Selective induction of apoptosis of human oral cancer cell lines by avocado extracts via a ROS-mediated mechanism

A state-of-the-science review of using mitochondrial DNA copy number as a biomarker for environmental exposure

Mitochondria are bioenergetic, biosynthetic, and signaling organelles in eukaryotes, and contain their own genomes, mitochondrial DNA (mtDNA), to supply energy to cells by generating ATP via oxidative phosphorylation. Therefore, the threat to mitochondria' integrity and health resulting from environmental exposure could induce adverse health effects in organisms. In this review, we summarized the association between mtDNA copy number (mtDNAcn), and environmental exposures as reported in the literature. We conducted a literature search in the Web of Science using [Mitochondrial DNA copy number] and [Exposure] as two keywords and employed three selection criteria for the final inclusion of 97 papers for review. The consensus of data was that mtDNAcn could be used as a plausible biomarker for cumulative exposures to environmental chemical and physical agents. In order to furtherly expand the application of mtDNAcn in ecological and environmental health research, we suggested a series of algorithms aiming to standardize the calculation of mtDNAcn based on the PCR results in this review. We also discussed the pitfalls of using whole blood/plasma samples for mtDNAcn measurements and regard buccal cells a plausible and practical alternative. Finally, we recognized the importance of better understanding the mechanistic analysis and regulatory mechanism of mtDNAcn, in particular the signals release and regulation pathways. We believe that the development of using mtDNAcn as an exposure biomarker will revolutionize the evaluation of chronic sub-lethal toxicity of chemicals to organisms in ecological and environmental health research that has not yet been implemented.

Enzymatic, Antioxidant, and Antimicrobial Activities of Bioactive Compounds from Avocado (Persea americana L.) Seeds

The aim of this research was to identify and quantify biologically active compounds from avocado (Persea americana L.) seeds (AS) utilizing different techniques with the use of ultrasound (US), ethanol (EtOH), and supercritical carbon dioxide (scCO₂) for possible applications in (bio)medicine, pharmaceutical, cosmetic, or other relevant industries. Initially, a study of the process efficiency (η) was carried out, which revealed yields in the range of 2.96-12.11 wt%. The sample obtained using scCO₂ was found to be the richest in total phenols (TPC) and total proteins (PC), while the sample obtained with the use of EtOH resulted in the highest content of proanthocyanidins (PAC). Phytochemical screening of AS samples, quantified by the HPLC method, indicated the presence of 14 specific phenolic compounds. In addition, the activity of the selected enzymes (cellulase, lipase, peroxidase, polyphenol oxidase, protease, transglutaminase, and superoxide dismutase) was quantified for the first time in the samples from AS. Using DPPH radical scavenging activity, the highest antioxidant potential (67.49%) was detected in the sample obtained with EtOH. The antimicrobial activity was studied using disc diffusion method against 15 microorganisms. Additionally, for the first time, the antimicrobial effectiveness of AS extract was quantified by determination of microbial growth-inhibition rates (MGIRs) at different concentrations of AS extract against three strains of Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas fluorescens) bacteria, three strains of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Streptococcus pyogenes) bacteria, and fungi (Candida albicans). MGIRs and minimal inhibitory concentration (MIC₉₀) values were determined after 8 and 24 h of incubation, thus enabling the screening of antimicrobial efficacy for possible further applications of AS extracts as antimicrobial agents in (bio)medicine, pharmaceutical, cosmetic, or other industries. For example, the lowest MIC₉₀ value was determined for B. cereus after 8 h of incubation in the case of UE and SFE extracts (70 μg/mL), indicating an outstanding result and the potential of AS extracts, as the MIC values for B. cereus have not been investigated so far.

In Vitro and In Silico Study on the Impact of Chlorogenic Acid in Colorectal Cancer Cells: Proliferation, Apoptosis, and Interaction with β-Catenin and LRP6

Colorectal cancer mortality rate and highly altered proteins from the Wnt/β-catenin pathway increase the scientific community's interest in finding alternatives for prevention and treatment. This study aims to determine the biological effect of chlorogenic acid (CGA) on two colorectal cancer cell lines, HT-29 and SW480, and its interactions with β-catenin and LRP6 to elucidate a possible modulatory mechanism on the Wnt/β-catenin pathway. These effects were determined by propidium iodide and DiOC6 for mitochondrial membrane permeability, MitoTracker Red for mitochondrial ROS production, DNA content for cell distribution on cell cycle phases, and molecular docking for protein-ligand interactions and binding affinity. Here, it was found that CGA at 2000 µM significantly affects cell viability and causes DNA fragmentation in SW480 cells rather than in HT-29 cells, but in both cell lines, it induces ROS production. Additionally, CGA has similar affinity and interactions for LRP6 as niclosamide but has a higher affinity for both β-catenin sites than C2 and iCRT14. These results suggest a possible modulatory role of CGA over the Wnt/β-catenin pathway in colorectal cancer.

Nerolidol assists Cisplatin to induce early apoptosis in human laryngeal carcinoma Hep 2 cells through ROS and mitochondrial-mediated pathway: An in vitro and in silico view

The objective of this study was to examine Nerolidol (NER) and Cisplatin (CIS) performed against human laryngeal carcinoma (Hep 2) cells. We evaluated the effect of NER, CIS, and NER + CIS on cell viability, cell migration, oxidative stress, mitochondrial membrane depolarization, nuclear condensation, apoptotic induction, and DNA damage in Hep 2 cells. We used the MTT assay to assess the cytotoxicity effect of NER and CIS on Hep 2 cells in terms of morphological alterations. Present results demonstrated that IC₅₀ values of NER and CIS have potential cytotoxicity against Hep 2 cells. NER effectively inhibited cell viability, increased reactive oxygen species generation, apoptotic induction, and DNA damage in Hep 2 cells. In addition, the docking study evaluated the structural binding interaction of NER with PI3K/Akt and PCNA protein. Furthermore, NER with PI3K/Akt, PCNA has a higher crucial score and affinity. Present results infer that NER could be used to target signaling molecules in anticancer studies. PRACTICAL APPLICATIONS: Nerolidol is a dietary phytochemical with high biological activity that can find in a variety of plants. Many researchers focused on Nerolidol to treat various diseases including cancer. However, there is no studies exist on laryngeal cancer. This study uses Nerolidol and Cisplatin to generate oxidative stress and stimulate apoptosis and DNA damage in human laryngeal cancer cells. Based on present findings, Nerolidol could be a choice of anticancer medication, either alone or in combination against oral squamous cell carcinomas in both in vitro and in vivo experimental systems.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

Cytotoxicity of a Lipid-Rich Extract from Native Mexican Avocado Seed (Persea americana var. drymifolia) on Canine Osteosarcoma D-17 Cells and Synergistic Activity with Cytostatic Drugs

Osteosarcoma is the most common malignant bone tumor in both children and dogs. It is an aggressive and metastatic cancer with a poor prognosis for long-term survival. The search for new anti-cancer drugs with fewer side effects has become an essential goal for cancer chemotherapy; in this sense, the bioactive compounds from avocado have proved their efficacy as cytotoxic molecules. The objective of this study was to determine the cytotoxic and antiproliferative effect of a lipid-rich extract (LEAS) from Mexican native avocado seed (Persea americana var. drymifolia) on canine osteosarcoma D-17 cell line. Also, the combined activity with cytostatic drugs was evaluated. LEAS was cytotoxic to D-17 cells in a concentration-dependent manner with an IC₅₀ = 15.5 µg/mL. Besides, LEAS induced caspase-dependent cell apoptosis by the extrinsic and intrinsic pathways. Moreover, LEAS induced a significant loss of mitochondrial membrane potential and increased superoxide anion production and mitochondrial ROS. Also, LEAS induced the arrest of the cell cycle in the G0/G1 phase. Finally, LEAS improved the cytotoxic activity of cisplatin, carboplatin, and in less extension, doxorubicin against the canine osteosarcoma cell line through a synergistic effect. In conclusion, avocado could be a potential source of bioactive molecules in the searching treatments for osteosarcoma.

