Vitexicarpin induces apoptosis in human prostate carcinoma PC-3 cells through G2/M phase arrest

Iceberg pharmacokinetic strategy for simultaneous evaluation of five flavonoids from Viticis fructus extract in rats using UHPLC-ESI-MS/MS

Viticis fructus (VF) is the dry and ripe fruit of Vitex trifolia L. var. simplicifolia Cham or Vitex trifolia L., which contains several flavonoids exhibiting promising pharmacological effects. However, the pharmacokinetic behaviors of these flavonoids and their metabolites remain unclear. This study aimed to comprehensively evaluate the pharmacokinetics of five flavonoids from VF in rats using ultra-high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) and the Iceberg pharmacokinetic strategy. After gavage administration of VF extract to rats, only small amounts of free vitexicarpin, chrysosplenol D and luteolin were detected in rat plasma, while the contents of free quercetin and kaempferol were both lower than their corresponding lower limits of quantification. In contrast, enzymatic hydrolysis with β-glucosidase revealed significant amounts of quercetin, kaempferol, vitexicarpin, chrysosplenol D, and luteolin. The maximum plasma concentration (Cmax) and the area under the curve from time zero to the last measurable concentration (AUC0-t) values of total vitexicarpin, chrysosplenol D and luteolin after enzymatic hydrolysis were all significantly higher than those free values before enzymatic hydrolysis, respectively (P < 0.05). These findings indicate that most flavonoids from VF primarily exist as phase II metabolites in rat plasma, which can prolong their residence time in the body through intestinal hepatic circulation and other pathways. These phase II metabolites with higher concentrations may be an essential material basis for their pharmacological effects.

Combination of Vitex pseudo-negundo methanolic-extract with cisplatin can induce antioxidant activity and apoptosis in HeLa and Caski cells

Background

Cisplatin-based chemotherapy as a common therapeutic regimen for cervical cancer patients, is becoming more and more ineffective due to high resistance. This urges the need for introducing novel metabolics such as botanical drugs with the capacity to increase the cisplatin effectiveness. In that regard, here we investigated the anticancer effects of the Cisplatin-Vitex pseudo-Negundo combination in cervical cancer cell lines.

Method and Material

V. pseudo-Negundo fruits were dried and extracted methanolic fraction. The MTT assay was performed to evaluate cytotoxicity of both drugs in CaSki and HeLa cells. Then, apoptosis, ROS production, and cell cycling were assessed by flow cytometry assay in cells treated with V. pseudo-Negundo and Cisplatin and their combination. Also, the rate of cell migration and colony formation were measured, using wound healing and colony formation assay, respectively. Also, the expression level of related genes (CD133, BAX, BCL2, Casp-3/8/9, MMP-3) was evaluated using the RT-PCR method.

Results

The obtained results established that the V. pseudo-Negundo plant has medicinal properties to induce apoptotic and antioxidant signals. The combination treatment of methanol extraction and Cisplatin had a cytotoxic effect on cervical cancer cell lines (HeLa and CaSki) compared to monotherapy. Also, combination therapy resulted in an increased apoptosis rate and diminished ROS production in both CaSki and HeLa cell lines. Furthermore, V. pseudo-Negundo and Cisplatin combination therapy leads to cell cycle arrest in the G2-M and G0-G1 phase in HeLa and CaSki cell lines, respectively. Moreover, combination therapy decreased the colony formation and cell motility in both cell lines and upregulated caspases gene expression.

Conclusion

The combination of V. pseudo-Negundo with Cisplatin therapy results in a significant anti-cancer and antioxidant effect compared to cisplatin, representing a promising candidate for future clinical investigations.

