelerating blood circulation and mitigating other “cold” syndromes. Traditionally, the clinical application of “Snow lotus” includes the treatments in inflammation-associated disorder, blood circulation acceleration and heat and dampness elimination. Recent studies suggested that “Snow lotus” possessed therapeutic effects associating with anti-cancer, anti-oxidation, adipogenesis suppression and neuroprotection activities, which were proposed to be related with its bioactive constitutes, i.e. acacetin, hispidulin, and rutin. In the present review, we aim to summarize pharmacological effects and underlying cell signaling pathways of “Snow lotus” in treating various medical problems.

New Saussurea (Asteraceae) species from Bogeda Mountain, eastern Tianshan, China, and inference of its evolutionary history and medical usage

In this study, Saussurea bogedaensis Yu-J. Wang & Jie Chen, a new species from Bogeda Mountain in the eastern part of the Tianshan Mountains, is described and discussed based on evidence in terms of both morphological and genetic data. S. bogedaensis is morphologically similar to S. involucrata, which is distributed in the western part of the Tianshan Mountains, and it is well known because of its beauty, rarity, and medicinal value. The new species is also similar to S. orgaadayi, which is distributed in the nearby Altai Mountains. Our genetic data support the close relationships among these three species. According to their allopathic distributions, we suggest that these three species are derived from the same ancestor but that they differentiated after reaching their current range. In addition, we propose that the new species might serve as an alternative to S. involucrata in medicine due to their very high similarity. However, this species appears to be rare because we only found six mature individuals in the field despite extensive investigations.

Hispidulin mediates apoptosis in human renal cell carcinoma by inducing ceramide accumulation

Hispidulin, a polyphenolic flavonoid extracted from the traditional Chinese medicinal plant S involucrata, exhibits anti-tumor effects in a wide array of human cancer cells, mainly through growth inhibition, apoptosis induction and cell cycle arrest. However, its precise anticancer mechanisms remain unclear. In this study, we investigated the molecular mechanisms that contribute to hispidulin-induced apoptosis of human clear-cell renal cell carcinoma (ccRCC) lines Caki-2 and ACHN. Hispidulin (10, 20 μmol/L) decreased the viability of ccRCC cells in dose- and time-dependent manners without affecting that of normal tubular epithelial cells. Moreover, hispidulin treatment dose-dependently increased the levels of cleaved caspase-8 and caspase-9, but the inhibitors of caspase-8 and caspase-9 only partly abrogated hispidulin-induced apoptosis, suggesting that hispidulin triggered apoptosis via both extrinsic and intrinsic pathways. Moreover, hispidulin treatment significantly inhibited the activity of sphingosine kinase 1 (SphK1) and consequently promoted ceramide accumulation, thus leading to apoptosis of the cancer cells, whereas pretreatment with K6PC-5, an activator of SphK1, or overexpression of SphK1 significantly attenuated the anti-proliferative and pro-apoptotic effects of hispidulin. In addition, hispidulin treatment dose-dependently activated ROS/JNK signaling and led to cell apoptosis. We further demonstrated in Caki-2 xenograft nude mice that injection of hispidulin (20, 40 mg·kg^-1·d^-1, ip) dose-dependently suppressed tumor growth accompanied by decreased SphK1 activity and increased ceramide accumulation in tumor tissues. Our findings reveal a new explanation for the anti-tumor mechanisms of hispidulin, and suggest that SphK1 and ceramide may serve as potential therapeutic targets for the treatment of ccRCC.

New Role of Hispidulin in Lipid Metabolism: PPARα Activator

Hispidulin is a naturally occurring flavonoid isolated from a traditional Chinese medicinal herb, Saussurea involucrata. In this study, the regulating role of hispidulin on the mRNA expression level of enzymes involved in lipid metabolism was examined in vitro and in vivo. Moreover, the in vivo lipid-modulating effect of hispidulin was compared with that of fenofibrate, a classical PPARα agonist. Our results in present study demonstrated that hispidulin can directly bind to and activate PPARα as an agonist and thus modulate the downstream lipid-metabolizing genes. Moreover, hispidulin could attenuate dyslipidemia in high fat diet induced dyslipidemia rat model. Although further studies are needed, this study provided evidence for the potential use of hispidulin in dyslipidemia management.