Phenolic-Rich Extracts from Avocado Fruit Residues as Functional Food Ingredients with Antioxidant and Antiproliferative Properties

In this study, the total phenolic compounds content and profile, the nutritional value, the antioxidant and antiproliferative activities of avocado peel, seed coat, and seed extracts were characterized. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The avocado peel extract possessed the highest content of phenolic compounds (309.95 ± 25.33 mMol GA/100 g of extract) and the lowest effective concentration (EC₅₀) against DPPH and ABTS radicals (72.64 ± 10.70 and 181.68 ± 18.47, respectively). On the other hand, the peel and seed coat extracts had the lowest energy densities (226.06 ± 0.06 kcal/100 g and 219.62 ± 0.49 kcal/100 g, respectively). Regarding the antiproliferative activity, the avocado peel extract (180 ± 40 µg/mL) showed the lowest inhibitory concentration (IC₅₀), followed by the seed (200 ± 21 µg/mL) and seed coat (340 ± 32 µg/mL) extracts. The IC₅₀ of the extracts induced apoptosis in Caco-2 cells at the early and late stages. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to hydroxysalidroside, salidroside, sakuranetin, and luteolin. Therefore, this study provides new insights regarding the potential use of these extracts as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress such as cancer.

Avocado oil: Production and market demand, bioactive components, implications in health, and tendencies and potential uses

Avocado is a subtropical/tropical fruit with creamy texture, peculiar flavor, and high nutritional value. Due to its high oil content, a significant quantity of avocado fruit is used for the production of oil using different methods. Avocado oil is rich in lipid-soluble bioactive compounds, but their content depends on different factors. Several phytochemicals in the oil have been linked to prevention of cancer, age-related macular degeneration, and cardiovascular diseases and therefore have generated an increase in consumer demand for avocado oil. The aim of this review is to critically and systematically analyze the worldwide production and commercialization of avocado oil, its extraction methods, changes in its fat-soluble phytochemical content, health benefits, and new trends and applications. There is a lack of information on the production and commercialization of the different types of avocado oil, but there are abundant data on extraction methods using solvents, centrifugation-assisted aqueous extraction, mechanical extraction by cold pressing (varying concentration and type of enzymes, temperature and time of reaction, and dilution ratio), ultrasound-assisted extraction, and supercritical fluid to enhance the yield and quality of oil. Extensive information is available on the content of fatty acids, although it is limited on carotenoids and chlorophylls. The effect of avocado oil on cancer, diabetes, and cardiovascular diseases has been demonstrated through in vitro and animal studies, but not in humans. Avocado oil continues to be of interest to the food, pharmaceutical, and cosmetic industries and is also generating increased attention in other areas including structured lipids, nanotechnology, and environmental care.

Bioactive Molecules From Native Mexican Avocado Fruit (Persea americana var. drymifolia): A Review

Avocado (Persea americana Mill.) is a tree native from central and eastern México that belongs to the Lauraceae family. Avocado has three botanical varieties known as Mexican (P. americana var. drymifolia), West Indian (P. americana var. americana), and Guatemalan (P. americana var. guatemalensis). It is an oil-rich fruit appreciated worldwide because of its nutritional value and the content of bioactive molecules. Several avocado molecules show attractive activities of interest in medicine. Avocado fatty acids have beneficial effects on cardiovascular disease risk factors. Besides, this fruit possesses a high content of carotenoids and phenolic compounds with possible antifungal, anti-cancer and antioxidant activities. Moreover, several metabolites have been reported with anti-inflammatory effects. Also, an unsaponifiable fraction of avocado in combination with soybean oil is used for the treatment of osteoarthritis. The Mexican variety is native from México and is characterized by the anise aroma in leaves and by small thin-skinned fruits of rich flavor and excellent quality. However, the study of the bioactive molecules of the fruit has not been addressed in detail. In this work, we achieved a literature review on the inflammatory, immunomodulatory and cytotoxic properties of long-chain fatty acids and derivatives from Mexican avocado seed. Also, the antioxidant and anti-inflammatory properties of the oil extracted from the avocado seed are referred. Finally, the antimicrobial, immunomodulatory, and cytotoxic activities of some antimicrobial peptides expressed in the fruit are reviewed.

Metformin induces caspase-dependent and caspase-independent apoptosis in human bladder cancer T24 cells

Bladder cancer (BC) is the sixth most common cancer in men. Moreover, chemotherapy for BC leads to various side effects. Metformin is known to induce apoptosis in vitro in many types of cancer. Furthermore, it has feasibility as a drug repositioning used for the treatment of cancer. The molecular mechanism of metformin mediating apoptosis in BC is still unclear. In this study, we showed that metformin stimulated the caspase-dependent apoptotic signaling pathway in T24 cells, a human BC cell line. Moreover, the induced apoptosis was partially inhibited by a general caspase inhibitor, z-VAD-fmk, which suggested that metformin-induced apoptosis in T24 cells is partially caspase-independent. Notably, we observed the nuclear translocation of apoptosis-inducing factors (AIFs) in metformin-promoted apoptosis, which is a typical characteristic of the caspase-independent apoptotic pathway. In addition, we found that metformin-mediated apoptosis occurred via degradation of the cellular FADD-like interleukin-1β-converting enzyme inhibitory protein (c-FLIP) by facilitating ubiquitin/proteasome-mediated c-FLIP_L degradation. Furthermore, treatment with the reactive oxygen species scavenger N-acetylcysteine, failed to suppress metformin-induced apoptosis and c-FLIP_L protein degradation in metformin-treated T24 cells. In conclusion, these results indicate that metformin-induced apoptosis was mediated through AIF-promoted caspase-independent pathways as well as caspase-dependent pathways in T24 cells. As such, metformin could be used as a possible apoptotic agent for the treatment of BC.

The Ethanol Extract of Avocado (Persea americana Mill. (Lauraceae)) Seeds Successfully Induces Implant Regression and Restores Ovarian Dynamic in a Rat Model of Endometriosis

Endometriosis is an estrogen-dependent disease with conventional therapies which do not have desirable effectiveness and possess many side effects. Scientific evidences suggest that medicinal plants with antioxidant, anti-inflammatory, and/or antiproliferative properties are potential alternatives for the treatment of endometriosis. The ethanol extract of Persea americana Mill. (Lauraceae) seeds was found exhibiting antiproliferative properties in vitro and in vivo. This study therefore is aimed at investigating the effects of such an extract on an experimental model of endometriosis. Endometriosis was induced by grafting uterine fragments onto the peritoneum of female Wistar rats. After checking the success of the transplantation surgery, animals with endometriosis were orally treated with the ethanol extract of P. americana seeds at the doses of 12.5, 25, and 50 mg/kg. The positive control was treated with letrozole (10 mg/kg) while the negative control received the vehicle. Treatments lasted 7 days and animals were sacrificed thereafter. Endometrial implant volume was determined. Estradiol and progesterone levels were measured in serum samples and endometriosis lesions. The oxidative status of endometriosis lesions was evaluated. Histological analysis of endometriosis lesions, uterus, and ovaries was also performed. Results showed that the ethanol extract of P. americana seeds decreased endometrial implant volume (p < 0.001) and serum levels of estradiol and progesterone (p < 0.01). The levels of estradiol also decreased in endometriosis lesions at doses of 12.5 and 50 mg/kg (p < 0.001). Both malondialdehyde and glutathione levels increased in endometriosis lesions (p < 0.001). The ectopic endometrium height decreased and the number of antral follicles and corpora lutea (p < 0.05) increased while that of luteinized unruptured follicles decreased (p < 0.001). In conclusion, the ethanol extract of P. americana seeds displayed an antiendometriosis effect suggesting that it could be a potential alternative for the treatment of endometriosis.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Lichen sclerosus: the role of oxidative stress in the pathogenesis of the disease and its possible transformation into carcinoma

Lichen sclerosus (LS) is an autoimmune chronic inflammatory disease usually involving the anogenital skin of both sexes; more rarely LS exclusively involves extragenital areas. As a chronic inflammatory disease, in most cases, LS evolves and progresses causing scleroatrophy of the skin or scars which may cause stenosis in the affected areas. A few LS patients are at risk of developing squamous cell carcinoma in their lifetime, but appropriate long-term treatment diminishes the possibility of a malignant evolution. Oxidative stress (OS) has been proven to play a role not only in the pathogenesis of LS, but also in the development and progression of the disease. OS, by causing DNA damage and lipid peroxidation, contributes directly to the possible malignant transformation of LS. Moreover, the increase in oxidative DNA damage is associated with mutations in tumor suppressor genes. Considering the role that OS plays in LS, therapeutic use of antioxidants appears to be rational and possible, in association with other treatments. Antioxidants would counteract the oxidative DNA damage, which is the most important factor for the progression of LS and its malignant transformation.