Traditional use, phytochemistry and pharmacology of Viticis Fructus

Ethnopharmacological relevance

Viticis Fructus (called Manjingzi in China) is the dried ripe fruits of the plant species Vitex trifolia subsp. litoralis Steenis and Vitex trifolia L. in the family Lamiaceae. Viticis Fructus has been used as a traditional Chinese medicine for thousands of years to treat illness such as colds, headache, vertigo, anesthesia, and hyperkinesias. More chemical constituents and medicinal effects have been discovered in Viticis Fructus with the development of modern technology.The aim of the review: This review aims to analyze the research progress of Viticis Fructus from the aspects of botany, ethnopharmacology, phytochemistry, and pharmacological activity, as well as to provide an outlook on the research and use prospects of Viticis Fructus.

Material and methods

A comprehensive literature search using online databases such Science Direct, CNKI, Wiley online library, Spring Link, Web of Science, PubMed, Wanfang Data and SCI-Finder. In addition, information was obtained from local and foreign books on ethnobotany and ethnomedicine.

Results

The application of Viticis Fructus as a medicine can be traced back to around 480 AD. So far, more than 190 compounds have been isolated from Viticis Fructus, including flavonoids, sterols, cyclic enol ether terpenoids, and diterpenoids. Modern pharmacological studies have shown that the extracts of Viticis Fructus have various pharmacological effects, such as anti-allergic, antioxidant, anti-inflammatory, anti-cancer, and anti-bacterial effects.

Conclusion

As a widely used traditional medicine, Viticis Fructus is rich in chemical compositions and has an obvious biological activity. However, the application and pharmacological activity of Viticis Fructus have not been scientifically evaluated or convincing due to poor methodology, unclear results and lack of clinical data. Systematic and comprehensive research evaluations are needed to verify its pharmaceutical activity, clinical therapeutic efficacy and safety. As an important herbal medicine, it should be further explored to facilitate the development of new medicines and treatments for a variety of diseases.

Casticin as potential anticancer agent: recent advancements in multi-mechanistic approaches

Plants, with their range of pharmacologically active molecules, represent the most promising source for the production of new anticancer drugs and for the formulation of adjuvants in chemotherapy treatments to reduce drug content and/or counteract the side effects of chemotherapy. Casticin is a major bioactive flavonoid isolated from several plants, mainly from the Vitex species. This compound is well known for its anti-inflammatory and antioxidant properties, which are mainly exploited in traditional medicine. Recently, the antineoplastic potential of casticin has attracted the attention of the scientific community for its ability to target multiple cancer pathways. The purpose of this review is, therefore, to present and critically analyze the antineoplastic potential of casticin, highlighting the molecular pathways underlying its antitumor effects. Bibliometric data were extracted from the Scopus database using the search strings "casticin" and "cancer" and analyzed using VOSviewer software to generate network maps to visualize the results. Overall, more than 50% of the articles were published since 2018 and even more recent studies have expanded the knowledge of casticin's antitumor activity by adding interesting new mechanisms of action as a topoisomerase IIα inhibitor, DNA methylase 1 inhibitor, and an upregulator of the onco-suppressive miR-338-3p. Casticin counteracts cancer progression through the induction of apoptosis, cell cycle arrest, and metastasis arrest, acting on several pathways that are generally dysregulated in different types of cancer. In addition, they highlight that casticin can be considered as a promising epigenetic drug candidate to target not only cancer cells but also cancer stem-like cells.

Molecular Basis of Prostate Cancer and Natural Products as Potential Chemotherapeutic and Chemopreventive Agents

Prostate cancer is the second most common malignant cancer in males. It involves a complex process driven by diverse molecular pathways that closely related to the survival, apoptosis, metabolic and metastatic characteristics of aggressive cancer. Prostate cancer can be categorized into androgen dependent prostate cancer and castration-resistant prostate cancer and cure remains elusive due to the developed resistance of the disease. Natural compounds represent an extraordinary resource of structural scaffolds with high diversity that can offer promising chemical agents for making prostate cancer less devastating and curable. Herein, those natural compounds of different origins and structures with potential cytotoxicity and/or in vivo anti-tumor activities against prostate cancer are critically reviewed and summarized according to the cellular signaling pathways they interfere. Moreover, the anti-prostate cancer efficacy of many nutrients, medicinal plant extracts and Chinese medical formulations were presented, and the future prospects for the application of these compounds and extracts were discussed. Although the failure of conventional chemotherapy as well as involved serious side effects makes natural products ideal candidates for the treatment of prostate cancer, more investigations of preclinical and even clinical studies are necessary to make use of these medical substances reasonably. Therefore, the elucidation of structure-activity relationship and precise mechanism of action, identification of novel potential molecular targets, and optimization of drug combination are essential in natural medicine research and development.

