Targeting Apoptosis with Dietary Bioactive Agents

Exploring natural products as apoptosis modulators in cancers: insights into natural product-based therapeutic strategies

Cancer remains a leading cause of mortality globally, necessitating ongoing research and development of innovative therapeutic strategies. Natural products from plants, herbs, and marine species have shown great promise as anti-cancer therapies due to their bioactive components that alter cellular pathways, particularly apoptosis. This review explores the mechanism by which natural chemicals trigger the apoptosis of cancerous cells, which is crucial for eliminating them and halting tumor growth. These can affect the mitochondrial process by controlling the Bcl-2 protein family, increasing cytochrome c release, and activating caspases. They also activate death receptors like Fas and TRAIL to enhance the extrinsic apoptotic pathway. We focus on the main signaling channels involved, such as the endoplasmic reticulum (ER) stress-mediated apoptosis, extrinsic death receptor, and intrinsic mitochondrial pathways. The review explores the role of natural substances such as polyphenols, terpenoids, alkaloids, and flavonoids in promoting apoptotic cell death and increasing cancer cell susceptibility, potentially aiding in cancer treatments and the potential of combining natural products with traditional chemotherapeutic medicines to combat medication resistance and enhance therapeutic efficacy. Understanding cancer development involves inhibiting cell proliferation, regulating it, targeting apoptosis pathways, and using plant and marine extracts as apoptotic inducers.

Chemistry, biosynthesis, and theranostics of antioxidant flavonoids and polyphenolics of genus Rhododendron: an overview

The genus Rhododendron is an ancient and most widely distributed genus of the family Ericaceae consisting of evergreen plant species that have been utilized as traditional medicine since a very long time for the treatment of various ailments including pain, asthma, inflammation, cold, and acute bronchitis. The chemistry of polyphenolics isolated from a number of species of the genus Rhododendron has been investigated. During the currently designed study, an in-depth study on the phytochemistry, natural distribution, biosynthesis, and pharmacological properties including their potential capability as free radical scavengers has been conducted. This work provides structural characteristics of phenolic compounds isolated from the species of Rhododendron with remarkable antioxidant potential. In addition, biosynthesis and theranostic study have also been encompassed with the aims to furnish a wide platform of valuable information for designing of new drug entities. The detailed information including names, structural features, origins, classification, biosynthetic pathways, theranostics, and pharmacological effects of about 171 phenolics and flavonoids isolated from the 36 plant species of the genus Rhododendron with the antioxidant potential has been covered in this manuscript. This study demonstrated that species of Rhododendron genus have excellent antioxidant activities and great potential as a source for natural health products. This comprehensive review might serve as a foundation for more investigation into the Rhododendron genus.

A recent update on the connection between dietary phytochemicals and skin cancer: emerging understanding of the molecular mechanism

Constant exposure to harmful substances from both inside and outside the body can mess up the body's natural ways of keeping itself in balance. This can cause severe skin damage, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. However, plant-derived compounds found in fruits and vegetables have been shown to protect against skin cancer-causing free radicals and other harmful substances. It has been determined that these dietary phytochemicals are effective in preventing skin cancer and are widely available, inexpensive, and well-tolerated. Studies have shown that these phytochemicals possess anti-inflammatory, antioxidant, and antiangiogenic properties that can aid in the prevention of skin cancers. In addition, they influence crucial cellular processes such as angiogenesis and cell cycle control, which can halt the progression of skin cancer. The present paper discusses the benefits of specific dietary phytochemicals found in fruits and vegetables, as well as the signaling pathways they regulate, the molecular mechanisms involved in the prevention of skin cancer, and their drawbacks.

Evolving Strategies for Use of Phytochemicals in Prevention and Long-Term Management of Cardiovascular Diseases (CVD)

This report describes major pathomechanisms of disease in which the dysregulation of host inflammatory processes is a major factor, with cardiovascular disease (CVD) as a primary model, and reviews strategies for countermeasures based on synergistic interaction between various agents, including drugs and generally regarded as safe (GRAS) natural medical material (NMM), such as Ginkgo biloba, spice phytochemicals, and fruit seed flavonoids. The 15 well-defined CVD classes are explored with particular emphasis on the extent to which oxidative stressors and associated ischemia-reperfusion tissue injury contribute to major symptoms. The four major categories of pharmaceutical agents used for the prevention of and therapy for CVD: statins, beta blockers (β-blockers), blood thinners (anticoagulants), and aspirin, are presented along with their adverse effects. Analyses of major cellular and molecular features of drug- and NMM-mediated cardioprotective processes are provided in the context of their development for human clinical application. Future directions of the evolving research described here will be particularly focused on the characterization and manipulation of calcium- and calcineurin-mediated cascades of signaling from cell surface receptors on cardiovascular and immune cells to the nucleus, with the emergence of both protective and pathological epigenetic features that may be modulated by synergistically-acting combinations of drugs and phytochemicals in which phytochemicals interact with cells to promote signaling that reduces the effective dosage and thus (often) toxicity of drugs.

Modulatory effect of ciprofloxacin, a broad spectrum antibacterial drug, on mPT pore using rat model with estradiol benzoate-induced endometrial hyperplasia

Mitochondrial permeability transition (mPT) pore has become a motive for drug evolvement pertinent to dysregulated apoptosis situations. Some chemical compounds impede tumor/cancer via the inception of mPT pore opening. Ciprofloxacin has been demonstrated to hinder growth and effect apoptosis in some cancer cells. However, using a rat model, this study investigated its effect on mitochondrial-mediated cell death via mPT pore opening and estradiol benzoate (EB)-induced endometrial hyperplasia. Mitochondria were isolated using differential centrifugation. The opening of the pore, cytochrome c release (CCR), mitochondrial ATPase (mATPase) activity, mitochondrial lipid peroxidation (mLPO), caspases 3 and 9 levels, and hepatic DNA fragmentation were determined. Histological evaluation of hepatic and uterine sections and immunoexpression levels of Bax, caspase 3, and anti-apoptotic Bcl-2 levels were quantified. The results show that ciprofloxacin caused mPT pore opening, CCR, mATPase activity, effected mLPO, caspases 3 and 9 activations, and hepatic DNA fragmentation. The histology of the liver section showed moderate to marked disseminated congestion at 100 mg/kg, while higher doses showed severe hepatic damage. Severe EH was detected in the EB-treated rats which was attenuated by ciprofloxacin in the treatment group. The Bax and caspase expressions were upregulated by ciprofloxacin while anti-apoptotic Bcl-2 was downregulated. Ciprofloxacin induces mitochondrial-mediated cell death via mPT pore opening and mitigates EB-induced EH in rat models via Bax/caspase/Bcl-2 signaling pathway.

Jaboticaba (Myrciaria jaboticaba) peel extracts induce reticulum stress and apoptosis in breast cancer cells

Jaboticaba peel (Myrciaria jaboticaba) is a source of bioactive compounds. We investigated the anticancer activity of ethyl acetate extract (JE1) and hydroethanolic extract (JE2) of Jaboticaba peel against breast cancer. Both JE1 and JE2 inhibited clonogenic potential of MDA-MB-231 cells while JE1 was particularly effective in MCF7 cells. Anchorage-independent growth and cell viability was also inhibited by JE1 and JE2. In addition to growth inhibition, JE1 and JE2 could also inhibit migration and invasion of cells. Interestingly, JE1 and JE2 show selective inhibition towards certain breast cancer cells and biological processes. Mechanistic evaluations showed that JE1 induced PARP cleavage, BAX and BIP indicating apoptotic induction. An elevation of phosphorylated ERK was observed in MCF7 cells in response to JE1 and JE2 along with increased IRE-α and CHOP expression indicating increased endoplasmic stress. Therefore, Jaboticaba peel extracts could be potentially considered for further development for breast cancer inhibition.

