Hedyotis diffusa Willd overcomes 5-fluorouracil resistance in human colorectal cancer HCT-8/5-FU cells by downregulating the expression of P-glycoprotein and ATP-binding casette subfamily G member 2

Sanguisorba officinalis L. enhances the 5-fluorouracil sensitivity and overcomes chemoresistance in 5-fluorouracil-resistant colorectal cancer cells via Ras/MEK/ERK and PI3K/Akt pathways

Sanguisorba officinalis L., a traditional Chinese medicine (TCM) called DiYu (DY) in China, has a strong tradition of utilization as a scorching, blood-cooling, and hemostatic medication, and was used for cancer prevention and treatment due to its potential immune-enhancing and hematological toxicity-reducing effects. Previous studies have reported significant effects of DY on cancers including colorectal cancer (CRC), which is one of the most common malignancies worldwide. The first-line cure 5-fluorouracil (5-FU) plays decisive commerce in the sedative of CRC as a clinically available chemotherapeutic agent. One of the primary causes of cancer treatment failure is the acquisition of chemotherapy drug resistance. In order to successfully combat the emergence of chemoresistance, it is essential to identify herbs or traditional Chinese medicine that have adjuvant therapeutic effects on CRC. Therefore, this study aimed to determine whether DY could improve the sensitivity, conquer the chemoresistance of 5-FU-resistant CRC cells, and investigate its intrinsic mechanism.

Materials and methods

MTT, Hoechst 33258 staining, and flow cytometry assays were used to determine the anticancer activity of DY alone or in combination with 5-FU against 5-FU-resistant CRC cells (RKO-R and HCT15-R) and wound healing assays were conducted to detect cell migration. Transcriptomic techniques were carried out to explore the effect and mechanism of DY on drug-resistant CRC cells. Western Blot and RT q-PCR assays were performed to validate the mechanism by which DY overcomes drug-resistant CRC cells.

Results

These results indicated that DY alone or in combination with 5-FU significantly inhibited the proliferation and the migration of resistant CRC cells, and potentiated the susceptibility of 5-FU to drug-resistant CRC cells. GO and KEGG enrichment analysis showed that the mechanisms of drug resistance in CRC cells and DY against drug-resistant CRC cells highly overlapped, involved in the modulation of biological processes such as cell migration, positive regulation of protein binding and cytoskeleton, and MAPK (Ras-ERK-MEK), PI3K/Akt, and other signaling pathways. Moreover, DY can mediate the expression of p-R-Ras, p-ERK1/2, p-MEK1/2, p-PI3K, p-AKT, HIF-1A and VEGFA proteins. In addition, DY significantly suppressed the expression of AKT3, NEDD9, BMI-1, and CXCL1 genes in resistant CRC cells.

Conclusion

In conclusion, DY could inhibit the proliferation and migration of 5-FU-resistant cells and strengthen the sensitivity of 5-FU to CRC-resistant cells. Furthermore, DY may prevail over chemoresistance through the Ras/MEK/ERK and PI3K/Akt pathways. These findings imply that DY may be a potential drug for clinical treatment or adjuvant treatment of drug-resistant CRC.

Ursolic acid silences CYP19A1/aromatase to suppress gastric cancer growth

INTRODUCTION

Gastric cancer (GCa) is a malignancy with few effective treatments. Ursolic acid (UA), a bioactive triterpenoid enriched in Hedyotis diffusa Willd, known to suppress GCa without identified target. CYP19A1 (cytochrome P450 family 19A1; also known as aromatase, Ar) was correlated to GCa prognosis. Relatedly, Ar silencers, which halt the expression of Ar exhibited anti-GCa effects in experimental models, are currently being investigated.

METHOD

The docking simulation score of UA was compared with Ar inhibitors, e.g., letrozole, exemestane, in Ar protein crystallization. Hedyotis diffusa Willd ethanol extract, UA, or 5-fluracil were applied onto AGS, SC-M1, MKN45 GCa cells for cancer inhibition tests. Immunoblot for measuring gene expressions upon drug treatments, or gene knockdown/overexpression. Treatments were also applied in a MKN45 implantation tumor model. A web-based GCa cohort for Ar expression association with prognosis was performed.

