In vitro investigation of cytotoxic and apoptotic effects of Cynara L. species in colorectal cancer cells

Potential therapeutic effects of apigenin for colorectal adenocarcinoma: A systematic review and meta-analysis

PURPOSE

Therapeutic management of colorectal cancer (CRC) does not yet yield promising long-term results. Therefore, there is a need for further investigation of possible therapeutic options. Various experiments have studied the effects of apigenin on CRC and have shown conflicting results. This systematic review and meta-analysis investigates the currently existing evidence on the effect of apigenin on CRC.

METHODS

Medline, Embase, Scopus, and Web of Science databases were searched for articles related to apigenin and its effect on CRC in the preclinical setting. Cell viability, growth inhibition, apoptosis, and cell cycle arrest for in-vitro, and body weight, tumor size, and mortality in in-vivo studies were extracted as outcomes.

RESULTS

Thirty-nine articles investigating colorectal adenocarcinoma were included in this meta-analysis. Thirty-seven of these studies had data for in vitro experiments, with eight studies having data for in vivo experiments. Six articles had both in vitro and in vivo assessments. Our analysis showed apigenin reduces cell viability and induces growth inhibition, apoptosis, and cell cycle arrest in in vitro studies. The few in vivo studies indicate that apigenin decreases tumor size while showing no effects on the body weight of animal colorectal adenocarcinoma models.

CONCLUSION

Our results demonstrated that apigenin, through reducing cell viability, inducing growth inhibition, apoptosis, and cell cycle arrest, and also by decreasing the tumor size, can be considered as a possible adjuvant agent in the management of colorectal adenocarcinoma. However, further in vivo studies are needed before any efforts to translate the current evidence into clinical studies.

Hepatoprotective effects of a chemically-characterized extract from artichoke (Cynara scolymus L.) against AFB1-induced toxicity in rats

This study was conducted to investigate the protective potential of a pharmaceutically formulated capsule of artichoke leaf powder (ArLP) against aflatoxin B1 (AFB1)-induced hepatotoxicity in male albino rats. In the 42-day experiment, rats were divided into five equal groups: (i) control, treated with sterile water, (ii) treated with 4% DMSO as AFB1 vehicle, (iii) ArLP of 100 mg kg-1 bw, (iv) AFB1 of 72 µg kg-1 bw, and (v) AFB1 plus ArLP. Exposure of rats to AFB1 resulted in hepatotoxicity as manifested by the intensification of oxidative stress, production of free radicals and significant increase in the activity levels of liver function enzymes relative to the control. Significant reductions in both the enzymatic and non-enzymatic antioxidant markers as well as histopathological abnormalities in liver tissues were also observed. Notably, the combined administration of ArLP with AFB1 clearly reduced AFB1-mediated adverse effects leading to the normalization of most of these parameters back to control levels. These findings clearly highlight the potential benefits of artichoke dietary supplements as a safe and natural solution in counteracting the adverse hepatotoxic effects conferred by AFB1 exposure. Further research is warranted to fully dissect the biochemical and molecular mechanism of action of the observed artichoke-mediated hepatoprotection.

Cynarin attenuates LPS-induced endothelial inflammation via upregulation of the negative regulator MKP-3

Clinical observations have revealed that non-resolving low-grade inflammation is linked to the pathogenesis of chronic inflammatory diseases, for example arthritis, atherosclerosis, Alzheimer’s disease, diabetes, and chronic kidney disease. Interestingly, low levels of circulating lipopolysaccharides (LPS) derived from the outer membrane of gram-negative bacteria appear to be one of the primary causes of persistent low-grade inflammation. The inner surface of the blood vessels is lined with endothelial cells; therefore, even low levels of circulating LPS can directly activate these cells and elicit specific cellular responses, such as an increase in the expression levels of cell adhesion molecules and proinflammatory mediators. In endothelial cells, LPS exposure results in an inflammatory response through activation of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases. Cynarin, a phytochemical found in artichokes, has several pharmacological properties against endothelial inflammation. In the present study, we discovered that cynarin suppressed the LPS-induced increase in the expression levels of vascular cell adhesion molecule-1 and proinflammatory mediators such as monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), and interleukin-1β in EA.hy926 cells. Further, cynarin inhibited the activation of p38 and NF-κB pathways by inducing the negative regulator mitogen-activated protein kinase phosphatase 3 (MKP-3) in LPS-stimulated EA.hy926 cells. In conclusion, cynarin alleviates inflammation by upregulating MKP-3, a negative regulator of p38 and NF-κB, and it may be a therapeutic option for treating endothelial inflammation-related diseases.

