Carnosol induces apoptosis through generation of ROS and inactivation of STAT3 signaling in human colon cancer HCT116 cells (original) (raw)

Carnosic acid inhibits STAT3 signaling and induces apoptosis through generation of ROS in human colon cancer HCT116 cells

Molecular Carcinogenesis, 2015

Carnosic acid (CA), the main antioxidant compound of Rosmarinus officinalis L., has been reported to possess anticancer activity. However, the molecular mechanisms underlying the anticancer effects of CA remain poorly understood. Our study revealed that CA treatment significantly reduced the viability of human colon cancer HCT116, SW480, and HT-29 cells. Treatment with CA induced apoptosis, which was associated with the induction of p53 and Bax, inhibition of Mdm2, Bcl-2, and Bcl-xl expression, activation of caspase-9, and-3, and the cleavage of PARP in HCT116 cells. CA inhibited the constitutive phosphorylation, the DNA binding and the reporter gene activity of STAT3 in HCT116 cells by blocking the phosphorylation of upstream JAK2 and Src kinases. Moreover, CA attenuated the expression of STAT3 target gene products, such as survivin, cyclin D1, D2, and D3. In STAT3-overexpressed HCT116 cells, CA inhibited cell viability and the expression of cyclin D1 and survivin. Furthermore, CA treatment induced the generation of ROS in these colon cancer cells. Pretreatment of cells with ROS scavenger N-acetyl cysteine abrogated the inhibitory effect of CA on the JAK2-STAT3/Src-STAT3 signaling and rescued cells from CA-induced apoptosis by blocking the induction of p53 and the cleavage of caspase-3 and PARP in HCT116 cells. However, L-buthionine-sulfoximine, a pharmacological inhibitor of GSH synthesis, increased CA-induced ROS production, thereby potentiating apoptotic effect of CA. In conclusion, our study provides the first report that CA induced apoptosis in HCT116 cells via generation of ROS, induction of p53, activation of caspases, and inhibition of STAT3 signaling pathway.

Carnosol, an antioxidant in rosemary, suppresses inducible nitric oxide synthase through down-regulating nuclear factor-kappaB in mouse macrophages

Carcinogenesis, 2002

Carnosol is a naturally occurring phytopolyphenol found in rosemary. Carnosol functions as antioxidant and anticarcinogen. In the present study, we compared the antioxidant activity of carnosol and other compounds extracted from rosemary. Carnosol showed potent antioxidative activity in α,α-diphenyl-β-picrylhydrazyl (DPPH) free radicals scavenge and DNA protection from Fenton reaction. High concentrations of nitric oxide (NO) are produced by inducible NO synthase (iNOS) in inflammation and multiple stages of carcinogenesis. Treatment of mouse macrophage RAW 264.7 cell line with carnosol markly reduced lipopolysaccharide (LPS)-stimulated NO production in a concentration-related manner with an IC 50 of 9.4 µM; but other tested compounds had slight effects. Western blot, reverse transcription-polymerase chain reaction, and northern blot analyses demonstrated that carnosol decreased LPS-induced iNOS mRNA and protein expression. Carnosol treatment showed reduction of nuclear factor-κB (NF-κB) subunits translocation and NF-κB DNA binding activity in activated macrophages. Carnosol also showed inhibition of iNOS and NF-κB promoter activity in transient transfection assay. These activities were referred to down-regulation of inhibitor κB (IκB) kinase (IKK) activity by carnosol (5 µM), thus inhibited LPSinduced phosphorylation as well as degradation of IκBα. Carnosol also inhibited LPS-induced p38 and p44/42 mitogen-activated protein kinase (MAPK) activation at a higher concentration (20 µM). These results suggest that carnosol suppresses the NO production and iNOS gene expression by inhibiting NF-κB activation, and provide possible mechanisms for its anti-inflammatory and chemopreventive action.