RESULT

The ethanol extracts of Hedyotis diffusa Willd, enrich with UA, exhibited cytotoxic activity against GCa cells. Molecular docking simulations with the 3D Ar structure revealed an excellent fitting score for UA. UA increase cytotoxic, and suppressed colony, in addition to its Ar silencing capacity. Moreover, UA synergistically facilitated 5-FU, (a standard GCa treatment) regimen in vitro. Consistent with those results, adding estradiol did not reverse the cancer-suppressing effects of UA, which confirmed UA acts as an Ar silencer. Furthermore, UA exhibited tumor-suppressing index (TSI) score of 90% over a 6-week treatment term when used for single dosing in xenograft tumor model. In the clinical setting, Ar expression was found to be higher in GCa tumors than normal parental tissue from the TCGA (The Cancer Genome Atlas) cohort, while high Ar expression associated with poor prognosis. Together, the results indicate UA could be used to treat GCa by silencing Ar expression in GCa. Hedyotis diffusa Willd ethanol extract could be an functional food supplements.

Molecular Mechanism of Anti-Colorectal Cancer Effect of Hedyotis diffusa Willd and Its Extracts

With the sharp change in our diet and lifestyle, the incidence of colorectal cancer (CRC) is increasing among young people and has become the second most common malignant tumor worldwide. Although the current treatment of CRC is getting updated rapidly, recurrence and metastasis are still inevitable. Therefore, new anticancer drugs are needed to break existing limitations. In recent years, Hedyotis diffusa Willd (HDW) extracts have been proved to demonstrate excellent anti-colorectal cancer effects and have been widely used in clinical practices. In this review, we aim to explore the advantages, potential signaling pathways, and representative active ingredients of HDW in the treatment of CRC from the perspective of molecular mechanism, in order to provide new ideas for the future treatment of CRC.

Dose-dependent effects of Hedyotis diffusa extract on the pharmacokinetics of tamoxifen, 4-hydroxytamoxifen, and N-desmethyltamoxifen

Tamoxifen, a widely prescribed medication in premenopausal women diagnosed with hormone-dependent breast cancer, is potentially co-prescribed with Hedyotis diffusa (H. diffusa), particularly in Taiwan. However, no related report has investigated the drug-herb interaction of H. diffusa on the pharmacokinetics of tamoxifen and its metabolites. In the present study, male Sprague-Dawley rats were administered different doses of H. diffusa extract for 5 consecutive days prior to the administration of tamoxifen (10 mg/kg). A validated ultra-liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) system was developed to monitor tamoxifen, 4-hydroxytamoxifen, N-desmethyltamoxifen, and endoxifen in rat plasma. Pharmacokinetic results demonstrated that the area under curves (AUCs) of tamoxifen and the relative bioavailability (%) of tamoxifen were dose-dependently decreased (31-68%) by pre-treatment with H. diffusa extract (3 g/kg and 6 g/kg). In addition, the conversion ratio of 4-hydroxytamoxifen was downregulated (0.5-fold change) and the N-desmethyltamoxifen conversion ratio was upregulated (2-fold change) by high-dose H. diffusa extract. As a result, the relative bioavailability and biotransformation changes affect the clinical efficacy of tamoxifen treatment. These preclinical findings reveal a hitherto unreported interaction between tamoxifen and H. diffusa extract that has implications for their therapeutic efficacy in treating breast cancer.

Some Bryophytes Trigger Cytotoxicity of Stem Cell-like Population in 5-Fluorouracil Resistant Colon Cancer Cells

Colorectal cancer is the third most common cancer worldwide. Cancer stem cells are known to play an important role in relapse, and metastases of the disease after chemotherapy. Investigation of new drugs, and their combinations targeting these cells and thus eliminating cancer is one of the most urgent needs of today's chemotherapy. The aim of the present study was to evaluate the effects of Bryophytes like Abietinella abietina (AA), Homolothecium sericeum (HS), Tortella tortuosa (TT), Syntrichia ruralis (SR), and Bryoerythrophyllum rubrum (BR) species extracted with ethyl alcohol on 5-fluorouracil(5-FU) resistant colorectal cancer cell lines (HCT116 and HT29). After extraction, stock solutions of bryophytes were prepared, and IC₅₀ values were detected in drug-resistant cells obtained with 5-FU application. CD24+, CD44+/CD133+ surface markers and P-glycoprotein (P-gp) mediated efflux were isolated from both 5-FU treated cells and analyzed using the flow cytometry. In all bryophyte-treated groups, the binding Rho123^low (low Rho fluorescence) and Rho^high (high Rho fluorescence) were sorted from 5-FU resistant HCT116, and HT-29 cells. All types of bryophytes were found cytotoxic. Bryophyte extract reduced the percentage of Rho^low cells in cultures incubated with 5-FU. In summary, the implementation of these bryophytes might be regarded as an effective approach for treatment of colorectal cancer due to their cytotoxic effect that decreases the recurrence of the disease.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1933098.