The Odyssey of Bioactive Compounds in Avocado (Persea americana) and Their Health Benefits

Persea americana, commonly known as avocado, has recently gained substantial popularity and is often marketed as a “superfood” because of its unique nutritional composition, antioxidant content, and biochemical profile. However, the term “superfood” can be vague and misleading, as it is often associated with unrealistic health claims. This review draws a comprehensive summary and assessment of research performed in the last few decades to understand the nutritional and therapeutic properties of avocado and its bioactive compounds. In particular, studies reporting the major metabolites of avocado, their antioxidant as well as bioavailability and pharmacokinetic properties, are summarized and assessed. Furthermore, the potential of avocado in novel drug discovery for the prevention and treatment of cancer, microbial, inflammatory, diabetes, and cardiovascular diseases is highlighted. This review also proposes several interesting future directions for avocado research.

Combination of metformin and paclitaxel suppresses proliferation and induces apoptosis of human prostate cancer cells via oxidative stress and targeting the mitochondria-dependent pathway

Previous studies have reported that metformin (MET) has anticancer activity. In combination with chemotherapeutic drugs, MET reduces the dosage of chemotherapeutic drugs required and enhances anticancer efficacy. In the present study, the combination of MET and paclitaxel (PTX) in three human prostate cancer (PCa) cell lines (22RV1, PC-3 and LNCaP) was evaluated to investigate the effects on proliferation and apoptosis of PCa cells. The present study explored whether their effects were associated with reactive oxygen species (ROS). An MTT assay and microscopy were used to study the effect of MET + PTX on cell growth. Half maximal inhibitory concentration (IC₅₀) values were obtained for MET (12.281±1.089 mM for 22RV1, 2.248±0.352 mM for PC-3 cells and 3.610±0.577 mM for LNCaP cells) and PTX (13.170±1.12 nM for PC-3 cells) at 48 h. Since the survival rate of 22RV1 and LNCaP cells did not decrease linearly with increasing PTX concentration, it is difficult to estimate accurate IC₅₀; therefore, only IC₅₀ values for PTX in PC-3 cells were given. When treating the cells with 5 mM MET, the IC₅₀ of PTX decreased to 5.423±0.734 nM for PC-3 cells. Annexin V and propidium iodide staining was used to investigate apoptosis by flow cytometry. The apoptotic mechanisms of MET + PTX in PCa were investigated by detecting the expression of apoptosis-related proteins, activities of caspase-3/7, intracellular ROS accumulation, mitochondrial membrane potential, and intracellular levels of adenosine 5′-triphosphate (ATP). MET + PTX induced PCa apoptosis and ROS accumulation, and decreased mitochondrial membrane potential and intracellular levels of ATP. Taken together, these results indicated that MET + PTX suppressed PCa cell proliferation in a dose- and time-dependent manner. In addition, MET + PTX induced apoptosis by increasing ROS levels, reducing mitochondrial membrane potential, and activating mitochondrial-dependent apoptotic pathways.

Novel triazole analogs of apigenin-7-methyl ether exhibit potent antitumor activity against ovarian carcinoma cells via the induction of mitochondrial-mediated apoptosis

Ovarian cancer is one of the main causes of cancer-associated mortality across the world. Currently, ovarian cancer is mainly treated with chemotherapy. However, ovarian cancer is detected at advanced stages and chemotherapy has numerous side effects. In addition, the results of current chemotherapy on the treatment of ovarian cancer are less than satisfactory. Therefore, there is an urgent need to develop novel and more viable chemotherapeutic agents that can be used to treat ovarian cancer. The present study was designed to synthesize a series of novel triazole analogs of the bioactive apigenin-7-methyl ether to evaluate its anticancer activity against three human ovarian cancer cell lines. A total of eight novel triazole derivatives were synthesized and screened for their anticancer activity. Of all the derivatives, a derivative named 3d exhibited significant and dose-dependent anticancer activity against the SKOV3 ovarian cancer cell line. The IC₅₀ of 3d was found to be 10 µM against the SKOV3 cancer cell line. It was also observed that 3d induced apoptosis in SKOV3 cancer cells through the accretion of reactive oxygen species and reduction in mitochondrial membrane potential. The molecule also modulated the expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein. Taken together, these results showed that the apigenein-7-methyl ether novel derivative 3d may prove an important lead molecule for the treatment of ovarian cancer.

Storage conditions modulate the metabolomic profile of a black raspberry nectar with minimal impact on bioactivity

Pre-clinical and clinical studies suggest black raspberries (BRBs) may inhibit the development of oral cancer. Lyophilized BRB powder is commonly used in these studies, but processed BRB products are more often consumed. The objective of this work was to understand how storage conditions influence the phytochemical profile and anti-proliferative activity of a BRB nectar beverage. Untargeted UHPLC-Q-TOF-MS based metabolomics analyses demonstrated that large chemical variation was introduced by storage above -20 °C over 60 days. However, minimal change in anti-proliferative activity was observed when stored nectar extracts were applied to SCC-83-01-82 premalignant oral epithelial cells. As proof of concept, cyanidin-3-O-rutinoside and its degradation product, protocatechuic acid, were administered in different ratios maintaining an equimolar dose, and anti-proliferative activity was maintained. This study shows the utility of metabolomics to profile global chemical changes in foods, while demonstrating that isolated phytochemicals do not explain the complete bioactivity of a complex food product.

Betulinic acid exerts potent antitumor effects on paclitaxel-resistant human lung carcinoma cells (H460) via G2/M phase cell cycle arrest and induction of mitochondrial apoptosis

Betulinic acid is a pentacyclic plant compound obtained from the bark of white birch trees and has been demonstrated to exhibit notable pharmacological properties. In the present study, the anticancer potential of betulinic acid on paclitaxel-resistant lung cancer cell line (H460) was evaluated. Cell viability was evaluated by an MTT assay, and a clonogenic assay was performed to assess the effects on cancer cell colony formation. DAPI staining using fluorescence microscopy and flow cytometry were employed to evaluate the effects of betulinic acid on apoptosis. The effects of betulinic acid on the cell cycle and mitochondrial membrane potential were also evaluated by flow cytometry. The effects of betulinic acid on the protein expression of B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated X (Bax) were evaluated by western blot analysis. The results of the present study indicated that the half-maximal inhibitory concentration value of betulinic acid on paclitaxel-resistant H460 lung cancer cells was 50 µM. The treatment with betulinic acid was able to inhibit the colony formation potential in a dose-dependent manner. A lower cytoxicity by betulinic acid against normal human epithelial FR2 cells was observed compared with H460 cells. The betulinic acid exerted anticancer activity via the induction of apoptosis by regulating the Bcl-2/Bax signaling pathway. Additionally, treatment with betulinic acid resulted in cell cycle arrest of paclitaxel-resistant lung cancer H460 cells at the G2/M phase. Betulinic acid was also reported to cause reductions in the mitochondrial membrane potential in a dose-dependent manner. In conclusion, the results of the present study indicated that betulinic acid may be a useful drug candidate for the management of drug-resistant lung cancer.