Resveratrol induces DNA damage-mediated cancer cell senescence through the DLC1-DYRK1A-EGFR axis

Inducing cell senescence is widely regarded as a potent tumor suppression mechanism. Resveratrol has attracted increasing attention for its capacity to prevent and suppress cancer. However, the mechanism of resveratrol on the induction of cancer cell senescence has not been well clarified. Our results showed that resveratrol inhibited cell viability and colony formation and promoted cell senescence along with augmentation of SA-β-gal activity and modulation of senescence-associated molecular markers p53, p21 and LaminB protein in breast and liver cancer cells. The underlying mechanism was that resveratrol increased ROS generation to enhance tumor suppressor gene DLC1 expression, and DLC1 further inhibited the DYRK1A-EGFR axis to trigger DNA damage accompanied by up-regulation of the DNA double strand break marker protein γH2AX and down-regulation of the DNA repair related proteins p-BRCA1 and RAD51, eventually leading to cancer cell senescence. Resveratrol also effectively inhibited the volume of transplanted tumor with increased SA-β-gal activity and DLC1 level in a chicken embryo allantoic membrane xenograft tumor model. This is the first report to investigate whether resveratrol induces DNA damage-mediated cancer cell senescence through the DLC1-DYRK1A-EGFR axis, which could provide a solid base for resveratrol's application in cancer prevention and clinical treatment as a food additive or adjuvant therapies.

Synergistic Combination of Luteolin and Asiatic Acid on Cervical Cancer In Vitro and In Vivo

Cervical cancer is an important issue globally because it is the second most common gynecological malignant tumor and conventional treatment effects have been shown to be limited. Lut and AsA are plant-derived natural flavonoid and triterpenoid products that have exhibited anticancer activities and can modulate various signaling pathways. Thus, the aim of the present study was to evaluate whether Lut combined with AsA could enhance the anticancer effect to inhibit cervical cancer cell proliferation and examine the underlying molecular mechanisms in vitro and in vivo. The results of a CCK-8 assay showed that Lut combined with AsA more effectively inhibited the proliferation of CaSki and HeLa cells than Lut or AsA treatment alone. Lut combined with AsA caused apoptosis induction and sub-G1-phase arrest in CaSki and HeLa cells, as confirmed by flow cytometry, mitoROS analysis, antioxidant activity measurement and western blot assay. In addition, Lut combined with AsA significantly inhibited the cell migration ability of CaSki and HeLa cells in a wound-healing assay. Furthermore, Lut combined with AsA induced apoptosis and inhibited migration through downregulated PI3K/AKT (PI3K, AKT and p70S6K), JNK/p38 MAPK and FAK (integrin β1, paxillin and FAK) signaling and upregulated ERK signaling. In an in vivo study, Lut combined with AsA markedly inhibited cervical cancer cell-derived xenograft tumor growth. Collectively, the present study showed that Lut combined with AsA may be used as an anticancer agent to improve the prognosis of cervical cancer. Indeed, with additional research to develop standardized dosages, Lut and AsA combination therapy could also be applied in clinical medicine.

Emergence of nutrigenomics and dietary components as a complementary therapy in cancer prevention

Cancer is an illness characterized by abnormal cell development and the capability to infiltrate or spread to rest of the body. A tumor is the term for this abnormal growth that develops in solid tissues like an organ, muscle, or bone and can spread to other parts of the body through the blood and lymphatic systems. Nutrition is a critical and immortal environmental component in the development of all living organisms encoding the relationship between a person's nutrition and their genes. Nutrients have the ability to modify gene expression and persuade alterations in DNA and protein molecules which is researched scientifically in nutrigenomics. These interactions have a significant impact on the pharmacokinetic properties of bioactive dietary components as well as their site of action/molecular targets. Nutrigenomics encompasses nutrigenetics, epigenetics, and transcriptomics as well as other "omic" disciplines like proteomics and metabolomics to explain the vast disparities in cancer risk among people with roughly similar life style. Clinical trials and researches have evidenced that alternation of dietary habits is potentially one of the key approaches for reducing cancer risk in an individual. In this article, we will target how nutrigenomics and functional food work as preventive therapy in reducing the risk of cancer.

Modulatory potential of Citrus sinensis and Moringa oleifera extracts and epiphytes on rat liver mitochondrial permeability transition pore

BACKGROUND

Bioactive agents from medicinal and dietary plants have been reported to modulate the mitochondrial membrane permeability transition pores.

OBJECTIVE

This study investigated the in vitro effects of C. sinensis (CSE) and M. oleifera (MOE) methanol leaf extracts and their epiphytes (CEP and MEP) on mitochondria permeability transition pores.

METHODS

In vitro antioxidant activities of the extracts were determined using standard procedures and quantification of polyphenolic compounds in the extracts was done using HPLC-DAD. Opening of the mitochondrial permeability transition pores was assessed as mitochondrial swelling and observed spectrophotometrically as changes in absorbance under succinate-energized conditions. Cytochrome c release was also assessed spectrophotometrically.

RESULTS

From the results, CSE, MOE, CEP, and MEP inhibited lipid peroxidation and scavenged nitric oxide and DPPH radicals in a concentration-dependent manner. All extracts exhibited greater ferric reducing antioxidant potential. More so, the results showed that CSE, MOE, CEP, and MEP possess the substantive amount of total flavonoids and total phenolics. CSE and MOE had higher total flavonoids and total phenolic content when compared with the epiphytes. HPLC-DAD results revealed Tangeretin as the most abundant in CSE; Eriocitrin in citrus epiphytes; Moringine in MOE and Flavones in moringa epiphytes. All extracts inhibited calcium-induced opening of the pores in a concentration-dependent manner with C. sinensis leaf extract (CSE) and moringa epiphyte (MEP) being the most potent in this regard with no significant release of cytochrome c at all concentrations.

CONCLUSION

The results suggest that CSE and MEP have bioactive agents which could be useful in the management of diseases where too much apoptosis occurs characterized by excessive tissue wastage such as neurodegenerative conditions.

In silico molecular docking and in vitro analysis of ethanolic extract Ocimum sanctum Linn.: Inhibitory and apoptotic effects against non-small cell lung cancer

Background and Aim:

Lung cancer, especially non-small cell lung cancer (NSCLC), has been identified as the leading cause of cancer deaths worldwide. The mortality rate from lung cancer has been estimated to be 18.4%. Until now, conventional treatments have not yielded optimal results, thus necessitating an investigation into the use of traditional herbal plants as potential candidates for its treatment. This study aimed to determine the inhibitory and apoptotic activity of the ethanolic extract from Ocimum sanctum Linn. (EEOS) by in silico molecular docking and through in vitro studies using NSCLC cells (A549 cell line).