The effectiveness of Hedyotis diffusa Willd extract in a mouse model of experimental autoimmune prostatitis

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a frustrating and often debilitating disease. Current studies have shown that Traditional Chinese Medicine (TCM) can improve patients' quality of life and alleviate CP/CPPS symptoms. In this study, the efficacy of Hedyotis diffusa Willd aqueous extraction in experimental autoimmune prostatitis (EAP) mice models was revealed. The C57BL/6 mice were randomly assigned to three groups. Except for the control group, all other groups were subcutaneously injected with 0.2 ml emulsion of T2 peptide, on day 0 and day 14, for inducing EAP models. After the EAP modelling, oral saline was given to the model group, while the H. diffusa group was treated with aqueous extract of H. diffusa Willd. Micturition habits and withdrawal response frequencies were measured. Haematoxylin and eosin staining and immunohistochemistry were used to investigate inflammatory cell infiltration and TNF-α in the prostate tissue respectively. TNF-α levels in the serum were evaluated by ELISA. The H. diffusa Willd aqueous extraction considerably reduced the urine spots number and increased the pain threshold in H. diffusa group. H. diffusa group showed significantly reduced inflammatory lesion and inflammatory cell infiltration than the model group. The levels of TNF-α in H. diffusa group were considerably reduced.

Effect of ABC transporter expression and mutational status on survival rates of cancer patients

ATP-binding cassette (ABC) transporters mediate multidrug resistance in cancer. In contrast to DNA single nucleotide polymorphisms in normal tissues, the role of mutations in tumors is unknown. Furthermore, the significance of their expression for prediction of chemoresistance and survival prognosis is still under debate. We investigated 18 tumors by RNA-sequencing. The mutation rate varied from 27,507 to 300885. In ABCB1, three hotspots with novel mutations were in transmembrane domains 3, 8, and 9. We also mined the cBioPortal database with 11,814 patients from 23 different tumor entities. We performed Kaplan-Meier survival analyses to investigate the effect of ABC transporter expression on survival rates of cancer patients. Novel mutations were also found in ABCA2, ABCA3, ABCB2, ABCB5, ABCC1-6, and ABCG2. Mining the cBioPortal database with 11,814 patients from 23 different tumor entities validated our results. Missense and in-frame mutations led to altered binding of anticancer drugs in molecular docking approaches. The ABCB1 nonsense mutation Q856* led to a truncated P-glycoprotein, which may sensitize tumors to anticancer drugs. The search for ABC transporter nonsense mutations represents a novel approach for precision medicine.. Low ABCB1 mRNA expression correlated with significantly longer survival in ovarian or kidney cancer and thymoma. In cancers of breast, kidney or lung, ABC transporter expression correlated with different tumor stages and human populations as further parameters to refine strategies for more individualized chemotherapy.

Combating Drug Resistance in Colorectal Cancer Using Herbal Medicines

Colorectal cancer (CRC) is one of the most prevalent and lethal cancer types around the world. Most of the CRC patients are treated with chemotherapeutic drugs alone or combined. However, up to 90% of metastatic cancer patients experience the failure of treatment mostly because of the acquired drug resistance, which can be led to multidrug resistance (MDR). In this study, we reviewed the recent literature which studied potential CRC MDR reversal agents among herbal medicines (HMs). Among abundant HMs, 6 single herbs, Andrographis paniculata, Salvia miltiorrhiza, Hedyotis diffusa, Sophora flavescens, Curcuma longa, Bufo gargarizans, and 2 formulae, Pien Tze Huang and Zhi Zhen Fang, were found to overcome CRC MDR by two or more different mechanisms, which could be a promising candidate in the development of new drugs for adjuvant CRC chemotherapy.