Metformin-induced apoptosis facilitates degradation of the cellular caspase 8 (FLICE)-like inhibitory protein through a caspase-dependent pathway in human renal cell carcinoma A498 cells

Renal cell carcinoma (RCC) is one of the most common types of cancer in adults. Previous studies have reported that the survival rate was significantly lower for renal cancer patients with diabetes than for those without diabetes. Metformin is a well-known anti-diabetic agent used for the treatment of type 2 diabetes mellitus (T2DM). It also inhibits cell proliferation and angiogenesis and is known to possess antitumor effects. However, the molecular mechanism for metformin-induced apoptosis in renal cell carcinoma is not understood. In the present study, treatment with metformin induced apoptosis in A498 cells in a dose-dependent manner. It was revealed that degradation of cellular caspase 8 (FLICE)-like inhibitory protein (c-FLIP) and activation of procaspase-8 were associated with metformin-mediated apoptosis. By contrast, treatment with metformin did not affect the mRNA level of c-FLIP_L in A498 cells. Treatment with benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (z-VAD-fmk, a pan-caspase inhibitor) almost completely blocked metformin-induced apoptosis and degradation of c-FLIP_L protein. However, N-acetyl-L-cysteine (NAC), a reactive oxygen species (ROS) scavenger, did not inhibit metformin-mediated apoptosis in A498 cells. Taken together, the results of the present study demonstrated that metformin-induced apoptosis involved degradation of the c-FLIP_L protein and activation of caspase-8 in human renal cell carcinoma A498 cells and suggested that metformin could be potentially used for the treatment of renal cancer.

Fucosterol exhibits selective antitumor anticancer activity against HeLa human cervical cell line by inducing mitochondrial mediated apoptosis, cell cycle migration inhibition and downregulation of m-TOR/PI3K/Akt signalling pathway

Cervical cancer greatly contributes to cancer-associated mortalities worldwide. The growing incidence of cervical cancer is of primary concern, and has signaled the need for multiple treatment options. Despite preliminary responses to chemotherapy and/or surgical interventions, the tumors consistently relapse. Previously, natural products gained attention for their diverse bioactivities, which include however are not limited to, neuroprotective, antimicrobial and anticancer effects. The present study evaluated the anticancer activity of fucosterol against a panel of human cancer cell lines. Results indicated that fucosterol exhibited selective inhibitory activity against human HeLa cervical cancer cell line with an IC₅₀ of 40 µM. Fucosterol also induced apoptosis in HeLa cells and prompted reactive oxygen species mediated alterations in mitochondrial membrane potential. It triggered cell cycle arrest of HeLa cells at G2/M check point and exerted inhibitory effects on cell migration. The activation of the phosphoinositide-3-kinase (PI3K)/AKT Serine/Threonine Kinase 1 (AKT)/mechanistic target of Rapamycin (mTOR) pathway is important in cancer tumorigenesis, progression and chemotherapy resistance. The results demonstrated that fucosterol significantly inhibited the expression levels of key proteins of the PI3K/Akt/mTOR signaling pathway. Overall, the results of the present study suggest that fucosterol may prove beneficial in the management of cervical cancer.

Anticancer activity of caffeic acid n‑butyl ester against A431 skin carcinoma cell line occurs via induction of apoptosis and inhibition of the mTOR/PI3K/AKT signaling pathway

Skin cancer is one of the primary causes of mortality worldwide. With an increasing frequency of skin cancers, there is an urgent requirement for the development of numerous treatment options. The present study investigated the anticancer activity of caffeic acid n-butyl ester (CAE) against the A431 skin cancer cell line. Antiproliferative effects were investigated using an MMT assay. Apoptosis was examined by DAPI and Annexin V/fluorescein isothiocyanate and propidium iodide staining. Reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and cell cycle analyses were performed via flow cytometry. Protein expression was determined by western blotting. The findings of the present study demonstrated that among a variety of cancer cell lines, CAE exhibited significant anticancer activity against the A431 skin cancer cell line with a half-maximal inhibitory concentration of 20 µM. CAE was associated with apoptosis and cell cycle arrest of A431 cells, and induced ROS-mediated alterations in MMP. In addition, CAE considerably suppressed the expression of some of the important proteins of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) cascade. The results of the present study indicated that CAE exerted anticancer effects on the A431 skin carcinoma cell line via the induction of apoptosis and suppression of the PI3K/AKT/mTOR signaling pathway. Therefore, CAE may be beneficial for the development of chemotherapy for skin cancers.

Recent Advances in the Application of Vitamin E TPGS for Drug Delivery

D-ɑ-tocopheryl polyethylene glycol succinate (Vitamin E TPGS or TPGS) has been approved by FDA as a safe adjuvant and widely used in drug delivery systems. The biological and physicochemical properties of TPGS provide multiple advantages for its applications in drug delivery like high biocompatibility, enhancement of drug solubility, improvement of drug permeation and selective antitumor activity. Notably, TPGS can inhibit the activity of ATP dependent P-glycoprotein and act as a potent excipient for overcoming multi-drug resistance (MDR) in tumor. In this review, we aim to discuss the recent advances of TPGS in drug delivery including TPGS based prodrugs, nitric oxide donor and polymers, and unmodified TPGS based formulations. These potential applications are focused on enhancing delivery efficiency as well as the therapeutic effect of agents, especially on overcoming MDR of tumors. It also demonstrates that the clinical translation of TPGS based nanomedicines is still faced with many challenges, which requires more detailed study on TPGS properties and based delivery system in the future.

Mecambridine induces potent cytotoxic effects, autophagic cell death and modulation of the mTOR/PI3K/Akt signaling pathway in HSC-3 oral squamous cell carcinoma cells

Plant secondary metabolites including alkaloids, demonstrate a complex diversity in their molecular scaffolds and exhibit tremendous pharmacological potential as anti-cancerous therapeutics. The present study aimed to evaluate the anticancer activity of a natural alkaloid, mecambridine, against human oral squamous cell carcinoma (OSCC). An MTT assay was used to evaluate cytotoxic effects of mecambridine on HSC-3 oral squamous cell carcinoma cells. Effects of mecambridine on autophagy-associated proteins were analyzed by western blotting. Effects on reactive oxygen species (ROS) and mitochondrial membrane potential were assessed by flow cytometry. Results indicated that mecambridine exhibited an IC₅₀ value of 50 µM and exerted its cytotoxic effects in a dose dependent manner on OSCC HSC-3 cells. Furthermore, it was observed that mecambridine decreases cell viability and induces autophagy in a dose-dependent manner. The underlying mechanism for the induction of autophagy was demonstrated to be associated with ROS-mediated alterations in mitochondrial membrane potential and modulation of the mechanistic target of rapamycin/phosphoinositide 3-kinase/protein kinase B (m-TOR/PI3K/Akt) signaling pathway in HSC-3 at the IC₅₀. In conclusion, the present study suggests that mecambridine exhibits substantial anticancer activity against OSCC HSC-3 cells by induction of autophagy and modulates the expression of the mTOR/PI3K/Akt signaling cascade which is considered a potential target pathway for anti-cancer agents.

Withaferin A Induces Oxidative Stress-Mediated Apoptosis and DNA Damage in Oral Cancer Cells

Withaferin A (WFA) is one of the most active steroidal lactones with reactive oxygen species (ROS) modulating effects against several types of cancer. ROS regulation involves selective killing. However, the anticancer and selective killing effects of WFA against oral cancer cells remain unclear. We evaluated whether the killing ability of WFA is selective, and we explored its mechanism against oral cancer cells. An MTS tetrazolium cell proliferation assay confirmed that WFA selectively killed two oral cancer cells (Ca9-22 and CAL 27) rather than normal oral cells (HGF-1). WFA also induced apoptosis of Ca9-22 cells, which was measured by flow cytometry for subG1 percentage, annexin V expression, and pan-caspase activity, as well as western blotting for caspases 1, 8, and 9 activations. Flow cytometry analysis shows that WFA-treated Ca9-22 oral cancer cells induced G2/M cell cycle arrest, ROS production, mitochondrial membrane depolarization, and phosphorylated histone H2A.X (γH2AX)-based DNA damage. Moreover, pretreating Ca9-22 cells with N-acetylcysteine (NAC) rescued WFA-induced selective killing, apoptosis, G2/M arrest, oxidative stress, and DNA damage. We conclude that WFA induced oxidative stress-mediated selective killing of oral cancer cells.