In vitro culture and production of syringin and rutin in Saussurea involucrata (Kar. et Kir.) - an endangered medicinal plant

BACKGROUND

Saussurea involucrata (Kar. et Kir.) commonly known as 'snow lotus' or 'Xue Lian' is an important plant in the traditional Chinese system of medicine. The plant contains flavonoids such as syringin and rutin. These compounds have been reported to be anti-rheumatic, anti-inflammatory and dilate blood vessels, lower blood pressure, prevent cardiovascular diseases, enhance immunity, and act as anti-aging, anti-cancer, and anti-fatigue agents. The species has become endangered due to the excessive collection of S. involucrata plants in the wild, slower plant growth and ecological destruction of natural habitats. There is a severe shortage of plant material, while the market demand is ever increasing. Hence, it is very important to apply tissue culture technique for plant propagation and production of the bioactive compounds of this species.

RESULTS

Multiple shoot induction and proliferation in shoot base explants derived from in vitro raised seedlings of S. involucrata was achieved on 3/4 strength of Murashige and Skoog's (MS) basal medium (MSBM) supplemented with 1.0 mg/L-1 BA and 1.5 mg/L-1 NAA. Rooting was induced in 100 % shoots cultured on 1/2X MSBM supplemented with 1.0 mg/L-1 IBA for one week and then transfer to auxin free medium. The plantlets could be acclimatized successfully by sachet technique and established in the greenhouse. Maximum callus induction and proliferation in leaf segments was achieved on 1/2X MSBM supplemented with 0.5 mg/L-1 BA, 0.5 mg/L-1 NAA, 0.4 % gelrite and on incubation at 20 °C. Container closures had an influence on the quality and quantity of callus and production of the active compounds. The HPLC analysis showed much higher syringin content in in vitro shoots and callus as compared to commercially available market crude drug.

CONCLUSION

The present study describes an in vitro culture protocol of Saussurea involucrata. The bioactive compounds, syringin and rutin could be produced through tissue culture technique without sacrificing the endangered Saussurea involucrata plants in the wild.

Saussurea involucrata: A review of the botany, phytochemistry and ethnopharmacology of a rare traditional herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Saussurea involucrata Matsum. & Koidz. is an endangered species of the Asteraceae family, growing in the high mountains of central Asia. It has been, and is, widely used in traditional Uyghur, Mongolian and Kazakhstan medicine as well as in Traditional Chinese Medicine as Tianshan Snow Lotus (Chinese: ). In traditional medical theory, S. involucrata can promote blood circulation, thereby alleviating all symptoms associated with poor circulation. It also reputedly eliminates cold and dampness from the body, diminishes inflammation, invigorates, and strengthens Yin and Yang. It has long been used to treat rheumatoid arthritis, cough with cold, stomach ache, dysmenorrhea, and altitude sickness in Uyghur and Chinese medicine.

AIM OF THE REVIEW

To comprehensively summarize the miscellaneous research that has been done regarding the botany, ethnopharmacology, phytochemistry, biological activity, and toxicology of S. involucrata.

METHOD

An extensive review of the literature was carried out. Apart from different electronic databases including SciFinder, Chinese National Knowledge Infrastructure (CNKI), ScienceDirect that were sourced for information, abstracts, full-text articles and books written in English and Chinese, including those traditional records tracing back to the Qing Dynasty. Pharmacopoeia of China and other local herbal records in Uighur, Mongolian and Kazakhstan ethnomedicines were investigated and compared for pertinent information.

RESULTS

The phytochemistry of S. involucrata has been comprehensively investigated. More than 70 compounds have been isolated and identified; they include phenylpropanoids, flavonoids, coumarins, lignans, sesquiterpenes, steroids, ceramides, polysaccharides. Scientific studies on the biological activity of S. involucrata are equally numerous. The herb has been shown to have anti-neoplastic, anti-inflammatory, analgesic, anti-oxidative, anti-fatigue, anti-aging, anti-hypoxic, neuroprotective and immunomodulating effects. Many have shown correlations to the traditional clinical applications in Traditional Chinese Medicine and medicines. The possible mechanisms of S. involucrata in treating various cancers are revealed in the article, these include inhibition of cancer cells by affecting their growth, adhesion, migration, aggregation and invasion, inhibition of epidermal growth factor receptor signaling in cancer cells, hindrance of cancer cell proliferation, causing cytotoxicity to cancer cells and promoting expression of tumor suppressor genes. Dosage efficacy is found to be generally concentration- and time-dependent. However, studies on the correlation between particular chemical constituents and specific bioactivities are limited.

