Sepia ink oligopeptide induces apoptosis in prostate cancer cell lines via caspase-3 activation and elevation of Bax/Bcl-2 ratio

Nematicidal Potentiality of Four Marine Molluscans' Defensive Secretions From the Red Sea Against Syphacia obvelata (Nematoda: Oxyuridae) In Vitro

The continuous requirement to substitute safe and affordable alternatives for helminth medications, as well as address the resistance of some used drug classes, introduced bioactive products derived from marine animals into the field of competition; however, almost all the previous research only focused on their impact on bacterial and protozoal infection. In the present work, we investigated the potential in vitro nematocidal effect of the aqueous extract of defense secretions for four species of marine mollusks: two cephalopods, namely the cuttlefish Sepia pharaonis and the common Octopus Octopus vulagris and two gastropods, the sea hare Aplysia argus and the sea slug Berthillina citrina, against the adult murine pinworm Syphacia obvelata. Data showed dose and time efficacy in all examined extracts. The sea slug's skin acid secretion has the highest impact, causing death in the cultivated worms, followed by the ink of the sea hare, the common octopus and the cuttlefish, where LC90 after 10 h of exposure were 250, 290, 316, and 391 µg/mL, respectively. Comparatively with the control and albendazole-treated groups, the skin acid secretion of the sea slug caused the highest levels of the antioxidant enzymes SOD, Cat and GSH-PX; however, albendazole prompted the highest level of GSH-PX enzyme in all experimental groups.

In Vitro Apoptotic and Antiproliferative Activity of Hypericum Perforatum Extract on Human Osteosarcoma Cell Line

Hypericum perforatum (HP) has been widely used as an alternative medicine due to its active pharmacological properties. While the antiproliferative effects of components such as hypericin and hyperforin have been demonstrated in malignant cell lines, most studies have focused on the pharmacological properties of the HP extract itself. Recent research has indicated that HP and its active substances possess anticancer activities; however, there is a lack of studies examining its effects on osteosarcoma. In addition, HP has demonstrated the ability to mitigate the toxicity of several drugs, including chemotherapeutic agents. Hence, the primary objective of this study was to explore the potential anticancer properties of HP in relation to osteosarcoma cells. MG-63 human osteosarcoma cells were cultured and treated with HP extract. Apoptotic factors were analyzed using ELISA, while cell viability was assessed using the MTT test. The results revealed a significant increase in the activities of proapoptotic proteins GRP78, Wee1, apoptosis-inducing factor (AIF), GADD153, Bax, and cleaved caspase-3 in MG-63 osteosarcoma cells after 48 hours of treatment with HP at a concentration of 0.8%. Conversely, the activity of Bcl-2, an antiapoptotic protein, significantly decreased. Moreover, HP extract demonstrated a dose-dependent reduction in cell viability in MG-63 cells. In conclusion, HP extract induces apoptosis in MG-63 osteosarcoma cells by upregulating the expressions of proapoptotic proteins GRP78, Wee1, AIF, GADD153, Bax, and cleaved caspase-3. This study will assist researchers in understanding the importance of alternative treatments using HP in the context of human osteosarcoma therapy, which many researchers are currently unaware of.

Bioactive peptides from food science to pharmaceutical industries: Their mechanism of action, potential role in cancer treatment and available resources

Cancer is known as the main cause of mortality in the world, and every year, the rate of incidence and death due to cancer is increasing. Bioactive peptides are one of the novel therapeutic options that are considered a suitable alternative to toxic chemotherapy drugs because they limit side effects with their specific function. In fact, bioactive peptides are short amino acid sequences that obtain diverse physiological functions to maintain human health after being released from parent proteins. This group of biological molecules that can be isolated from different types of natural protein sources has attracted much attention in the field of pharmaceutical and functional foods production. The current article describes the therapeutic benefits of bioactive peptides and specifically and extensively reviews their role in cancer treatment, available sources for discovering anticancer peptides, mechanisms of action, production methods, and existing challenges.

Antimicrobial and cytotoxic activities of flavonoid and phenolics extracted from Sepia pharaonis ink (Mollusca: Cephalopoda)

BACKGROUND

Several studies have been reported previously on the bioactivities of different extracts of marine molluscs. Therefore, we decided to evaluate the cytotoxic and antimicrobial activities of S. pharaonis ink as a highly populated species in the Red Sea. We extracted the flavonoids from the ink and analyzed their composition. Then we evaluated systematically the cytotoxic and antimicrobial properties of this extract. A pharmacokinetic study was also conducted using SwissADME to assess the potential of the identified flavonoids and phenolic compounds from the ink extract to be orally active drug candidates.