Icariin exerts inhibitory effects on the growth and metastasis of KYSE70 human esophageal carcinoma cells via PI3K/AKT and STAT3 pathways

Esophageal cancer is one of the leading causes of cancer related mortality across the globe. The current treatment options are insufficient and are associated with number of side effects. Therefore there is a pressing need to develop effective and more efficient strategies for the treatment of esophageal cancer. Consistently, natural products are considered potential candidates for develop of cancer chemotherapy. Icariin is a naturally occurring flavonol glucoside and has been reported to possess tremendous pharmacological potential ranging from neuroprotection to anticancer activity. However, the pharmacological role of icariin in esophageal cancer is still largely unclear. Here in the present study, icariin was evaluated for its anticancer activity against KYSE70 esophageal cancer cells and the possible underlying mechanism was determined. Icariin induced cytotoxicity with an IC₅₀ of 40μM in esophageal cancer cells. These inhibitory effects were due to apoptosis through reactive oxygen species (ROS) mediated alterations in mitochondrial membrane potential (MMP). The results indicated that icariin enhanced the accretion of ROS upto 260% and reduced the MMP upto 48% at 100μM. Icariin also induced G2/M cell cycle arrest as evident from the significant increase in the G2 cell populations of KYSE70 esophageal cancer cells. Additionally, icariin inhibited esophageal cancer cell migration, invasion and metastasis by regulating the expression of epithelial to mesenchymal transition (EMT) markers. Results also indicated that icariin reduced cell viability and migration in part through suppression of the PI3K/AKT and STAT3 pathways. Taken together, our results indicate that icariin may prove a potential natural anticancer molecule against esophageal cancer.

Withaferin-A Induces Apoptosis in Osteosarcoma U2OS Cell Line via Generation of ROS and Disruption of Mitochondrial Membrane Potential

Background

Withaferin-A (WF-A) is a well-known dietary compound isolated from Withania sominifera. It has tremendous pharmacological potential and has been shown to exhibit antiproliferative activity against several types of cancerous cells. Currently, the main focus of anti-cancer therapeutic development is to identify apoptosis inducing drug-like molecules. Osteosarcoma is a rare type of osteocancer, affecting human. The present study therefore focused on the evaluation of antitumor potential of WF-A against several osteosarcoma cell lines.

Materials and Methods:

MTT assay was used to evaluate WF-A against osteosarcoma cell lines and to calculate the IC₅₀. DAPI staining was used to confirm the apoptosis inducing potential of WF-A. Mitochondrial membrane potential, reactive oxygen species (ROS) assay, and Western blotting were used to confirm the basis of apoptosis.

Results:

The results revealed that that WF-A exhibited strong antiproliferative activity against all the cells lines, with IC₅₀ ranging from 0.32 to 7.6 μM. The lowest IC₅₀ (0.32 μM) was observed against U2OS cell line and therefore it was selected for further analysis. DAPI staining indicated that WF-A exhibited antiproliferative activity via induction of apoptosis. Moreover, WF-A induced ROS-mediated reduction in mitochondrial membrane potential ΔΨm) in a dose-dependent manner and activation of caspase-3 in osteosarcoma cells.

Conclusion

We propose that WF-A may prove a potent therapeutic agent for inducing apoptosis in osteosarcoma cell lines via generation of ROS and disruption of mitochondrial membrane potential.

SUMMARY

WF-A exhibits strong anticancer activity against osteosarcoma cell lines

Antiproliferative activity of WF-A is via induction of apoptosis

WF-A induced ROS-mediated reduction in mitochondrial membrane potential

WF-A induced expression of caspase-3 in osteosarcoma cells.

Abbreviations used: WA: Withaferin A; ROS: Reactive oxygen species; OS: Osteosarcoma; MMP: Mitochondrial membrane potential.

Cinnamomum cassia essential oil and its major constituent cinnamaldehyde induced cell cycle arrest and apoptosis in human oral squamous cell carcinoma HSC-3 cells

Cinnamomum cassia essential oil (CC-EO) has various functional properties, such as anti-microbial, hypouricemic, anti-tyrosinase and anti-melanogenesis activities. The present study aimed to evaluate the anti-cancer activities of CC-EO and its major constituent, cinnamaldehyde, in human oral squamous cell carcinoma HSC-3 cells. Determination of the cell viability, apoptotic characteristics, DNA damage, cell cycle analysis, reactive oxygen species (ROS) production, mitochondrial membrane potential, cytosolic Ca²⁺ level and intracellular redox status were performed. Our results demonstrated that CC-EO and cinnamaldehyde significantly decreased cell viability and caused morphological changes. The cell cycle analysis revealed that CC-EO and cinnamaldehyde induced G2/M cell cycle arrest in HSC-3 cells. The apoptotic characteristics (DNA laddering and chromatin condensation) and DNA damage were observed in the CC-EO-treated and cinnamaldehyde-treated HSC-3 cells. Moreover, CC-EO and cinnamaldehyde promoted an increase in cytosolic Ca²⁺ levels, induced mitochondrial dysfunction and activated cytochrome c release. The results of ROS production and intracellular redox status demonstrated that CC-EO and cinnamaldehyde significantly increased the ROS production and thiobarbituric acid reactive substance levels, and the cellular glutathione content and glutathione peroxidase activity were significantly reduced in HSC-3 cells. Our results suggest that CC-EO and cinnamaldehyde may possess anti-oral cancer activity in HSC-3 cells. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 456-468, 2017.

Roe Protein Hydrolysates of Giant Grouper (Epinephelus lanceolatus) Inhibit Cell Proliferation of Oral Cancer Cells Involving Apoptosis and Oxidative Stress

Roe protein hydrolysates were reported to have antioxidant property but the anticancer effects were less addressed, especially for oral cancer. In this study, we firstly used the ultrafiltrated roe hydrolysates (URH) derived from giant grouper (Epinephelus lanceolatus) to evaluate the impact of URH on proliferation against oral cancer cells. We found that URH dose-responsively reduced cell viability of two oral cancer cells (Ca9-22 and CAL 27) in terms of ATP assay. Using flow cytometry, URH-induced apoptosis of Ca9-22 cells was validated by morphological features of apoptosis, sub-G1 accumulation, and annexin V staining in dose-responsive manners. URH also induced oxidative stress in Ca9-22 cells in terms of reactive oxygen species (ROS)/superoxide generations and mitochondrial depolarization. Taken together, these data suggest that URH is a potential natural product for antioral cancer therapy.

Functional Characterisation of Anticancer Activity in the Aqueous Extract of Helicteres angustifolia L. Roots

Helicteres angustifolia L. is a shrub that forms a common ingredient of several cancer treatment recipes in traditional medicine system both in China and Laos. In order to investigate molecular mechanisms of its anticancer activity, we prepared aqueous extract of Helicteresangustifolia L. Roots (AQHAR) and performed several in vitro assays using human normal fibroblasts (TIG-3) and osteosarcoma (U2OS). We found that AQHAR caused growth arrest/apoptosis of U2OS cells in a dose-dependent manner. It showed no cytotoxicity to TIG-3 cells at doses up to 50 μg/ml. Biochemical, imaging and cell cycle analyses revealed that it induces ROS signaling and DNA damage response selectively in cancer cells. The latter showed upregulation of p53, p21 and downregulation of Cyclin B1 and phospho-Rb. Furthermore, AQHAR-induced apoptosis was mediated by increase in pro-apoptotic proteins including cleaved PARP, caspases and Bax. Anti-apoptotic protein Bcl-2 showed decrease in AQHAR-treated U2OS cells. In vivo xenograft tumor assays in nude mice revealed dose-dependent suppression of tumor growth and lung metastasis with no toxicity to the animals suggesting that AQHAR could be a potent and safe natural drug for cancer treatment.