Improved Storage Properties and Cellular Uptake of Casticin-Loaded Nanoemulsions Stabilized by Whey Protein-Lactose Conjugate

Casticin has wide-ranging functional activities, but its water solubility is poor in food products. Here, a nanoemulsion stabilized by Maillard whey protein isolate conjugates (MWPI) was fabricated to encapsulate casticin. The nanoemulsion, with an average diameter of 200 nm, possessed the capability to load 700 μg/g casticin. MWPI-stabilized nanoemulsion showed better stability than that of the WPI nanoemulsion during 4 weeks of storage. Both the inhibition effects of the casticin-loaded nanoemulsion on cancer cells and the process of cellular uptake were studied. Results revealed that the casticin-loaded nanoemulsion had better inhibitory activity in HepG2 and MCF-7 cells than free casticin. Cellular uptake of the nanoemulsion displayed a time-dependent manner. After the nanoemulsion passed into HepG2 and MCF-7 cells, it would locate in the lysosome but not in the nucleus. The main pathway for the nanoemulsion to enter HepG2 cells was pinocytosis, whereas, it entered MCF-7 predominantly through the clathrin-mediated pit. This work implies that MWPI-stabilized nanoemulsions could be utilized as an effective delivery system to load casticin and have the potential to be applied in the food and pharmaceutical industries.

An Overview of the Potential Antineoplastic Effects of Casticin

Cancer persists as one of the leading causes of deaths worldwide, contributing to approximately 9.6 million deaths per annum in recent years. Despite the numerous advancements in cancer treatment, there is still abundant scope to mitigate recurrence, adverse side effects and toxicities caused by existing pharmaceutical drugs. To achieve this, many phytochemicals from plants and natural products have been tested against cancer cell lines in vivo and in vitro. Likewise, casticin, a flavonoid extracted from the Vitex species, has been isolated from the leaves and seeds of V. trifolia and V. agnus-castus. Casticin possesses a wide range of therapeutic properties, including analgesic, anti-inflammatory, antiangiogenic, antiasthmatic and antineoplastic activities. Several studies have been conducted on the anticancer effects of casticin against cancers, including breast, bladder, oral, lung, leukemia and hepatocellular carcinomas. The compound inhibits invasion, migration and proliferation and induces apoptosis (casticin-induced, ROS-mediated and mitochondrial-dependent) and cell cycle arrest (G0/G1, G2/M, etc.) through different signaling pathways, namely the PI3K/Akt, NF-κB, STAT3 and FOXO3a/FoxM1 pathways. This review summarizes the chemo-preventive ability of casticin as an antineoplastic agent against several malignancies.

Casticin inhibits human prostate cancer DU 145 cell migration and invasion via Ras/Akt/NF-κB signaling pathways

