Oridonin triggers apoptosis in colorectal carcinoma cells and suppression of microRNA-32 expression augments oridonin-mediated apoptotic effects

Oridonin, a small molecule inhibitor of cancer stem cell with potent cytotoxicity and differentiation potential

Cancer stem cells (CSCs) drive malignant tumor progression, recurrence, and metastasis with unique characteristics, including self-renewal and resistance to conventional treatments. Conventional differentiation inducers, although promising, have limited cytotoxicity and may inadvertently enhance CSC stemness. To address these challenges, ongoing efforts are dedicated to developing strategies that can effectively combine both cytotoxicity and differentiation-inducing effects. In this study, we introduce oridonin (Ori), a small molecule with dual differentiation-inducing and cytotoxicity properties capable of eliminating tumor CSCs. We isolated CSCs in B16F10 cells using the Hoechst side population method and assessed the differentiation effect of Ori. Ori's differentiation-inducing effect was further evaluated using human acute promyelocytic leukemia. The cytotoxic potential of Ori against MCF-7 and B16F10 cell lines was assessed through various methods. In vivo anti-tumor and anti-CSC efficacy of Ori was investigated using mouse melanoma and CSCs melanoma models. Safety evaluation included zebrafish embryotoxicity and mouse acute toxicity experiments. As a result, Ori effectively dismantles tumorspheres, inhibits proliferation, and reduces the expression of CSC-specific markers. It induces significant differentiation, especially in the case of NB4. Additionally, Ori upregulates TP53 expression, mitigates the hypoxic tumor microenvironment, suppresses stemness, and inhibits PD-L1 expression, prompting a robust anti-cancer immune response. Ori demonstrates pronounced cytotoxicity, inducing notable pro-apoptotic effects on B16F10 and MCF-7 cells, with specific triggering of mitochondrial apoptosis. Importantly, Ori maintains a commendable biosafety record. The dual-action prowess of Ori not only induces the differentiation of CSCs but also dispatches differentiated and residual tumor cells, effectively thwarting the relentless march of tumor progression.

Oridonin from Rabdosia rubescens: An emerging potential in cancer therapy - A comprehensive review

Cancer incidences are rising each year. In 2020, approximately 20 million new cancer cases and 10 million cancer-related deaths were recorded. The World Health Organization (WHO) predicts that by 2024 the incidence of cancer will increase to 30.2 million individuals annually. Considering the invasive characteristics of its diagnostic procedures and therapeutic methods side effects, scientists are searching for different solutions, including using plant-derived bioactive compounds, that could reduce the probability of cancer occurrence and make its treatment more comfortable. In this regard, oridonin (ORI), an ent-kaurane diterpenoid, naturally found in the leaves of Rabdosia rubescens species, has been found to have antitumor, antiangiogenesis, antiasthmatic, antiinflammatory, and apoptosis induction properties. Extensive research has been performed on ORI to find various mechanisms involved in its anticancer activities. This review article provides an overview of ORI's effectiveness on murine and human cancer populations from 1976 to 2022 and provides insight into the future application of ORI in different cancer therapies.

Management of Colorectal Cancer Using Nanocarriers-based Drug Delivery for Herbal Bioactives: Current and Emerging Approaches

Colorectal cancer (CRC) is a complex and multifactorial disorder in middle-aged people. Several modern medicines are available for treating and preventing it. However, their therapeutic uses are limited due to drawbacks, such as gastric perforation, diarrhea, intestinal bleeding, abdominal cramps, hair loss, nausea, vomiting, weight loss, and adverse reactions. Hence, there is a continuous quest for safe and effective medicines to manage human health problems, like CRC. In this context, herbal medicines are considered an alternative disease control system. It has become popular in countries, like American, European, and Asian, due to its safety and effectiveness, which has been practiced for 1000 years. During the last few decades, herbal medicines have been widely explored through multidisciplinary fields for getting active compounds against human diseases. Several herbal bioactives, like curcumin, glycyrrhizin, paclitaxel, chlorogenic acid, gallic acid, catechin, berberine, ursolic acid, betulinic acid, chrysin, resveratrol, quercetin, etc., have been found to be effective against CRC. However, their pharmacological applications are limited due to low bioavailability and therapeutic efficacy apart from their several health benefits. An effective delivery system is required to increase their bioavailability and efficacy. Therefore, targeted novel drug delivery approaches are promising for improving these substances' solubility, bioavailability, and therapeutic effects. Novel carrier systems, such as liposomes, nanoparticles, micelles, microspheres, dendrimers, microbeads, and hydrogels, are promising for delivering poorly soluble drugs to the target site, i.e., the colon. Thus, the present review is focused on the pathophysiology, molecular pathways, and diagnostic and treatment approaches for CRC. Moreover, an emphasis has been laid especially on herbal bioactive-based novel delivery systems and their clinical updates.