Microtubule-stabilizing properties of the avocado-derived toxins (+)-(R)-persin and (+)-(R)-tetrahydropersin in cancer cells and activity of related synthetic analogs

The avocado toxin (+)-R-persin (persin) is active at low micromolar concentrations against breast cancer cells and synergizes with the estrogen receptor modulator 4-hydroxytamoxifen. Previous studies in the estrogen receptor-positive breast cancer cell line MCF-7 indicate that persin acts as a microtubule-stabilizing agent. In the present study, we further characterize the properties of persin and several new synthetic analogues in human ovarian cancer cells. Persin and tetrahydropersin cause G2M cell cycle arrest and increase intracellular microtubule polymerization. One analog (4-nitrophenyl)-deshydroxypersin prevents cell proliferation and blocks cells in G1 of the cell cycle rather than G2M, suggesting an additional mode of action of these compounds independent of microtubules. Persin can synergize with other microtubule-stabilizing agents, and is active against cancer cells that overexpress the P-glycoprotein drug efflux pump. Evidence from Flutax-1 competition experiments suggests that while the persin binding site on β-tubulin overlaps the classical taxoid site where paclitaxel and epothilone bind, persin retains activity in cell lines with single amino acid mutations that affect these other taxoid site ligands. This implies the existence of a unique binding location for persin at the taxoid site.

Antiproliferation of Cryptocarya concinna-derived cryptocaryone against oral cancer cells involving apoptosis, oxidative stress, and DNA damage

Background

Cryptocarya-derived crude extracts and their compounds have been reported to have an antiproliferation effect on several types of cancers but their impact on oral cancer is less well understood.

Methods

We examined the cell proliferation effect and mechanism of C. concinna-derived cryptocaryone (CPC) on oral cancer cells in terms of cell viability, apoptosis, reactive oxygen species (ROS), mitochondrial depolarization, and DNA damage.

Results

We found that CPC dose-responsively reduced cell viability of two types of oral cancer cells (Ca9-22 and CAL 27) in MTS assay. The CPC-induced dose-responsive apoptosis effects on Ca9-22 cells were confirmed by flow cytometry-based sub-G1 accumulation, annexin V staining, and pancaspase analyses. For oral cancer Ca9-22 cells, CPC also induced oxidative stress responses in terms of ROS generation and mitochondrial depolarization. Moreover, γH2AX flow cytometry showed DNA damage in CPC-treated Ca9-22 cells. CPC-induced cell responses in terms of cell viability, apoptosis, oxidative stress, and DNA damage were rescued by N-acetylcysteine pretreatment, suggesting that oxidative stress plays an important role in CPC-induced death of oral cancer cells.

Conclusions

CPC is a potential ROS-mediated natural product for anti-oral cancer therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1073-5) contains supplementary material, which is available to authorized users.

Sinuleptolide inhibits proliferation of oral cancer Ca9-22 cells involving apoptosis, oxidative stress, and DNA damage

OBJECTIVE

Sinuleptolide, a soft corals-derived bioactive norditerpenoid, is a marine natural product with a potent anti-inflammatory effect. We evaluate the potential anti-oral cancer effects of sinuleptolide and investigate the possible mechanisms involved.

DESIGNS

Cell viability, cell cycle, apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and DNA damage analyses were performed.

RESULTS

In a cell viability assay, we found that sinuleptolide is dose-responsively antiproliferative against oral gingival cancer Ca9-22 cells but less harmful to normal human gingival fibroblast (HGF-1) cells (P<0.001). In cell cycle analysis, sinuleptolide induced subG1 accumulation at a higher dose and led to G2/M arrest of Ca9-22 cells (P<0.005). Apoptosis was significantly increased in sinuleptolide-treated Ca9-22 cells based on annexin V and poly(ADP-ribose) polymerase (PARP) expressions (P<0.05-0.0001). Based on flow cytometer analysis, sinuleptolide also induced the generation of ROS and decreased MMP in a dose-responsive manner (P<0.05-0.0001). DNA damage increased dose-responsively after sinuleptolide treatments (P < 0.001) based on comet and γH2AX assays.

CONCLUSION

Sinuleptolide can induce an antiproliferation of oral cancer Ca9-22 cells involving apoptosis, oxidative stress and DNA damage, suggesting that sinuleptolide represents a potential chemotherapeutic drug for oral cancer treatment.

Oily fish, coffee and walnuts: Dietary treatment for nonalcoholic fatty liver disease

Rates of non-alcoholic fatty liver disease (NAFLD) are increasing worldwide in tandem with the metabolic syndrome, with the progressive form of disease, non-alcoholic steatohepatitis (NASH) likely to become the most common cause of end stage liver disease in the not too distant future. Lifestyle modification and weight loss remain the main focus of management in NAFLD and NASH, however, there has been growing interest in the benefit of specific foods and dietary components on disease progression, with some foods showing protective properties. This article provides an overview of the foods that show the most promise and their potential benefits in NAFLD/NASH, specifically; oily fish/ fish oil, coffee, nuts, tea, red wine, avocado and olive oil. Furthermore, it summarises results from animal and human trials and highlights potential areas for future research.

In situ allicin generation using targeted alliinase delivery for inhibition of MIA PaCa-2 cells via epigenetic changes, oxidative stress and cyclin-dependent kinase inhibitor (CDKI) expression

Allicin, an extremely active constituent of freshly crushed garlic, is produced upon reaction of substrate alliin with the enzyme alliinase (EC 4.4.1.4). Allicin has been shown to be toxic to several mammalian cells in vitro in a dose-dependent manner. In the present study this cytotoxicity was taken to advantage to develop a novel approach to cancer treatment, based on site directed generation of allicin. Alliinase was chemically conjugated to a monoclonal antibody (mAb) which was directed against a specific pancreatic cancer marker, CA19-9. After the CA19-9 mAb-alliinase conjugate was bound to targeted pancreatic cancer cells (MIA PaCa-2 cells), on addition of alliin, the cancer cell-localized alliinase produced allicin, which effectively induced apoptosis in MIA PaCa-2 cells. Specificity of anticancer activity of in situ generated allicin was demonstrated using a novel in vitro system-integrated discrete multiple organ co-culture technique. Further, allicin-induced caspase-3 expression, DNA fragmentation, cell cycle arrest, p21(Waf1/Cip1) cyclin-dependent kinase inhibitor expression, ROS generation, GSH depletion, and led to various epigenetic modifications which resulted in stimulation of apoptosis. This approach offers a new therapeutic strategy, wherein alliin and alliinase-bound antibody work together to produce allicin at targeted locations which would reverse gene silencing and suppress cancer cell growth, suggesting that combination of these targeted agents may improve pancreatic cancer therapy.

