Oridonin induces G2/M cell cycle arrest and apoptosis via the PI3K/Akt signaling pathway in hormone-independent prostate cancer cells

Design, Synthesis, and Anticancer Activity of Novel Enmein-Type Diterpenoid Derivatives Targeting the PI3K/Akt/mTOR Signaling Pathway

The enmein-type diterpenoids are a class of anticancer ent-Kaurane diterpnoids that have received much attention in recent years. Herein, a novel 1,14-epoxy enmein-type diterpenoid 4, was reported in this project for the first time. A series of novel enmein-type diterpenoid derivatives were also synthesized and tested for anticancer activities. Among all the derivatives, compound 7h exhibited the most significant inhibitory effect against A549 cells (IC50 = 2.16 µM), being 11.03-folds better than its parental compound 4. Additionally, 7h exhibited relatively weak anti-proliferative activity (IC50 > 100 µM) against human normal L-02 cells, suggesting that it had excellent anti-proliferative selectivity for cancer cells. Mechanism studies suggested that 7h induced G0/G1 arrest and apoptosis in A549 cells by inhibiting the PI3K/AKT/mTOR pathway. This process was associated with elevated intracellular ROS levels and collapsed MMP. In summary, these data identified 7h as a promising lead compound that warrants further investigation of its anticancer properties.

Functionalized graphene oxide as a nanocarrier for delivering oridonin to improve anti-breast cancer cell activity

In this study, a targeted nanocarrier was developed by functionalizing graphene oxide with polyethyleneimine and folic acid, intended for loading oridonin. The nanocarrier was successfully synthesized and characterized using an ultraviolet spectrum, Fourier transform infrared spectroscopy and scanning electron microscopy. The nanocarrier demonstrated a remarkable oridonin loading capacity, reaching 424.8 μg/mg, as determined by ultra-high performance liquid chromatography. In vitro drug release experiments exhibited a pH-dependent release profile, with a higher cumulative release in an acidic environment. The release mechanism followed the Ritger-Peppas equation model. Cytotoxicity assays indicated minimal toxicity of the nanocarrier. Enhanced cellular uptake by MCF7 cells was observed for carriers functionalized with folate and polyethyleneimine. These findings highlight the potential of functionalized graphene oxide as a promising carrier for oridonin delivery in biomedical applications.

Integrating Epigenetics, Proteomics, and Metabolomics to Reveal the Involvement of Wnt/β-Catenin Signaling Pathway in Oridonin-Induced Reproductive Toxicity

Oridonin is the primary active component in the traditional Chinese medicine Rabdosia rubescens, displaying anti-inflammatory, anti-tumor, and antibacterial effects. It is widely employed in clinical therapy for acute and chronic pharyngitis, tonsillitis, as well as bronchitis. Nevertheless, the clinical application of oridonin is significantly restricted due to its reproductive toxicity, with the exact mechanism remaining unclear. The aim of this study was to investigate the mechanism of oridonin-induced damage to HTR-8/SVneo cells. Through the integration of epigenetics, proteomics, and metabolomics methodologies, the mechanisms of oridonin-induced reproductive toxicity were discovered and confirmed through fluorescence imaging, RT-qPCR, and Western blotting. Experimental findings indicated that oridonin altered m6A levels, gene and protein expression levels, along with metabolite levels within the cells. Additionally, oridonin triggered oxidative stress and mitochondrial damage, leading to a notable decrease in WNT6, β-catenin, CLDN1, CCND1, and ZO-1 protein levels. This implied that the inhibition of the Wnt/β-catenin signaling pathway and disruption of tight junction might be attributed to the cytotoxicity induced by oridonin and mitochondrial dysfunction, ultimately resulting in damage to HTR-8/SVneo cells.

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.

Oridonin suppresses gastric cancer SGC-7901 cell proliferation by targeting the TNF-alpha/androgen receptor/TGF-beta signalling pathway axis

Statistics provided by GLOBOCAN list gastric cancer as the sixth most common, with a mortality ranking of third highest for the year 2020. In China, a herb called Rabdosia rubescens (Hemsl.) H.Hara, has been used by local residents for the treatment of digestive tract cancer for hundreds of years. Oridonin, the main ingredient of the herb, has a curative effect for gastric cancer, but the mechanism has not been previously clarified. This study mainly aimed to investigate the role of TNF-alpha/Androgen receptor/TGF-beta signalling pathway axis in mediating the proliferation inhibition of oridonin on gastric cancer SGC-7901 cells. MTT assay, cell morphology observation assay and fluorescence assay were adopted to study the efficacy of oridonin on cell proliferation. The network pharmacology was used to predict the pathway axis regulated by oridonin. Western blot assay was adopted to verify the TNF-α/Androgen receptor/TGF-β signalling pathway axis regulation on gastric cancer by oridonin. The results showed Oridonin could inhibit the proliferation of gastric cancer cells, change cell morphology and cause cell nuclear fragmentation. A total of 11signaling pathways were annotated by the network pharmacology, among them, Tumour necrosis factor alpha (TNF-α) signalling pathway, androgen receptor (AR) signalling pathway and transforming growth factor (TGF-β) signalling pathway account for the largest proportion. Oridonin can regulate the protein expression of the three signalling pathways, which is consistent with the results predicted by network pharmacology. These findings indicated that oridonin can inhibit the proliferation of gastric cancer SGC-7901 cells by regulating the TNF-α /AR /TGF-β signalling pathway axis.