NLRP3 inflammasome in cognitive impairment and pharmacological properties of its inhibitors

Cognitive impairment is a multifactorial and multi-step pathological process that places a heavy burden on patients and the society. Neuroinflammation is one of the main factors leading to cognitive impairment. The inflammasomes are multi-protein complexes that respond to various microorganisms and endogenous danger signals, helping to initiate innate protective responses in inflammatory diseases. NLRP3 inflammasomes produce proinflammatory cytokines (interleukin IL-1β and IL-18) by activating caspase-1. In this review, we comprehensively describe the structure and functions of the NLRP3 inflammasome. We also explore the intrinsic relationship between the NLRP3 inflammasome and cognitive impairment, which involves immune cell activation, cell apoptosis, oxidative stress, mitochondrial autophagy, and neuroinflammation. Finally, we describe NLRP3 inflammasome antagonists as targeted therapies to improve cognitive impairment.

Oridonin promotes endoplasmic reticulum stress via TP53-repressed TCF4 transactivation in colorectal cancer

BACKGROUND

The incidence of colorectal cancer and cancer death rate are increasing every year, and the affected population is becoming younger. Traditional Chinese medicine therapy has a unique effect in prolonging survival time and improving the prognosis of patients with colorectal cancer. Oridonin has been reported to have anti-cancer effects in a variety of tumors, but the exact mechanism remains to be investigated.

METHODS

Cell Counting Kit-8 assay (CCK8) and 5-Ethynyl-2'-deoxyuridine (EdU) staining assay, Tranwell, and Wound healing assays were performed to measure cell proliferation, invasion, and migration capacities, respectively. The protein and mRNA expression levels of various molecules were reflected by Western blot and Reverse Transcription quantitative Polymerase Chain Reaction (qRT-PCR). Transcription Factor 4 (TCF4) and its target genes were analyzed by Position Weight Matrices (PWMs) software and the Gene Expression Omnibus (GEO) database. Immunofluorescence (IF) was performed to visualize the expression and position of Endoplasmic Reticulum (ER) stress biomarkers. The morphology of the ER was demonstrated by the ER tracker-red. Reactive Oxygen Species (ROS) levels were measured using a flow cytometer (FCM) or fluorescent staining. Calcium ion (Ca²⁺) concentration was quantified by Fluo-3 AM staining. Athymic nude mice were modeled with subcutaneous xenografts.

RESULTS

Oridonin inhibited the proliferation, invasion, and migration of colorectal cancer, and this effect was weakened in a concentration-dependent manner by ER stress inhibitors. In addition, oridonin-induced colorectal tumor cells showed increased expression of ER stress biomarkers, loose morphology of ER, increased vesicles, and irregular shape. TCF4 was identified as a regulator of ER stress by PWMs software and GEO survival analysis. In vitro and in vivo experiments confirmed that TCF4 inhibited ER stress, reduced ROS production, and maintained Ca²⁺ homeostasis. In addition, oridonin also activated TP53 and inhibited TCF4 transactivation, further exacerbating the elevated ROS levels and calcium ion release in tumor cells and inhibiting tumorigenesis in colorectal cancer cells in vivo.

CONCLUSIONS

Oridonin upregulated TP53, inhibited TCF4 transactivation, and induced ER stress dysregulation in tumor cells, promoting colorectal cancer cell death. Therefore, TCF4 may be one of the important nodes for tumor cells to regulate ER stress and maintain protein synthesis homeostasis. And the inhibition of the TP53/TCF4 axis plays a key role in the anti-cancer effects of oridonin.