Casticin, a polymethoxyflavone derived from natural plants, has biological activities including induction of cell apoptosis. In this study, we showed the beneficial effects of casticin on the inhibition of prostate cancer cell metastasis. Casticin reduced total viable cell number, thus, we selected low doses of casticin for following experiments. Casticin decreased cell mobility, suppressed cell migration and invasion, and reduced cell gelatinolytic activities of MMP-2/-9. Furthermore, casticin inhibited the protein levels of AKT, GSK3 αβ, Snail, and MMPs (MMP-2, -9, -13, and -7) at 24 and 48 hr treatment. Casticin diminished the expressions of NF-κB p65, GRB2, SOS-1, MEK, p-ERK1/2, and p-JNK1/2 at 48 hr treatment only. However, casticin reduced the level of E-cadherin at 24 hr treatment but elevated at 48 hr. The novel findings suggest that casticin may represent a new and promising therapeutic agent for the metastatic prostate cancer. PRACTICAL APPLICATIONS: Casticin derived from natural plants had been used for Chinese medicine in Chinese population for thousands of years. In the present study, casticin attenuated metastatic effects, including decreasing viable cell number, inhibiting the migration, invasion, and adhesion, and reducing matrix metalloproteinases activity on human prostate DU 145 cancer cells. In addition, the results also provided possible pathways involved in casticin anti-metastasis mechanism. We conclude that casticin may be an aptitude anticancer agent or adjuvant for the metastatic prostate cancer in the future.

Flavonoids in Cancer and Apoptosis

Cancer is the second leading cause of death globally. Although, there are many different approaches to cancer treatment, they are often painful due to adverse side effects and are sometimes ineffective due to increasing resistance to classical anti-cancer drugs or radiation therapy. Targeting delayed/inhibited apoptosis is a major approach in cancer treatment and a highly active area of research. Plant derived natural compounds are of major interest due to their high bioavailability, safety, minimal side effects and, most importantly, cost effectiveness. Flavonoids have gained importance as anti-cancer agents and have shown great potential as cytotoxic anti-cancer agents promoting apoptosis in cancer cells. In this review, a summary of flavonoids and their effectiveness in cancer treatment targeting apoptosis has been discussed.

Structure-activity relationship and pharmacokinetic studies of 3-O-substitutedflavonols as anti-prostate cancer agents

Thirty-eight 3-O-substituted-3',4'-dimethoxyflavonols and twenty-five 3-O-substituted-3',4',7-trimethoxyflavonols have been synthesized for systematic investigation on the structure-activity relationships of 3-O-substituted-3',4'-dimethoxyflavonols in three human prostate cancer cell models. Our findings indicate that incorporation of an appropriate amino group to 3-OH of 3',4'-dimethoxyflavonol and 3',4',7-trimethoxyflavonol through a 3- to 5-carbon linker can substantially improve the in vitro antiproliferative potency in three human prostate cancer cell models, but not in two non-neoplastic human epithelial cell models (MCF 10A and PWR-1E). 1-Methylpiperazine, pyrrolidine, and dibutylamine are optimal terminal amine groups that, in combination with a 3- to 5-carbon linker, are notably beneficial to the anti-proliferative potency of 3-O-substituted-3',4'-dimethoxyflavonols. It is worth noting that 3-O-(4-methylpiperazin-1-yl)propyl-3',4',7-trimethoxyflavonol (76) induces PC-3 cell death in a completely different way from 3-O-pyrrolidinopentyl-3',4',7-trimethoxyflavonol (81) even though they belong to 3-O-substituted-3',4',7-trimethoxyflavonols and exhibit similar potency in inhibiting PC-3 cell proliferation, suggesting that the mechanism of action for each specific 3-O-substitutedflavonol varies with different amino moiety. 3-O-(N,N-Dibutylamino)propyl-3',4'-dimethoxyflavonol (42) emerged as the most promising derivative due to its substantially improved potency in cell models, superior bioavailability in rats, and good selectivity of inhibiting prostate cancer cell proliferation over non-neoplastic human epithelial cell proliferation.

Casticin from Vitex species: a short review on its anticancer and anti-inflammatory properties

This short review provides an update of the anticancer and anti-inflammatory properties of casticin from Vitex species. Casticin is a polymethylflavone with three rings, an orthocatechol moiety, a double bond, two hydroxyl groups and four methoxyl groups. Casticin has been isolated from various tissues of plants in the Vitex genus: fruits and leaves of V. trifolia, aerial parts and seeds of V. agnus-castus and leaves of V. negundo. Studies have reported the antiproliferative and apoptotic activities of casticin from Vitex species. The compound is effective against many cancer cell lines via different molecular mechanisms. Studies have also affirmed the anti-inflammatory properties of casticin, with several molecular mechanisms identified. Other pharmacological properties include anti-asthmatic, tracheospasmolytic, analgesic, antihyperprolactinemia, immunomodulatory, opioidergic, oestrogenic, anti-angiogenic, antiglioma, lung injury protection, rheumatoid arthritis amelioration and liver fibrosis attenuation activities. Clinical trials and commercial use of the casticin-rich fruit extract of V. agnus-castus among women with premenstrual syndrome were briefly discussed.