Materials and Methods:

Dried simplicia of Ocimum sanctum was converted into EEOS using the maceration method. Spectrophotometry was then employed to analyze the EEOS compound. The known main active compounds were further analyzed for inhibitory and apoptotic effects on gene signaling using in silico molecular docking involving the downloading of active compounds from PubChem and target proteins from the Protein Data Bank; the active compounds and proteins were then prepared using the Discovery Studio software v. 19.0.0 and the PyRX 0.8 program, interacted with the HEX 8.0.0 program, and visualized with the Discovery Studio Visualizer v. 19.0. Finally, an in vitro analysis was performed using an antiproliferative-cytotoxic test (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay in the NSCLC A549 cell line).

Results:

The analysis revealed that the active compounds in the ethanolic extract were dominated by quercetin (flavonoids) (47.23% b/b) and eugenol (phenolic) (12.14% b/b). These active compounds interacted with the active sites (residual amino acids) of the αvβ3 integrin, a5b1 integrin, caspase-3, caspase-9, and vascular endothelial growth factor. Hydrogen bonds and Pi-cation and Pi-alkyl interactions were involved in the relationships between the active compounds and the active sites and thus may reveal an antioxidant property of the extract. Furthermore, in vitro analysis showed the inhibitory and antiproliferative effects of the EEOS against non-small cell cancer (A549).

Conclusion:

Taken together, our data showed the ability of EEOS as an inhibitor and apoptotic agent for lung cancer; however, further research is needed to determine the exact mechanism of EEOS as an herbal medication.

Formulation, Optimization and Evaluation of Luteolin-Loaded Topical Nanoparticulate Delivery System for the Skin Cancer

In the present study, luteolin (LT)-loaded nanosized vesicles (LT-NVs) were prepared by a solvent evaporation-hydration method using phospholipid and edge activator. The formulation was optimized using three factors at a three-level Box-Behnken design. The formulated LT-NVs were prepared using the three independent variables phospholipid (A), edge activator (B) and sonication time (C). The effect of used variables was assessed on the vesicle size (Y1) and encapsulation efficiency (Y2). The selection of optimum composition (LT-NVopt) was based on the point prediction method of the software. The prepared LT-NVopt showed the particle size of 189.92 ± 3.25 nm with an encapsulation efficiency of 92.43 ± 4.12% with PDI and zeta potential value of 0.32 and -21 mV, respectively. The formulation LT-NVopt was further converted into Carbopol 934 gel (1% w/v) to enhance skin retention. LT-NVoptG was further characterized for viscosity, spreadability, drug content, drug release, drug permeation and antioxidant, antimicrobial and cytotoxicity assessment. The evaluation result revealed optimum pH, viscosity, spreadability and good drug content. There was enhanced LT release (60.81 ± 2.87%), as well as LT permeation (128.21 ± 3.56 µg/cm2/h), which was found in comparison to the pure LT. The antioxidant and antimicrobial study results revealed significantly (p ˂ 0.05) better antioxidant potential and antimicrobial activity against the tested organisms. Finally, the samples were evaluated for cytotoxicity assessment using skin cancer cell line and results revealed a significant difference in the viability % at the tested concentration. LT-NVoptG showed a significantly lower IC50 value than the pure LT. From the study, it can be concluded that the prepared LT-NVoptG was found to be an alternative to the synthetic drug as well as conventional delivery systems.

Insights into the mechanism of Cymbopogan martinii essential oil in topical therapy of acne vulgaris

Aim: The present study investigated the essential oil of Cymbopogan martinii (palmarosa oil; PRO) as a potential topical therapy in acne vulgaris. Materials & methods: GC-MS profiling and biocompatibility studies of PRO were undertaken. The antimicrobial potential was assessed against Cutibacterium acnes. anti-inflammatory, antityrosinase activity and lipid peroxidation were also evaluated. Results: Geraniol was identified as the major phytoconstituent, and the oil was found to be safe for topical application. The minimum inhibitory concentration and minimum bactericidal concentration values were noted as 16 μl/ml. PRO reduced the cytokine levels of TNF-α, IL-12 and IL-8 and inhibited tyrosinase. A low concentration of the oil (up to 0.5 μl/ml) produced malondialdehyde levels equivalent to that of untreated cells. Conclusion: PRO may prove useful as a natural topical agent in the management of acne.

Modulatory effect of methanol extract of Annona muricata stem bark on mitochondrial membrane permeability transition pore in normal rat liver and monosodium glutamate-induced uterine hyperplasia

OBJECTIVES

Uterine fibroids are benign tumors that develop in many women of reproductive age. Surgery is the main approach to treatment while other options are also associated with adverse effects. Studies have shown that certain bioactive agents present in medicinal plants elicit their anti-tumor activity by induction of mitochondrial permeability transition (mPT) opening. This research therefore aimed at investigating the effect of methanol extract of Annona muricata (MEAM) on mPT pore opening in normal and monosodium glutamate-induced uterine hyperplasia using female Wistar rats.

METHODS

Mitochondria, isolated from rat liver were exposed to different concentrations (20, 60, 100, 140 and 180 μg/mL) of MEAM. The mPT pore opening, cytochrome c release, mitochondrial ATPase (mATPase) activity and the percentage lipid peroxidation were assessed spectrophotometrically. Histological effects of MEAM on the liver, brain and uterus of normal and MSG-treated rats were investigated.

RESULTS

The in vitro results showed a significant induction of mPT pore opening by 2.4, 4.2 and 6.4 folds, release of cytochrome c and enhancement of mATPase activity at 100,140 and 180 μg/mL, respectively. However, oral administration of MEAM did not induce mPT pore opening, neither any significant release of cytochrome c nor enhancement of mATPase activity at all the dosages used. However, histological assay revealed the presence of MSG-induced cellular damage and uterine hyperplasia which was ameliorated by MEAM co-administration.

CONCLUSIONS

These findings suggest that MEAM contains phytochemicals that can ameliorate MSG-induced damage and uterine hyperplasia in rats; however, the mechanism might not be via upregulation of mitochondrial-mediated apoptosis.

Nutrigenomics and Life Style Facet- A Modulatory Molecular Evidence in Progression of Breast and Colon Cancer with Emerging Importance

Legitimate nutrition assumes a significant role in preventing diseases and, in this way, nutritional interventions establish vital strategies in the area of public health. Nutrigenomics centres on the different genes and diet in an individual and how an individual's genes influence the reaction to bioactive foodstuff. It targets considering the genetic and epigenetic interactions with nutrients to lead to a phenotypic alteration and consequently to metabolism, differentiation, or even apoptosis. Nutrigenomics and lifestyle factors play a vital role in health management and represent an exceptional prospect for the improvement of personalized diets to the individual at risk of developing diseases like cancer. Concerning cancer as a multifactorial genetic ailment, several aspects need to be investigated and analysed. Various perspectives should be researched and examined regarding the development and prognosis of breast and colon cancer. Malignant growth occurrence is anticipated to upsurge in the impending days, and an effective anticipatory strategy is required. The effect of dietary components, basically studied by nutrigenomics, looks at gene expression and molecular mechanisms. It also interrelates bioactive compounds and nutrients because of different 'omics' innovations. Several preclinical investigations demonstrate the pertinent role of nutrigenomics in breast and colon cancer, and change of dietary propensities is conceivably a successful methodology for reducing cancer risk. The connection between the genomic profile of patients with breast or colon cancer and their supplement intake, it is conceivable to imagine an idea of personalized medicine, including nutrition and medicinal services.