Rosemary (Rosmarinus officinalis) extract causes ROS-induced necrotic cell death and inhibits tumor growth in vivo

Scientific Reports

Colorectal cancer is the third most common diagnosed cancer globally. Although substantial advances have been obtained both in treatment and survival rates, there is still a need for new therapeutical approaches. Natural compounds are a realistic source of new bioactive compounds with anticancer activity. Among them, rosemary polyphenols have shown a vast antiproliferative capacity against colon cancer cells in vitro and in animal models. We have investigated the antitumor activity of a rosemary extract (RE) obtained by using supercritical fluid extraction through its capacity to inhibit various signatures of cancer progression and metastasis such as proliferation, migration, invasion and clonogenic survival. RE strongly inhibited proliferation, migration and colony formation of colon cancer cells regardless their phenotype. Treatment with RE led to a sharp increase of intracellular ROS that resulted in necrosis cell death. Nrf2 gene silencing increased RE cytotoxic effects, thus suggesting that this pathway was involved in cell survival. These in vitro results were in line with a reduction of tumor growth by oral administration of RE in a xenograft model of colon cancer cells using athymic nude mice. These findings indicate that targeting colon cancer cells by increasing intracellular ROS and decreasing cell survival mechanisms may suppose a therapeutic option in colon cancer through the combination of rosemary compounds and chemotherapeutic drugs. Colorectal cancer (CRC) is the second most commonly diagnosed cancer type in females and the third in males globally, with increasing prevalence even in traditionally low-risk countries. Nevertheless, a decrease in colorectal cancer mortality rates have been noticed in a large number of countries, most probably due to reduced prevalence of risk factors, CRC screening practices and/or improved treatments 1. Several dietary components found in plant-derived foods, medicinal plants as well as their bioactive compounds have shown protective effects against a wide range of cancers, including colon cancer 2-4. Therefore, it seems to be of relevance to identify new bioactive food or components with an anticancer potential to prevent and/or treat human cancers 5-7. Rosemary (Rosmarinus officinalis L.) is a bush of the Lamiaceae family that is mostly distributed in the Mediterranean area. In recent decades, experimental research has confirmed the pharmacological potential of rosemary and some of its primary compounds such as the diterpenes carnosic acid (CA) and carnosol (CAR), also expanding the range of its possible therapeutic applications. In fact, rosemary extracts have demonstrated chemoprotective effects against hepatotoxicity 8 and gastric ulcerative lesions, and 9 anticancer 10-13 , antimicrobial 14,15 , antioxidant 16 and antidiabetic effects 17 , both in vitro and in vivo. Recently, the antiproliferative effect of a terpenes-enriched rosemary extract (RE) obtained using supercritical fluid extraction has been demonstrated in colon cancer cell models 13. A transcriptomic and metabolomic analysis in colon cancer cells indicated that RE treatment activated the expression of genes related to cell cycle progression and phase II antioxidant enzymes 18,19. The bio-guided assay fractionation of the extract revealed that CA and

Comprehensive Foodomics Study on the Mechanisms Operating at Various Molecular Levels in Cancer Cells in Response to Individual Rosemary Polyphenols

Analytical Chemistry, 2014

In previous works, rosemary extracts (REs) obtained in our laboratory using supercritical fluid extraction exhibited inhibitory effect on proliferation of several cancer cell lines. However, the observed antiproliferative activity was not correlated to any compound present in the extract. In order to address this question, in this work the contribution of carnosic acid (CA) and carnosol (CS), two major compounds present in the RE, against colon cancer HT-29 cells proliferation is investigated using a comprehensive Foodomics approach. Although CA and CS exhibit additive antiproliferative effect when they are combined in solution at a molar ratio of 6.9:1, the results reveal that CA contributes more significantly than CS to the activity of RE against colon cancer cells proliferation. The Foodomics study reveals that CA induces transcriptional activation of genes that encode detoxifying enzymes and altered the expression of genes linked to other relevant functions such as transport and biosynthesis of terpenoids in the colon cancer cell line. Functional analysis highlighted the activation of the ROS metabolism and alteration of several genes involved in pathways describing oxidative degradation of relevant endogenous metabolites, providing new evidences about the transcriptional change induced by CA in HT-29 cells. Metabolomics analysis showed that the treatment with CA affected the intracellular levels of glutathione. Elevated levels of GSH provided additional evidences to transcriptomic results regarding chemopreventive response of cells to CA treatment. Moreover, the Foodomics approach was useful to establish the links between decreased levels of N-acetylputrescine and its degradation pathway at the gene level. The findings from this work and the predictions based on microarray data will help exploring novel metabolic processes and potential signaling pathways to further elucidate de effect of CA in colon cancer cells.