Cancer stem cells promote lymph nodes metastasis of breast cancer by reprogramming tumor microenvironment

Breast cancer progression and metastasis are governed by a complex interplay within the tumor immune microenvironment (TIME), involving numerous cell types. Lymph node metastasis (LNM) is a key prognostic marker associated with distant organ metastasis and reduced patient survival, but the mechanisms underlying its promotion by breast cancer stem cells (CSCs) remain unclear. Our study sought to unravel how CSCs reprogram TIME to facilitate LNM. Utilizing single-cell RNA sequencing, we profiled TIME in primary cancer and corresponding metastatic lymph node samples from patients at our institution. To verify the derived data, we cultured CSCs and performed validation assays employing flow cytometry and CyTOF. Our analysis revealed distinct differences in cellular infiltration patterns between tumor and LNM samples. Importantly, RAC2 and PTTG1 double-positive CSCs, which exhibit the highest stem-like attributes, were markedly enriched in metastatic lymph nodes. These CSCs are hypothesized to foster metastasis via activation of specific metastasis-related transcription factors and signaling pathways. Additionally, our data suggest that CSCs might modulate adaptive and innate immune cell evolution, thereby further contributing to metastasis. In summary, this study illuminates a critical role of CSCs in modifying TIME to facilitate LNM. The enrichment of highly stem-like CSCs in metastatic lymph nodes offers novel therapeutic targeting opportunities and deepens our understanding of breast cancer metastasis.

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.

Oridonin inhibits Hela cell proliferation via downregulation of glutathione metabolism: a new insight from metabolomics

Objectives

This study aims to elucidate Oridonin' s inhibitory mechanism to cervical cancer using metabolomics methods and pharmacological assays.

Methods

Network pharmacology and KEGG pathway analysis are used to identify overlapped targets and involved metabolic pathways. UPLC-MS/MS metabolomics analysis is used to determine altered metabolites after Oridonin treatment. Other bioassays are also employed to uncover the changes in critical molecules that are highly related to altered metabolites.

Key findings

Seventy-five overlapped targets are identified between Oridonin and cervical cancer. Twenty-one metabolites involved in tricarboxylic acid cycle glutathione metabolism, branched-chain amino acid metabolism and so on changes significantly after Oridonin treatment. Oridonin treatment significantly reduces the content of cysteine and inhibit the catalytic activity of glutamine–cysteine ligase subunit, a rate-limiting enzyme for the synthesis of glutathione. As a result, the content of glutathione is also reduced. The antioxidant enzyme glutathione peroxidase 4 which uses glutathione as a cofactor, is inactivated, resulting in a burst release of reactive oxygen species. The ATP content is also significantly reduced in Hela cells after Oridonin treatment.

Conclusions

This study finds that Oridonin treatment induces Hela cell apoptosis possibly via inhibition of the glutathione metabolism.

Preparation, characterization, and pharmacokinetics of oridonin-loaded liposomes

The aim of this study was to prepare oridonin liposomes and evaluate the physicochemical characteristics and pharmacokinetics in rats. A three-level, three-factor Box-Behnken design was used to optimize the preparation of oridonin liposomes. A highly sensitive high-performance liquid chromatographic quantification method using ultraviolet detection was established and validated for the determination of oridonin in rat plasma. Twelve Sprague-Dawley rats were randomly assigned and injected with 15 mg/kg of oridonin or oridonin liposomes via the tail vein. Pharmacokinetic parameters were estimated using a compartmental modeling approach using PKsolver software. The optimum conditions were as follows: soybean phospholipids/cholesterol ratio, 3.9:1; soybean phospholipids/drug ratio, 8.5:1; and soybean phospholipid concentration, 1.1%. Under these conditions, the mean particle size, polydispersity index, zeta potential, and encapsulation efficiency of oridonin liposomes were 170.5 nm, 0.246, -30.3 mV, and 76.15%, respectively. The pharmacokinetic results showed that liposomes could significantly prolong the elimination half-life (from 2.88 ± 0.55 to 13.67 ± 3.52 h), increase the area under the concentration-time curve (from 1.65 ± 0.17 to 6.22 ± 0.83 μg h/ml), and decrease the clearance (from 6.62 ± 1.38 to 1.96 ± 0.24 L/kg h). The oridonin liposomes increased the elimination half-life and area under the concentration-time curve and provided a reference for the development of drugs with a short half-life.

Recent advances in oridonin derivatives with anticancer activity

Cancer is a leading cause of mortality responsible for an estimated 10 million deaths worldwide in 2020, and its incidence has been rapidly growing over the last decades. Population growth and aging, as well as high systemic toxicity and chemoresistance associated with conventional anticancer therapies reflect these high levels of incidence and mortality. Thus, efforts have been made to search for novel anticancer drugs with fewer side effects and greater therapeutic effectiveness. Nature continues to be the main source of biologically active lead compounds, and diterpenoids are considered one of the most important families since many have been reported to possess anticancer properties. Oridonin is an ent-kaurane tetracyclic diterpenoid isolated from Rabdosia rubescens and has been a target of extensive research over the last few years. It displays a broad range of biological effects including neuroprotective, anti-inflammatory, and anticancer activity against a variety of tumor cells. Several structural modifications on the oridonin and biological evaluation of its derivatives have been performed, creating a library of compounds with improved pharmacological activities. This mini-review aims to highlight the recent advances in oridonin derivatives as potential anticancer drugs, while succinctly exploring their proposed mechanisms of action. To wind up, future research perspectives in this field are also disclosed.

Therapeutic targets and signaling pathways of active components of QiLing decoction against castration-resistant prostate cancer based on network pharmacology

QiLing decoction (QLD) is a traditional Chinese medicine compound. This study aims to explore the therapeutic effect of QLD in castration-resistant prostate cancer (CRPC) and its potential bio-targets. A total of 51 active components and QLD 149 targets were identified using bioinformatics analysis. Additionally, five optimal hub target genes were screened including tumor protein P53 (TP53), interleukin-6 (IL-6), vascular endothelial growth factor-A (VEGF-A), caspase-3 (CASP-3), and estrogen receptor-1 (ESR-1). The interrelated network between active components of QLD and their potential targets was constructed. The molecular function, biological processes, and signaling pathways of QLD-against CRPC were identified. Moreover, QLD was found to efficiently exert a repressive effect on CRPC tumor growth mainly by suppressing the activation of HIF-α/VEGFA and TNF-α/IL6 signaling pathways, and increasing the P53 expression level. These results successfully indicated the potential anti-CRPC mechanism of the active components of QLD.