Anti-Cancer Effects of Asiatic Acid, a Triterpene from Centilla asiatica L: A Review

BACKGROUND

Centilla asiatica L is a medicinal herb that has been widely used in folk medicine to treat various diseases. Asiatic Acid (AA), a triterpene and a known component of this herb, has been shown to display important biological activities, including anti-inflammatory, antibacterial, antidiabetic and antihyperlipidemic, neuroprotective, anxiolytic and antidepressant, hepatoprotective, pancreas protective, and cardio- protective.

OBJECTIVE

This review focuses on AA's anti-cancer effects on the basis of published literature found in a number of databases such as PubMed and Science Direct. Emphasis has been given to the mechanisms of action of its anti-cancer effect.

METHODS

A literature survey was conducted using known databases such as PubMed and Science Direct using the keywords 'Asiatic acid', pairing with 'cancer', 'tumor', 'anti-cancer effect', 'cytotoxic effect', 'anti-tumor activity', 'cell line', 'animal cancer', and 'human cancer'.

RESULTS

Findings suggest that AA exerts anti-cancer effects in several test systems through various pathways, including oxidative/antioxidant, anti-inflammatory, cytotoxicity, apoptotic cell death, necrosis, anti-angiogenesis, inhibition of proliferation and cell migration, and chemoprevention.

CONCLUSION

AA may be an effective plant-based cancer chemotherapeutic agent and a promising lead for the development of potent anticancer drugs.

Chemical profile and therapeutic potentials of Xylocarpus moluccensis (Lam.) M. Roem.: A literature-based review

ETHNOPHARMACOLOGICAL RELEVANCE

Historically, mangrove plants are among the potential sources of foods and remedies for humans living in the forests and nearby communities. Xylocarpus moluccensis (Lam.) M. Roem., an important mangrove medicinal plant, has been traditionally used for many purposes such as treatment of fever, dysentery, diarrhea, swelling, and abdominal disorders. The aim of the present work was to summarize the chemical reports and biological activities of the mangrove medicinal plant X. moluccensis based on information collected from different databases.

MATERIALS AND METHODS

An up-to-date search (till Aug 2019) was carried out in databases such as PubMed, Science Direct, Google Scholar, and various patient offices (e.g., WIPO, CIPO, USPTO) using the keywords: 'Xylocarpus moluccensis', and/or paired with 'ethnobotanical use', and 'phytochemical'. In vitro, ex vivo, or in vivo studies were included.

RESULTS

Findings suggest that X. moluccensis contains various important minerals and phytochemicals, where flavonoids, terpenes and terpenoids are the most prominent isolated phyto-constituents of X. moluccensis. Extracts/fractions or isolated compounds from this plant possess diverse biological activities, including anti-inflammatory, anti-microbial, antineoplastic, anti-diarrheal, insecticidal, anti-feedant, neuropharmacological (e.g., central nervous system depressant), anti-atherosclerotic, and lipid-lowering activity. Only one report suggests that the methanol and aqueous extracts of this plant did not exert cytotoxic effects on normal mouse fibroblast cells. However, no clinical studies were reported.

CONCLUSIONS

Taken all together, X. moluccensis may be one of the best sources of pharmacologically active lead compounds. More research, however, is necessary to establish the safety and efficacy, and its toxicogenetic effects in animal models.

The therapeutic effect of resveratrol: Focusing on the Nrf2 signaling pathway

Resveratrol is a natural polyphenol derived from grapes, berries, red wine, peanuts amongst other fruits and nuts. Beneficial effects such as anti-inflammatory, antioxidant, hepatoprotective, neuroprotective, cardioprotective, renoprotective, anti-obesity, anti-diabetic, and anti-cancer of resveratrol have been demonstrated by preclinical and clinical research. A possibility is that these therapeutical effects are associated with modulation of the Nrf2 signaling pathway in the following way: resveratrol may potentiate Nrf2 signaling through blockage of Keap1, by means of changing the Nrf2 mediators, its expression and its nuclear translocation. This article reviews the evidence of the Nrf2 modulating hypothesis as a possible molecular mechanism underlying the medicinal properties of resveratrol.

Luteolin attenuates migration and invasion of lung cancer cells via suppressing focal adhesion kinase and non-receptor tyrosine kinase signaling pathway

BACKGROUND/OBJECTIVES

Non-small cell lung cancer is mostly recognized among other types of lung cancer with a poor prognosis by cause of chemotherapeutic resistance and increased metastasis. Luteolin has been found to decrease cell metastasis. However, its underlying mechanisms remain unresolved. The objective of this study was to examine the effect (and its mechanism) of luteolin on the migration and invasion of human non-small cell lung cancer A549 cells.

MATERIALS/METHODS

Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing and transwell assays were evaluated to assess migration and invasion, respectively. Western blot analysis and immunofluorescence were further performed to investigate the role of luteolin and its mechanisms of action.

RESULTS

Administration with up to 40 µM luteolin showed no cytotoxic activity on lung cancer A549 cells or non-cancer MRC-5 cells. Additionally, luteolin at 20-40 µM significantly suppressed A549 cells' migration, invasion, and the formation of filopodia in a concentration-dependent manner at 24 h. This is similar with western blot analysis, which revealed diminished the phosphorylated focal adhesion kinase (pFAK), phosphorylated non-receptor tyrosine kinase (pSrc), Ras-related C3 botulinum toxin substrate 1 (Rac1), cell division control protein 42 (Cdc42), and Ras homolog gene family member A (RhoA) expression levels.

CONCLUSIONS

Overall, our data indicate that luteolin plays a role in controlling lung cancer cells' migration and invasion via Src/FAK and its downstream Rac1, Cdc42, and RhoA pathways. Luteolin might be considered a promising candidate for suppressing invasion and metastasis of lung cancer cells.

Luteolin, a flavonoid, as an anticancer agent: A review

Many food-derived phytochemicals and their derivatives represent a cornucopia of new anti-cancer compounds. Luteolin (3,4,5,7-tetrahydroxy flavone) is a flavonoid found in different plants such as vegetables, medicinal herbs, and fruits. It acts as an anticancer agent against various types of human malignancies such as lung, breast, glioblastoma, prostate, colon, and pancreatic cancers. It also blocks cancer development in vitro and in vivo by inhibition of proliferation of tumor cells, protection from carcinogenic stimuli, and activation of cell cycle arrest, and by inducing apoptosis through different signaling pathways. Luteolin can additionally reverse epithelial-mesenchymal transition (EMT) through a mechanism that involves cytoskeleton shrinkage, induction of the epithelial biomarker E-cadherin expression, and by down-regulation of the mesenchymal biomarkers N-cadherin, snail, and vimentin. Furthermore, luteolin increases levels of intracellular reactive oxygen species (ROS) by activation of lethal endoplasmic reticulum stress response and mitochondrial dysfunction in glioblastoma cells, and by activation of ER stress-associated proteins expressions, including phosphorylation of eIF2α, PERK, CHOP, ATF4, and cleaved-caspase 12. Accordingly, the present review article summarizes the progress of recent research on luteolin against several human cancers.