RESULTS

Cytotoxic activity was evaluated against 5 cell lines (MCF7, Hep G2, A549, and Caco2) at different concentrations (0.4 µg/mL, 1.6 µg/mL, 6.3 µg/mL, 25 µg/mL, 100 µg/mL). The viability of examined cells was reduced by the extract in a concentration-dependent manner. The highest cytotoxic effect of the extract was recorded against A549 and Hep G2 cancer cell lines cells with IC50 = 2.873 and 7.1 µg/mL respectively. The mechanistic analysis by flow cytometry of this extract on cell cycle progression and apoptosis induction indicated that the extract arrests the cell cycle at the S phase in Hep G2 and MCF7, while in A549 cell arrest was recorded at G1 phase. However, it causes G1 and S phase arrest in Caco2 cancer cell line. Our data showed that the extract has significant antimicrobial activity against all tested human microbial pathogens. However, the best inhibitory effect was observed against Candida albicans ATCC 10,221 with a minimum inhibitory concentration (MIC) of 1.95 µg/mL. Pharmacokinetic analysis using SwissADME showed that most flavonoids and phenolics compounds have high drug similarity as they satisfy Lipinski's criteria and have WLOGP values below 5.88 and TPSA below 131.6 Å2.

CONCLUSION

S. pharaonis ink ethanolic extract showed a promising cytotoxic potency against various cell lines and a remarkable antimicrobial action against different pathogenic microbial strains. S. pharaonis ink is a novel source of important flavonoids that could be used in the future in different applications as a naturally safe and feasible alternative of synthetic drugs.

Gastrointestinal digestion of food proteins: Anticancer, antihypertensive, anti-obesity, and immunomodulatory mechanisms of the derived peptides

Food proteins and their peptides play a significant role in the important biological processes and physiological functions of the body. The peptides show diverse biological benefits ranging from anticancer to antihypertensive, anti-obesity, and immunomodulatory, among others. In this review, an overview of food protein digestion in the gastrointestinal tract and the mechanisms involved was presented. As some proteins remain resistant and undigested, the multifarious factors (e.g. protein type and structure, microbial composition, pH levels and redox potential, host factors, etc.) affecting their colonic fermentation, the derived peptides, and amino acids that evade intestinal digestion are thus considered. The section that follows focuses on the mechanisms of the peptides with anticancer, antihypertensive, anti-obesity, and immunomodulatory effects. As further considerations were made, it is concluded that clinical studies targeting a clear understanding of the gastrointestinal stability, bioavailability, and safety of food-based peptides are still warranted.

Activity Changes of the Peptic Lactoferrin Hydrolysate in Human Gastric Cancer AGS Cells in Response to Cu(II) or Mn(II) Addition

Lactoferrin is an interesting bioactive protein in milk and can interact with various metal ions of trace elements such as copper, iron, manganese, and others. In this study, a lactoferrin hydrolysate (LFH) was generated from commercial bovine lactoferrin by protease pepsin, fortified with Cu²⁺ (or Mn²⁺) at two levels of 0.64 and 1.28 (or 0.28 and 0.56) mg/g protein, respectively, and then measured for the resultant bioactivity changes in the well-differentiated human gastric cancer AGS cells. The assaying results indicated that the LFH and Cu/Mn-fortified products had long-term anti-proliferation on the cells, while the treated cells showed DNA fragmentation and increased apoptotic cell proportions. Regarding the control cells, the cells treated with the LFH and especially Cu/Mn-fortified LFH had remarkably up-regulated mRNA expression of caspase-3 and Bax by respective 1.21-3.23 and 2.23-2.83 folds, together with down-regulated mRNA expression Bcl-2 by 0.88-0.96 folds. Moreover, Western-blot assaying results also indicated that the cells exposed to the LFH and Cu/Mn-fortified LFH (especially Mn at higher level) for 24 h had an enhanced caspase-3 expression and increased ratio of Bax/Bcl-2. It can thus be concluded that the used Cu/Mn-addition to the LFH may lead to increased bioactivity in the AGS cells; to be more specific, the two metal ions at the used addition levels could endow LFH with a higher ability to cause cell apoptosis by activating caspase-3 and increasing the Bax/Bcl-2 ratio.