CONCLUSION

In this review, we have documented the existing traditional uses of S. involucrata and summarized recent research into the phytochemistry and pharmacology of S. involucrata. Many of the traditional uses have been validated by phytochemical and modern pharmacological studies but there are still some areas where the current knowledge could be improved. Although studies have confirmed that S. involucrata has a broad range of bioactivities, further in-depth studies on the exact bioactive molecules and the mechanism of action are expected. Whether we should use this herb independently or in combination deserves to be clarified. The exact quality control as well as the toxicology studies is necessary to guarantee the stability and safety of the clinic use. The sustainable use of this endangered resource was also addressed. In conclusion, this review was anticipated to highlight the importance of S. involucrata and provides some directions for the future development of this plant.

Protective effect of hispidulin on kainic acid-induced seizures and neurotoxicity in rats

Hispidulin is a flavonoid compound which is an active ingredient in a number of traditional Chinese medicinal herbs, and it has been reported to inhibit glutamate release. The purpose of this study was to investigate whether hispidulin protects against seizures induced by kainic acid, a glutamate analog with excitotoxic properties. The results indicated that intraperitoneally administering hispidulin (10 or 50mg/kg) to rats 30 min before intraperitoneally injecting kainic acid (15 mg/kg) increased seizure latency and decreased seizure score. In addition, hispidulin substantially attenuated kainic acid-induced hippocampal neuronal cell death, and this protective effect was accompanied by the suppression of microglial activation and the production of proinflammatory cytokines such as interleukin-1β, interleukin-6, and tumor necrosis factor-α in the hippocampus. Moreover, hispidulin reduced kainic acid-induced c-Fos expression and the activation of mitogen-activated protein kinases in the hippocampus. These data suggest that hispidulin has considerable antiepileptic, neuroprotective, and antiinflammatory effects on kainic acid-induced seizures in rats.

Hispidulin induces apoptosis through mitochondrial dysfunction and inhibition of P13k/Akt signalling pathway in HepG2 cancer cells

Hispidulin is a flavonoid compound which is an active ingredient in a number of traditional Chinese medicinal herbs. However, it's therapeutic activity remains poorly understood. The present study investigated the pro-apoptotic effects and mechanism by which Hispidulin induces apoptosis in human hepatoblastoma cancer (HepG2) cells. The results showed that Hispidulin induced cell death in a dose- and time-dependent manner in HepG2 cells whereas no toxic reaction was observed in normal human liver cells at indicated concentration. This study also demonstrated that Hispidulin induces apoptosis through mitochondrial dysfunction, which is characterized by decreased Bcl-2/Bax ratio, disrupted mitochondrial membrane potential and increased release of cytochrome C and activated capase-3. Our results also showed that mitochondrial dysfunction was triggered by Hispidulin-induced excessive ROS generation. Hispidulin also significantly inhibited Akt activation. ROS inhibitor NAC abrogated the inhibitory effect of Hispidulin on P13k/Akt signalling pathway and the proapoptotic effect in HepG2 cells. Our results demonstrate for the first time that Hispidulin induces apoptosis in HepG2 cells and suggested that the pro-apoptotic effect of Hispidulin was mediated through mitochondrial dysfunction and inhibition of P13k/Akt signalling pathway. Since no toxic effect was observed when normal liver cells were treated with Hispidulin, Hispidulin may have the potential to be used as therapeutic for liver cancer.

Small molecule adenosine 5'-monophosphate activated protein kinase (AMPK) modulators and human diseases

Adenosine 5'-monophosphate activated protein kinase (AMPK) is a master sensor of cellular energy status that plays a key role in the regulation of whole-body energy homeostasis. AMPK is a serine/threonine kinase that is activated by upstream kinases LKB1, CaMKKβ, and Tak1, among others. AMPK exists as αβγ trimeric complexes that are allosterically regulated by AMP, ADP, and ATP. Dysregulation of AMPK has been implicated in a number of metabolic diseases including type 2 diabetes mellitus and obesity. Recent studies have associated roles of AMPK with the development of cancer and neurological disorders, making it a potential therapeutic target to treat human diseases. This review focuses on the structure and function of AMPK, its role in human diseases, and its direct substrates and provides a brief synopsis of key AMPK modulators and their relevance in human diseases.

Atherosclerosis and tumor suppressor molecules (review)