Total Phenols from Grape Leaves Counteract Cell Proliferation and Modulate Apoptosis-Related Gene Expression in MCF-7 and HepG2 Human Cancer Cell Lines

Grape leaves influence several biological activities in the cardiovascular system, acting as antioxidants. In this study, we aimed at evaluating the effect of ethanolic and water extracts from grape leaves grown in Algeria, obtained by accelerator solvent extraction (ASE), on cell proliferation. The amount of total phenols was determined using the modified Folin-Ciocalteu method, antioxidant activities were evaluated by the 2,2-diphenyl-l-picrylhydrazyl free radical (DPPH*) method and ^·OH radical scavenging using electron paramagnetic resonance (EPR) spectroscopy methods. Cell proliferation of HepG2 hepatocarcinoma, MCF-7 human breast cancer cells and vein human umbilical (HUVEC) cells, as control for normal cell growth, was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay (MTT). Apoptosis- related genes were determined by measuring Bax and Bcl-2 mRNA expression levels. Accelerator solvent extractor yield did not show significant difference between the two solvents (ethanol and water) (p > 0.05). Total phenolic content of water and ethanolic extracts was 55.41 ± 0.11 and 155.73 ± 1.20 mg of gallic acid equivalents/g of dry weight, respectively. Ethanolic extracts showed larger amounts of total phenols as compared to water extracts and interesting antioxidant activity. HepG2 and MCF-7 cell proliferation decreased with increasing concentration of extracts (0.5, 1, and 2 mg/mL) added to the culture during a period of 1⁻72 h. In addition, the expression of the pro-apoptotic gene Bax was increased and that of the anti-apoptotic gene Bcl-2 was decreased in a dose-dependent manner, when both MCF-7 and HepG2 cells were cultured with one of the two extracts for 72 h. None of the extracts elicited toxic effects on vein umbilical HUVEC cells, highlighting the high specificity of the antiproliferative effect, targeting only cancer cells. Finally, our results suggested that ASE crude extract from grape leaves represents a source of bioactive compounds such as phenols, with potential antioxidants activity, disclosing a novel antiproliferative effect affecting only HepG2 and MCF-7 tumor cells.

Protective and therapeutic potential of ginger (Zingiber officinale) extract and [6]-gingerol in cancer: A comprehensive review

Natural dietary agents have attracted considerable attention due to their role in promoting health and reducing the risk of diseases including cancer. Ginger, one of the most ancient known spices, contains bioactive compounds with several health benefits. [6]-Gingerol constitutes the most pharmacologically active among such compounds. The aim of the present work was to review the literature pertaining to the use of ginger extract and [6]-gingerol against tumorigenic and oxidative and inflammatory processes associated with cancer, along with the underlying mechanisms of action involved in signaling pathways. This will shed some light on the protective or therapeutic role of ginger derivatives in oxidative and inflammatory regulations during metabolic disturbance and on the antiproliferative and anticancer properties. Data collected from experimental (in vitro or in vivo) and clinical studies discussed in this review indicate that ginger extract and [6]-gingerol exert their action through important mediators and pathways of cell signaling, including Bax/Bcl2, p38/MAPK, Nrf2, p65/NF-κB, TNF-α, ERK1/2, SAPK/JNK, ROS/NF-κB/COX-2, caspases-3, -9, and p53. This suggests that ginger derivatives, in the form of an extract or isolated compounds, exhibit relevant antiproliferative, antitumor, invasive, and anti-inflammatory activities.

Theanine, an antitumor promoter, induces apoptosis of tumor cells via the mitochondrial pathway

Theanine, an active component of green tea (Camellia sinensis), is considered a modulator of chemotherapy. To further investigate the anticancer activity of theanine, the present study investigated the cytotoxic effect of theanine at the concentration of 600 µg/ml, in the human HepG2 hepatoblastoma and HeLa adenocarcinoma cell lines, in comparison with the normal L02, H9c2 and HEK293 cell lines using a MTT assay. It was found that theanine induced cell death in the tumor cells, but not in the normal cells. Notably, when glutamine was restricted or reduced in the cell culture medium, the cell death induced by theanine was significantly enhanced. A terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling assay indicated that DNA damage was induced in theanine‑treated HepG2 cells. Further experiments demonstrated that theanine caused HepG2 cell apoptosis through the mitochondrial pathway, with a loss of membrane potential and the release of apoptosis‑inducing factor, endonuclease G and cytochrome c. Western blot analysis and caspase activity detection also revealed that caspase‑9 and caspase‑3 were activated, whereas caspase‑8 remained inactive. These observations suggested that theanine exerted potent cytotoxicity on tumor cells when glutamine was restricted.

Anti-inflammatory potential of Lactobacillus plantarum LS/07 in acute colitis in rats

To evaluate the efficiency of the probiotic strain Lactobacillus plantarum LS/07 in dextran sulphate sodium (DSS) induced acute colitis selected biochemical (activity of β-glucuronidase), microbiological (counts of lactobacilli and coliforms), and immunological (IL-6, IL-8, IL-13, NF-κB, MPO) parameters were assessed. Sprague-Dawley rats were divided into groups: Control, Acute colitis, and Probiotic. Acute colitis was induced using 5% DSS in drinking water for 7d. DSS induced an inflammatory process in the colonic tissue, increased the activity of β-glucuronidase (p<0.001), increased the counts of coliform bacteria and decreased lactobacilli counts (p<0.05), and activated the production of the measured parameters (NF-κB, MPO, IL-6, IL-8) except of IL-13. Lactobacillus plantarum LS/07 in the diet alleviated the DSS induced inflammatory process by inhibiting the production of IL-6, IL-8, the activities of NF-κB and MPO, and stimulated the production of IL-13. The probiotic reduced the activity of β-glucuronidase (p<0.05), increased lactobacilli counts and decreased coliform bacteria. These results indicate that dietary intake of Lactobacillus plantarum LS/07 suppressed the expression of markers playing an important role in the inflammatory process. We conclude that the anti-inflammatory properties of Lactobacillus plantarum LS/07 makes its suitable for the prevention or treatment of colitis.

Hard clam extracts induce atypical apoptosis in human gastric cancer cells

Hard clams (HCs) are a nutritionally high-quality and popular seafood, and are established to be a potent antitumor food. The aim of the present study was to determine whether HC extracts induce apoptosis in the human gastric cancer cell line, AGS. In contrast with previously reported methods of extraction, crude extracts of HC were obtained by freezing and thawing and by a method free of hot water or organic solvents. The composition, quality and properties of the HC extracts were demonstrated to be stable since the extracts that were evaluated by capillary electrophoresis and HPLC analysis at different timepoints were similar. HC extracts also have an inhibitory effect against the survival of AGS cells. Treatment with HC extracts induced a marked sub-G1 DNA peak and reduced the expression of the anti-apoptotic genes BIRC5 and KPNA2. However, hallmarks of classical apoptosis such as DNA fragmentation and apoptotic body formation were not observed, indicating atypical apoptosis. Furthermore, it was revealed that HC extracts interrupted cell cycle progression in AGS cells through altered expression of six cell cycle-associated genes: CDC20, KPNA2, BIRC5, ANAPC2, CDKN1A and RB1. The present findings suggest that HC may contribute to a novel future anticancer agent.