Caffeic acid phenethyl ester induces radiosensitization via inhibition of DNA damage repair in androgen-independent prostate cancer cells

In the present study, we evaluated the radiomodulatory potential of caffeic acid phenethyl ester (CAPE), an active component of traditional herbal medicine propolis. CAPE has been identified as a potent anticancer agent in multiple cancer types and is reported to have the dual role of radioprotection and radiosensitization. However, the radiomodulatory potential of CAPE in prostate cancer (PCa), which eventually becomes radioresistant is not known. Therefore, we studied the effect of co-treatment of CAPE and gamma radiation on androgen-independent DU145 and PC3 cells. The combination treatment sensitized PCa cells to radiation in a dose-dependent manner. The radiosensitizing effect of CAPE was observed in both cell lines. CAPE enhanced the level of ionizing radiation (IR)-induced gamma H2AX foci and cell death by apoptosis. The combination treatment also decreased the migration potential of PCa cells. This was confirmed by increased expression of E-cadherin and decrease in vimentin expression. CAPE sensitized PCa cells to radiation in vitro and induced apoptosis, augmented phosphorylation of Akt/mTOR, and hampered cell migration. At the mechanistic level, co-treatment of CAPE and IR inhibited cell growth by decreasing RAD50 and RAD51 proteins involved in DNA repair. This resulted in enhanced DNA damage and cell death. CAPE might represent a promising new adjuvant for the treatment of hormone-refractory radioresistant PCa.

Preparation, Characterization, and Evaluation of Liposomes Containing Oridonin from Rabdosia rubescens

Due to the remarkable anti-tumor activities of oridonin (Ori), research on Rabdosia rubescens has attracted more and more attention in the pharmaceutical field. The purpose of this study was to extract Ori from R. rubescens by ultrasound-assisted extraction (UAE) and prepare Ori liposomes as a novel delivery system to improve the bioavailability and biocompatibility. Response surface methodology (RSM), namely Box-Behnken design (BBD), was applied to optimize extraction conditions, formulation, and preparation process. The results demonstrated that the optimal extraction conditions were an ethanol concentration of 75.9%, an extraction time of 35.7 min, and a solid/liquid ratio of 1:32.6. Under these optimal conditions, the extraction yield of Ori was 4.23 mg/g, which was well matched with the predicted value (4.28 mg/g). The optimal preparation conditions of Ori liposomes by RSM, with an ultrasonic time of 41.1 min, a soybean phospholipids/drug ratio of 9.6 g/g, and a water bath temperature of 53.4 °C, had higher encapsulation efficiency (84.1%). The characterization studies indicated that Ori liposomes had well-dispersible spherical shapes and uniform sizes with a particle size of 137.7 nm, a polydispersity index (PDI) of 0.216, and zeta potential of −24.0 mV. In addition, Ori liposomes presented better activity than free Ori. Therefore, the results indicated that Ori liposomes could enhance the bioactivity of Ori, being proposed as a promising vehicle for drug delivery.

Selective synergistic anticancer effects of cisplatin and oridonin against human p53-mutant esophageal squamous carcinoma cells

Oridonin (ORI) is known to pose anticancer activity against cancer, which could induce the therapeutic impact of chemotherapy drugs. However, such simple combinations have numerous side effects such as higher toxicity to normal cells and tissues. To enhance the therapeutic effects with minimal side effects, here we used ORI in combination with cisplitin (CIS) against different esophageal squamous cell carcinoma (ESCC) cell lines in vitro, to investigate the synergistic anticancer effects of the two drugs against ESCC. Calcusyn Graphing Software was used to assess the synergistic effect. Apoptosis, wound healing and cell invasion assay were conducted to further confirm the synergistic effects of ORI and CIS. Intracellular glutathione (GSH) and reactive oxygen species assay, immunofluorescence staining and western blot were used to verify the mechanism of synergistic cytotoxicity. ORI and CIS pose selective synergistic effects on ESCC cells with p53 mutations. Moreover, we found that the synergistic effects of these drugs are mediated by GSH/ROS systems, such that intracellular GSH production was inhibited, whereas the ROS generation was induced following ORI and CIS application. In addition, we noted that DNA damage was induced as in response to ORI and CIS treatment. Overall, these results suggest that ORI can synergistically enhance the effect of CIS, and GSH deficiency and p53 mutation, might be biomarkers for the combinational usage of ORI and CIS.

Combination of oridonin and TRAIL induces apoptosis in uveal melanoma cells by upregulating DR5

AIM

To investigate the inhibitory effect of the combined use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and oridonin on choroidal melanoma cell lines, and to explore its underlying mechanism.

METHODS

MUM-2B and C918 cells were treated with different concentrations of TRAIL and oridonin, and MTT assay used to evaluate the inhibition rate of the two compounds on cells. Then, the cell cycle distribution and apoptosis were detected by flow cytometry, and changes in apoptosis-related proteins such as death receptor 5 (DR5), a-caspase-3, and x-linked inhibitor of apoptosis protein (XIAP) were detected by Western blot. MUM-2B cells were transfected with si-DR5, which interfered with the expression of the DR5 gene. MTT and Western blot assay were used to detect cell activity and apoptosis-related proteins.

RESULTS

When TRAIL and oridonin were simultaneously administered to the MUM-2B cells, the apoptosis rate was significantly higher than that by the two drugs individually. However, the effect of combined use of TRAIL and oridonin on C918 cells was not significantly different from that used alone. Cell cycle analysis showed that TRAIL and oridonin could induce G2/M arrest in MUM-2B cells. The Western blot results showed that the protein expression levels of the DR5, a-caspase-3, and BAX increased, while the expression levels of the anti-apoptosis-related proteins XIAP and BCL-2 were suppressed when TRAIL and oridonin simultaneously administered to MUM-2B cells. Interfering the expression of DR5 gene in MUM-2B cells could reverse the inhibitory effect of oridonin and TRAIL on the proliferation and apoptosis induction of MUM-2B cells.

CONCLUSION

The inhibitory effects of oridonin and TRAIL on MUM-2B cells are significantly enhanced when they were administered as a combined treatment, which may ascribe to up-regulation of DR5.