Atherosclerosis, the major cause of heart attack and stroke, is a chronic inflammatory disease characterized by the formation of atherosclerotic plaque. Oxidized low-density lipoprotein through increased oxidative stress has been identified as one of the primary factors responsible for atherogenesis. Cell proliferation and death are key processes in the progression of atherosclerosis. The oxidative environment in areas of lipid accumulation is mainly created by the production of reactive oxygen species, which are assumed to mediate vascular tissue injury. Oxidative DNA damage and levels of DNA repair are reduced during dietary lipid lowering. The tumor suppressor molecules play a pivotal role in regulating cell proliferation, DNA repair and cell death, which are important processes in regulating the composition of atherosclerotic plaque. Accordingly, in this review, we discuss the fundamental role of tumor suppressor molecules in regulating atherogenesis. In particular, we discuss how tumor suppressor molecules are activated in the complex environment of atherosclerotic plaque, and regulate growth arrest, cell senescence and the apoptosis of vascular smooth muscle cells, which may protect against the progression of atherosclerosis. In addition, we discuss promising alternatives to the use of medications (such as statin) against atherosclerosis, namely diet, with the use of plant-derived supplements to modulate the expression and/or activity of tumor suppressor molecules. We also summarize the progress of research made on herbs with a focus on the modulatory roles of tumor suppressors, and on the molecular mechanisms underlying the prevention if atherosclerosis, supporting designs for further research in this field.

Antifatigue and Antioxidant Activity of Alcoholic Extract from Saussurea involucrata

Fatigue is a noticeable and highly prevalent symptom in tense, industriously, and economically affluent modern society. Therefore, new antifatigue agents to smooth the fatigue feature are an energetic topic. The total ethanol extract (ESI) of Saussurea involucrata Kar et Kir., known as Tian-Shan snow lotus, was evaluated for antifatigue activity in ICR mice with mice forced swimming test and the determination of the contents of blood lactic acid and serum urea nitrogen. ESI (0.05, 0.15, 0.25 g/kg) was administered orally to mice for 4 weeks. The average swimming times to exhaustion of the ESI-treated ICR mice (0.15, 0.25 g/kg) were prolonged by 132% and 180% (p<0.001) with a lessening of fatigue compared with that of the control group. Analysis of biochemical parameters showed that levels of serum urea nitrogen and blood lactic acid of experimental groups were also decreased significantly (p<0.001) compared with that of the control group. The antioxidant activity of ESI was investigated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay and the hydrogen peroxide-induced luminol chemiluminescence assay and the results indicated that ESI exerts DPPH scavenging ability and reducing power. These results provide scientific evidence that S. involucrata may have been potential as an antifatigue agent.

3,4-Dihydroxytoluene, a metabolite of rutin, inhibits inflammatory responses in lipopolysaccharide-activated macrophages by reducing the activation of NF-κB signaling

BACKGROUND

Saussurea involucrata (Kar. et Kir.) (S. involucrate), is a rare traditional Chinese medicinal herb. Rutin and hispidulin as well as their metabolites are flavonoids of the flavonol type that abound in S. involucrata, which has been reported to inhibit nonoxidative advanced glycation end products which was involved in physiological inflammation. This study aims to investigate the role of 3,4-dihydroxytoluene (DHT), a metabolite of rutin, in inflammatory inhibition and its involved mechanism.

METHODS

This study utilized lipopolysaccharide (LPS) stimulated murine macrophage cell line RAW 264.7 as inflammatory model. The inhibitory effects of DHT were evaluated by the expression level of several inflammation markers such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW264.7 after LPS treatment. In addition, underlying mechanisms, the activation of mitogen-activated protein kinases (MAPKs) and NF-κB, were also investigated.

RESULTS

Our results showed that DHT significantly suppressed the LPS-induced production of nitric oxide (NO), iNOS, and COX-2 in a dose-dependent manner without cytotoxicity. DHT also reduced the generation of proinflammatory cytokines majorly in tumor necrosis factor (TNF)-α and minor in interleukin (IL)-1β and IL-6. In addition, LPS-stimulated I-κBα phosphorylation and degradation followed by translocation of the nuclear factor κB (NF-kB)-p65 from the cytoplasm to the nucleus were attenuated after DHT treatment.

CONCLUSIONS

Combined, the results suggest that DHT might exert anti-inflammatory effects in vitro in LPS stimulated RAW 264.7 macrophages and is potential in adjuvant treatment in inflammation disease.

3,4-Dihydroxytoluene, a metabolite of rutin, inhibits inflammatory responses in lipopolysaccharide-activated macrophages by reducing the activation of NF-κB signaling

Background

Saussurea involucrata (Kar. et Kir.) (S. involucrate), is a rare traditional Chinese medicinal herb. Rutin and hispidulin as well as their metabolites are flavonoids of the flavonol type that abound in S. involucrata, which has been reported to inhibit nonoxidative advanced glycation end products which was involved in physiological inflammation. This study aims to investigate the role of 3,4-dihydroxytoluene (DHT), a metabolite of rutin, in inflammatory inhibition and its involved mechanism.