Pro-Apoptotic Activity of Artichoke Leaf Extracts in Human HT-29 and RKO Colon Cancer Cells

(1) Background: Cynara cardunculus L. subsp. scolymus (L.) Hegi, popularly known as artichoke, is an herbaceous plant belonging to the Asteraceae family. Artichoke leaf extracts (ALEs) have been widely used in traditional medicine because of their hepatoprotective, cholagogic, hypoglycaemic, hypolipemic and antibacterial properties. ALEs are also recognized for their antioxidative and anti-inflammatory activities. In this study, we evaluated the cytotoxic, genotoxic, and apoptotic activities, as well as effect on cell growth of ALEs on human colon cancer HT-29 and RKO cells. HT-29 and RKO cells exhibit a different p53 status: RKO cells express the wild-type protein, whereas HT-29 cells express a p53-R273H contact mutant. (2) Methods: Four different ALEs were obtained by sequential extraction of dried artichoke leaves; ALEs were characterized for their content in chlorogenic acid, cynaropicrin, and caffeoylquinic acids. HT-29 and RKO cells were used for in vitro testing (i.e., cytotoxicity and genotoxicity assessment, cell cycle analysis, apoptosis induction). (3) Results: Two out of the four tested ALEs showed marked effects on cell vitality toward HT-29 and RKO tumour cells. The effect was accompanied by a genotoxic activity exerted at a non-cytotoxic concentrations, by a significant perturbation of cell cycle (i.e., with increase of cells in the sub-G₁ phase), and by the induction of apoptosis. (4) Conclusions: ALEs rich in cynaropicrin, caffeoylquinic acids, and chlorogenic acid showed to be capable of affecting HT-29 and RKO colon cancer cells by inducing favourable biological effects: cell cycle perturbation, activation of mitochondrial dependent pathway of apoptosis, and the induction of genotoxic effects probably mediated by the induction of apoptosis. Taken together, these results weigh in favour of a potential cancer chemotherapeutic activity of ALEs.

Artichoke extracts in cancer therapy: do the extraction conditions affect the anticancer activity?

Background

Artichoke is an edible plant that is grown in the Mediterranean region and is known for its antimicrobial, antifungal, antibacterial, antioxidant and anticancer activities. Different artichoke extraction methods can impressively affect the nature as well as the yield of the extracted components.

Main body

The different methods of artichoke extraction and the influence of the extraction conditions on the extraction efficiency are summarized herein. In addition, cancer causalities and hallmarks together with the molecular mechanisms of artichoke active molecules in cancer treatment are also discussed. Moreover, a short background is given on the common types of cancer that can be treated with artichoke extracts as well as their pathogenesis. A brief discussion of the previous works devoted to the application of artichoke extracts in the treatment of these cancers is also given.

Conclusion

This review article covers the extraction methods, composition, utilization and applications of artichoke extracts in the treatment of different cancers.

Expression of miR-711 and mechanism of proliferation and apoptosis in human gastric carcinoma

MicroRNAs (miRs) are involved in many aspects of cell biology, including cell proliferation and apoptosis, two critical aspects of tumor biology. We investigated the effect of miR-711 on Bcl-2 expression in human MGC803 gastric cancer cells and the mechanism of cell proliferation, apoptosis, and invasion. Expression of miR-711 and Bcl-2 was significantly increased in gastric adenocarcinoma compared to adjacent normal tissue. Inhibition of miR-711 in MGC803 gastric cancer cells decreased the expression of Bcl-2, decreased cell proliferation, decreased the invasion ability, and increased apoptosis. The expression of Bcl-2 protein correlated with clinical staging, lymph node metastasis, and tumor differentiation in patients with gastric cancer. The expression of miR-711 positively correlated with the expression of Bcl-2, suggesting that miR-711 and Bcl-2 are co-regulated and involved in the development of gastric cancer.