A bioguided identification of the active compounds that contribute to the antiproliferative/cytotoxic effects of rosemary extract on colon cancer cells

Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2015

Rosemary extracts have exhibited potential cytostatic or cytotoxic effects in several cancer cell models but their bioactive compounds are yet to be discovered. In this work, the anticancer activity of a rosemary-leaf extract and its fractions were assayed to identify the phenolic compounds responsible for their antiproliferative/cytotoxic effects on a panel of human colon cancer cell lines. Bioguided fractionation of the rosemary-leaf extract was achieved by semi-preparative chromatography. The rosemary extract and the compounds in the fractions were characterized and quantified by HPLC-ESI-QTOF-MS. Cellular viability in the presence of these fractions and the whole extract was determined after 24 or 48 h incubations by using an MTT assay. Fractions containing diterpenes or triterpenes were the most active but not as much as the whole extract. In conclusion, carnosic acid, carnosol, 12-methoxycarnosic acid, taxodione, hinokione and betulinic acid were the putative candidates that c...

Inhibitory Effects of Rosemary Extracts, Carnosic Acid and Rosmarinic Acid on the Growth of Various Human Cancer Cell Lines

Plant Foods for Human Nutrition, 2010

The leaves of Rosmarinus officinalis harvested from three different locations of Turkey were extracted by both methanolic and supercritical CO 2 extraction. Subsequently, six extracts and the active compounds, carnosic acid, and rosmarinic acid were applied to various human cancer cell lines including NCI-H82 (human, small cell lung, carcinoma), DU-145 (human, prostate, carcinoma), Hep-3B (human, black, liver, carcinoma, hepatocellular), K-562 (human chronic myeloid leukemia), MCF-7 (human, breast, adenocarcinoma), PC-3 (human, prostate, adenocarcinoma) and MDA-MB-231 (human, breast, adenocarcinoma) by MTT assay. Supercritical CO 2 extracts had superior antiproliferative effect compared to the soxhlet extracts. Although the extracts exhibited various cytotoxic effects against different cell lines, comparatively low IC 50 values ranging between 12.50 and 47.55 μg/ml were attained against K-562, being the most sensitive cell line. Moreover, carnosic acid caused the lowest cell viability with values ranging from 13 to 30 % at a concentration of 19 μM after 48 h of treatments, resulting in superior antiproliferative effect. Rosemary extract is a potential candidate to be included in the anti-cancer diet with pre-determined doses avoiding toxicity.

Anticancer Effects of Rosemary (Rosmarinus officinalis L.) Extract and Rosemary Extract Polyphenols

Cancer cells display enhanced growth rates and a resistance to apoptosis. The ability of cancer cells to evade homeostasis and proliferate uncontrollably while avoiding programmed cell death/apoptosis is acquired through mutations to key signaling molecules, which regulate pathways involved in cell proliferation and survival. Compounds of plant origin, including food components, have attracted scientific attention for use as agents for cancer prevention and treatment. The exploration into natural products offers great opportunity to evaluate new anticancer agents as well as understand novel and potentially relevant mechanisms of action. Rosemary extract has been reported to have antioxidant, anti-inflammatory, antidiabetic and anticancer properties. Rosemary extract contains many polyphenols with carnosic acid and rosmarinic acid found in highest concentrations. The present review summarizes the existing in vitro and in vivo studies focusing on the anticancer effects of rosemary extract and the rosemary extract polyphenols carnosic acid and rosmarinic acid, and their effects on key signaling molecules.