Methods

This study utilized lipopolysaccharide (LPS) stimulated murine macrophage cell line RAW 264.7 as inflammatory model. The inhibitory effects of DHT were evaluated by the expression level of several inflammation markers such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW264.7 after LPS treatment. In addition, underlying mechanisms, the activation of mitogen-activated protein kinases (MAPKs) and NF-κB, were also investigated.

Results

Our results showed that DHT significantly suppressed the LPS-induced production of nitric oxide (NO), iNOS, and COX-2 in a dose-dependent manner without cytotoxicity. DHT also reduced the generation of proinflammatory cytokines majorly in tumor necrosis factor (TNF)-α and minor in interleukin (IL)-1β and IL-6. In addition, LPS-stimulated I-κBα phosphorylation and degradation followed by translocation of the nuclear factor κB (NF-kB)-p65 from the cytoplasm to the nucleus were attenuated after DHT treatment.

Conclusions

Combined, the results suggest that DHT might exert anti-inflammatory effects in vitro in LPS stimulated RAW 264.7 macrophages and is potential in adjuvant treatment in inflammation disease.

Rutin, a flavonoid and principal component of saussurea involucrata, attenuates physical fatigue in a forced swimming mouse model

This study investigated the antifatigue effects of rutin, a flavonoid extracted from the ethyl acetate extract of S. involucrata. Mice were subjected to a weight-loaded forced swim test (WFST) on alternate days for 3 wk. Rutin was administered orally to the mice for 7 days in dosages of 15, 30, and 60 mg/kg body weight, and several biomarkers of physical fatigue were evaluated: swimming time, change in body weight, lipid peroxidation, lactic acid (LA), glycogen, and the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx). On Day 7, the rutin-treated mice had a 3-fold longer exhaustive swimming time than the control mice, as well as significantly reduced blood LA concentrations. The 15, 30, and 60 mg/kg body weight rutin-supplemented groups displayed 11.2%, 22.5%, and 37.7% reduced malondialdehyde (MDA) concentrations, respectively, in brain and muscle tissues compared with the control exercised group. Our results indicated that the administration of rutin protected the mice against the depletion of SOD and GPx activities significantly. Following 7 days of rutin treatment, we sacrificed the mice and analyzed their soleus muscle and brain for peroxisome proliferator-activated receptor-α coactivator (PGC-1α) and sirtuin 1 (SIRT1) mRNA expression. We observed that rutin treatment increased PGC-1α and SIRT1 mRNA and protein expression. The changes in these markers of mitochondrial biogenesis were associated with increased maximal endurance capacity. The application of 2D gel electrophoresis to analyze the rutin-responsive protein profiles in the WFST mouse brain further revealed the upregulation of the CB1 cannabinoid receptor-interacting protein 1, myelin basic protein, Rho GDP dissociation inhibitor (GDI) alpha, and TPI, indicating that rutin might inhibit anxiety through the upregulation of the expression of anxiety-associated proteins. Western blot analysis of MAPK expression further confirmed the antianxiety effects of rutin. Our study results thus indicate that rutin treatment ameliorates the various impairments associated with physical fatigue.

Chemical constituents and anticancer activity of Curcuma zedoaria roscoe essential oil against non-small cell lung carcinoma cells in vitro and in vivo

In this study, we report that the essential oil obtained from Curcuma zedoaria Roscoe, known as zedoary, possesses efficient cytotoxic effects on non-small cell lung carcinoma (NSCLC) cells and causes cell apoptosis. Zedoary essential oil increased the sub-G1 population and the level of annexin-V binding and induced cleavage and activation of caspase-3, -8, and -9 and poly(ADP ribose) polymerase. Decreases in the levels of Bcl-2 and Bcl-xL and an increase in the Bax/Bcl-2 ratio were also observed following zedoary essential oil treatment. Notably, zedoary essential oil led to the release of AIF, endonuclease G, and cytochrome c into the cytosol and increased levels of p53 in H1299 cells. Our results indicate that zedoary essential oil slightly inhibited the phosphorylation of ERK1/2 and enhanced the phosphorylation of JNK1/2 and p38. Zedoary essential oil also inhibited AKT/NF-κB signaling pathways in H1299 cells. Moreover, intraperitoneal administration of zedoary essential oil significantly suppressed the growth of H1299 cells in vivo. In addition, potential active compounds were detected using gas chromatography and mass spectrometry. 8,9-Dehydro-9-formyl-cycloisolongifolene, 6-ethenyl-4,5,6,7-tetrahydro-3,6-dimethyl-5-isopropenyl-trans-benzofuran, eucalyptol, and γ-elemene were found in zedoary essential oil. In summary, our findings provide insight into the molecular mechanisms underlying zedoary essential oil-induced apoptosis in NSCLC cells that are worthy of further study.