Effects of miR-21 on proliferation and apoptosis in human gastric adenocarcinoma cells

The present study investigated the expression of miR-21 in MGC803 gastric cancer cells and its effects on Bcl-2 expression and cell proliferation, apoptosis, and invasion. In total 50 patients were recruited with gastric cancer who were admitted to the Henan Province People's Hospital. The samples of gastric cancer and the adjacent normal tissues were collected after surgery. We found that mRNA levels of miR-21 and Bcl-2 were significantly elevated in tumor tissues compared to control tissue. The expression of Bcl-2 protein was also elevated in cancerous tissue. This high expression of Bcl-2 was associated with clinical stage, lymph node metastasis, and tumor differentiation degree. Inhibition of miR-21 reduced the levels of miR-21 and Bcl-2 in MGC803 cells, and lowered cell proliferation and invasiveness. These results indicate that miR-21 and Bcl-2 may participate in the occurrence and development of gastric adenocarcinoma, suggesting their potential role as biomarkers and therapeutic targets.

Cynara scolymus affects malignant pleural mesothelioma by promoting apoptosis and restraining invasion

Malignant pleural mesothelioma is a poorly treated neoplasia arising from the pleural mesothelial lining. Here we document that the leaf extract of Cynara scolymus exerts broad antitumoral effects both in vitro and in vivo on mesothelioma cell lines. We found that Cynara scolymus treatment affects strongly cell growth, migration and tumor engraftment of mesothelioma cell lines. Strikingly, dietary feeding with Cynara scolymus leaf extract reduces the growth of mesothelioma xenografted tumors similarly to pemetrexed, a commonly employed drug in the treatment of mesothelioma. In aggregate our findings suggest that leaf extract of Cynara scolymus holds therapeutic potential for the treatment of mesothelioma.

Polyphenols as Modulator of Oxidative Stress in Cancer Disease: New Therapeutic Strategies

Cancer onset and progression have been linked to oxidative stress by increasing DNA mutations or inducing DNA damage, genome instability, and cell proliferation and therefore antioxidant agents could interfere with carcinogenesis. It is well known that conventional radio-/chemotherapies influence tumour outcome through ROS modulation. Since these antitumour treatments have important side effects, the challenge is to develop new anticancer therapeutic strategies more effective and less toxic for patients. To this purpose, many natural polyphenols have emerged as very promising anticancer bioactive compounds. Beside their well-known antioxidant activities, several polyphenols target epigenetic processes involved in cancer development through the modulation of oxidative stress. An alternative strategy to the cytotoxic treatment is an approach leading to cytostasis through the induction of therapy-induced senescence. Many anticancer polyphenols cause cellular growth arrest through the induction of a ROS-dependent premature senescence and are considered promising antitumour therapeutic tools. Furthermore, one of the most innovative and interesting topics is the evaluation of efficacy of prooxidant therapies on cancer stem cells (CSCs). Several ROS inducers-polyphenols can impact CSCs metabolisms and self-renewal related pathways. Natural polyphenol roles, mainly in chemoprevention and cancer therapies, are described and discussed in the light of the current literature data.

Medicinal plants combating against cancer--a green anticancer approach

Cancer is the most deadly disease that causes the serious health problems, physical disabilities, mortalities, and morbidities around the world. It is the second leading cause of death all over the world. Although great advancement have been made in the treatment of cancer progression, still significant deficiencies and room for improvement remain. Chemotherapy produced a number of undesired and toxic side effects. Natural therapies, such as the use of plant-derived products in the treatment of cancer, may reduce adverse and toxic side effects. However, many plants exist that have shown very promising anticancer activities in vitro and in vivo but their active anticancer principle have yet to be evaluated. Combined efforts of botanist, pharmacologist and chemists are required to find new lead anticancer constituent to fight disease. This review will help researchers in the finding of new bioactive molecules as it will focus on various plants evaluated for anticancer properties in vitro and in vivo.