Chinese herbal medicines for prevention and treatment of colorectal cancer: From molecular mechanisms to potential clinical applications

Worldwide, colorectal cancer (CRC) is one of the most common malignant tumors, leading to immense social and economic burdens. Currently, the main treatments for CRC include surgery, chemotherapy, radiotherapy and immunotherapy. Despite advances in the diagnosis and treatment of CRC, the prognosis for CRC patients remains poor. Furthermore, the occurrence of side effects and toxicities severely limits the clinical use of these therapies. Therefore, alternative medications with high efficacy but few side effects are needed. An increasing number of modern pharmacological studies and clinical trials have supported the effectiveness of Chinese herbal medicines (CHMs) for the prevention and treatment of CRC. CHMs may be able to effectively reduce the risk of CRC, alleviate the adverse reactions caused by chemotherapy, and prolong the survival time of patients with advanced CRC. Studies of molecular mechanisms have provided deeper insight into the roles of molecules from CHMs in treating CRC. This paper summarizes the current understanding of the use of CHMs for the prevention and treatment of CRC, the main molecular mechanisms involved in these processes, the role of CHMs in modulating chemotherapy-induced adverse reactions, and CHM's potential role in epigenetic regulation of CRC. The current study provides beneficial information on the use of CHMs for the prevention and treatment of CRC in the clinic, and suggests novel directions for new drug discovery against CRC.

Protective Antioxidant Effects of Amentoflavone and Total Flavonoids from Hedyotis diffusa on H2 O2 -Induced HL-O2 Cells through ASK1/p38 MAPK Pathway

In this study, total flavonoids and total triterpenoid acid were extracted with ethyl acetate from Hedyotis diffusa Willd, and hepatoprotective activities of them and five compounds from total flavonoids against H₂ O₂ induced hepatocyte damage on HL-02 cells were determined. In particular, amentoflavone and total flavonoids had influence on the leakage of ALT, AST, LDH, the activities of SOD and the content of MDA. They effectively reduced the loss of MMP, the release of Cyt C, and then inhibited activation of caspase-3/caspase-9 cascade in hepatotoxic cells. The contents of ROS were significantly reduced to inhibit p38 in amentoflavone and flavonoids groups which decreased ASK1 and p-p38 levels through increasing thioredoxin Trx1 and reductase TrxR1. These results suggesting that the antioxidant protection of amentoflavone and flavonoids might be reducing ROS to inhibit the H₂ O₂ -induced upstream of pathway via increasing levels of Trx1 and TrxR1, which were pivotal in blocking the down streaming effectors of ASK1/p38 MAPK pathway and alleviating hepatotoxicity.

Spica Prunellae Extract Enhances Fluorouracil Sensitivity of 5-Fluorouracil-Resistant Human Colon Carcinoma HCT-8/5-FU Cells via TOP2α and miR-494

The use of 5-fluorouracil (5-FU) has been proven benefits, but it also has adverse events in colorectal cancer (CRC) chemotherapy. In this study, we explored the mechanism of 5-FU resistance by bioinformatics analysis of the NCBI public dataset series GSE81005. Fifteen hub genes were screened out of 582 different expressed genes. Modules of the hub genes in protein-protein interaction networks gathered to TOP2α showed a decrease in HCT-8 cells but an increase in 5-FU-resistant HCT-8/5-FU cells with 5-FU exposure. Downregulation of TOP2α with siRNA or miR-494 transfection resulted in an increase of cytotoxicity and decrease of cell colonies to 5-FU for HCT-8/5-FU cells. Moreover, we found that an ethanol extract of Spica Prunellae (EESP), which is a traditional Chinese medicine with clinically beneficial effects in various cancers, was able to enhance the sensitivity of 5-FU in HCT-8/5-FU cells and partly reverse the 5-FU resistance effect. It significantly helped suppress cell growth and induced cell apoptosis in HCT-8/5-FU cells with the expression of TOP2α being significantly suppressed, which increased by 5-FU. Consistently, miR-494, which reportedly regulates TOP2α, exhibited reverse trends in EESP/5-FU combination treatment. These results suggested that Spica Prunellae may be beneficial in the treatment of 5-FU-resistant CRC patients.