Carob leaf polyphenols trigger intrinsic apoptotic pathway and induce cell cycle arrest in colon cancer cells

Journal of Functional Foods, 2017

Chemoprevention of Colorectal cancer (CRC) is the major concern for improving public health. We investigated the protective effects of carob, Ceratonia siliqua L., leaf polyphenols (CLP) against CRC. Phenolic content analysis showed that CLP is enriched with gallic acid and m-coumaric acid. We observed that CLP exerted a dose dependent cytotoxic effect through the induction of apoptosis on CRC cell lines, with an IC50 around 20 lg/mL. CLP induced intrinsic apoptotic pathway through the caspase-9 activation and PARP cleavage in HCT-116 and CT-26 cells. Moreover, CLP induced cell cycle arrest in the G1 phase through p53 activation. Gallic acid and m-coumaric acid exerted similar effect of CLP but at higher concentration to that expected to be present in CLP, suggesting the synergistic effect between polyphenols in CLP activity. Interestingly, the carob leaf infusion reduced CT-26 tumour growth in BALB/c mice. This study suggests that CLP can be used for the prevention of CRC.

Effect of rosemary polyphenols on human colon cancer cells: transcriptomic profiling and functional enrichment analysis

Genes & Nutrition, 2012

In this work, the effect of rosemary extracts rich on polyphenols obtained using pressurized fluids was investigated on the gene expression of human SW480 and HT29 colon cancer cells. The application of transcriptomic profiling and functional enrichment analysis was done via two computational approaches, Ingenuity Pathway Analysis and Gene Set Enrichment Analysis. These two approaches were used for functional enrichment analysis as a previous step for a reliable interpretation of the data obtained from microarray analysis. Reverse transcription quantitative-PCR was used to confirm relative changes in mRNA levels of selected genes from microarrays. The selection of genes was based on their expression change, adjusted p value, and known biological function. According to genome-wide transcriptomics analysis, rosemary polyphenols altered the expression of *4 % of the genes covered by the Affymetrix Human Gene 1.0ST chip in both colon cancer cells. However, only *18 % of the differentially expressed genes were common to both cell lines, indicating markedly different expression profiles in response to the treatment. Differences in induction of G2/ M arrest observed by rosemary polyphenols in the two colon adenocarcinoma cell lines suggest that the extract may be differentially effective against tumors with specific mutational pattern. From our results, it is also concluded that rosemary polyphenols induced a low degree of apoptosis indicating that other multiple signaling pathways may contribute to colon cancer cell death.

Antiproliferation effect of Rosemary (Rosmarinus officinalis) on human ovarian cancer cells in vitro

Phytomedicine : international journal of phytotherapy and phytopharmacology, 2012

Rosemary (Rosmarinus officinalis L.) is a popular culinary/medicinal herb. Recent studies have shown it has pharmacologic activities for cancer chemoprevention and therapy. This study evaluated the antiproliferation activity of rosemary extract (RE) against human ovarian cancer cells, and whether the extract and its three main active ingredients carnosol (CS), carnosic acid (CA) and rosmarinic acid (RA) can enhance the antiproliferation activity of cisplatin (CDDP). Our study showed that RE has significant antiproliferation activity on human ovarian cancer A2780 and its CDDP resistant daughter cell line A2780CP70, with IC(50) (50% inhibitory concentration) estimated at 1/1000 and 1/400 dilutions respectively. RE enhanced the antiproliferation effect with CDDP on both A2780 and A2780CP70 cells. A2780 cells were consistently more sensitive to CS, CA, and RA than A2780CP70 cells between 2.5 and 20μg/ml. CS and RA also showed synergistic antiproliferation effect with CDDP on A2780 cells...