Insights into Common Octopus (Octopus vulgaris) Ink Proteome and Bioactive Peptides Using Proteomic Approaches

The common octopus (Octopus vulgaris) is nowadays the most demanded cephalopod species for human consumption. This species was also postulated for aquaculture diversification to supply its increasing demand in the market worldwide, which only relies on continuously declining field captures. In addition, they serve as model species for biomedical and behavioral studies. Body parts of marine species are usually removed before reaching the final consumer as by-products in order to improve preservation, reduce shipping weight, and increase product quality. These by-products have recently attracted increasing attention due to the discovery of several relevant bioactive compounds. Particularly, the common octopus ink has been described as having antimicrobial and antioxidant properties, among others. In this study, the advanced proteomics discipline was applied to generate a common octopus reference proteome to screen potential bioactive peptides from fishing discards and by-products such as ink. A shotgun proteomics approach by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) using an Orbitrap Elite instrument was used to create a reference dataset from octopus ink. A total of 1432 different peptides belonging to 361 non-redundant annotated proteins were identified. The final proteome compilation was investigated by integrated in silico studies, including gene ontology (GO) term enrichment, pathways, and network studies. Different immune functioning proteins involved in the innate immune system, such as ferritin, catalase, proteasome, Cu/Zn superoxide dismutase, calreticulin, disulfide isomerase, heat shock protein, etc., were found in ink protein networks. Additionally, the potential of bioactive peptides from octopus ink was addressed. These bioactive peptides can exert beneficial health properties such as antimicrobial, antioxidant, antihypertensive, and antitumoral properties and are therefore considered lead compounds for developing pharmacological, functional foods or nutraceuticals.

Intriguing diverse chemistry and unique molecular mechanisms: new medicines with diverse pharmacological activities from cephalopods ink

The ink that cephalopods secrete to hide and frighten the enemies contains a treasury rich in bioactive diverse compounds like DOPA, melanin, melanin synthase, tyrosinase, angiotensin converting enzyme, catecholamines, oligopeptides, polyphenols, flavonoids, alkaloids, polysaccharides, fatty acids and minerals. These groups of the aforementioned compounds have promising unique in-vitro and in-vivo biological activities like antioxidant activity, anti-inflammatory, vasopressin, anti-Parkinson, anti-cancer, anti-coagulant, antimicrobial, anti-retroviral, anti-ulcerogenic and immune boosting activities. Cephalopods ink can be offered in its raw state or after separation and purification of its chemical constituents for use as natural medicine to treat many diverse diseases.

Therapeutic Potential of Marine Peptides in Prostate Cancer: Mechanistic Insights

Prostate cancer (PCa) is the leading cause of cancer death in men, and its treatment is commonly associated with severe adverse effects. Thus, new treatment modalities are required. In this context, natural compounds have been widely explored for their anti-PCa properties. Aquatic organisms contain numerous potential medications. Anticancer peptides are less toxic to normal cells and provide an efficacious treatment approach via multiple mechanisms, including altered cell viability, apoptosis, cell migration/invasion, suppression of angiogenesis and microtubule balance disturbances. This review sheds light on marine peptides as efficacious and safe therapeutic agents for PCa.

Preparation of Nereid oligopeptide and investigation of the mechanism underlying the induction of apoptosis in human lung cancer H1299 cells

In the present study, oligopeptides from Nereid (Perinereis aibuhitensis) were prepared via enzymatic hydrolysis, and the mechanism underlying the induction of apoptosis in H1299 cells was investigated. According to the analysis of the inhibition rate on proliferation, alkaline protease demonstrated the best enzymatic efficiency. The optimal conditions for hydrolysis were as follows: 50°C and pH 10 for 6 h; a material-to-liquid ratio of 1:1 (g/ml); and addition of 400 U/g enzyme. The hydrolysates were purified using ultrafiltration, anion chromatography, gel filtration chromatography, and high-performance liquid chromatography. The Nereid oligopeptide (NOP), with a molecular weight of 841 kDa and an amino acid sequence of glutamine-isoleucine-asparagine-glutamine-histidine-leucine, was obtained. NOP inhibited the proliferation of H1299 cells in a time- and dose-dependent manner. Morphological changes and apoptosis were also induced by NOP in H1299 cells. The western blot analysis revealed that the B-cell lymphoma 2/Bcl-2 associated X (Bcl-2/Bax) ratio was reduced by 24.7% in the NOP treatment group compared with the control group. The relative expression levels of cleaved caspase-9 (cleaved-CASP9) and cleaved caspase-3 (cleaved-CASP3) in the NOP treatment group were 2.55- and 1.71-fold higher than those measured in the control group, respectively. These results suggested that NOP exerts antitumor effects by influencing the proliferation and apoptosis of H1299 cells.