CAC1 knockdown reverses drug resistance through the downregulation of P-gp and MRP-1 expression in colorectal cancer

CDK2-associated cullin domain 1 (CAC1) is as a novel cell cycle regulator widely expressed in colorectal cancer (CRC). However, its expression and function in drug resistant CRC cells remains elusive. Therefore, the present study aimed to assess the biochemical function and relevance of CAC1 in drug resistant CRC cells, and detect the potential mechanism. For this purpose, a total of 83 CRC cases were collected for the immunohistochemical analysis of CAC1 expression. Functional studies (stable transfection, flow cytometry, colony formation, and invasion and migration assays) were performed in SW480, LoVo and their corresponding 5-FU resistant cells. In addition, a nude mice xenograft model was established for further observation in vivo. In the present study, CAC1 protein expression was higher in CRC tissues than that in normal tissues (P<0.05). Furthermore, CAC1 protein expression was higher in SW480/5-FU cells than in SW480 cells. CAC1 knockdown arrested 5-FU resistant cells at the G1/S phase and increased the sensitivity of 5-FU resistant cells to 5-FU by inducing apoptosis. In addition, CAC1 reduced the invasive and migration ability of SW480/5-FU and LoVo/5-FU cells in vitro, and reduced their tumorigenicity and metastatic ability in vivo. Finally, CAC1 knockdown resulted in decreased P-glycoprotein and MRP-1 protein expression. Based on these results, it can be concluded that CAC1 plays an important role in the occurrence and promotion of drug resistance in CRC. Therefore, the knockdown of CAC1 may be considered as a new strategy for the development of CRC drug resistance treatments in the future.

Synergistic effect of kaempferol and 5‑fluorouracil on the growth of colorectal cancer cells by regulating the PI3K/Akt signaling pathway

Combination chemotherapy with chemosensitizers can exert synergistic therapeutic effects, reduce toxicity, and delay the induction of drug resistance. In the present study, the antitumor effects were investigated, and the possible underlying mechanisms of kaempferol combined with 5‑fluorouracil (5‑FU) in colorectal cancer cells were explored. HCT‑8 or HCT‑116 cells were treated with various concentrations of kaempferol and/or 5‑FU for the indicated time‑points. An MTT assay was used to determine cell viability, whereas the synergistic effects were assessed by calculating the combination indices of kaempferol and 5‑FU. Annexin V analysis and Hoechst staining were used to determine cell apoptosis. q‑PCR and western blotting were performed to determine the expression levels of Bax, Bcl‑2, thymidylate synthase (TS), PTEN, PI3K, AKT, and p‑AKT. The combination of kaempferol and 5‑FU was determined to be more effective in inhibiting cell viability than either of the agents alone. The inhibition of tumors in response to kaempferol and 5‑FU was associated with the reduction in proliferation ability and stimulation of apoptosis. The protein results indicated that kaempferol and 5‑FU could significantly upregulate the expression levels of Bax and downregulate the expression levels of Bcl‑2 and TS. Furthermore, the combination treatment greatly inhibited the activation of the PI3K/Akt pathway, suggesting the involvement of this pathway in the synergistic effects. The present study demonstrated that kaempferol has a synergistic effect with 5‑FU by inhibiting cell proliferation and inducing apoptosis in colorectal cancer cells via suppression of TS or attenuation of p‑Akt activation. The combination of kaempferol and 5‑FU may be used as an effective therapeutic strategy for colorectal cancer.

Cardamonin, a natural chalcone, reduces 5-fluorouracil resistance of gastric cancer cells through targeting Wnt/β-catenin signal pathway

Objectives Cardamonin (CD), an active chalconoid, has been extensively studied in a wide variety of human tumors. However, the effects and underlying mechanism of cardamonin on 5-fluorouracil (5-FU)-resistant gastric cancer (GC) remain largely unclear. This study aimed to investigate the antitumor effects of cardamonin on 5-FU-resistant GC cells and explore the molecular mechanisms underlying its therapeutic potential. Methods The antitumor activities of cardamonin, 5-FU and their combination against BGC-823 and BGC-823/5-FU cells were determined using cytotoxicity assay, flow cytometry-based cell cycle analysis and Annexin V apoptosis assay. The effect of cardamonin on P-glycoprotein activity was assessed by Rh123 uptake assay. Real-time PCR, Western blotting and Co-immunoprecipitation analysis were carried out to assess the inhibition of Wnt/β-catenin signaling pathway. A xenograft mouse model was established using BALB/c nude mice to examine the combinatorial effects of cardamonin and 5-FU on tumor growth. Results Our data provided the first demonstration that cardamonin significantly enhanced the chemosensitivity of 5-FU in GC cells via suppression of Wnt/β-catenin signaling pathway. Additionally, the combination of cardamonin and 5-FU might result in the apoptosis and cell cycle arrest of BGC-823/5-FU cells, accompanied by the downregulated expression levels of P-glycoprotein, β-catenin and TCF4. More importantly, our results demonstrated that cardamonin specifically disrupted the formation of β-catenin/TCF4 complex, leading to TCF4-mediated transcriptional activation in 5-FU-resistant GC cells. Besides, through a xenograft mouse model, co-administration of cardamonin and 5-FU significantly retarded tumor growth in vivo, thus, confirming our in vitro findings. Conclusions Overall, this study revealed that cotreatment of cardamonin and 5-FU could strongly potentiate the antitumor activity of 5-FU, and put forth cardamonin as a rational therapeutic strategy for drug-resistant GC treatment.