Potential Therapeutic Role of Hispidulin in Gastric Cancer through Induction of Apoptosis via NAG-1 Signaling

Gastric cancer is one of the most common malignant cancers due to poor prognoses and high mortality rates worldwide. However, an effective chemotherapeutic drug without side effects remains lacking. Saussurea involucrata (SI) Kar. et Kir., also known as snow lotus, grows in mountainous rocky habitats at 2600 m elevation in the Tian Shan and A'er Tai regions of China. The ethyl acetate extract of SI had been shown to inhibit proliferation and induce apoptosis in various tumor cells. In this study, we demonstrated that Hispidulin, active ingredients in SI, inhibits the growth of AGS gastric cancer cells. After Hispidulin treatment, NAG-1 remained highly expressed, whereas COX-2 expression was downregulated. Flow cytometric analysis indicated that Hispidulin induces G1/S phase arrest and apoptosis in time- and concentration-dependent manners. G1/S arrest correlated with upregulated p21/WAF1 and p16 and downregulated cyclin D1 and cyclin E, independent of p53 pathway. In addition, Hispidulin can elevate Egr-1 expression and ERK1/2 activity, whereas ERK1/2 inhibitor markedly attenuated NAG-1 mediated apoptosis. Taken together, Hispidulin can efficiently activate ERK1/2 signaling followed by NAG-1 constitutive expression and trigger cell cycle arrest as well as apoptosis in cancer cell. It can be a potential compound for combination therapy of gastric cancer in the future.

Metabolic engineering of the phenylpropanoid pathway enhances the antioxidant capacity of Saussurea involucrata

The rare wild species of snow lotus Saussurea involucrata is a commonly used medicinal herb with great pharmacological value for human health, resulting from its uniquely high level of phenylpropanoid compound production. To gain information on the phenylpropanid biosynthetic pathway genes in this critically important medicinal plant, global transcriptome sequencing was performed. It revealed that the phenylpropanoid pathway genes were well represented in S. involucrata. In addition, we introduced two key phenylpropanoid pathway inducing transcription factors (PAP1 and Lc) into this medicinal plant. Transgenic S. involucrata co-expressing PAP1 and Lc exhibited purple pigments due to a massive accumulation of anthocyanins. The over-expression of PAP1 and Lc largely activated most of the phenylpropanoid pathway genes, and increased accumulation of several phenylpropanoid compounds significantly, including chlorogenic acid, syringin, cyanrine and rutin. Both ABTS (2,2′-azinobis-3-ethylbenzotiazo-line-6-sulfonic acid) and FRAP (ferric reducing anti-oxidant power) assays revealed that the antioxidant capacity of transgenic S. involucrata lines was greatly enhanced over controls. In addition to providing a deeper understanding of the molecular basis of phenylpropanoid metabolism, our results potentially enable an alternation of bioactive compound production in S. involucrata through metabolic engineering.

CLC604 preferentially inhibits the growth of HER2-overexpressing cancer cells and sensitizes these cells to the inhibitory effect of Taxol in vitro and in vivo

HER2 has become a solicitous therapeutic target in metastatic and clinical drug-resistant cancer. Here, we evaluated whether or not 1-benzyl-3-(5-hydroxymethyl-2-furyl)indazole (YC-1) and its furopyrazole and thienopyrazole analogues repress the expression of the HER2 protein. Among the test compounds, (1-benzyl-3-(p-hydroxymethylphenyl)-5-methylfuro[3,2-c]pyrazol) (CLC604), an isosteric analogue of YC-1, significantly suppressed the expression of HER2, and preferentially inhibited cell proliferation and induced apoptosis in HER2-overexpressing cancer cells. Our results revealed that CLC604 reduced HER2 expression through a post-transcriptional mechanism and involvement of proteasomal activity. CLC604 disrupted the association of 90-kDa heat shock protein (Hsp90) with HER2 resulting from the inhibition of Hsp90 ATPase activity. Moreover, we found that CLC604 significantly enhanced the antitumor efficacy of clinical drugs against HER2-overexpressing tumors and efficiently reduced HER2-induced drug resistance in vitro and in vivo. These findings suggest that CLC604 should be developed further as a novel antitumor drug candidate for the treatment of drug-resistant cancer.