Sea cucumber peptides inhibit the malignancy of NSCLC by regulating miR-378a-5p targeted TUSC2

Lung cancer is a common cancer with high mortality worldwide, and non-small cell lung cancer (NSCLC) accounts for the majority. The clinical treatment effect of NSCLC is not ideal. The aim of this study was to investigate the inhibitory effect of sea cucumber peptide (SCP) on NSCLC and its mechanism. The results showed that SCP could effectively inhibit the proliferation, migration and invasion of A549 cells. In addition, SCP can also inhibit the formation of pleural effusion and tumor growth in lung cancer mice, reduce liver and kidney injury, increase the levels of IL-2 and IL-12, decrease the levels of IL-6 and TNF-α, and prolong the survival time of mice. The microRNA sequencing and immunohistochemistry of mouse tumors showed that the tumor suppressor gene TUSC2 targeted by miR-378a-5p was involved in the inhibition of tumor growth by SCP. This study provides an experimental basis for the further development of SCP as an anti-tumor nutritional supplement, and provides a new idea for exploring the molecular mechanism of food derived active peptides in anti-tumor applications.

An anti-cancer effect of Sambou bamboo saltTM in melanoma skin cancer both in vivo and in vitro models

Bamboo salt has anti-allergic, anti-inflammatory, anti-oxidant, diabetics, anti-aging, and immune-enhancing effects, which are closely related to anti-cancer effect. The aim of this study was to investigate the anti-cancer effects of Sambou bamboo salt^TM (SBS) in melanoma skin cancer in vivo and in vitro models. SBS-administered mice effectively reduced tumor growth and increased survival rate compared with B16F10 cell-inoculated mice without tissue damage, hepatotoxicity, and nephrotoxicity. SBS enhanced levels of immune-enhancing mediators, such as interferon-γ, interleukin (IL)-2, IL-6, IL-12, tumor necrosis factor-α, and IgE in serum and melanoma tissues. Furthermore, SBS enhanced activities of caspases and levels of Bax and p53, whereas decreased levels of Bcl-2. This reduction was a consequence of apoptosis signaling pathway. In conclusion, these results suggest that SBS is a potential substance for cancer therapy. SBS has the potential to be developed either as Korean traditional medicine or as a health functional food for cancer therapy. PRACTICAL APPLICATIONS: In these days cancer is one of the world's largest health problems. Bamboo salt is used as a Korean traditional food or medicine and has beneficial effect on inflammation. We have identified Sambou bamboo salt^TM (SBS) is a potential substance for cancer therapy. These insights suggest that SBS can potentially be utilized for health functional foods for cancer treatment as well as improve various cancer diseases such as melanoma skin cancer.

Recent Advances in Small Peptides of Marine Origin in Cancer Therapy

Cancer is one of the leading causes of death in the world, and antineoplastic drug research continues to be a major field in medicine development. The marine milieu has thousands of biological species that are a valuable source of novel functional proteins and peptides, which have been used in the treatment of many diseases, including cancer. In contrast with proteins and polypeptides, small peptides (with a molecular weight of less than 1000 Da) have overwhelming advantages, such as preferential and fast absorption, which can decrease the burden on human gastrointestinal function. Besides, these peptides are only connected by a few peptide bonds, and their small molecular weight makes it easy to modify and synthesize them. Specifically, small peptides can deliver nutrients and drugs to cells and tissues in the body. These characteristics make them stand out in relation to targeted drug therapy. Nowadays, the anticancer mechanisms of the small marine peptides are still largely not well understood; however, several marine peptides have been applied in preclinical treatment. This paper highlights the anticancer linear and cyclic small peptides in marine resources and presents a review of peptides and the derivatives and their mechanisms.

Octopus vulgaris ink extracts exhibit antioxidant, antimutagenic, cytoprotective, antiproliferative, and proapoptotic effects in selected human cancer cell lines

Cancer is a noncommunicable disease of rising worldwide concern. Marine food products such as Octopus vulgaris ink (OI) could be sources of compounds addressing these concerns. This study aimed to evaluate the antimutagenic, cytoprotective, antiproliferative, proapoptotic, and antioxidant capacity of OI extracts on human cancer cell lines (22Rv1, HeLa, A549). The ARPE-19 cell line was used as a reference human cell line to evaluate the ink's cytotoxicity. The water extract exhibited the highest antimutagenic and cytoprotective effect, but the dichloromethane extract (DM) showed the lowest half lethal concentration against 22Rv1 cells. Structural elucidation of purified DM fractions (F1, F2, F3) identified an unreported compound, N-(2-ozoazepan-3-yl)-pyrrolidine-2-carboxamide (OPC). DM-F2 showed high antiproliferative effect (LC₅₀ = 27.6 µg/mL), reactive species modulation, early-apoptosis induction (42.9%), and nuclei disruption in 22Rv1 cells. In silico analysis predicted high OPC affinity with Cyclin D1 (-6.70 kcal/mol), suggesting its potential impact on cell cycle arrest. These results highlight the antimutagenic, cytoprotective, and antiproliferative potential health benefits derived from underutilized marine food products such as OI. Further investigations at in vitro or in vivo levels are required to elucidate mechanisms and health benefits from OI. PRACTICAL APPLICATION: O. vulgaris ink is an underutilized marine natural product that could be a source of biological compounds with potential health benefits such as antioxidant activity and cancer prevention.