The combination of curcumin and 5-fluorouracil in cancer therapy

5-Fluorouracil (5-FU) alone or in combination with other therapeutic drugs has been widely used for clinical treatment of various cancers. However, 5-FU-based chemotherapy has limited anticancer efficacy in clinic due to multidrug resistance and dose-limiting cytotoxicity. Some molecules and genes in cancer cells, such as nuclear factor kappa B, insulin-like growth factor-1 receptor, epidermal growth factor receptor, cyclooxygenase-2, signal transducer and activator of transcription 3, phosphatase and tensin homolog deleted on chromosome ten and Bcl-2 etc. are related to the chemoresistance and sensitivity of cancer cells to 5-FU. The activation of these molecules and genes expressions in cancer cells will be increased or decreased with long-term exposure of 5-FU. Curcumin has been found to be able to negatively regulate these processes. In order to overcome the problems of 5-FU, curcumin has been used to combine with 5-FU in cancer therapy.

Hedyotis diffusa Willd inhibits proliferation and induces apoptosis of 5‑FU resistant colorectal cancer cells by regulating the PI3K/AKT signaling pathway

Hedyotis diffusa Willd (HDW) is a major component frequently used in Traditional Chinese Medicine for the clinical treatment of colorectal cancer (CRC) and its associated drug resistance. However, the underlying mechanism of HDW circumventing drug resistance of cancer cells remains to be elucidated. Cancer cell resistance to apoptosis and activation of the phosphatidylinositol‑3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway have been implicated as major factors in the acquired resistance to chemotherapeutic anti‑cancer drugs. The present study investigated the effect and mechanisms of action of ethanol extract of Hedyotis diffusa Willd (EEHDW) on the proliferation and apoptosis of CRC 5‑fluorouracil (5‑FU) resistant (HCT‑8/5‑FU) cells. CRC HCT‑8/5‑FU cell viability following treatment with EEHDW was determined using MTT and colony formation assay. In addition, Annexin V/propidium iodide staining with flow cytometry analysis and 4',6‑diamidino‑2‑phenylindole staining were used to determine the apoptosis of drug‑resistant cancer cells following treatment with EEHDW. The mRNA and protein expression levels of B cell leukemia/lymphoma (Bcl‑2), Bcl‑2 associated X (Bax), cyclin dependent kinase 4 (CDK4), cyclin D1 and p21 were evaluated using reverse transcription‑polymerase chain reaction and western blot analysis, respectively. Furthermore, activation of the PI3K/AKT signaling pathway and expression of phosphatase and tensin homolog (PTEN), PI3K, AKT and phosphorylated (p)‑AKT were determined. EEHDW significantly reduced cell viability, inhibited cell colony formation and promoted apoptosis of HCT‑8/5‑FU cells. Furthermore, EEHDW significantly downregulated the expression of Bcl‑2, cyclin D1 and CDK4 and upregulated the expression of Bax and p21. In addition, EEHDW inhibited the activation of the PI3K/AKT pathway by increasing expression of PTEN and suppressing the expression of PI3K and p‑AKT. The present study provided the first direct evidence that EEHDW may overcome drug‑resistance in human CRC cells by inhibiting PI3K/AKT signaling pathway and provides a basis for the improved therapeutic use of HDW in the clinical treatment of cancer.