Protection against Cancer with Medicinal Herbs via Activation of Tumor Suppressor

Cancer remains a major cause of death, although research is ongoing for the development of more effective drugs. Some herbs have shown potential in preventing the occurrence and/or progression of cancer and other chronic diseases. They are being screened comprehensively to explore the possibility of development of feasible anticancer drugs. However, more information is required about the response to and the molecular target for specific herbs. It seems that there is a relationship between some medicinal herbs and tumor suppressor molecules which protect a cell from cancer. In this paper, we summarize the progress of recent research on herbs, with a particular focus on its anticancer role and molecular mechanisms underlying the cancer prevention property, supporting design for further research in this field.

Rutin, a Flavonoid That Is a Main Component of Saussurea involucrata, Attenuates the Senescence Effect in D-Galactose Aging Mouse Model

Saussurea involucrata (Kar. et Kir.), known as the snow lotus, grows in the Tian Shan and A'er Tai areas of China. It has recently been reported that the ethyl acetate extract of S. involucrata (SI-2) can inhibit proliferation and induce apoptosis in PC-3 human prostate cancer cells. This study investigated the protective effect of ethyl acetate extract of S. involucrata (SI-2) or rutin, a flavonoid extracted from ethyl acetate extract of S. involucrata (SI-2), on D-galactose- (D-gal-) induced brain injury in mice. Administering SI-2 or rutin (30 mg/kg/d and 30 mg/kg/d) for 6 weeks, concomitant with D-gal injection, significantly increased superoxide dismutase and glutathione peroxidase activities and decreased the MDA level in plasma. Furthermore, the result showed that the percentages of cleaved caspase-3 and PARP in the D-gal-treated mice were much higher than those in the control. Pretreatment using SI-2 or rutin decreased the expression of cyclooxygenase-2 via downregulation of NF-kappaB, resulting in a decrease in lipid peroxidation. Furthermore, our results also showed that oral administration of rutin to these mice significantly improved behavioral performance in a step-through passive avoidance task and these results suggest that SI-2 or rutin exerts potent antiaging effects on D-gal in mice via antioxidative mechanisms.

Signal transducer and activator of transcription 3 (STAT3): a promising target for anticancer therapy

Signal transducer and activator of transcription 3 (STAT3) is an oncogenic protein whose inhibition is sought for the prevention and treatment of cancer. In this review, the validated therapeutic strategy to block aberrant activity of STAT3 in many tumor cell lines is evaluated by presenting the most promising inhibitors to date. The compounds are discussed in classes based on their different mechanisms of action, which are critically explained. In addition, their future clinical development as anticancer agents is considered. Furthermore, the efforts devoted to the comprehension of the structure-activity relationships and to the identification of the biological effects are brought to attention. The synthetic and technological approaches recently developed to overcome the difficulties in the obtainment of clinically suitable drugs are also presented.

Quality evaluation of snow lotus (Saussurea): quantitative chemical analysis and antioxidant activity assessment

Snow lotus is commonly used as a medicinal plant and has great pharmacological value. To protect these endangered plants, in vitro propagation and cell cultures have been established in order to meet the growing market demand. The phenolic composition, antioxidant activities, total phenolic content (TPC) and total flavonoid content (TFC) from three most commonly used species, in vitro propagated lines and the cell cultures were investigated to qualify their pharmacological value. Quantitative analysis showed that the phenolics varied greatly among different species and the same species at different habitats. From this it can be inferred that the phenolics were influenced by genetic background and the environmental conditions. Significant correlations were observed between the antioxidant activity and several phenolics/TPC/TFC, suggesting that the phenolics are a major contributor of the antioxidant activity and are important for quality evaluation of snow lotus. Based on the abundance of phenolics, TPC, TFC and antioxidant activity, the order of the quality for wild species would be Saussurea involucrata > Saussurea medusa > Saussurea gossypiphora. For S. medusa, its quality judged by origin would be Shigatse > Lhasa > Nagqu. For in vitro propagated plants, the matured plants could be a reliable substitute for wild plants, and the dynamics of phenolics is critical for quality control of this monocarpic species. We provide the first report of quality comparison between the wild plants and the cell cultures. The advantages of developing cell cultures as alternatives for plants collected from the wild are discussed.