Effects of preparation method on the biochemical characterization and cytotoxic activity of New Zealand surf clam extracts

Molluscan extracts confer a wide range of health promoting properties, one of them is cytotoxicity. Extraction and processing can affect the efficacy and properties of bioactive molecules. New Zealand (NZ) surf clams have never been thoroughly studied for bioactives until recently. However, the effect of cold and heat extraction procedure on biochemical composition and cytotoxic activities of NZ surf clam remains unanswered. The objective is to compare the effects on cytotoxicity of three NZ surf clams (Diamond shell, Crassula aequilatera; Storm shell, Mactra murchisoni; and Deepwater Tua tua, Paphies donacina) extracts via cold or heat process across cancer cell lines to find out which process can preserve bioactivity better. Fractions of extracts prepared via cold or heat procedures were tested for cell growth inhibition, apoptosis induction and cell cycle arrest in seven cancer cell lines. Apoptosis was induced through all cell lines, as further evidenced in Caspase-3/7 activities. Cell cycle arrest was focused on G2/M- and S- phases. Petroleum ether and ethyl acetate fractions, with the greatest bioactivity in this study, are rich in lipids and proteins, indicating likely bioactive sources. Cold preparation was responsible for the lowest cancer cell viability and induced greater apoptosis. Cold process retained better bioactivity/cytotoxicity than that of heat-processed extracts. This information may guide future health/nutraceutical clam product development.

Screening of Natural Stilbene Oligomers from Vitis vinifera for Anticancer Activity on Human Hepatocellular Carcinoma Cells

The characterization of bioactive resveratrol oligomers extracted from Vitis vinifera canes has been recently reported. Here, we screened six of these compounds (ampelopsin A, trans-ε-viniferin, hopeaphenol, isohopeaphenol, R2-viniferin, and R-viniferin) for their cytotoxic activity to human hepatocellular carcinoma (HCC) cell lines p53 wild-type HepG2 and p53-null Hep3B. The cytotoxic efficacy depended on the cell line. R2-viniferin was the most toxic stilbene in HepG2, with inhibitory concentration 50 (IC₅₀) of 9.7 ± 0.4 µM at 72 h, 3-fold lower than for resveratrol, while Hep3B was less sensitive (IC₅₀ of 47.8 ± 2.8 µM). By contrast, hopeaphenol (IC₅₀ of 13.1 ± 4.1 µM) and isohopeaphenol (IC₅₀ of 26.0 ± 3.0 µM) were more toxic to Hep3B. Due to these results, and because it did not exert a large cytotoxicity in HH4 non-transformed hepatocytes, R2-viniferin was selected to investigate its mechanism of action in HepG2. The stilbene tended to arrest cell cycle at G2/M, and it also increased intracellular reactive oxygen species (ROS), caspase 3 activity, and the ratio of Bax/Bcl-2 proteins, indicative of apoptosis. The distinctive toxicity of R2-viniferin on HepG2 encourages research into the underlying mechanism to develop the oligostilbene as a therapeutic agent against HCC with a particular genetic background.

Caspase 3-mediated cytotoxicity of mealworm larvae (Tenebrio molitor) oil extract against human hepatocellular carcinoma and colorectal adenocarcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Mealworm larvae (MWL) (Tenebrio molitor) have been traditionally used in Asian countries for the treatment of liver diseases, including cancer. However, to date, there is marginal information on the mechanisms underlying the anticancer activity of MWL oil.

AIM OF THE STUDY

This study aims to determine the in vitro effect of MWL oil on human hepatocellular carcinoma (HepG2) and colorectal adenocarcinoma (Caco-2) cells growth in order to produce insect-derived chemotherapeutic agents against cancer.

MATERIALS AND METHODS

MWL oil was extracted, and its effects on cancer cells growth were investigated, by the MTT reduction, AO/EB staining, Hoechst 33258 nuclear staining, apoptosis, comet, and caspase activity assays.