Oridonin Dose-Dependently Modulates the Cell Senescence and Apoptosis of Gastric Cancer Cells

Gastric cancer (GC) is the fourth most lethal cancer. Effective treatments are lacking, and our knowledge of the pathogenic mechanisms in play is poor. Oridonin from the Chinese herb Rabdosia rubescens exerts various anticancer activities. However, the dose-dependent effects of oridonin on human GC remain unclear. Here, we found that oridonin inhibited GC cell growth in a time- and dose-dependent manner. Low-dose oridonin induced GC cell cycle arrest at G0/G1 and cell senescence by suppressing the c-Myc-AP4 pathway and enhancing p53-p21 signaling. AP4 overexpression partly abrogated the oridonin-induced senescence of GC cells. High-dose oridonin induced apoptosis and autophagy, with the autophagy inhibitor BafA1 attenuating oridonin-induced apoptosis. Together, the findings indicate that oridonin at different doses modulates GC cell senescence and apoptosis; oridonin may thus usefully treat GC.

Oridonin: A Review of Its Pharmacology, Pharmacokinetics and Toxicity

Oridonin, as a natural terpenoids found in traditional Chinese herbal medicine Isodon rubescens (Hemsl.) H.Hara, is widely present in numerous Chinese medicine preparations. The purpose of this review focuses on providing the latest and comprehensive information on the pharmacology, pharmacokinetics and toxicity of oridonin, to excavate the therapeutic potential and explore promising ways to balance toxicity and efficacy of this natural compound. Information concerning oridonin was systematically collected from the authoritative internet database of PubMed, Elsevier, Web of Science, Wiley Online Library and Europe PMC applying a combination of keywords involving "pharmacology," "pharmacokinetics," and "toxicology". New evidence shows that oridonin possesses a wide range of pharmacological properties, including anticancer, anti-inflammatory, hepatorenal activities as well as cardioprotective protective activities and so on. Although significant advancement has been witnessed in this field, some basic and intricate issues still exist such as the specific mechanism of oridonin against related diseases not being clear. Moreover, several lines of evidence indicated that oridonin may exhibit adverse effects, even toxicity under specific circumstances, which sparked intense debate and concern about security of oridonin. Based on the current progress, future research directions should emphasize on 1) investigating the interrelationship between concentration and pharmacological effects as well as toxicity, 2) reducing pharmacological toxicity, and 3) modifying the structure of oridonin-one of the pivotal approaches to strengthen pharmacological activity and bioavailability. We hope that this review can provide some inspiration for the research of oridonin in the future.

Phytochemicals in cancer and their effect on the PI3K/AKT-mediated cellular signalling

Protein kinases belong to the largest family of enzymes controlling every aspect of cellular activity including gene expression, cell division, differentiation and metabolism. They are part of major intracellular signalling pathways. Hence, it is not surprising that they are involved in the development of major diseases such as cardiovascular disorders, diabetes, dementia and, most importantly, cancer when they undergo mutations, modifications and unbalanced expression. This review will explore the possibility to draw a connection between the application of natural phytochemicals and the treatment of cancer. We have chosen to focus on the PI3K/AKT cellular signalling pathway which has been shown to be a major target by natural compounds in cell cultures and animal models.

Natural products: A lead for drug discovery and development

Natural products are used since ancient times in folklore for the treatment of various ailments. Plant-derived products have been recognized for many years as a source of therapeutic agents and structural diversity. A literature survey has been carried out to determine the utility of natural molecules and their modified analogs or derivatives as pharmacological active entities. This review presents a study on the importance of natural products in terms of drug discovery and development. It describes how the natural components can be utilized after small modifications in new perspectives. Various new modifications in structure offer a unique opportunity to establish a new molecular entity with better pharmacological potential. It was concluded that in this current era, new attempts are taken to utilize the compounds derived from natural sources as novel drug candidates, with a focus to find and discover new effective molecules that were referred to as "new entities of natural product drug discovery."

An Insight into the Anti-Angiogenic and Anti-Metastatic Effects of Oridonin: Current Knowledge and Future Potential

Cancer is one of the leading causes of death worldwide, with a mortality rate of more than 9 million deaths reported in 2018. Conventional anti-cancer therapy can greatly improve survival however treatment resistance is still a major problem especially in metastatic disease. Targeted anti-cancer therapy is increasingly used with conventional therapy to improve patients' outcomes in advanced and metastatic tumors. However, due to the complexity of cancer biology and metastasis, it is urgent to develop new agents and evaluate the anti-cancer efficacy of available treatments. Many phytochemicals from medicinal plants have been reported to possess anti-cancer properties. One such compound is known as oridonin, a bioactive component of Rabdosia rubescens. Several studies have demonstrated that oridonin inhibits angiogenesis in various types of cancer, including breast, pancreatic, lung, colon and skin cancer. Oridonin's anti-cancer effects are mediated through the modulation of several signaling pathways which include upregulation of oncogenes and pro-angiogenic growth factors. Furthermore, oridonin also inhibits cell migration, invasion and metastasis via suppressing epithelial-to-mesenchymal transition and blocking downstream signaling targets in the cancer metastasis process. This review summarizes the recent applications of oridonin as an anti-angiogenic and anti-metastatic drug both in vitro and in vivo, and its potential mechanisms of action.

Recent Progress of Oridonin and Its Derivatives for the Treatment of Acute Myelogenous Leukemia

First stage human clinical trial (CTR20150246) for HAO472, the L-alanine-(14-oridonin) ester trifluoroacetate, was conducted by a Chinese company, Hengrui Medicine Co. Ltd, to develop a new treatment for acute myelogenous leukemia. Two patents, WO2015180549A1 and CN201410047904.X, covered the development of the I-type crystal, stability experiment, conversion rate research, bioavailability experiment, safety assessment, and solubility study. HAO472 hewed out new avenues to explore the therapeutic properties of oridonin derivatives and develop promising treatment of cancer originated from naturally derived drug candidates. Herein, we sought to overview recent progress of the synthetic, physiological, and pharmacological investigations of oridonin and its derivatives, aiming to disclose the therapeutic potentials and broaden the platform for the discovery of new anticancer drugs.