Promise of the NLRP3 Inflammasome Inhibitors in In Vivo Disease Models

Nucleotide-binding oligomerization domain NOD-like receptors (NLRs) are conserved cytosolic pattern recognition receptors (PRRs) that track the intracellular milieu for the existence of infection, disease-causing microbes, as well as metabolic distresses. The NLRP3 inflammasome agglomerates are consequent to sensing a wide spectrum of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Certain members of the NLR family have been documented to lump into multimolecular conglomerates called inflammasomes, which are inherently linked to stimulation of the cysteine protease caspase-1. Following activation, caspase-1 severs the proinflammatory cytokines interleukin (IL)-1β and IL-18 to their biologically active forms, with consequent commencement of caspase-1-associated pyroptosis. This type of cell death by pyroptosis epitomizes a leading pathway of inflammation. Accumulating scientific documentation has recorded overstimulation of NLRP3 (NOD-like receptor protein 3) inflammasome involvement in a wide array of inflammatory conditions. IL-1β is an archetypic inflammatory cytokine implicated in multiple types of inflammatory maladies. Approaches to impede IL-1β's actions are possible, and their therapeutic effects have been clinically demonstrated; nevertheless, such strategies are associated with certain constraints. For instance, treatments that focus on systemically negating IL-1β (i.e., anakinra, rilonacept, and canakinumab) have been reported to result in an escalated peril of infections. Therefore, given the therapeutic promise of an NLRP3 inhibitor, the concerted escalated venture of the scientific sorority in the advancement of small molecules focusing on direct NLRP3 inflammasome inhibition is quite predictable.

Oridonin improves the therapeutic effect of lentinan on lung cancer

Oridonin, a compound from Rabdosia rubescens, has been shown to exhibit a potent ability to improve the antitumor effects of lentinan (LNT). In the present study, the effects of oridonin, LNT, and the combination of these treatments were assessed on the normal human fetal lung fibroblast cell line MRC-5, as well as the non-small cell lung cancer cell line A549. Next, their effects on metastasis and survival in vivo were assessed in a mouse model of lung cancer. The effects of the treatments on the mRNA and protein expression levels of several regulatory factors in A549 cells and lung tissues were determined using reverse transcription-quantitative PCR and western blotting. The results showed that the viability of MRC-5 and A549 cells were not affected by 0-20 µg/ml oridonin; 0-300 µg/ml LNT did not affect the viability of MRC-5 cells, but 50-400 µg/ml LNT reduced the viability of A549 cells. Thus, 20 µg/ml oridonin and 100 or 300 µg/ml LNT were used in the subsequent experiments. Treatment with oridonin and LNT, alone or combined, had no effect on MRC-5 cell viability. Oridonin treatment had no effect on A549 cell viability; however, LNT suppressed A549 cell viability, and oridonin promoted the suppressive effects of LNT on A549 cells. In vivo analysis showed that oridonin alone had no effect on metastasis and survival, but LNT decreased metastasis and survival in mice. Oridonin augmented the effects of LNT against metastasis and further improved the survival rates of mice. In both A549 cells and lung tissues, LNT increased the mRNA and protein expression levels of caspase-3, caspase-8, caspase-9, Bax, p53, p21 and inhibitor of nuclear factor-κB (NF-κB)-α, and reduced the mRNA and protein expression levels of Bcl-2 and NF-κB. Oridonin augmented all the effects of LNT on expression of these proteins in the cells. Together, the results showed that oridonin enhanced the antitumor effects of LNT, and may thus serve as an adjuvant alongside LNT as a novel anticancer regimen for treatment of lung cancer.

The NLRP3 Inflammasome and Its Role in the Pathogenicity of Leukemia

Chronic inflammation contributes to the development and progression of various tumors. Especially where the inflammation is mediated by cells of the innate immune system, the NLRP3 inflammasome plays an important role, as it senses and responds to a variety of exogenous and endogenous pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). The NLRP3 inflammasome is responsible for the maturation and secretion of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18 and for the induction of a type of inflammatory cell death known as pyroptosis. Overactivation of the NLRP3 inflammasome can be a driver of various diseases. Since leukemia is known to be an inflammation-driven cancer and IL-1β is produced in elevated levels by leukemic cells, research on NLRP3 in the context of leukemia has increased in recent years. In this review, we summarize the current knowledge on leukemia-promoting inflammation and, in particular, the role of the NLRP3 inflammasome in different types of leukemia. Furthermore, we examine a connection between NLRP3, autophagy and leukemia.