RESULTS

MWL oil inhibited HepG2 and Caco-2 growth, with IC₅₀ (48 h) values of 0.98% for HepG2 and 0.37% for Caco-2 cells. In addition, flow cytometry analysis demonstrated that 24 h-MWL oil treatment increased early and late apoptosis from 0.04% to 39.77% and from 2.06% to 74.34% on HepG2 and Caco-2 cells, respectively. The mechanism of apoptosis was associated with the death receptor pathway by the activation of caspases -8, -9, and -3, and correlated to its fatty acids action.

CONCLUSION

Results of this study demonstrated the potential of MWL oil in the development of natural anticancer therapeutic agents.

Insight the Biological Activities of Selected Abietane Diterpenes Isolated from Plectranthus spp

Natural compounds isolated from plants are excellent starting points in drug design and have been widely studied as anticancer agents; they hence find use in a considerable proportion of anticancer drugs. The genus Plectranthus (Lamiaceae) comprises a large and widespread group of species with various applications in traditional medicine. Therefore, the aim of the present study was to determine the effectiveness of treatment with four abietane diterpenoids isolated from P. madagascariensis and P. ecklonii, 6,7-dehydroroyleanone, 7β,6β-dihydroxyroyleanone, 7α-acetoxy-6β-hydroxyroyleanone and parvifloron D, in initiating apoptosis in a glioma cell line. The pure compounds were found to exhibit anticancer effects in primary H7PX glioma cells line by inducing apoptosis G2/M cell cycle arrest and double-strand breaks, indicated by increased levels of phosphorylated H2A.X and decreasing mitochondrial membrane potential; they also influenced the expression of pro- and anti-apoptotic genes (Bax, Bcl-2, TP53, or Cas-3). Our findings indicate that these compounds may offer potential as beneficial antitumor drugs but further in vivo studies are needed.

Squid Ink Polysaccharides Protect Human Fibroblast Against Oxidative Stress by Regulating NADPH Oxidase and Connexin43

Oxidation injury to skin is one of the main reasons for skin aging. The aim of the present study was to explore the protective effect of squid ink polysaccharides and its mechanism of action against H₂O₂-induced dermal fibroblast damage. Our results show that squid ink polysaccharides effectively reduce the fibroblast oxidative damage mediated by the up-regulation of NADPH oxidase and Connexin43. Concurrently, squid ink polysaccharides decrease the ROS induced up-regulation of MMP1 and MMP9 to decrease MMP-mediated skin aging. Therefore, we hypothesize that squid ink polysaccharides play an antioxidant role by inhibiting the expression of NADPH oxidase and connexin43. This provides a new target for the effective clinical prevention and treatment of oxidative skin damage.

Peptides obtained from edible mushrooms: Hericium erinaceus offers the ability to scavenge free radicals and induce apoptosis in lung cancer cells in humans

This research examined the antioxidant abilities of peptides derived from the Hericium erinaceus mushroom produced via three microbial proteases at varying concentrations.

A Potential Antineoplastic Peptide of Human Prostate Cancer Cells Derived from the Lesser Spotted Dogfish (Scyliorhinus canicula L.)

The purpose of the present paper is to investigate the mechanism of action of a pyroglutamate-modified peptide (pE-K092D) on in vitro growth inhibition of MDA-Pca-2b prostate cancer cells. This peptide was derived from a peptide previously isolated from the testis of the lesser spotted dogfish and identified as QLTPEALADEEEMNALAAR (K092D). The effect of the peptide on cell proliferation and cell death mechanisms was studied by flow cytometry. Cellular morphology and cytoskeleton integrity of peptide-treated cells were observed by immunofluorescence microscopy. Results showed the onset of peptide induced early cytoskeleton perturbation, inhibition of autophagy, inhibition of cell proliferation and, at the end, non-apoptotic cell death mechanisms (membrane destabilization and necrosis). All those mechanisms seem to contribute to MDA-Pca-2b growth inhibition by a main cytostatic fate.

The androgen receptor antagonist enzalutamide induces apoptosis, dysregulates the heat shock protein system, and diminishes the androgen receptor and estrogen receptor β1 expression in prostate cancer cells