High expression of CDCA7 predicts tumor progression and poor prognosis in human colorectal cancer

Colorectal cancer (CRC) is one of the most fatal types of cancer worldwide. This study aimed to determine the predictive and prognostic values of cell division cycle associated protein 7 (CDCA7) in CRC. Firstly, the relationship between CDCA7 and CRC was assessed through bioinformatics analysis. Subsequently, CDCA7 expression levels were detected in various CRC cell lines, as well as 15 fresh human CRC tissues and their paired adjacent normal colorectal tissues using reverse transcription‑quantitative PCR and western blotting. Additionally, immunohistochemical staining was used to determine the levels of CDCA7 in 104 CRC tissues and their paired adjacent normal colorectal tissues. The present study revealed that CDCA7 expression was upregulated in CRC tissues and cell lines. The positive expression rates of CDCA7 in normal and CRC tissues were 26.92 and 75.96%, respectively. The intensities of CDCA7 immunostaining were significantly associated with CRC invasion depth, lymph node metastasis, tumor‑node‑metastasis stage and distant metastasis. However, no significant differences in sex, age, tumor size and CRC differentiation were found between high and low CDCA7 expression groups. Furthermore, patients with low CDCA7 expression exhibited a greater overall survival rate of CRC compared to those with high CDCA7 expression. The findings of this study indicated that CDCA7 may serve a significant role in CRC prognosis and progression, and may be considered a novel biomarker for the prediction of patient survival after colectomy.

Oridonin induces the apoptosis of mucoepidermoid carcinoma cell lines in a myeloid cell leukemia‑1‑dependent manner

Oridonin, an active diterpenoid isolated from Rabdosia rubescens, has been reported to exhibit anticancer activities in several tumors. The aim of the present study was to investigate the anticancer effects and molecular mechanisms of oridonin in mucoepidermoid carcinoma (MEC). Treatment with oridonin induced the apoptosis of MC‑3 and YD‑15 cell and inhibited the expression of myeloid cell leukemia‑1 (MCL‑1) through the regulation of the protein level through post‑translational regulation in these cell lines. Oridonin significantly increased the expression level of truncated Bid (t‑Bid) as a downstream target of MCL‑1 and subsequently decreased the mitochondrial membrane potential. The ectopic expression of MCL‑1 protein was sufficient to reverse the induction of apoptosis and the increased t‑Bid expression induced by oridonin in both cell lines. Taken together, these results suggest that oridonin exerts an apoptotic effect through the modulation of MCL‑1 and t‑Bid in human MEC cell lines and may thus be a potential anticancer drug candidate for the treatment of human MEC.

Mechanistic Pathways and Molecular Targets of Plant-Derived Anticancer ent-Kaurane Diterpenes

Since the first discovery in 1961, more than 1300 ent-kaurane diterpenoids have been isolated and identified from different plant sources, mainly the genus Isodon. Chemically, they consist of a perhydrophenanthrene subunit and a cyclopentane ring. A large number of reports describe the anticancer potential and mechanism of action of ent-kaurane compounds in a series of cancer cell lines. Oridonin is one of the prime anticancer ent-kaurane diterpenoids that is currently in a phase-I clinical trial in China. In this review, we have extensively summarized the anticancer activities of ent-kaurane diterpenoids according to their plant sources, mechanistic pathways, and biological targets. Literature analysis found that anticancer effect of ent-kauranes are mainly mediated through regulation of apoptosis, cell cycle arrest, autophagy, and metastasis. Induction of apoptosis is associated with modulation of BCL-2, BAX, PARP, cytochrome c, and cleaved caspase-3, -8, and -9, while cell cycle arrest is controlled by cyclin D1, c-Myc, p21, p53, and CDK-2 and -4. The most common metastatic target proteins of ent-kauranes are MMP-2, MMP-9, VEGF, and VEGFR whereas LC-II and mTOR are key regulators to induce autophagy.

NLRP1 and NLRP3 inflammasomes as a new approach to skin carcinogenesis

Inflammasomes are key innate immune system receptors that detect pathogenic endo- and exogenous stressors like microorganisms or ultraviolet radiation (UVR) which activate the highly proinflammatory cytokines interleukin-1β and interleukin-18. Inflammasomes are not only involved in inflammation, but also in carcinogenesis and tumor progression. Due to the dynamic increase in non-melanoma skin cancers (NMSC), it has become necessary to determine how UVR, which plays a key role in NMSC development, can regulate the structure and function of inflammasomes. In the present study, the regulatory mechanisms of NOD-Like Receptor Family Pyrin Domain Containing 1 and 3 inflammasome activation as well as an effective inflammasome-mediated immune response after UVR exposition are discussed. The differences and similarities between these molecular complexes that monitor cellular health, inflammation, and skin carcinogenesis are also highlighted. Despite numerous scientific data, more studies are still required to better understand the biology of inflammasomes in skin cancer development and to explore their therapeutic potential.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Andrographolide Protects against HG-Induced Inflammation, Apoptosis, Migration, and Impairment of Angiogenesis via PI3K/AKT-eNOS Signalling in HUVECs

Andrographolide (Andr) is a major component isolated from the plant Andrographis paniculata. Inflammation, apoptosis, and impaired angiogenesis are implicated in the pathogenesis of high glucose (HG)-induced injury of vascular endotheliocytes. Our study is aimed at evaluating the effect of Andr on HG-induced HUVEC injury and the underlying mechanism. HUVECs were exposed to HG levels (33 mM) and treated with Andr (0, 12.5, 25, and 50 μM). Western blot analysis, real-time PCR, immunofluorescence staining, the scratch test, and the tube formation assay were performed to assess the effects of Andr. We discovered that Andr inhibited the inflammatory response (IL-1β, IL-6, and TNFα), decreased the apoptosis ratio and cell migration, and promoted tube formation in response to HG stimulation. Andr ameliorated the levels of phosphorylated PI3K (p-PI3K), phosphorylated AKT (p-AKT), and phosphorylated eNOS (p-eNOS). The expression of vascular endothelial growth factor (VEGF) protein, a vital factor in angiogenesis, was improved by Andr treatment under HG stimulation. LY294002 is a blocker of PI3K, MK-2206 2HCI (MK-2206) is a highly selective AKT inhibitor, and L-NAME is a suppressor of eNOS, all of which significantly reduce Andr-mediated protective effects in vitro. Hence, Andr may be involved in regulating HG-induced injury by activating PI3K/AKT-eNOS signalling in HUVECs.