Therapeutic modulation of inflammasome pathways

Inflammasomes are macromolecular complexes formed in response to pathogen‐associated molecular patterns (PAMPs) and danger‐associated molecular patterns (DAMPs) that drive maturation of the pro‐inflammatory cytokines interleukin (IL)‐1β and IL‐18, and cleave gasdermin D (GSDMD) for induction of pyroptosis. Inflammasomes are highly important in protecting the host from various microbial pathogens and sterile insults. Inflammasome pathways are strictly regulated at both transcriptional and post‐translational checkpoints. When these checkpoints are not properly imposed, undue inflammasome activation may promote inflammatory, metabolic and oncogenic processes that give rise to autoinflammatory, autoimmune, metabolic and malignant diseases. In addition to clinically approved IL‐1‐targeted biologics, upstream targeting of inflammasome pathways recently gained interest as a novel pharmacological strategy for selectively modulating inflammasome activation in pathological conditions.

Apoptotic Pathway as the Therapeutic Target for Anticancer Traditional Chinese Medicines

Cancer is a leading cause of morbidity and mortality worldwide. Apoptosis is a process of programmed cell death and it plays a vital role in human development and tissue homeostasis. Mounting evidence indicates that apoptosis is closely related to the survival of cancer and it has emerged as a key target for the discovery and development of novel anticancer drugs. Various studies indicate that targeting the apoptotic signaling pathway by anticancer drugs is an important mechanism in cancer therapy. Therefore, numerous novel anticancer agents have been discovered and developed from traditional Chinese medicines (TCMs) by targeting the cellular apoptotic pathway of cancer cells and shown clinically beneficial effects in cancer therapy. This review aims to provide a comprehensive discussion for the role, pharmacology, related biology, and possible mechanism(s) of a number of important anticancer TCMs and their derivatives mainly targeting the cellular apoptotic pathway. It may have important clinical implications in cancer therapy.

Recent advances in the mechanisms of NLRP3 inflammasome activation and its inhibitors

The NLRP3 inflammasome is a multimeric protein complex that initiates an inflammatory form of cell death and triggers the release of proinflammatory cytokines IL-1β and IL-18. The NLRP3 inflammasome has been implicated in a wide range of diseases, including Alzheimer’s disease, Prion diseases, type 2 diabetes, and some infectious diseases. It has been found that a variety of stimuli including danger-associated molecular patterns (DAMPs, such as silica and uric acid crystals) and pathogen-associated molecular patterns (PAMPs) can activate NLRP3 inflammasome, but the specific regulatory mechanisms of NLRP3 inflammasome activation remain unclear. Understanding the mechanisms of NLRP3 activation will enable the development of its specific inhibitors to treat NLRP3-related diseases. In this review, we summarize current understanding of the regulatory mechanisms of NLRP3 inflammasome activation as well as inhibitors that specifically and directly target NLRP3.

miR-32 promotes esophageal squamous cell carcinoma metastasis by targeting CXXC5

MicroRNA-32 (miR-32) functioned as a tumor oncogene in some cancer, which control genes involved in important biological and pathological functions and facilitate the tumor growth and metastasis. However, the role of miR-32 modulates esophageal squamous cell carcinoma (ESCC) malignant transformation has not been clarified. Here, we focused on the function and the underlying molecular mechanism of miR-32 in ESCC. Results discovered a significant increased expression of miR-32 in ESCC tissues and cells. Downregulation of miR-32 inhibited the migration, invasion, adhesion of ESCC cell lines (EC9706 and KYSE450), and the levels of EMT protein in vitro. In vivo, miR-32 inhibitors decrease tumor size, tumor weight, and the number of metastatic nodules. Hematoxylin and eosin (H&E) results revealed that inhibition of miR-32 attenuate lung metastasis. Immunohistochemistry and immunofluorescence assay showed increased level of E-cadherin and decreased level of N-cadherin and Vimentin with treatment of miR-32 inhibitors. Furthermore, miR-32 targeted the 3'-untranslated region (3'-UTR) of CXXC5, and inhibited the level of mRNA and protein of CXXC5. There is a negative correlation between the expressions of CXXC5 and miR-32. Then, after EC9706 and KYSE450 cells cotransfected with si-CXXC5 and miR-32 inhibitors, the ability of cell migration, invasion, and adhesion was significantly reduced. In addition, the protein expression of EMT and TGF-β signaling was also depressed. Collectively, these data supply an insight into the positive role of miR-32 in ESCC progression and metastasis, and its biological effects may attribute the inhibition of TGF-β signaling mediated by CXXC5.