Luteolin and gefitinib regulation of EGF signaling pathway and cell cycle pathway genes in PC-3 human prostate cancer cells

cRNA microarray and real-time PCR (qPCR) studies from our lab identified five Cell Cycle Pathway (CCP) genes (CCNA2, CCNE2, CDC25A, CDKN1B, and PLK-1) as targets for luteolin in PC-3 prostate cancer cells [Shoulars et al., J. Steroid Biochem. Mol. Biol. 118 (2010) 41-50]. In this paper, Ingenuity Pathway Analysis of the microarray data identified 7 luteolin-regulated genes (EGFR, c-Fos, SOS, GRB2, JNK1, MKK4 and RasGAP) in the Epidermal Growth Factor Signaling Pathway (EGFSP) potentially involved in luteolin regulation of CCP genes and cell proliferation. To address these possibilities, we compared the response profiles (RNA and protein) of these EGFSP and CCP genes to luteolin and gefitinib by real-time PCR (qPCR) and Western blot analyses. Luteolin and gefitinib are known antagonists of EGFR-associated tyrosine protein kinase. Thus, the response profiles of EGFR regulated EGFSP or CCP genes should be very similar if genes in both pathways are controlled through this common mechanism of action. Treatment of PC-3 cell with luteolin for 24h caused a 4-fold stimulation of c-Fos gene expression, significant inhibition (p<0.001) of the CCP genes and G2/M arrest. Treatment of PC-3 cells with gefitinib also inhibited most of the CCP genes in a fashion similar to that of luteolin, however, the EGFR antagonist inhibited c-Fos gene expression, stimulated CDKN1B (p27) and arrested the cells in G0/G1. Thus, although the response patterns of most of the CCP genes to luteolin or gefitinib were similar, the effects of the two compounds on EGFSP gene expression and cell cycle arrest were clearly different. Combination studies revealed that the response of EGFSP genes to luteolin was not affected by gefitinib, even though the two compounds were additive with respect to their abilities to inhibit CCNA2, CCNE2, CDC25A and PCNA. These findings suggest that luteolin and gefitinib regulate CCP gene expression through a common mechanism involving EGFR-associated tyrosine kinase. Conversely, luteolin regulates PC-3 cell proliferation through an EGFR-tyrosine kinase independent mechanism(s), likely involving the epigenetic control of gene EGFSP gene expression through histone H4 binding interactions resulting in the upregulation of c-Fos and p21 gene expression.

Hispidulin sensitizes human ovarian cancer cells to TRAIL-induced apoptosis by AMPK activation leading to Mcl-1 block in translation

Whether hispidulin, a flavone from traditional Chinese medicine, can modulate the anticancer effects of the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), the cytokine currently in clinical trials was investigated. In the present study, we found that hispidulin potentiated the TRAIL-induced apoptosis in human ovarian cancer cells and converted TRAIL-resistant cells to TRAIL-sensitive cells. When examined for its mechanism, we found that hispidulin was highly effective in activation of caspases 8 and caspase 3 and consequent poly(ADP-ribose) polymerase (PARP) cleavage. Moreover, we found that hispidulin downregulated the expression of Mcl-1, Bcl-2, and Bcl-xL. Whereas the downregulation of Bcl-2 and Bcl-xL was less pronounced, the downregulation of Mcl-1 was quite dramatic and was time-dependent. This sensitization is controlled through the adenosine monophosphate (AMP)-activated protein kinase (AMPK), which is the central energy-sensing system of the cell. Interestingly, we determined that AMPK is activated upon hispidulin treatment, resulting in mammalian target of rapamycin (mTOR) inhibition leading to Mcl-1 decrease. Therefore, our results show a novel mechanism for the sensitization to TRAIL-induced apoptosis linking hispidulin treatment to Mcl-1 downexpression. In addition, this study provides a rationale for the combined use of death receptor (DR) ligands with AMPK activators or mTOR inhibitors in the treatment of human cancers.

Hispidulin potently inhibits human glioblastoma multiforme cells through activation of AMP-activated protein kinase (AMPK)

Glioblastoma multiforme (GBM) is the most common and lethal type of primary brain tumor. Despite recent therapeutic advances in other cancers, the treatment of GBM remains ineffective and essentially palliative. The current focus lies in the finding of components that activate the AMP-activated protein kinase (AMPK), one key enzyme thought to be activated during the caloric restriction (CR). In the present study, we found that treatment of hispidulin, a flavone isolated from Saussurea involucrate Kar. et Kir., resulted in dose-dependent inhibition of GBM cellular proliferation. Interestingly, we show that hispidulin activated AMPK in GBM cells. The activation of AMPK suppressed downstream substrates, such as the mammalian target of rapamycin (mTOR) and eukaryotic initiation factor 4E-binding protein-1 (4E-BP1), and resulted in a general decrease in mRNA translation. Moreover, hispidulin-activated AMPK decreases the activity and/or expression of lipogenic enzymes, such as fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC). Furthermore, hispidulin blocked the progression of the cell cycle at the G1 phase and induced apoptosis by inducing p53 expression and further upregulating p21 expression in GBM cells. On the basis of these results, we demonstrated that hispidulin has the potential to be a chemopreventive and therapeutic agent against human GBM.