Chinese Medicines in the Treatment of Prostate Cancer: From Formulas to Extracts and Compounds

In order to fully understand the progresses and achievements in Chinese medicines for the treatment of prostate cancer, we summarize all the available reports on formulas, extracts, and compounds of Chinese medicines against prostate cancer. A number of clinical trials verified that traditional Chinese formulas had some unique advantages in the treatment of prostate cancer. Many Chinese medicine extracts could protect against prostate cancer, and many compounds isolated from Chinese traditional medicines showed a clear anti-prostate cancer effect. However, Chinese medicines are facing many problems regarding their multicomponent nature, complicated mechanisms of action, and high doses required for therapy. Herein, we review the functions of Chinese medicines in prostate cancer and focus on their mechanisms. The review will deepen the understanding of Chinese medicines potential in the anti-prostate cancer field. In addition, we put forward a question concerning the current research on Chinese medicines: in order to better illustrate that Chinese medicines can be used in the clinical treatment of prostate cancer, should our research focus on formulas, extracts, or compounds?

SRVF, a novel herbal formula including Scrophulariae Radix and Viticis Fructus, disrupts focal adhesion and causes detachment-induced apoptosis in malignant cancer cells

When cells lose adhesion, they undergo detachment-induced apoptosis, known as anoikis. In contrast, tumor cells acquire resistance to anoikis, enabling them to survive, even after separating from neighboring cells or the ECM. Therefore, agents that restore anoikis sensitivity may serve as anti-cancer candidates. In this study, we constructed a novel herbal formula, SRVF, which contains Scrophulariae Radix (SR) and Viticis Fructus (VF). SRVF rapidly decreased cell adhesion, altered the cell morphology to round, and induced cell death; however, SR, VF, or their co-treatment did not. SRVF arrested HT1080 cells in G₂/M phase, increased the levels of pro-apoptotic proteins, and decreased the levels of anti-apoptotic proteins. Furthermore, SRVF efficiently reduced cell-cell and cell-ECM interactions by disrupting the F-actin cytoskeleton and down-regulating the levels of focal adhesion-related proteins, suggesting that SRVF efficiently triggers detachment-induced apoptosis (i.e., anoikis) in malignant cancer cells. In xenograft mouse models, daily oral administration of 50 or 100 mg/kg SRVF retarded tumor growth in vivo, and repeated administration of SRVF did not cause systemic toxicity in normal mice. These data collectively indicate that SRVF induces cancer cell death by restoring anoikis sensitivity via disrupting focal adhesion. Therefore, SRVF may be a safe and potent anti-cancer herbal decoction.

3-O-Substituted-3',4',5'-trimethoxyflavonols: Synthesis and cell-based evaluation as anti-prostate cancer agents

Twenty-two 3-O-substituted-3',4',5'-trimethoxyflavonols have been designed and synthesized for their anti-proliferative activity towards three human prostate cancer cell lines. Our results indicate that most of them are significantly more potent than the parent 3',4',5'-trimethoxyflavonol in inhibiting the cell proliferation in PC-3 and LNCaP prostate cancer cell models. 3-O-Substituted-3',4',5'-trimethoxyflavonols have generally higher potency towards PC-3 and LNCaP cell lines than the DU145 cell line. Incorporation of an ethyl group to 3-OH of 3',4',5'-trimethoxyflavonol leads to 3-O-ethyl-3',4',5'-trimethoxyflavonol as the optimal derivative with up to 36-fold enhanced potency as compared with the corresponding lead compound 3',4',5'-trimethoxyflavonol, but with reversed PC-3 cell apoptotic response. Introduction of a dipentylaminopropyl group to 3-OH increases not only the antiproliferative potency but also the ability in activating PC-3 cell apoptosis. Our findings imply that modification on 3-OH of trimethoxyflavonol can further enhance its in vitro anti-proliferative potency and PC-3 cell apoptosis induction.