Oridonin inhibits growth and induces apoptosis of human neurocytoma cells via the Wnt/β-catenin pathway

Central neurocytoma (CN) is a rare periventricular tumor of the central nervous system in young adults. Typically, patients with CN exhibit a favorable prognosis, but in certain cases the clinical course is more aggressive. Therefore, investigating effective therapeutic approaches is important. Oridonin has attracted attention due to its antitumor activities. However, the role of oridonin in tumorigenesis and progression remains unknown. The present study examined the antitumor function of oridonin in CN cells, and investigated the underlying molecular mechanism. An MTT assay suggested that treatment with oridonin was able to significantly inhibit the proliferation of CN cells. The annexin V-fluorescein isothiocyanate/propidium iodide assay and western blot analysis demonstrated that oridonin was able to induce apoptosis and alter the expression of apoptosis-associated proteins by downregulating anti-apoptotic protein, B-cell lymphoma-2 (Bcl-2), and upregulating pro-apoptosis proteins, Bcl-2-like protein 4, cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase 1. Subsequently, the Wnt/β-catenin signaling pathway was examined. Western blot analysis indicated that oridonin markedly decreased the expression of β-catenin, cyclin D1 and v-myc avian myelocytomatosis viral oncogene homolog. Furthermore, β-catenin was silenced by small interference RNA or overexpressed in CN cells, and the effect on cell proliferation was examined. The results indicated that silencing of β-catenin enhanced the inhibitory effect of oridonin on cell growth, whereas the overexpression of β-catenin attenuated this effect. These data indicated that oridonin inhibited proliferation and induced apoptosis to exert its antitumor activity in CN cells by repressing Wnt/β-catenin signaling. Therefore, the present study suggested that oridonin might be an effective adjuvant agent, and that the Wnt/β-catenin signaling pathway may be a potent target for the therapy in CN.

Oridonin inhibits oral cancer growth and PI3K/Akt signaling pathway

Oridonin, a bioactive diterpenoid purified from Rabdosia rubescens, has been shown to possess anticancer capacity in several cancer types. However, its effects on oral squamous cell carcinoma (OSCC) cells remain unclear. This study aimed to investigate the anticancer ability of oridonin in OSCC cells, including proliferation, apoptosis and underlying mechanisms using the OSCC cell lines, UM1 and SCC25. The results showed that oridonin not only inhibited proliferation and clonal formation but also induced G2/M cell cycle arrest and apoptosis in UM1 and SCC25 cells in a dose-dependent manner. Western blot revealed that oridonin treatment increased the ratio of Bax/Bcl-2, and activated the cleavage of caspase-3, caspase-9 and PARP-1. Oridonin also induced G2/M phase arrest in OSCC cells via down-regulating the G2/M transition-related proteins such as cyclin B1 or up-regulating cyclin D1, cyclin D3, P21, p-CDK1 and cyclin A2. In addition, oridonin treatment significantly inhibited the phosphorylation of PI3K and Akt and inhibited tumor growth of OSCC xenograft in nude mice. Taken together, these results suggested that oridonin possesses anti-oral cancer capacity via inhibiting the PI3K/Akt signaling and induce apoptosis and G2/M-phase arrest. Therefore, oridonin may be a potential anticancer drug for the treatment of oral cancer.

Production of oridonin-rich extracts from Rabdosia rubescens using hyphenated ultrasound-assisted supercritical carbon dioxide extraction

BACKGROUND

Among active components in Rabdosia rubescens, oridonin has been considered a key component and the most valuable compound because it has a wide range of activities beneficial to human health. To produce a high-quality oridonin extract, an alternative hyphenated procedure involving an ultrasound-assisted and supercritical carbon dioxide (HSC-CO₂ ) extraction method to extract oridonin from R. rubescens was developed in this study. Fictitious solubilities of oridonin in supercritical CO₂ (SC-CO₂ ) with ultrasound assistance were measured by using the dynamic method at temperatures ranging from 305.15 K to 342.15 K over a pressure range of 11.5 to 33.5 MPa.