Delivery of Oridonin and Methotrexate via PEGylated Graphene Oxide

Graphene oxide (GO) possessing plenty of hydroxyls and carboxyls is often used in the field of biomedicine. To improve its water solubility and biocompatibility, 6-armed poly(ethylene glycol) (PEG) was bonded on the surface of GO sheets via a facile amidation process to form the universal drug delivery platform (GO-PEG_10K-6arm) with a 200 nm size in favor of the enhanced permeability and retention effect. Herein, we prepared the stable and biocompatible platform of GO-PEG_10K-6arm under mild conditions and characterized the chemical structure and micromorphology via thermogravimetric analysis and atomic force microscopy. This nanosized GO-PEG_10K-6arm was found to be of very low toxicity to human normal cells of 293T and tumor cells of CAL27, MG63, and HepG2. Moreover, oridonin and methotrexate (MTX), widely used hydrophobic cancer chemotherapy drugs, were compounded with GO-PEG_10K-6arm via π-π stacking and hydrophobic interactions so as to afford nanocomplexes of oridonin@GO-PEG_10K-6arm and MTX@GO-PEG_10K-6arm, respectively. Both nanocomplexes could quickly enter into tumor cells, which was evidenced by inverted fluorescence microscopy using fluorescein isothiocyanate as a probe, and they both showed remarkably high cytotoxicity to the tumor cells of CAL27, MG63, and HepG2 within a broad range of concentration in comparison with free drugs. This kind of nanoscale drug delivery system based on GO-PEG_10K-6arm may have potential applications in biomedicine, and GO-PEG_10K-6arm would be a universal and available carrier for extensive hydrophobic anticarcinogens.

Zirconium-Porphyrin PCN-222: pH-responsive Controlled Anticancer Drug Oridonin

Drug delivery carriers with a high drug loading capacity and biocompatibility, especially for controlled drug release, are urgently needed due to the side effects and frequent dose in the traditional therapeutic method. Guided by nanomaterials, we have successfully synthesized zirconium-based metal-organic frameworks, Zr-TCPP (TCPP: tetrakis (4-carboxyphenyl) porphyrin), namely, PCN-222, which is synthesized by solvothermal method. And it has been designed as a drug delivery system (DDS) with a high drug loading of 38.77 wt%. In our work, PCN-222 has achieved pH-sensitive drug release and showed comprehensive SEM, TEM, PXRD, DSC, FTIR, and N2 adsorption-desorption. The low cytotoxicity and good biocompatibility of PCN-222 were certificated by the in vitro results from an MTT assay, DAPI staining, and Annexin V/PI double-staining even cultivated L02 cells and HepG2 cells for 48h. Furthermore, Oridonin, a commonly used cancer chemotherapy drug, is adsorbed into PCN-222 via the solvent diffusion technique. Based on an analysis of the Oridonin release profile, results suggest that it can last for more than 7 days in vitro. And cumulative release rate of Ori at the 7 d was about 86.29% and 63.23% in PBS (pH 5.5 and pH 7.2, respectively) at 37°C. HepG2 cells were chosen to research the cytotoxicity of PCN-222@Ori and free Oridonin. The results demonstrated that the PCN-222@Ori nanocarrier shows higher cytotoxicity in HepG2 cells compared to Oridonin.

New quinoline/chalcone hybrids as anti-cancer agents: Design, synthesis, and evaluations of cytotoxicity and PI3K inhibitory activity

A series of quinoline-chalcone hybrids was designed as potential anti-cancer agents, synthesized and evaluated. Different cytotoxic assays revealed that compounds experienced promising activity. Compounds 9i and 9j were the most potent against all the cell lines tested with IC₅₀ = 1.91-5.29 µM against A549 and K-562 cells. Mechanistically, 9i and 9j induced G₂/M cell cycle arrest and apoptosis in both A549 and K562 cells. Moreover, all PI3K isoforms were inhibited non selectively with IC₅₀s of 52-473 nM when tested against the two mentioned compounds with 9i being most potent against PI3K-γ (IC₅₀ = 52 nM). Docking of 9i and 9j showed a possible formation of H-bonding with essential valine residues in the active site of PI3K-γ isoform. Meanwhile, Western blotting analysis revealed that 9i and 9j inhibited the phosphorylation of PI3K, Akt, mTOR, as well as GSK-3β in both A549 and K562 cells, suggesting the correlation of blocking PI3K/Akt/mTOR pathway with the above antitumor activities. Together, our findings support the antitumor potential of quinoline-chalcone derivatives for NSCLC and CML by inhibiting the PI3K/Akt/mTOR pathway.