RGD-conjugated mesoporous silica-encapsulated gold nanorods enhance the sensitization of triple-negative breast cancer to megavoltage radiation therapy

Multifunctional nanoprobes have great potential as effective radiosensitizers and drug carriers. RGD-modified gold nanorods could increase the uptake of nanoparticles via receptor-mediated endocytosis in integrin alphaV beta3-overexpressing breast cancer cells, which could enhance the effects of radiation on tumor cells, leading to further radiosensitization. The purpose of our study was to demonstrate that RGD-conjugated mesoporous silica-encapsulated gold nanorods significantly enhanced the sensitization of triple-negative breast cancer to megavoltage energy. The results indicated that RGD-conjugated mesoporous silica-encapsulated gold nanorod multifunctional nanoprobes could achieve radiosensitization in vitro and in vivo, which suggests the potential translation of this nanotechnology to clinical applications in tumor-targeting and selective therapy.

A candidate Chinese medicine preparation-Fructus Viticis Total Flavonoids inhibits stem-like characteristics of lung cancer stem-like cells

Background

Cancer stem cells (CSCs) are considered as the origin of tumor relapse. Here, we investigated the effects of Fructus Viticis total flavonoids (FVTF) on the characteristics of lung cancer stem-like cells (LCSLCs) derived from human small cell lung cancer NCI-H446 cell line and its potential mechanism.

Methods

Human small cell lung cancer NCI-H446 cell line was cultured in vitro. The CD133⁺ cells were sorted from NCI-H446 cell line by magnetic separation.

The suspended culture with stem cell-conditioned medium was used to amplify CD133⁺ sphere-forming cells (SFCs). The stem cell characteristics of CD133⁺ SFCs were evaluated using cell self-renewal capacity by tumor sphere formation assay, migration and invasion capacity by Transwell assay, tumorigenicity by xenograft model in nude mouse and cancer stem cell markers expression levels by western blot. The effects of FVTF on the properties of LCSLCs were examined by tumorsphere formation assay and transwell chamber assay. The expression level of p-Akt was determined by western blot analysis.

Result

CD133⁺ SFCs derived from human small cell lung cancer NCI-H446 cells exhibited stemness properties of tumorsphere formation and tumorigenesis capacity comparing to the parental cells. FVTF relative selectively inhibited the proliferation of LCSLCs, suppressed tumor sphere forming capacity and migration and invasion of LCSLCs, and down-regulated the protein expression of stem cell markers (CD133, CD44 and ALDH1), self-renewal associated transcription factors (Bmi1, Nanog and OCT4) and invasion associated transcription factors (Twist1 and Snail1) in a dose-dependent manner. Moreover, we found that FVTF treatment could significantly decrease the phosphorylation level of Akt in LCSLCs. Meanwhile, LY294002 and FVTF synergistically inhibited the characteristics of LCSLCs.

Conclusion

FVTF inhibits the characteristics of LCSLCs through down-regulating expression of p-Akt.