RESULTS

Fictitious solubilities of oridonin at different temperatures and pressures were over the range of 2.13 × 10^-6 to 10.09 × 10^-6 (mole fraction) and correlated well with the density-based models, including the Bartle model, the Chrastil model, the Kumar and Johnston model and the Mendez-Santiago and Teja model, with overall average absolute relative deviations (AARDs) of 6.29%, 4.39%, 3.12% and 5.07%, respectively.

CONCLUSION

Oridonin exhibits retrograde solubility behaviour in the supercritical state. Fictitious solubility data were further determined and obtained a good fit with four semi-empirical models. Simultaneously, the values of the total heat of solution, vaporisation and solvation of oridonin were estimated. © 2016 Society of Chemical Industry.

Oridonin synergizes with Nutlin-3 in osteosarcoma cells by modulating the levels of multiple Bcl-2 family proteins

The small-molecule inhibitors of p53-murine double minute 2 interaction, such as Nutlin-3, are effective against cancers bearing wild-type p53. However, murine double minute 2 inhibitors often are unable to completely eliminate solid tumor cells. To address this issue, we investigated the anticancer effects of Nutlin-3 in combination with Oridonin in osteosarcoma cells. We found that Oridonin at sub-toxic concentrations synergistically enhanced Nutlin-3-mediated cell viability inhibition in wild-type p53 U2OS and SJSA-1, but not in p53-mutant MNNG/HOS and in null-p53 Saos-2 osteosarcoma cell lines. Importantly, in the presence of Oridonin, Nutlin-3 could completely abolish cell viability in the wild-type p53 osteosarcoma cell lines. Western blotting analysis showed that Oridonin treatment rapidly and distinctly increased the levels of all three forms of Bim and also markedly reduced the levels of Bcl-2 and Bcl-xl in osteosarcoma cells. Western blotting analysis further showed that Oridonin considerably enhanced Nutlin-3-triggered activation of caspases-9 and -3 and poly(ADP-ribose) polymerase cleavage. Flow cytometry assay showed that Oridonin significantly enhanced Nutlin-3-mediated apoptosis in wild-type p53 osteosarcoma cells. Overall, our results suggest that the combined treatment of Nutlin-3 plus Oridonin may offer a novel therapeutic strategy for osteosarcoma.

Diterpenes and Their Derivatives as Potential Anticancer Agents

As therapeutic tools, diterpenes and their derivatives have gained much attention of the medicinal scientists nowadays. It is due to their pledging and important biological activities. This review congregates the anticancer diterpenes. For this, a search was made with selected keywords in PubMed, Science Direct, Web of Science, Scopus, The American Chemical Society and miscellaneous databases from January 2012 to January 2017 for the published articles. A total 28, 789 published articles were seen. Among them, 240 were included in this study. More than 250 important anticancer diterpenes and their derivatives were seen in the databases, acting in the different pathways. Some of them are already under clinical trials, while others are in the nonclinical and/or pre-clinical trials. In conclusion, diterpenes may be one of the lead molecules in the treatment of cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Oridonin induces autophagy via inhibition of glucose metabolism in p53-mutated colorectal cancer cells

The Warburg effect is an important characteristic of tumor cells, making it an attractive therapeutic target. Current anticancer drug development strategies predominantly focus on inhibitors of the specific molecular effectors involved in tumor cell proliferation. These drugs or natural compounds, many of which target the Warburg effect and the underlying mechanisms, still need to be characterized. To elucidate the anticancer effects of a natural diterpenoid, oridonin, we first demonstrated the anticancer activity of oridonin both in vitro and in vivo in colorectal cancer (CRC) cells. Then miRNA profiling of SW480 cells revealed those intracellular signaling related to energy supply was affected by oridonin, suggesting that glucose metabolism is a potential target for CRC therapy. Moreover, our results indicated that oridonin induced metabolic imbalances by significantly inhibiting glucose uptake and reducing lactate export through significantly downregulating the protein levels of GLUT1 and MCT1 in vitro and vivo. However, the ATP level in oridonin-treated CRC cells was not decreased when oridonin blocked the glucose supply, indicating that oridonin induced autophagy process, an important ATP source in cancer cells. The observation was then supported by the results of LC3-II detection and transmission electron microscopy analysis, which confirmed the presence of autophagy. Furthermore, p-AMPK was rapidly deactivated following oridonin treatment, resulting in downregulation of GLUT1 and induction of autophagy in the cancer cells. Thus our finding helped to clarify the anticancer mechanisms of oridonin and suggested it could be applied as a glucose metabolism-targeting agent for cancer treatment.