Strategies to Target Glucose Metabolism in Tumor Microenvironment on Cancer by Flavonoids

The imbalance between glucose metabolism and cancer cell growth in tumor microenvironment (TME), which are closely related with the occurrence and progression of cancer. Accumulating evidence has demonstrated that flavonoids exert many biological properties, including antioxidant and anticarcinogenic activities. Recently, the roles and applications of flavonoids, particularly in relation to glucose metabolism in cancers, have been highlighted. Thus, the identification of flavonoids targeting alternative glucose metabolism pathways in TME may represent an attractive approach to the more effective therapeutic strategies for cancer. In this review, we will focus on the roles of flavonoids in regulating glucose metabolism and cancer cell growth in TME, such as proliferation advantage, cell mobility, and chemoresistance to cancer, as well as modifiers of thermal sensitivity. Not only have such large-scale endeavors been useful in providing fundamental insights into natural and synthesized flavonoids that can prevent and treat cancer, but also have led to the discovery of potential targets for cancer therapy.

Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices

Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2)-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish) rat model. Female ACI rats were given either control diet (AIN 93M) or diet supplemented with 7.5% (w/w) of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold) enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA) in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα). The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92 days in control group. At the end of the study (25 weeks), the tumor incidence was 96% in the control group compared with only 70% in the caraway group. A significant reduction in tumor volume (661 ± 123 vs. 313 ± 81 mm³) and tumor multiplicity (4.2 ± 0.4 vs. 2.5 ± 0.5 tumors/animal) was also observed in the caraway group compared with the control group. Together, our data show dietary caraway can significantly delay and prevent the hormonal mammary tumorigenesis by modulating different cellular and molecular targets.

A novel curcumin analogue is a potent chemotherapy candidate for human hepatocellular carcinoma

Curcumin (CUR) has been demonstrated to protect against carcinogenesis and to prevent tumor development in cancer; however, the clinical application of CUR is limited by its instability and poor metabolic properties. The present study offers an strategy for a novel CUR analogue, (1E,4E)-1,5-bis(2-bromophenyl)penta-1,4-dien-3-one (GL63), to be used as a potential therapeutic agent for hepatocellular carcinoma (HCC) in vitro and in vivo. The current study demonstrated that GL63 exhibited more potent inhibition of proliferation of HCC cells than CUR. GL63 induced G0/G1 phase cell cycle arrest and apoptosis in SK-HEP-1 cells in a dose-dependent manner, and was more potent than CUR, according to the flow cytometry data. The present study demonstrated for the first time that the inhibition of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway by GL63 resulted in a protective effect against HCC cell growth. GL63 was more effective than CUR in regulating STAT3 downstream targets, which contributed to the suppression of cell proliferation and the induction of cell apoptosis. In addition, the effects of GL63 were tested in a model of N-nitrosodiethylamine (DEN)-induced HCC in Wistar rats. Although macroscopic and microscopic features suggested that both GL63 and CUR were effective in inhibiting DEN-induced hepatocarcinogenesis, GL63 exerted a stronger effect than CUR. Immunohistochemical analysis for proliferating cell nuclear antigen demonstrated significant differences among the DEN-bearing non-treated, DEN-bearing GL63-treated and DEN-bearing, CUR-treated groups (P=0.039). It was concluded that GL63 was a potent agent able to suppress the proliferation of HCC cells by inhibition of the JAK2/STAT3 signaling pathway, with more favorable pharmacological activity than CUR, and may be a more potent compound for the prevention of DEN-induced hepatocarcinogenesis in rats than CUR.

Artonin E Induces Apoptosis via Mitochondrial Dysregulation in SKOV-3 Ovarian Cancer Cells

Artonin E is a prenylated flavonoid isolated from the stem bark of Artocarpus elasticus Reinw.(Moraceae). This study aimed to investigate the apoptotic mechanisms induced by artonin E in a metastatic human ovarian cancer cell line SKOV-3 in vitro. MTT assay, clonogenic assay, acridine orange and propidium iodide double staining, cell cycle and annexin V analyses were performed to explore the mode of artonin E-induced cell death at different time points. DNA laddering, activation of caspases-3, -8, and -9, multi-parametric cytotoxicity-3 analysis by high-content screening, measurement of reactive oxygen species generation, and Western blot were employed to study the pathways involved in the apoptosis. MTT results showed that artonin E inhibited the growth of SKOV-3 cells, with IC50 values of 6.5±0.5 μg/mL after 72 h treatment, and showed less toxicity toward a normal human ovarian cell line T1074, with IC50 value of 32.5±0.5 μg/mL. Results showed that artonin E induced apoptosis and cell cycle arrest at the S phase. This compound also promoted the activation of caspases-3, -8, and -9. Further investigation into the depletion of mitochondrial membrane potential and release of cytochrome c revealed that artonin E treatment induced apoptosis via regulation of the expression of pro-survival and pro-apoptotic Bcl-2 family members. The expression levels of survivin and HSP70 proteins were also down regulated in SKOV-3 cells treated with artonin E. We propose that artonin E induced an antiproliferative effect that led to S phase cell cycle arrest and apoptosis through dysregulation of mitochondrial pathways, particularly the pro- and anti-apoptosis signaling pathways.

Antioxidant Activity and Cytotoxicity Effect of Cocoa Beans Subjected to Different Processing Conditions in Human Lung Carcinoma Cells

Lung cancer is a common malignancy in men and the second leading cause of cancer-related mortality in men in the western world. Phenolic cocoa ingredients have a strong antioxidative activity and the potential to have a protective effect against cancer. In the present study, we have evaluated the influence of cocoa beans subjected to different processing conditions on cell viability and apoptosis of human lung cancer cells (A549). We measured the viability of lung cells treated with cocoa beans, unroasted slates (US), roasted slates (RS), unroasted well fermented (UWF) cocoa, and roasted well fermented (RWF) cocoa for 24 h. Using an MTT assay, we observed a decrease in the viability of A549 cells after treatment with cocoa bean extracts. Flow cytometer analysis revealed that cocoa beans increased the percentage of cells in sub-G₁ phase and promoted up to twofold increase of apoptotic cells when compared to the control group. Taken together, the present study suggests that cocoa beans may have a protective effect against lung cancer.

A Comprehensive Review on the Chemotherapeutic Potential of Piceatannol for Cancer Treatment, with Mechanistic Insights

Cancer is a diverse class of diseases characterized by uncontrolled cell growth that constitutes the greatest cause of mortality and morbidity worldwide. Despite steady progress, the treatment modalities of cancer are still insufficient. Several new concepts have emerged for therapeutic intervention in malignant diseases with the goal of identifying specific targets and overcoming resistance against current cytotoxic therapies. Many studies have reported the remarkable and significant properties of dietary plant polyphenols such as curcumin, resveratrol, flavopiridol, indirubin, magnolol, piceatannol, parthenolide, epigallocatechin gallate, and cucurbitacin as anticancer agents known for their pleiotropic effects on cancer, immune cells, and inflammation. Piceatannol, an analogue and metabolite of resveratrol, is a natural stilbene commonly found in grape skins and wine. Compared to resveratrol, this molecule exhibits superior bioactivities as an inhibitor of COX-1/2 and the CSN-associated kinase. Piceatannol is thought to be a potent natural compound with many therapeutic effects, such as the prevention of hypercholesterolemia, arrhythmia, atherosclerosis, angiogenesis, and cardiovascular diseases. It also demonstrates vasorelaxation, antioxidant, and anticancer activities. This comprehensive review summarizes the current data regarding the mechanisms of action of piceatannol, its chemopreventive properties, and its possible therapeutic potential against various types of human cancer.