A new class of flavonol-based anti-prostate cancer agents: Design, synthesis, and evaluation in cell models

Flavonoids are a large class of polyphenolic compounds ubiquitously distributed in dietary plants with an array of biological activities. Flavonols are a major sub-class of flavonoids featuring a hydroxyl group at C-3. Certain natural flavonols, such as quercetin and fisetin, have been shown by in vitro cell-based and in vivo animal experiments to be potential anti-prostate cancer agents. However, the Achilles' heel of flavonols as drug candidates is their moderate potency and poor pharmacokinetic profiles. This study aims to explore the substitution effect of 3-OH in flavonols on the in vitro anti-proliferative potency against both androgen-sensitive and androgen-insensitive human prostate cancer cell lines. Our first lead flavonol (3',4'-dimethoxyflavonol), eight 3-O-alkyl-3',4'-dimethoxyflavonols, and six 3-O-aminoalkyl-3',4'-dimethoxyflavonols have been synthesized through aldol condensation and the Algar-Flynn-Oyamada (AFO) reaction. The WST-1 cell proliferation assay indicates (i) that all synthesized 3-O-alkyl-3',4'-dimethoxyflavonols and 3-O-aminoalkyl-3',4'-dimethoxyflavonols are more potent than the parent 3',4'-dimethoxyflavonol and the natural flavonol quercetin in suppressing prostate cancer cell proliferation; and (ii) that incorporation of a dibutylamino group to the 3-OH group through a three- to five-carbon linker leads to the optimal derivatives with up to 292-fold enhanced potency as compared with the parent flavonol. Flow cytometry analysis showed that the most potent derivative 22 can activate PC-3 cell cycle arrest at the G2/M phase and induce PC-3 cell apoptosis. No inhibitory ability of 22 up to 50μM concentration was observed against PWR-1E normal human epithelial prostate cells, suggesting its in vitro safety profile. The results indicate that chemical modulation at 3-OH is a vital strategy to optimize flavonols as anti-prostate cancer agents.

Mangiferin inhibition of proliferation and induction of apoptosis in human prostate cancer cells is correlated with downregulation of B-cell lymphoma-2 and upregulation of microRNA-182

Mangiferin, a flavonoid extracted from the mango tree, possesses anti-inflammatory, antibacterial, anti-herpes simplex and antitumor activity, and is able to affect immune function. The present study investigated the anticancer effects of mangiferin treatment on PC3 human prostate cancer cells, and the potential underlying mechanisms. In the present study, an MTT assay was used to analyze the proliferation of PC3 cells. Subsequently, flow cytometry and colorimetric assay kits were utilized to measure the PC3 cell apoptotic rate. The expression levels of B-cell lymphoma-2 (Bcl-2) and microRNA-182 (miR-182) were detected using western blot analysis and quantitative reverse transcription-polymerase chain reaction, respectively. Finally, miR-182 and anti-miR-182 were transfected into PC3 cells, which were used to investigate the effects of mangiferin. Mangiferin treatment reduced the proliferation of PC3 human prostate cancer cells in a concentration- and time-dependent manner. In addition, mangiferin was able to promote apoptosis and induce the caspase-3 activity of PC3 human prostate cancer cells. Mangiferin treatment was also able to significantly reduce Bcl-2 expression levels and enhance miR-182 expression in PC3 cells. Finally, it was observed that mangiferin inhibited proliferation and induced apoptosis in PC3 human prostate cancer cells, and this effect was correlated with downregulation of Bcl-2 and upregulation of miR-182.

Synergistic anti-tumor effect of KLF4 and curcumin in human gastric carcinoma cell line

Kruppel-like factor 4 is a transcription factor which plays an important role in development and progression of various carcinomas. Curcumin characterized by excellent anti-cancer properties is regarded as a serviceable natural compound used in carcinoma therapy. This study aimed at exploring the impact of KLF4 overexpression in cooperation with curcumin on the proliferation, apoptosis and invasion of human gastric carcinoma BGC- 823 cells. Flow cytometry analysis, CCK-8 assays, transwell assays and Western blot results showed that KLF4 overexpression combined with curcumin had significant anti-proliferation, pro-apoptosis and anti-invasion effects on BGC-823 cells. We also found that KLF4 had synergistic effects with curcumin, better promoting apoptosis and inhibiting proliferation and invasion of gastric carcinona cells. These results indicate that KLF4 could be used as a potential therapeutic target; curcumin could act as an auxiliary and provide a promising therapeutic strategy in stomach cancer.