Proteomic analysis of oridonin-induced apoptosis in multiple myeloma cells

Oridonin is a diterpenoid compound isolated from the medicinal herb Rabdosia rubescens, and has shown marked antitumor effects against different types of cancer. However, the definitive systematic molecular mechanism underlying the antitumor activity of oridonin in multiple myeloma remains to be elucidated. In the present study, cell viability and cytotoxicity were examined to determine the appropriate concentration for proteomic investigation. In addition, cell apoptosis was evaluated using flow cytometry and transmission electron microscopy. A proteomic investigation using a two‑dimensional electrophoresis system and mass spectrometry was performed to identify and characterize the global proteome of the apoptosis induced by oridonin. Of the proteins identified, seven were involved in the anticancer effects of oridonin. Regulation of the expression and function of target proteins, stathmin, dihydrofolate reductase and pyruvate dehydrogenase E1β, may be potential, therapeutic strategies to effectively treat multiple myeloma. These findings provide novel information on the molecular mechanisms underlying the anticancer properties of oridonin in multiple myeloma.

Identification and comparative oridonin metabolism in different species liver microsomes by using UPLC-Triple-TOF-MS/MS and PCA

Oridonin (ORI) is an active natural ent-kaurene diterpenoid ingredient with notable anti-cancer and anti-inflammation activities. Currently, a strategy was developed to identify metabolites and to assess the metabolic profiles of ORI in vitro using ultra-high-performance liquid chromatography-Triple/time-of-flight mass spectrometry (UPLC-Triple-TOF-MS/MS). Meanwhile, the metabolism differences of ORI in the liver microsomes of four different species were investigated using a principal component analysis (PCA) based on the metabolite absolute peak area values as the variables. Based on the proposed methods, 27 metabolites were structurally characterized. The results indicate that ORI is universally metabolized in vitro, and the metabolic pathway mainly includes dehydration, hydroxylation, di-hydroxylation, hydrogenation, decarboxylation, and ketone formation. Overall, there are obvious inter-species differences in types and amounts of ORI metabolites in the four species. These results will provide basic data for future pharmacological and toxicological studies of ORI and for other ent-kauranes diterpenoids. Meanwhile, studying the ORI metabolic differences helps to select the proper animal model for further pharmacology and toxicological assessment.

Oridonin inhibits pancreatic cancer cell migration and epithelial-mesenchymal transition by suppressing Wnt/β-catenin signaling pathway

BACKGROUND

Oridonin (ORI) can inhibit proliferation and migration in various types of cancer cell lines. However, the exact mechanism remains unclear. We investigated the migration inhibitory effect of ORI on human pancreatic cancer SW1990 cells and dissected the possible molecular mechanism(s).

METHODS

CCK-8 assay was used to observe the cell viability. Wound healing assay, transwell assay and spontaneous metastasis model were used to observe the migration activities. Real-time PCR, immunofluorescence, western blot analysis and immunohistochemistry methods were used to observe the expression of genes or proteins.

RESULTS

ORI inhibited the migration of SW1990 cells. Real-time PCR and immuno-fluorescence analyses of epithelial-to-mesenchymal transition (EMT) markers were compared between control group and ORI group. The expression of mesenchymal molecular markers, such as vimentin, snail and slug decreased. The expression of epithelial-related marker E-cadherin increased. Wnt/β-catenin signalling was inhibited by ORI using luciferase reporter assay. ORI can decrease the β-catenin protein level not only in the nucleus, but also in the cytoplasm and the whole cell after the treatment with ORI and glycogen synthase kinase 3β (GSK3β) was increased in the ORI-treated group. CHIR could attenuate the effects of ORI in SW1990 cells. We established a mice model by injecting 1 × 10(6) SW1990 cells into nude mice intraperitoneally to test whether ORI affects tumour metastasis. Metastatic formation was inhibited by ORI (5 and 10 mg/kg) compared with the control group. Tumour sections stained with anti-E-cadherin, anti-vimentin and anti-β-catenin antibodies revealed that ORI inhibited EMT, as well as the Wnt/β-catenin pathway in vivo.