Induction of rat hepatic mitochondrial membrane permeability transition pore opening by leaf extract of Olax subscorpioidea

BACKGROUND

The induction of the mitochondrial membrane permeability transition (MMPT) pore has been implicated in the cascade of events involved in apoptosis (programmed cell death). Olax subscorpioidea is traditionally used for the treatment of several diseases and infection. However, its role on MMPT is not yet established. This study was aimed at evaluating the effects of varying concentrations of the methanol leaf extract of O. subscorpioidea (MEOS) on MMPT pore opening, mitochondrial adenosine triphosphatase (ATPase), and mitochondrial lipid peroxidation.

MATERIALS AND METHODS

Opening of the pore was spectrophotometrically assayed under succinate-energized conditions.

RESULTS

In the absence of triggering agent (calcium), MEOS induced MMPT pore opening by 350, 612, 827, 845% at 36, 60, 86 and 112 μg/ml, respectively. MEOS further induced MMPT pore opening in the presence of a triggering agent by 866, 905, 831, 840, 949% at 12, 36, 60, 86 and 112 μg/ml, respectively. The extract significantly induced mitochondrial membrane lipid peroxidation in all the concentration used. MEOS also significantly increased mitochondrial ATP hydrolysis by mitochondrial ATPase in all concentration of the extract used.

CONCLUSION

It may be deduced from this results, that MEOS contains certain bioactive components that may find use in pathological conditions that require an enhanced rate of apoptosis.

Advances in molecular signaling mechanisms of β-phenethyl isothiocyanate antitumor effects

β-Phenethyl isothiocyanate (PEITC) is an important phytochemical from cruciferous vegetables and is being evaluated for chemotherapeutic activity in early phase clinical trials. Moreover, studies in cell culture and in animals found that the anticarcinogenic activities of PEITC involved all the major stages of tumor growth: initiation, promotion, and progression. A number of mechanisms have been proposed for the chemopreventive activities of this compound. Here, we focus on the major molecular signaling pathways for the anticancer activities of PEITC. These include (1) activation of apoptosis pathways; (2) induction of cell cycle arrest; and (3) inhibition of the survival pathways. Furthermore, we also discussed the regulation of drug-metabolizing enzymes, including cytochrome P450s, metabolizing enzymes, and multidrug resistance.

Diet-based strategies for cancer chemoprevention: the role of combination regimens using dietary bioactive components

Chemopreventive agents that the general population can consume for prolonged periods of time with minimal risk of any side effects are of great interest to all in search of a solution to the pervasive incidence of cancer. Dietary bioactive components have been found to modulate many deregulated molecular pathways associated with the initiation and progression of different types of cancer. Combination regimens with dietary bioactive components are a promising strategy for cancer chemoprevention because they may offer enhanced protective effects against cancer development but cause little or no adverse effects. This article provides an overview of studies examining the combination of dietary bioactive components for the chemoprevention of major types of cancer. A better understanding of existing research on the combination of dietary bioactive components will provide an important basis for the rational design of future combination studies and the successful development of cancer chemoprevention strategies.

Carnosol induces ROS-mediated beclin1-independent autophagy and apoptosis in triple negative breast cancer

Background

In this study we investigated the in vitro and in vivo anticancer effect of carnosol, a naturally occurring polyphenol, in triple negative breast cancer.

Results

We found that carnosol significantly inhibited the viability and colony growth induced G2 arrest in the triple negative MDA-MB-231. Blockade of the cell cycle was associated with increased p21/WAF1 expression and downregulation of p27. Interestingly, carnosol was found to induce beclin1-independent autophagy and apoptosis in MDA-MB-231 cells. The coexistence of both events, autophagy and apoptosis, was confirmed by electron micrography. Induction of autophagy was found to be an early event, detected within 3 h post-treatment, which subsequently led to apoptosis. Carnosol treatment also caused a dose-dependent increase in the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2). Moreover, we show that carnosol induced DNA damage, reduced the mitochondrial potential and triggered the activation of the intrinsic and extrinsic apoptotic pathway. Furthermore, we found that carnosol induced a dose-dependent generation of reactive oxygen species (ROS) and inhibition of ROS by tiron, a ROS scavenger, blocked the induction of autophagy and apoptosis and attenuated DNA damage. To our knowledge, this is the first report to identify the induction of autophagy by carnosol.

Conclusion

In conclusion our findings provide strong evidence that carnosol may be an alternative therapeutic candidate against the aggressive form of breast cancer and hence deserves more exploration.

Effects of crude extracts from medicinal herbs Rhazya stricta and Zingiber officinale on growth and proliferation of human brain cancer cell line in vitro

Hitherto, limited clinical impact has been achieved in the treatment of glioblastoma (GBMs). Although phytochemicals found in medicinal herbs can provide mankind with new therapeutic remedies, single agent intervention has failed to bring the expected outcome in clinical trials. Therefore, combinations of several agents at once are gaining increasing attractiveness. In the present study, we investigated the effects of crude alkaloid (CAERS) and flavonoid (CFEZO) extracts prepared from medicinal herbs, Rhazya stricta and Zingiber officinale, respectively, on the growth of human GBM cell line, U251. R. stricta and Z. officinale are traditionally used in folkloric medicine and have antioxidant, anticarcinogenic, and free radical scavenging properties. Combination of CAERS and CFEZO treatments synergistically suppressed proliferation and colony formation and effectively induced morphological and biochemical features of apoptosis in U251 cells. Apoptosis induction was mediated by release of mitochondrial cytochrome c, increased Bax : Bcl-2 ratio, enhanced activities of caspase-3 and -9, and PARP-1 cleavage. CAERS and CFEZO treatments decreased expression levels of nuclear NF-κBp65, survivin, XIAP, and cyclin D1 and increased expression level of p53, p21, and Noxa. These results suggest that combination of CAERS and CFEZO provides a useful foundation for studying and developing novel chemotherapeutic agents for the treatment of GBM.

Association of cancer metabolism-related proteins with oral carcinogenesis - indications for chemoprevention and metabolic sensitizing of oral squamous cell carcinoma?

Background

Tumor metabolism is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC).

Methods

Expression of IGF-R1, glycolysis-related proteins (GLUT-1, HK 2, PFK-1, LDHA, TKTL1), mitochondrial enzymes (SDHA, SDHB, ATP synthase) were analyzed in normal oral mucosa (n = 5), oral precursor lesions (simple hyperplasia, n = 11; squamous intraepithelial neoplasia, SIN I-III, n = 35), and OSCC specimen (n = 42) by immunohistochemistry and real-time polymerase chain reaction (qPCR) analysis in OSCC cell lines. Metabolism-related proteins were correlated with proliferation activity (Ki-67) and apoptotic properties (TUNEL assay) in OSCC. Specificity of antibodies was confirmed by western blotting in cancer cell lines.

Results

Expression of IGF-R1, glycolysis-related proteins (GLUT-1, HK 2, LDHA, TKTL1), and mitochondrial enzymes (SDHA, SDHB, ATP synthase) were significantly increased in the carcinogenesis of OSCC. Metabolic active regions of OSCC were strongly correlated with proliferating cancer (Ki-67+) cells without detection of apoptosis (TUNEL assay).