Biocompatible Fe-Based Micropore Metal-Organic Frameworks as Sustained-Release Anticancer Drug Carriers

Sustained-release preparation is a hot spot in antitumor drug research, where the first task is to select suitable drug carriers. Research has revealed that carboxylic acid iron metal⁻organic frameworks (MOFs), constructed from iron (Fe) ions and terephthalic acid, are nontoxic and biocompatible. Due to the breathing effect, the skeleton of this mesoporous material is flexible and can reversibly adapt its pore size through drug adsorption. Therefore, we chose one kind of Fe-MOF, MIL-53(Fe), as a carrier for the anticancer drug oridonin (Ori). In this work, we report the design and synthesis of MIL-53(Fe) and explore its ability as a transport vehicle to deliver Ori. MIL-53(Fe) is characterized by scanning electron microscopy and X-ray powder diffraction. A loading capacity of 56.25 wt % was measured by high performance liquid chromatography. This carrier was safe and nontoxic (cell viability > 95.27%), depending on the results of 3-(4,5-dimethylthiazol-2-yl)--2,5-diphenyltetrazolium bromide assays, lactate dehydrogenase assays, and Annexin V-fluoresce isothiocyanate/propidium iodide double-staining assays. After loading the drug, the structure of the MIL-53(Fe) was not destroyed, and Ori was amorphous in MIL-53(Fe). Based on an analysis of the Ori release profile, results suggest that it lasts for more than seven days in vitro. The cumulative release rate of Ori at the seventh day was about 82.23% and 91.75% in phosphate buffer saline solution at 37 °C under pH 7.2 and pH 5.5, respectively. HepG2 cells were chosen to study the cytotoxicity of Ori@MIL-53(Fe), and the results show that the anticancer ratio of Ori@MIL-53(Fe) system reaches 90.62%. Thus, MIL-53 can be used as a carrier for anticancer drugs and Ori@MIL-53(Fe) is a promising sustained-release drug delivery system for the cancer therapy.

Anticancer effects of oridonin on colon cancer are mediated via BMP7/p38 MAPK/p53 signaling

Colon cancer is a prevalent malignancy affecting the gastrointestinal tract. Oridonin (ORI) is a promising chemotherapeutic drug used in the treatment of colon cancer. In this study, we examined the anticancer activity of ORI against colon cancer and elucidated the underlying molecular mechanisms. Cell counting kit-8, flow cytometric and western blot analyses were conducted to analyze the growth inhibitory effects of ORI on SW620 cells; we employed BMP7 and p53 recombinant adenovirus to detect the influence of ORI on the p38 MAPK signal pathway; PT-qPCR, cell immunofluorescence staining and western blot analysis were used to detect the expression of BMP7, p38 and p-p38, p53 and p-p53. A xenograft tumor model and histological evaluation were introduced to detect the effects of ORI and BMP7 in SW620 cells in vivo. ORI inhibited the proliferation of SW620 cells and induced apoptosis. ORI also increased the total and phosphorylated levels of p53. The overexpression of p53 was found to enhance the anti-proliferative effects of ORI on the SW620 cells, while the inhibition of p53 partially reversed these effects. ORI increased the expression of bone morphogenetic protein 7 (BMP7) in the SW620 cells. The overexpression of BMP7 also enhanced the antiproliferative effects of ORI on the SW620 cells and reduced the growth rate of tumors in mice. BMP7-induced immunosuppression markedly decreased the anti-proliferative effects of ORI. ORI was not found to exert any substantial effect on the phosphorylation levels of Smad1/5/8, although it increased the level of p-p38 significantly. The inhibition of p38 significantly attenuated the ORI-induced increase in the levels of p-p53. The overexpression of BMP7 enhanced the promoting effects of ORI on the p-p53 and p-p38 levels, while BMP7-induced immunosuppression reduced the effects of ORI on p-p38 and p-p53. On the whole, the findings of this study suggest that ORI may be a promising agent for use in the treatment of colon cancer, and the anticancer effects of ORI may be partially mediated through the BMP7/p38 MAPK/p53 signaling pathway.

A natural ent‑kaurane diterpenoid induces antiproliferation in ovarian cancer cells via ERK1/2 regulation and inhibition of cellular migration and invasion

Ovarian cancer is one of the most common causes of female mortalities from gynecological tumors. An ent‑kaurane diterpenoid compound CRT1 (ent‑18‑acetoxy‑7β‑hydroxy kaur‑15‑oxo‑16‑ene), mainly isolated from the Vietnamese herb Croton tonkinesis has been used in folk medicine in Vietnam for cancer treatment. However, the effect of this compound on human ovarian cancer cells has not yet been reported. The objective of the present study was to determine the effect of CRT1 on the cell viability, apoptosis and metastasis of SKOV3 human ovarian cancer cells using a Cell Counting Kit‑8 assay, flow cytometric analysis of Annexin V‑fluorescein isothiocyanate/propidium iodide staining, western blot analysis, soft agar colony forming assay, wound healing assay and Matrigel invasion assay. The results revealed that CRT1 possessed significant anti‑proliferative effects on SKOV3 cells. CRT1 treatment at 25 and 50 µM induced apoptosis, enhanced the percentage of Annexin V‑positive cells, increased the expression of pro‑apoptotic protein B‑cell lymphoma 2 (Bcl‑2)‑associated X protein, cytochrome c release from the mitochondria to the cytosol, cleaved caspase‑3, caspase‑7, caspase‑9, and poly (adenosine diphosphate‑ribose) polymerase. However, it decreased the expression of Bcl‑2 in a dose‑dependent manner. The percentage of necrotic cells increased following CRT1 treatment at <10 µM. CRT1 at 50 µM significantly induced the phosphorylation of extracellular signal‑regulated kinase (ERK). Growth inhibition and the apoptotic effects of CRT1 could be reversed by PD98059, an ERK inhibitor. Additionally, CRT1 inhibited cell migration and invasion via ERK1/2 activation in SKOV3 cells. These results indicated that CRT1, an ent‑kaurane diterpenoid, may be a potential inhibitor of ovarian cancer by the activating ERK1/2/p90 ribosomal S6 kinase signaling pathway.