CONCLUSIONS

ORI can inhibit pancreatic cancer cell SW1990 migration and EMT by down-regulating Wnt/β-catenin signal transduction in vitro and in vivo. Therefore, it can be potentially and effectively used in the clinical management of pancreatic cancer.

Oridonin induces apoptosis through the mitochondrial pathway in human gastric cancer SGC-7901 cells

Oridonin is one of the most important antitumor active ingredients of Rabdosia rubescens. Recently published studies from our laboratory have demonstrated that oridonin was able to arrest human gastric cancer SGC-7901 cells at G2/M phase. However, little is known about inducing apoptosis in gastric cancer. The aim of this study was to investigate the effect of oridonin on antineoplastic capability of SGC-7901 cells and the detailed molecular mechanism of oridonin-mediated intrinsic pathway of apoptosis. Cell proliferation was assessed by MTT assay while apoptosis induced by oridonin was determined by Hoechst 33342 staining assay and Annexin V/PI double staining assay. Early apoptotic rate was stained by Annexin V/PI and detected by flow cytometry. Apoptosis pathway was analyzed by western blot analysis of Bcl-2, Bax, cytochrome c and caspase-3 expression. The results showed that oridonin was able to inhibit the SGC-7901 cell proliferation, the 50% growth inhibition (IC50) was 22.74 µM. Oridonin could induce cell apoptosis of SGC-7901 cells and the early apoptotic rates induced by 0, 20, 40, 80 µmol/l oridonin were 1.53±0.67, 3.33±0.29, 84.80±0.82 and 96.43±0.51%, respectively. Western blot analysis revealed that oridonin downregulated Bcl-2 protein (the anti-apoptotic factor) and upregulated Bax protein (pro-apoptotic factor), eventually leading to a reduction in the ratio of Bcl-2/Bax proteins. Furthermore, oridonin induced the release of cytochrome c from the mitochondria to the cytosol and the activation of caspase-3. Taken together, the current study suggested that oridonin induced apoptosis in SGC-7901 cells via the mitochondrial signal pathway, which may represent one of the major mechanisms of oridonin-mediated apoptosis in SGC-7901 cells.

Oridonin derivative ameliorates experimental colitis by inhibiting activated T-cells and translocation of nuclear factor-kappa B

OBJECTIVE

To confirm the potential therapeutic efficacy of HAO472 against inflammatory bowel disease (IBD), we investigated the modulatory functions of HAO472 in a mouse model of trinitrobenzene sulfonic acid (TNBS)-induced colitis.

METHODS

Colitis was induced via an intrarectal injection of TNBS in mice. HAO472 (5.0 mg/kg or 7.5 mg/kg) or 1 mg/kg dexamethasone (DX) was injected intraperitoneally into the mice after the TNBS administration. Behavioral and weight changes, macroscopic and histological assessments of colon, the expressions of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-17A, cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-κB) in the colonic tissues were evaluated. The effect of HAO472 on NF-κB signaling pathway in lymphocytes was also invesigated.

RESULTS

HAO472 significantly ameliorated the clinical symptoms, reduced the severity of the inflammation and decreased mortality in the mouse model. HAO472 also reduced TNF-α, IFN-γ, IL-17A, iNOS/COX-2 and lymphocyte proliferation. These changes were associated with a significant decrease in NF-κB p65 expression and activity.

CONCLUSION

HAO472 has positive effects on TNBS-induced colitis by modulating the subsets and functions of lymphocytes, suppressing inflammation and inhibiting the nuclear translocation of NF-κB p65 subunits.

Bioactive Enmein-Type ent-Kaurane Diterpenoids from Isodon phyllostachys

Thirty-two enmein-type ent-kaurane diterpenoids, including 13 new compounds, were isolated from the aerial parts of Isodon phyllostachys. Compounds 1 and 2 are the first examples of 3,20:6,20-diepoxyenmein-type ent-kauranoids, and the structures of these new compounds were established mainly by analyzing NMR and HREIMS data. The absolute configurations of 1 and 8 and the relative configuration of 9 were determined using single-crystal X-ray diffraction. Compounds 11, 15, 20, and 21 were active against five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW-480), with IC50 values ranging from 1.2 to 5.0 μM. Compounds 3, 11, 15, 17, 20, 21, 25, and 29 strongly inhibited NO production in LPS-stimulated RAW264.7 cells, with IC50 values ranging from 0.74 to 4.93 μM.