Conclusions

This study provides the first evidence of the expression of IGF-R1, glycolysis-related proteins GLUT-1, HK 2, PFK-1, LDHA, and TKTL1, as well as mitochondrial enzymes SDHA, SDHB, and ATP synthase in the multi-step carcinogenesis of OSCC. Both, hypoxia-related glucose metabolism and mitochondrial oxidative phosphorylation characteristics are associated with the carcinogenesis of OSCC. Acidosis and OXPHOS may drive a metabolic shift towards the pentose phosphate pathway (PPP). Therefore, inhibition of the PPP, glycolysis, and targeted anti-mitochondrial therapies (ROS generation) by natural compounds or synthetic vitamin derivatives may act as sensitizer for apoptosis in cancer cells mediated by adjuvant therapies in OSCC.

Chemical constituents from Phyllanthus emblica and the cytoprotective effects on H2O2-induced PC12 cell injuries

Two new compounds (1-2), including a bisabolane-type sesquiterpenoid (1), one new diphenyl ether derivative (2), together with 23 known compounds (3-25), were isolated from the fruits of Phyllanthus emblica. Their structures were elucidated by detailed spectroscopic analysis. All the isolated compounds were screened for the DPPH scavenging effects and cytoprotective effects against H2O2 induced PC12 cells injury. Compounds 12-15 showed significant DPPH scavenging effects with the IC50 values in the range of 3.25-4.18 μM. Among these potential antioxidants, compound 14 improved the survival of PC12 cells after H2O2 exposure without showing any cytotoxicity at the tested concentrations.

Differential modulation of apoptotic processes by proanthocyanidins as a dietary strategy for delaying chronic pathologies

Apoptosis is a biological process necessary for maintaining cellular homeostasis. Several diseases can result if it is deregulated. For example, inhibition of apoptotic signaling pathways is linked to the survival of pathological cells, which contributes to cancer, whereas excessive apoptosis is linked to neurodegenerative diseases, partially via oxidative stress. The activation or restoration of apoptosis via extrinsic or intrinsic pathways combined with cell signaling pathways triggered by reactive oxygen specises (ROS) formation is considered a key strategy by which bioactive foods can exert their health effects. Proanthocyanidins, a class of flavonoids naturally found in fruits, vegetables, and beverages, have attracted a great deal of attention not only because they are strong antioxidants but also because they appear to exert a different modulation of apoptosis, stimulating apoptosis in damaged cells, thus preventing cancer or reducing apoptosis in healthy cells, and as a result, preserving the integrity of normal cells and protecting against neurodegenerative diseases. Therefore, proanthocyanidins could provide a defense against apoptosis induced by oxidative stress or directly inhibit apoptosis, and they could also provide a promising treatment for a variety of diseases. Emerging data suggest that proanthocyanidins, especially those that humans can be persuaded to consume, may be used to prevent and manage cancer and mental disorders.

Robustaside B and para‑hydroxyphenol: phenolic and antioxidant compounds purified from Cnestis ferruginea D.C induced membrane permeability transition in rat liver mitochondria

The antioxidant properties of robustaside B and para‑hydroxyphenol isolated from Cnestis ferruginea were measured as the rate of inhibition of thiobarbituric acid reactive substance (TBARS) production in the Fe2+/ascorbate system. The modulatory effects of the compounds on mitochondrial membrane permeability transition (MMPT) were monitored spectrophotometrically as decreases in light scattering at 540 nm. The varying concentrations of robustaside B and para‑hydroxyphenol (0.05, 0.1, 0.2, 0.25, 0.5, 0.75 and 1 mM) significantly reduced (P<0.05) the amount of TBARS generated by the Fe2+/ascorbate system by 85.3, 86.4, 86.0, 86.1, 86.0, 86.0 and 86.0% and 86.7, 81.3, 81.3, 80, 80, 82.6 and 83.1%, respectively. Similarly, quercetin, a standard antioxidant, was found to induce an 80% reduction in the amount of TBARS produced. The same IC50 value of 0.025 mM was observed for robustaside B, para‑hydroxyphenol and quercetin. Pre‑incubation of varying concentrations of robustaside B (0.125, 0.2, 0.5 and 1 mM) with succinate‑energized mitochondria induced MMPT pore opening by 0, ‑33.3, ‑59.3 and ‑218.5%, compared with control mitochondria. Para‑hydroxyphenol at 0.1, 0.2, 0.25 and 0.5 mM induced MMPT pore opening in a concentration‑dependent manner up to 0.25 mM by ‑21, ‑54.4 and ‑107.0%, respectively. Quercetin at 0.05, 0.1, 0.25, 0.5, 0.75 and 1 mM also induced MMPT pore opening in the absence of calcium in a concentration‑dependent manner by 5, 3.7, ‑42.6, ‑81.5, ‑187 and ‑161.1%, respectively. The current observations confirm the antioxidant properties of robustaside B and para‑hydroxyphenol, and indicate a potential therapeutic use of the compounds for the treatment of diseases requiring the induction of cell death, including cancer.

Selenium compounds induced ROS-dependent apoptosis in myelodysplasia cells

Several authors have demonstrated the chemoprotective and anti-carcinogenic role of selenium. However, the therapeutic potential of selenium in myelodysplastic syndrome (MDS) as single agent and as co-adjuvant of the current therapies has not been previously studied. Sodium selenite and selenomethionine, alone and in combination with cytarabine, induce a decrease in cell viability in a time-, dose- and administration-dependent manner inducing cell death by apoptosis in F36P cells (MDS cell line). These compounds increased superoxide production and induced mitochondrial membrane depolarization. The increase in BAX/BCL-2 ratio and in the activated caspase 3 expression levels, the decrease in mitochondria membrane potential, as well as the increase in superoxide production, supports the mitochondria contribution on selenium-induced apoptosis. These findings suggest that selenium may offer a new therapeutic approach in myelodysplastic syndrome in monotherapy and/or as co-adjuvant therapy to conventional anti-carcinogenic.

Oxidative stress mediates apoptotic effects of ascorbate and dehydroascorbate in human Myelodysplasia cells in vitro

The Myelodysplastic Syndromes are stem cell heterogeneous disorders characterized by peripheral cytopenias and hypercellular bone marrow, which can evolute to acute leukaemia. Vitamin C can act as an antioxidant, ascorbic acid (AA) donates two electrons and becomes oxidized to dehydroascorbic acid (DHA). Under physiological conditions, vitamin C predominantly exists in its reduced (AA) form but also exists in trace quantities in the oxidized form (DHA). This study evaluates the therapeutic potential of vitamin C in Myelodysplastic Syndromes (MDSs). F36P cells (MDS cell line) were treated with ascorbate and dehydroascorbate alone and in combination with cytarabine. Cell proliferation and viability were assessed by trypan blue assay and cell death was evaluated by optical microscopy and flow cytometry. The role of reactive oxygen species, mitochondrial membrane potential, BAX, BCL-2 and cytochrome C were also assessed. Vitamin C decreases cell proliferation and viability in a concentration, time and administration dependent-manner inducing cell death by apoptosis, which was shown to be associated to an increased in superoxide production, mitochondrial membrane depolarization. These compounds modulate BCL-2, BAX and cytochrome C release. These results suggest that vitamin C induces cell death trough apoptosis in F36P cells and may be a new therapeutic approach in Myelodysplasia.