Hedyotis diffusa willd extract suppresses colorectal cancer growth through multiple cellular pathways

The development of colorectal cancer (CRC) is strongly associated with the imbalance of various intracellular signal transduction cascades, including protein kinase B (AKT), mitogen-activated protein kinase 1 (MAPK), signal transducer and activator of transcription 3 (STAT3), as well as crosstalk between these signaling networks. At present, anti-tumor agents are often single-targeted and therefore are not always therapeutically effective. Moreover, long-term use of these anti-tumor agents often generates drug resistance and potential side effects. These problems highlight the urgent need for the development of novel and more effective anti-cancer drugs. Hedyotis diffusa Willd (HDW) has been used as a major component in traditional Chinese medicine for the clinical treatment of colorectal cancer, with a limited number of adverse effects. However, the molecular mechanisms, which underlie its anti-cancer activity, still require further elucidation. In the present study, using xenograft models and various different human CRC cell lines, the efficacy of the ethanol extract of HDW (EEHDW) against tumor growth was evaluated, and its underlying molecular mechanisms of action were investigated. It was demonstrated that EEHDW was able to inhibit cancer growth in vivo and in vitro. Furthermore, EEHDW was able to suppress the activation of several CRC-associated signaling pathways and was able to regulate the expression of various inflammatory and angiogenic factors. This resulted in the induction of apoptosis and inhibition of cellular proliferation, as well as tumor angiogenesis. The present study demonstrated that EEHDW is able to exhibit anti-cancer activity due to its ability to affect multiple intracellular targets, which suggests that it may be a novel multi-potent therapeutic agent for the treatment of colorectal cancer.

Hedyotis diffusa Willd suppresses metastasis in 5‑fluorouracil‑resistant colorectal cancer cells by regulating the TGF‑β signaling pathway

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract, and threatens the survival and health of patients with CRC. Chemotherapy remains one of the main therapeutic approaches for patients with CRC; however, drug resistance limits the long‑term use. CRC cells with multi‑drug resistance (MDR) exhibit increased survival times and metastatic potential, which may lead to the recurrence and metastasis of CRC. In addition, MDR is one of the major causes of chemotherapy failure in clinical treatment. Hedyotis diffusa Willd (HDW) has been used in the treatment of inflammation‑associated diseases and malignant tumors, including CRC. The authors previously demonstrated that HDW could reverse MDR in CRC cells; however, its underlying mechanism, particularly in MDR‑associated metastasis, remains to be elucidated. In the present study, the drug‑resistant CRC cell line HCT‑8/5‑fluorouracil (5‑FU) was used to investigate the effect of HDW on the growth and metastasis of cancer cells. Cell viability was assessed using the MTT assay. Cell adhesion potential was evaluated using adhesion experiments. Cell migration was assessed using wound healing and Transwell assays. The mRNA and protein expression levels of crucial factors in the transforming growth factor‑β (TGF‑β) signaling pathway, including TGF‑β, Mothers against decapentaplegic homolog 4 (SMAD4), neural (N)‑cadherin, and epithelial (E)‑cadherin, were analyzed using the reverse transcription‑semi‑quantitative polymerase chain reaction and western blotting, respectively. The results demonstrated that the HCT‑8/5‑FU cell line was more resistant to 5‑FU and thus can be used as the resistant cell model. HDW was able to inhibit the viability, and adhesive, migratory and invasion potential of the HCT‑8/5‑FU cells. In addition, HDW was able to downregulate the expression of TGF‑β, SMAD4 and N‑cadherin, and upregulate E‑cadherin, at the gene and protein level. In conclusion, the results demonstrated that HDW may suppress the metastasis of 5‑FU‑resistant CRC cells via regulation of the TGF‑β signaling pathway, which was also considered to be one of the underlying mechanisms of its anti‑CRC effect.

Synergistic inhibition of leukemia WEHI-3 cell growth by arsenic trioxide and Hedyotis diffusa Willd extract in vitro and in vivo