Enzalutamide's accepted mode of action is by targeting the androgen receptor's (AR) activity. In clinical practice, enzalutamide demonstrates a good benefit-risk profile for the treatment of advanced prostate cancer (PC), even after poor response to standard antihormonal treatment. However, since both, well-established antiandrogens and enzalutamide, target AR functionality, we hypothesized that additional unknown mechanisms might be responsible for enzalutamide's superior anticancer activity. In the current study, PC cells were incubated with enzalutamide and enzalutamide-dependent modulation of apoptotic mechanisms were assessed via Western blot analysis, TDT-mediated dUTP-biotin nick end-labeling assay, and nuclear morphology assay. Alterations of heat shock protein (HSP), AR, and estrogen receptor (ER) expression were examined by Western blot analysis. Enzalutamide attenuated the proliferation of PC cells in a time- and dose-dependent manner. In the presence of enzalutamide, apoptosis occurred which was shown by increased BAX expression, decreased Bcl-2 expression, nuclear pyknosis, and genomic DNA fragmentation. Moreover, enzalutamide inhibited the expression of HSPs primarily involved in steroid receptor stabilization and suppressed AR and ERβ1 expression. This study demonstrates for the first time that enzalutamide treatment of PC cells triggers varying molecular mechanisms resulting in antiproliferative effects of the drug. In addition to the well-characterized antagonistic inhibition of AR functionality, we have shown that enzalutamide also affects the intracellular synthesis of steroid receptor-associated HSPs, thereby diminishing the expression of AR and ERβ1 proteins and inducing apoptotic pathways. According to an indirect attenuation of HSP-associated factors such as steroid receptors, endometrial carcinoma, uterine leiomyosarcoma, and mamma carcinoma cells also demonstrated inhibited cell growth in the presence of enzalutamide. Our data, therefore, suggest that enzalutamide's high efficacy is at least partially independent of AR and p53 protein expression, which are frequently lost in advanced PC.

The relationship between the structural characteristics of lactobacilli-EPS and its ability to induce apoptosis in colon cancer cells in vitro

Colon cancer is one of the most common cancer around the world. Exopolysaccharides (EPSs) produced by lactobacilli as potential prebiotics have been found to have an anti-tumor effect. In this study, lyophilized EPSs of four Lactobacillus spp. for their impact on apoptosis in colon cancer cells (HT-29) was evaluated using flow cytometry. The relationship between capability of a lactobacilli-EPS to induce apoptosis and their monosaccharide composition, molecular weight (MW), and linkage type was investigated by HPLC, SEC, and NMR, respectively. Changes in apoptotic-markers were examined by qPCR and Western Blotting. EPSs were capable of inhibiting proliferation in a time-dependent manner and induced apoptosis via increasing the expression of Bax, Caspase 3 and 9 while decreasing Bcl-2 and Survivin. All EPSs contained mannose, glucose, and N-acetylglucosamine with different relative proportions. Some contained arabinose or fructose. MW ranged from 102-104Da with two or three fractions. EPS of L. delbrueckii ssp. bulgaricus B3 having the highest amount of mannose and the lowest amount of glucose, showed the highest apoptosis induction. In conclusion, lactobacilli-EPSs inhibit cell proliferation in HT-29 via apoptosis. Results suggest that a relationship exists between the ability of EPS to induce apoptosis and its mannose and glucose composition.

A Novel Peptide from Abalone (Haliotis discus hannai) to Suppress Metastasis and Vasculogenic Mimicry of Tumor Cells and Enhance Anti-Tumor Effect In Vitro

Vasculogenic mimicry (VM) formed by tumor cells plays a vital role in the progress of tumor, because it provides nutrition for tumor cells and takes away the metabolites. Therefore, the inhibition of VM is crucial to the clinical treatment of tumors. In this study, we investigated the anti-tumor effect of a novel peptide, KVEPQDPSEW (AATP), isolated from abalone (Haliotis discus hannai) on HT1080 cells by migration, invasion analysis and the mode of action. The results showed that AATP effectively inhibited MMPs by blocking MAPKs and NF-κB pathways, leading to the downregulation of metastasis of tumor cells. Moreover, AATP significantly inhibited VM and pro-angiogenic factors, including VEGF and MMPs by suppression of AKT/mTOR signaling. In addition, molecular docking was used to study the interaction of AATP and HIF-1α, and the results showed that AATP was combined with an active site of HIF-1α by a hydrogen bond. The effect of AATP on anti-metastatic and anti-vascular in HT1080 cells revealed that AATP may be a potential lead compound for treatment of tumors in the future.

Cytotoxicity of Extracts from New Zealand Surf Clams Against Organ Cancer Cell Lines

In this study, we examined the cytotoxic effects of four fractions from three species of New Zealand (NZ) surf clam on four common organ cancer cells. In most cases, a dose- and time-dependent inhibition on the proliferation of the cancer cells was observed. This was most significant in WiDr (colon) cells, where the percentages of viability reduced to as low as 6%, 5%, and 17% (at 1000 µg 72 h) by extracts from Diamond shell, Storm shell, and Tua tua species, respectively. A549 (lung) cells were the least susceptible to the treatment, with viability percentages at 82%, 15%, and 45%, under the same conditions. Induction of caspase-dependent apoptosis and alterations to the cell cycle further supported the observed morphological analysis. The ethanol, petroleum ether, and ethyl acetate fractions of NZ surf clam, rich in lipids and proteins, were more potent than their water-based counterpart. This is the first demonstration where extracts from NZ surf clams show the ability to inhibit the growth and proliferation of cancer cell lines. We suggest that NZ surf clam extracts have the potential to be further studied and developed as candidates for cancer supplementary management/treatment.