High Potency of a Novel Resveratrol Derivative, 3,3',4,4'-Tetrahydroxy-trans-stilbene, against Ovarian Cancer Is Associated with an Oxidative Stress-Mediated Imbalance between DNA Damage Accumulation and Repair

We explored the effect of a new resveratrol (RVT) derivative, 3,3′,4,4′-tetrahydroxy-trans-stilbene (3,3′,4,4′-THS), on viability, apoptosis, proliferation, and senescence of three representative lines of ovarian cancer cells, that is, A2780, OVCAR-3, and SKOV-3, in vitro. In addition, the mechanistic aspects of 3,3′,4,4′-THS activity, including cell redox homeostasis (the production of reactive oxygen species, activity of enzymatic antioxidants, and magnitude of DNA damage accumulation and repair), and the activity of caspases (3, 8, and 9) and p38 MAPK were examined. The study showed that 3,3′,4,4′-THS affects cancer cell viability much more efficiently than its parent drug. This effect coincided with increased generation of reactive oxygen species, downregulated activity of superoxide dismutase and catalase, and excessive accumulation of 8-hydroxy-2′-deoxyguanosine and its insufficient repair due to decreased expression of DNA glycosylase I. Cytotoxicity elicited by 3,3′,4,4′-THS was related to increased incidence of apoptosis, which was mediated by caspases 3 and 9. Moreover, 3,3′,4,4′-THS inhibited cancer cell proliferation and accelerated senescence, which was accompanied by the activation of p38 MAPK. Collectively, our findings indicate that 3,3′,4,4′-THS may constitute a valuable tool in the fight against ovarian malignancy and that the anticancer capabilities of this stilbene proceed in an oxidative stress-dependent mechanism.

Antiproliferative and Apoptosis Inducing Effects of Non-Polar Fractions from Lawsonia inermis L. in Cervical (HeLa) Cancer Cells

Two non-polar fractions viz. hexane (Hex-LI) and chloroform fraction (CHCl3-LI) of Lawsonia inermis were studied for their antiproliferative potential in various cancer cell lines viz. HeLa, MCF-7, A549 and C6 glioma cells. Both the fractions showed more than 60 % of growth inhibition in all the tested cell lines at highest tested concentration. In clonogenic assay, different concentrations of Hex-LI and CHCl3-LI decreased the number and size of colonies as compared to control in HeLa cells. The apoptotic effects as nuclear condensation, fragmentation were visualized with Hoechst-33342 staining of HeLa cells using confocal microscope. Both fractions induced apoptotic cell death in human cervical carcinoma (HeLa) cells as evident from flow cytometric analysis carried out using Annexin V-FITC and propidium iodide dyes. CHCl3-LI treated cells significantly induced apoptosis (25.43 %) in comparison to control. Results from Neutral Comet assay demonstrated that both fractions induced double stranded breaks (DSB's) in HeLa cells. Our data indicated that Hex-LI and CHCl3-LI treated cells showed significant increase of 32.2 and 18.56 % reactive oxygen species (ROS) levels in DCFH-DA assay respectively. Further, experimental studies to decipher exact pathway via which these fractions induce cell death are in progress.

Antiproliferative effects of methanolic extracts of Cryptocarya concinna Hance roots on oral cancer Ca9-22 and CAL 27 cell lines involving apoptosis, ROS induction, and mitochondrial depolarization

Cryptocarya-derived natural products were reported to have several biological effects such as the antiproliferation of some cancers. The possible antioral cancer effect of Cryptocarya-derived substances was little addressed as yet. In this study, we firstly used the methanolic extracts of C. concinna Hance roots (MECCrt) to evaluate its potential function in antioral cancer bioactivity. We found that MECCrt significantly reduced cell viability of two oral cancer Ca9-22 and CAL 27 cell lines in dose-responsive manners (P < 0.01). The percentages of sub-G1 phase and annexin V-positive of MECCrt-treated Ca9-22 and CAL 27 cell lines significantly accumulated (P < 0.01) in a dose-responsive manner as evidenced by flow cytometry. These apoptotic effects were associated with the findings that intracellular ROS generation was induced in MECCrt-treated Ca9-22 and CAL 27 cell lines in dose-responsive and time-dependent manners (P < 0.01). In a dose-responsive manner, MECCrt also significantly reduced the mitochondrial membrane potential in these two cell lines (P < 0.01–0.05). In conclusion, we demonstrated that MECCrt may have antiproliferative potential against oral cancer cells involving apoptosis, ROS generation, and mitochondria membrane depolarization.

Determination of changes in the metabolic profile of avocado fruits (Persea americana) by two CE-MS approaches (targeted and non-targeted)

A CZE method with two different MS detection conditions (MRM and Full Scan) was developed to determine qualitative and quantitative changes in the metabolic profile of avocado fruits (Persea americana). LODs in MRM approach were found between 20.1 and 203.0 ppb for abscisic acid and perseitol, respectively, whilst in Full Scan, varied within the range 0.22–1.90 ppm for the same metabolites. The RSDs for reproducibility test did not exceed 11.45%. The two MS approaches were used to quantify 10 metabolites (phenolic acids, flavonoids, a carbohydrate, an organic acid, a vitamin and a phytohormone) in 18 samples of avocado at different ripening states, and the achieved results were compared. Perseitol, quinic, chlorogenic, trans-cinnamic, pantothenic and abscisic acids, as well as epicatechin and catechin decreased during the ripening process, whereas ferulic and p-coumaric acids showed the opposite trend. Moreover, some other unknown compounds whose concentration changed largely during ripening were also studied by MS/MS and QTOF MS to get a tentative identification.

Pro-apoptotic effect of Persea americana var. Hass (avocado) on Jurkat lymphoblastic leukemia cells

Abstract Context: Therapy for leukemia has a limited efficacy. There is a need to search for alternative anti-leukemia therapies. Persea americana Mill var. Hass (Lauraceae) is a tropical fruit (avocado) that might be used against cancer. Objective: To investigate whether P. americana induces death in Jurkat lymphoblastic leukemia cells. Materials and methods: Four ethanol extracts (0.1, 0.5, 1, 2 and 5 mg/mL) from avocado fruit (endocarp, whole seed, seed and leaves) were analyzed against Jurkat cells. Hydrogen peroxide generation by oxidation of 2',7'-dichlorodihydrofluorescein diacetate to the fluorescent compound 2',7'-dichlorfluorescein assay, acridine orange/ethidium bromide staining, flow cytometry analysis of annexin-V/7-amino-actinomycin, mitochondrial membrane potential and immunocytochemistry detection of transcription factor p53, caspase-3 and apoptosis-inducing factor (AIF) were evaluated. Results: Endocarp, seed, whole seed, and leaf (0.1 mg/mL) extracts induced significant apoptosis in Jurkat cells (p < 0.001) in an oxidative stress-dependent fashion via mitochondrial membrane depolarization (52-87%), activation of transcription factor p53 (6.3-25.4%), protease caspase-3 (8.3-20%) and predominance of AIF reactivity (20.6-36%) in all extracts. Similar results were obtained with 0.5 mg/mL extracts. However, extract ≥1 mg/mL concentration induced necrosis (100%). Conclusions: P. americana extracts function as a pro-apoptotic compound. Leukemic cells are eliminated through an oxidative stress mechanism. This study contributes to the understanding of the molecular mechanism of the avocado and its therapeutic action on leukemia.

Hass avocado composition and potential health effects

Hass avocados, the most common commercial avocado cultivars in the world, contain a variety of essential nutrients and important phytochemicals. Although the official avocado serving is one-fifth of a fruit (30 g), according to NHANES analysis the average consumption is one-half an avocado (68 g), which provides a nutrient and phytochemical dense food consisting of the following: dietary fiber (4.6 g), total sugar (0.2 g), potassium (345 mg), sodium (5.5 mg), magnesium (19.5 mg), vitamin A (43 μg), vitamin C (6.0 mg), vitamin E (1.3 mg), vitamin K1 (14 μg), folate (60 mg), vitamin B-6 (0.2 mg), niacin (1.3 mg), pantothenic acid (1.0 mg), riboflavin (0.1 mg), choline (10 mg), lutein/zeaxanthin (185 μg), phytosterols (57 mg), and high-monounsaturated fatty acids (6.7 g) and 114 kcals or 1.7 kcal/g. The avocado oil consists of 71% monounsaturated fatty acids (MUFA), 13% polyunsaturated fatty acids (PUFA), and 16% saturated fatty acids (SFA), which helps to promote healthy blood lipid profiles and enhance the bioavailability of fat soluble vitamins and phytochemicals from the avocado or other fruits and vegetables, naturally low in fat, which are consumed with avocados. There are eight preliminary clinical studies showing that avocado consumption helps support cardiovascular health. Exploratory studies suggest that avocados may support weight management and healthy aging.