Targeting AKT with Oridonin Inhibits Growth of Esophageal Squamous Cell Carcinoma In Vitro and Patient-Derived Xenografts In Vivo

Overexpression or activation of AKT is very well known to control cell growth, survival, and gene expression in solid tumors. Oridonin, an inflammatory medical and diterpenoid compound isolated from Rabdosia rubescens, has exhibited various pharmacologic and physiologic properties, including antitumor, antibacterial, and anti-inflammatory effects. In this study, we demonstrated that oridonin is an inhibitor of AKT and suppresses proliferation of esophageal squamous cell carcinoma (ESCC) in vitro and in vivo The role of AKT in ESCC was studied using immuno-histochemical analysis of a tumor microarray, the effect of AKT knockdown on cell growth, and treatment of cells with MK-2206, an AKT inhibitor. Oridonin blocked AKT kinase activity and interacted with the ATP-binding pocket of AKT. It inhibited growth of KYSE70, KYSE410, and KYSE450 esophageal cancer cells in a time- and concentration-dependent manner. Oridonin induced arrest of cells in the G₂-M cell-cycle phase, stimulated apoptosis, and increased expression of apoptotic biomarkers, including cleaved PARP, caspase-3, caspase-7, and Bim_s in ESCC cell lines. Mechanistically, we found that oridonin diminished the phosphorylation and activation of AKT signaling. Furthermore, a combination of oridonin and 5-fluorouracil or cisplatin (clinical chemotherapeutic agents) enhanced the inhibition of ESCC cell growth. The effects of oridonin were verified in patient-derived xenograft tumors expressing high levels of AKT. In summary, our results indicate that oridonin acts as an AKT inhibitor to suppress the growth of ESCC by attenuating AKT signaling. Mol Cancer Ther; 17(7); 1540-53. ©2018 AACR.

Oridonin Targets Multiple Drug-Resistant Tumor Cells as Determined by in Silico and in Vitro Analyses

Drug resistance is one of the main reasons of chemotherapy failure. Therefore, overcoming drug resistance is an invaluable approach to identify novel anticancer drugs that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients for effective chemotherapy. Oridonin is a cytotoxic diterpenoid isolated from Rabdosia rubescens with in vivo anticancer activity. In the present study, we evaluated the cytotoxicity of oridonin toward a panel of drug-resistant cancer cells overexpressing ABCB1, ABCG2, or ΔEGFR or with a knockout deletion of TP53. Interestingly, oridonin revealed lower degree of resistance than the control drug, doxorubicin. Molecular docking analyses pointed out that oridonin can interact with Akt/EGFR pathway proteins with comparable binding energies and similar docking poses as the known inhibitors. Molecular dynamics results validated the stable conformation of oridonin docking pose on Akt kinase domain. Western blot experiments clearly revealed dose-dependent downregulation of Akt and STAT3. Pharmacogenomics analyses pointed to a mRNA signature that predicted sensitivity and resistance to oridonin. In conclusion, oridonin bypasses major drug resistance mechanisms and targets Akt pathway and might be effective toward drug refractory tumors. The identification of oridonin-specific gene expressions may be useful for the development of personalized treatment approaches.

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.

Oridonin inhibits migration, invasion, adhesion and TGF-β1-induced epithelial-mesenchymal transition of melanoma cells by inhibiting the activity of PI3K/Akt/GSK-3β signaling pathway

Epithelial-mesenchymal transition (EMT) has been reported to play pivotal roles in tumor invasion and metastasis. Inhibition of EMT may exert beneficial effects in regulating metastasis. Oridonin (ORI), an active diterpenoid compound isolated from Rabdosia rubescens, was found to be a potent anti-metastatic agent. However, the possible involvement of ORI in the EMT in malignant melanoma is unclear. The present study found that ORI inhibited cell migration, invasion, and adhesion in A375 and B16-F10 melanoma cells. The transforming growth factor-β1 (TGF-β1)-induced EMT was also inhibited in ORI-treated cells, as reflected in the upregulation of E-cadherin, and downregulation of vimentin and Snail. Similar results were observed in A375 and B16-F10 melanoma cells treated with ORI. Furthermore, pre-treatment with ORI blocked the TGF-β1-induced phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (Akt)/glycogen synthase kinase (GSK)-3β signaling pathway activation. These effects mimicked PI3 kinase inhibitor LY294002 treatment. ORI interfered with the PI3K/Akt/GSK-3β pathway, and reversed TGF-β1-induced EMT, which suppressed the invasion and metastasis of melanoma cells. Taken together, the present study demonstrated that ORI inhibits melanoma cells migration, invasion, and adhesion and TGF-β1-induced EMT through the PI3K/Akt/GSK-3β signaling pathway. These findings suggest that ORI is a promising anti-metastasis agent for melanoma.

GE11 peptide conjugated selenium nanoparticles for EGFR targeted oridonin delivery to achieve enhanced anticancer efficacy by inhibiting EGFR-mediated PI3K/AKT and Ras/Raf/MEK/ERK pathways

Selenium nanoparticles (Se NPs) have attracted increasing interest in recent decades because of their anticancer, immunoregulation, and drug carrier functions. In this study, GE11 peptide-conjugated Se NPs (GE11-Se NPs), a nanosystem targeting EGFR over-expressed cancer cells, were synthesized for oridonin delivery to achieve enhanced anticancer efficacy. Oridonin loaded and GE11 peptide conjugated Se NPs (GE11-Ori-Se NPs) were found to show enhanced cellular uptake in cancer cells, which resulted in enhanced cancer inhibition against cancer cells and reduced toxicity against normal cells. After accumulation into the lysosomes of cancer cells and increase of oridonin release under acid condition, GE11-Ori-Se NPs were further transported into cytoplasm after the damage of lysosomal membrane integrity. GE11-Ori-Se NPs were found to induce cancer cell apoptosis by inducting reactive oxygen species (ROS) production, activating mitochondria-dependent pathway, inhibiting EGFR-mediated PI3K/AKT and inhibiting Ras/Raf/MEK/ERK pathways. GE11-Se NPs were also found to show active targeting effects against the tumor tissue in esophageal cancer bearing mice. And in nude mice xenograft model, GE11-Ori-Se NPs significantly inhibited the tumor growth via inhibition of tumor angiogenesis by reducing the angiogenesis-marker CD31 and activation of the immune system by enhancing IL-2 and TNF-α production. The selenium contents in mice were found to accumulate into liver, tumor, and kidney, but showed no significant toxicity against liver and kidney. This cancer-targeted design of Se NPs provides a new strategy for synergistic treating of cancer with higher efficacy and reduced side effects, introducing GE11-Ori-Se NPs as a candidate for further evaluation as a chemotherapeutic agent for EGFR over-expressed esophageal cancers.