Arsenic trioxide (ATO) is clinically used to treat acute promyelocytic leukemia (APL); however, the therapeutic dose of ATO may prompt critical cardiac side effects. Combination therapy may be used to improve the therapeutic efficiency. To evaluate this possibility, the present study determined the combined effects of Hedyotis diffusa Willd (HDW) extract and ATO in leukemic WEHI-3 cells. The results demonstrated that co-treatment of HDW with ATO resulted in a synergistic augmentation of cytotoxicity in cells at the concentration tested. In order to investigate the potential therapeutic application for leukemia, the combined effects of HDW and ATO were analyzed on the WEHI-3 cell-induced orthotopic leukemia animal model in vivo. The WEHI-3 cells in mice with leukemia were established by injecting murine WEHI-3 cells into BALB/c mice, and treating them with HDW and/or combined with ATO. The results indicated that HDW alone or HDW combined with ATO promoted the total survival rate of mice with leukemia, and these effects are dose-dependent. HDW alone or HDW combined with ATO did not affect the body weight, decreased the spleen weight and did not affect the liver weight. Furthermore, the results demonstrated that HDW alone or HDW combined with ATO resulted in a synergistic augmentation of apoptosis in WEHI-3 cells at the concentration tested. In order to further reveal the detailed mechanism of this synergistic effect on apoptosis, apoptosis-related proteins were also evaluated. The data revealed that HDW alone or HDW combined with ATO induced the expression of death receptor 4 (DR4) and DR5 and the activation of poly adenosine diphosphate ribose polymerase, caspase-3, -8 and -9. Furthermore, HDW alone or HDW combined with ATO decreased the expression levels of B-cell lymphoma 2, B-cell lymphoma-extra large and survivin, and increased the expression levels of Bak and t-Bid. Altogether, the results indicate that the combination of HDW with ATO may be a promising strategy used to increase the clinical efficacy of ATO in the treatment of APL.

The anti-tumor effect and bioactive phytochemicals of Hedyotis diffusa willd on ovarian cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hedyotis diffusa willd (HDW) is a widely used medicinal herb in China. It processed various medicinal properties including antioxidative, anti-inflamatory and anti-cancer effects. This study aimed to investigate the anti-tumor effects of HDW on ovarian cancer cells and the underlying mechanisms as well as identify the bioactive compounds.

MATERIALS AND METHODS

Effects of HDW on the viability of ovarian cancer A2780 cells were detected by MTT assay. Apoptosis was detected by cell morphologic observation through DAPI staining and flow cytometry analysis. The migration of ovarian cancer cells which exposed to HDW were detected by wound healing and transwell assays. The protein levels of caspase 3/9, Bcl-2 and MMP-2/9 in human ovarian cancer cells treated with HDW were assessed by western blotting analysis. The potential bioactive compounds were characterized by HPLC-Q-TOF-MS.

RESULTS

HDW significantly inhibited the growth of A2780 ovarian cancer cells and induced apoptosis. The induction of apoptosis by HDW was associated with down-regulation of anti-apoptotic protein Bcl-2 and the activation of caspase 3/9. Wound healing and transwell chamber assays indicated HDW suppressed the migration of ovarian cancer cells. HDW dramatically decreased MMP-2/9 expression. A HPLC-Q-TOF-MS analysis of HDW indicated the presence of 13 flavonoids compounds and one anthraquinone compound, which may contribute to the anticancer activity of the HDW.

CONCLUSIONS

HDW effectively restricted the growth of ovarian cancer cells and induced apoptosis through the mitochondria-associated apoptotic pathway. Furthermore, HDW suppressed the migration of ovarian cancer cells through down-regulation of MMP-2 and MMP-9 expression. These results showed that HDW hold potential therapeutic effect for ovarian cancer patients.

The Hedyotis diffusa Willd. (Rubiaceae): A Review on Phytochemistry, Pharmacology, Quality Control and Pharmacokinetics

Hedyotis diffusa Willd (H. diffusa) is a well-known Chinese medicine with a variety of activities, especially its anti-cancer effect in the clinic. Up to now, 171 compounds have been reported from H. diffusa, including 32 iridoids, 26 flavonoids, 24 anthraquinones, 26 phenolics and their derivatives, 50 volatile oils and 13 miscellaneous compounds. In vitro and in vivo studies show these phytochemicals and plant extracts to exhibit a range of pharmacological activities of anti-cancer, antioxidant, anti-inflammatory, anti-fibroblast, immunomodulatory and neuroprotective effects. Although a series of methods have been established for the quality control of H. diffusa, a feasible and reliable approach is still needed in consideration of its botanical origin, collecting time and bioactive effects. Meanwhile, more pharmacokinetics researches are needed to illustrate the characteristics of H. diffusa in vivo. The present review aims to provide up-to-date and comprehensive information on the phytochemistry, pharmacology, quality control and pharmacokinetic characteristics of H. diffusa for its clinical use and further development.