Anti-proliferative effect of methanolic extract of Gracilaria tenuistipitata on oral cancer cells involves apoptosis, DNA damage, and oxidative stress

Background

Methanolic extracts of Gracilaria tenuistipitata (MEGT) were obtained from the edible red algae. Previously, we found that water extract of G. tenuistipitata was able to modulate oxidative stress-induced DNA damage and its related cellular responses.

Methods

In this study, the methanol extraction product MEGT was used to evaluate the cell growth inhibition in oral cancer cells and its possible mechanism was investigated.

Results

The cell viability of MEGT treated Ca9-22 oral cancer cell line was significantly decreased in a dose–response manner (p < 0.05). The sub-G1 population and annexin V intensity of MEGT-treated Ca9-22 cancer cells were significantly increased in a dose–response manner (p < 0.0005 and p < 0.001, respectively). The γH2AX intensities of MEGT-treated Ca9-22 cancer cells were significantly increased in a dose–response manner (p < 0.05). The reactive oxygen species (ROS) and glutathione (GSH)-positive intensities of MEGT-treated Ca9-22 oral cancer cells were significantly increased and decreased, respectively, in a dose–response manner (p < 0.05). The DiOC₂(3) intensity for mitochondrial membrane potential (MMP) of MEGT-treated Ca9-22 cancer cells was significantly decreased in a dose–response manner (p < 0.05).

Conclusions

These results indicated that MEGT had apoptosis-based cytotoxicity against oral cancer cells through the DNA damage, ROS induction, and mitochondrial depolarization. Therefore, MEGT derived from the edible algae may have potential therapeutic effects against oral squamous cell carcinoma (OSCC).

Dichloromethane and Methanol Extracts of Scrophularia oxysepala Induces Apoptosis in MCF-7 Human Breast Cancer Cells

PURPOSE

Breast cancer is the most common cause of cancer-related death in women worldwide. Therefore, there is an urgent need to identify and develop therapeutic strategies against this deadly disease. This study is the first to investigate the cytotoxic effects and the mechanism of cell death of Scrophularia oxysepala extracts in MCF-7 human breast cancer cells.

METHODS

Three extracts of Scrophularia oxysepala including the n-hexane, dichloromethane and methanol extracts were examined. MTT (3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and Trypan-blue assays were performed in MCF-7 cells as well as Human umbilical vein endothelial cells (HUVEC) to analyze the cytotoxic activity of the extracts of Scrophularia oxysepala. Further, the apoptosis inducing action of the extracts was determined by TUNEL (terminal deoxy transferase (TdT)-mediated dUTP nick- end labeling) test and cell death assay.

RESULTS

The results showed that the n-hexane extract had no cytotoxic effects but dichloromethane and methanol extracts significantly inhibited cell growth and viability in a dose and time dependent manner without inducing damage to non-cancerous cell line HUVEC. In addition, Cell death assay and DNA fragmentation analysis using TUNEL indicated induction of apoptosis by dichloromethane and methanol extracts of Scrophularia oxysepala in MCF-7 cells.

CONCLUSION

Our studies suggest that this plant may contain potential bioactive compound(s) for the treatment of breast cancer.

Antiproliferative effects of goniothalamin on Ca9-22 oral cancer cells through apoptosis, DNA damage and ROS induction

Goniothalamin (GTN), a plant bioactive styryl-lactone, is a natural product with potent anti-tumorigenesis effects for several types of cancer. Nonetheless, the anticancer effect of GTN has not been examined in oral cancer. The present study was designed to evaluate its potential anticancer effects in an oral squamous cell carcinoma (OSCC) model and to determine the possible mechanisms with respect to apoptosis, DNA damage, reactive oxygen species (ROS) induction, and mitochondrial membrane potential. Our data demonstrated that cell proliferation was significantly inhibited by GTN in Ca9-22 OSCC cancer cells in concentration- and time-dependent manners (p<0.05). For cell cycle and apoptotic effects of GTN-treated Ca9-22 cancer cells, the sub-G1 population and annexin V-intensity significantly increased in a concentration-dependent manner (p<0.001). For the analysis of DNA double strand breaks, γH2AX intensity significantly increased in GTN-treated Ca9-22 cancer cells in concentration-response relationship (p<0.05). Moreover, GTN significantly induced intracellular ROS levels in Ca9-22 cancer cells in a concentration- and time-dependent manner (p<0.05). For membrane depolarization of mitochondria, the DiOC(2)(3) (3,3'-diethyloxacarbocyanine iodide) intensity of GTN-treated Ca9-22 cancer cells was significantly decreased in concentration- and time-dependent relationships (p<0.001). Taken together, these results suggest that the anticancer effect of GTN against oral cancer cells is valid and GTN-induced growth inhibition and apoptosis influence the downstream cascade including ROS induction, DNA damage, and mitochondria membrane depolarization. Therefore, GTN has potential as a chemotherapeutic agent against oral cancer.

Bio-functional constituents from the stems of Liriodendron tulipifera

Four known compounds have been isolated from the stems of Liriodendron tulipifera, and the structures of these pure constituents were determined using spectroscopic analysis. Isolated compounds were screened for free radical scavenging ability, metal chelating power assay and ferric reducing antioxidant power assay (FRAP). The anti-tyrosinase effects of L. tulipifera compounds were calculated the inhibition of hydroxylation of L-tyrosine to L-dopa according to an in vitro mushroom tyrosinase assay. The study also examined the bio-effects of the four compounds on the human melanoma A375.S2, and showed that liriodenine (1) and (-)-norglaucine (4) significantly inhibited the proliferation of melanoma cells in the cell viability assay. Wound healing results indicated that liriodenine (1), (-)-glaucine (3) and (-)-norglaucine (4) exerted anti-migration potential. Interestingly, (-)-glaucine (3), neither liriodenine (1) nor (-)-norglaucine (4) showed promising anti-migration potential without inducing significant cytotoxicity. Furthermore, a dramatically increased level of intracellular reactive oxygen species (ROS) was detected from (-)-glaucine (3). The cell cycle assessment demonstrated a moderate G2/M accumulation by (-)-glaucine (3). The above results revealed the anti-cancer effects of L. tulipifera compounds, especially on the anti-migration ability indicating the promising chemopreventive agents to human skin melanoma cells.

Isoalantolactone induces reactive oxygen species mediated apoptosis in pancreatic carcinoma PANC-1 cells

Isoalantolactone, a sesquiterpene lactone compound possesses antifungal, antibacteria, antihelminthic and antiproliferative activities. In the present study, we found that isoalantolactone inhibits growth and induces apoptosis in pancreatic cancer cells. Further mechanistic studies revealed that induction of apoptosis is associated with increased generation of reactive oxygen species, cardiolipin oxidation, reduced mitochondrial membrane potential, release of cytochrome c and cell cycle arrest at S phase. N-Acetyl Cysteine (NAC), a specific ROS inhibitor restored cell viability and completely blocked isoalantolactone-mediated apoptosis in PANC-1 cells indicating that ROS are involved in isoalantolactone-mediated apoptosis. Western blot study showed that isoalantolactone increased the expression of phosphorylated p38 MAPK, Bax, and cleaved caspase-3 and decreased the expression of Bcl-2 in a dose-dependent manner. No change in expression of phosphorylated p38 MAPK and Bax was found when cells were treated with isoalantolactone in the presence of NAC, indicating that activation of these proteins is directly dependent on ROS generation. The present study provides evidence for the first time that isoalantolactone induces ROS-dependent apoptosis through intrinsic pathway. Furthermore, our in vivo toxicity study demonstrated that isoalantolactone did not induce any acute or chronic toxicity in liver and kidneys of CD1 mice at dose of 100 mg/kg body weight. Therefore, isoalantolactone may be a safe chemotherapeutic candidate for the treatment of human pancreatic carcinoma.