A polymethoxyflavone from Laggera pterodonta induces apoptosis in imatinib-resistant K562R cells via activation of the intrinsic apoptosis pathway

Background

Treatment with imatinib mesylate (IM) (a tyrosine kinase inhibitor) is the first line of standard care for patients newly diagnosed with CML. Despite the success of IM and other tyrosine kinase inhibitors (TKIs), chronic myeloid leukemia (CML) remains largely incurable, and a number of CML patients die due to Abl mutation-related drug resistance and blast crisis. 3, 5-Dihydroxy-6, 7, 3′4′-tetramethoxyflavone (DHTMF) is a polymethoxyflavone isolated from Laggera pterodonta which is a herbal medicine used to treat cancer in the Chinese folk. In the previous study, we found DHTMF demonstrated good antiproliferative activities against a number of cancer cell lines and induced the apoptosis of CNE cells in vitro in a time- and dose-dependent manner while exhibiting low cytotoxicity in the two normal cell lines Vero and EVC304. The aim of the present study was to evaluate the proliferation inhibition and apoptosis induced by DHTMF alone and in combination with IM in the IM-resistant CML cell line K562R.

Methods

Cell proliferation was assayed with the cell counting kit-8 (CCK8) method. The apoptosis percentage was determined by flow cytometry (FCM). Mitochondrial transmembrane potential was detected using FCM and confocal laser-scanning microscopy. The level of proteins involved in apoptosis was detected by Western blotting.

Results

DHTMF suppressed K562R cell viability in both time- and dose-dependent manners. DHTMF combined with IM enhanced the inhibitory effects and apoptosis in K562R cells as compared with DHTMF alone. DHTMF alone and in combination with IM significantly decreased the mitochondrial membrane potential and increased the levels of cleaved caspase-9, caspase-7, caspase-3, and PARP in K562R cells.

Conclusions

We demonstrated that DHTMF could inhibit IM-resistant K562R cell proliferation and induces apoptosis via the intrinsic mitochondrial apoptotic pathway. These results suggest that DHTMF may be a potential therapeutic drug with lower side effects against IM resistance in CML cells.

Radio-sensitization by Piper longumine of human breast adenoma MDA-MB-231 cells in vitro

BACKGROUND

The current study investigated the effects of Piper longumine on radio-sensitization of human breast cancer MDA-MB-231 cells and underlying mechanisms.

MATERIALS AND METHODS

Human breast cancer MDA-MB-231 cells were cultured in vitro and those in logarithmic growth phase were selected for experiments divided into four groups: control, X-ray exposed, Piper longumine, and Piper longumine combined with X-rays. Conogenic assays were performed to determine the radio-sensitizing effects. Cell survival curves were fitted by single-hit multi-target model and then the survival fraction (SF), average lethal dose (D0), quasi-threshold dose (Dq) and sensitive enhancement ratio (SER) were calculated. Cell apoptosis was analyzed by flow cytometry (FCM).Western blot assays were employed for expression of apoptosis-related proteins (Bc1-2 and Bax) after treatment with Piper longumine and/or X-ray radiation. The intracellular reactive oxygen species (ROS) level was detected by FCM with a DCFH-DA probe.

RESULTS

The cloning formation capacity was decreased in the group of piperlongumine plus radiation, which displayed the values of SF2, D0, Dq significantly lower than those of radiation alone group and the sensitive enhancement ratio (SER) of D0 was1.22 and 1.29, respectively. The cell apoptosis rate was increased by the combination treatment of Piper longumine and radiation. Piper longumine increased the radiation-induced intracellular levels of ROS. Compared with the control group and individual group, the combination group demonstrated significantly decreased expression of Bcl-2 with increased Bax.

CONCLUSIONS

Piper longumine at a non-cytotoxic concentration can enhance the radio-sensitivity of MDA- MB-231cells, which may be related to its regulation of apoptosis-related protein expression and the increase of intracellular ROS level, thus increasing radiation-induced apoptosis.