Anti-Proliferation Activity of a Decapeptide from Perinereies aibuhitensis toward Human Lung Cancer H1299 Cells

Perinereis aibuhitensis peptide (PAP) is a decapeptide (Ile-Glu-Pro-Gly-Thr-Val-Gly-Met-Met-Phe, IEPGTVGMMF) with anticancer activity that was purified from an enzymatic hydrolysate of Perinereis aibuhitensis. In the present study, the anticancer effect of PAP on H1299 cell proliferation was investigated. Our results showed that PAP promoted apoptosis and inhibited the proliferation of H1299 cells in a time- and dose-dependent manner. When the PAP concentration reached 0.92 mM, more than 95% of treated cells died after 72 h of treatment. Changes in cell morphology were further analyzed using an inverted microscope and AO/EB staining and flow cytometry was adopted for detecting apoptosis and cell cycle phase. The results showed that the early and late apoptosis rates of H1299 cells increased significantly after treatment with PAP and the total apoptosis rate was significantly higher than that of the control group. Moreover, after treatment with PAP, the number of cells in the S phase of cells was significantly reduced and the ability for the cells to proliferate was also reduced. H1299 cells were arrested in the G2/M phase and cell cycle progression was inhibited. Furthermore, the results of western blotting showed that nm23-H1 and vascular endothelial growth factor (VEGF) protein levels decreased in a dose-dependent manner, while the pro-apoptotic protein and anti-apoptotic protein ratios and the level of apoptosis-related caspase protein increased in a dose-dependent manner. In conclusion, our results indicated that PAP, as a natural marine bioactive substance, inhibited proliferation and induced apoptosis of human lung cancer H1299 cells. PAP is likely to be exploited as the functional food or adjuvant that may be used for prevention or treatment of human non-small cell lung cancer in the future.

Induction of Apoptosis by Extract of Persian Gulf Marine Mollusk, Turbo Coronatus through the ROS-Mediated Mitochondrial Targeting on Human Epithelial Ovarian Cancer Cells

Despite recent improvements in treatment, ovarian cancer is still the leading cause of death from gynaecological malignancies. Today, marine mollusks are considered as natural source of new biologically and pharmacologically active compounds by scientists and the pharmaceutical industries. The aim of this study is to investigate the selective apoptotic effects of Turbo coronatus crude extract fractions on human epithelial ovarian cancer (EOC) cells and mitochondria. The cells and mitochondria were isolated from cancerous and non-cancerous ovarian tissues and exposed to IC₅₀ concentration of F1 fraction for evaluation of mitochondrial and cellular parameters. Our results showed that F1 fraction of T. coronatus crude extract significantly induced toxic effects only in the cancerous ovarian mitochondria, including increased reactive oxygen species (ROS) formation, mitochondrial membrane depolarization, mitochondrial swelling, and cytochrome c release.Flow-cytometry analysis demonstrated that F1 fraction of T. coronatus progressively induced apoptosis and necrosis only on EOC but not non-cancerous cells. We eventuallyconcluded that F1 fraction of T. coronatus crude extract selectively induces apoptosis in EOC through a ROS- mediated pathway.

Anti-proliferative Effect of a Novel Anti-oxidative Peptide in Hanwoo Beef on Human Colorectal Carcinoma Cells

The present study aimed to characterise anti-oxidant peptides from water-soluble protein extracts of Hanwoo beef and evaluate their anti-proliferative effect on human colorectal carcinoma cells (HCT116). Antioxidant peptides were purified from the low-molecular-weight fraction (<3 kDa) of Hanwoo beef extract. Antioxidant activity of peptide fractions was determined using the oxygen radical absorbance capacity (ORAC) assay. Purified peptide (P3) displayed higher ORAC activity than the low-molecular-weight fraction (202.66 μM TE/g vs 167.38 μM TE/g of dry matter, respectively) (p<0.05). The peptide sequence of P3 was Cys-Cys-Cys-Cys-Ser-Val-Gln-Lys (888.30 Da). The novel peptide P3, at 250 μg/mL, also significantly inhibited HCT116 cell proliferation up to 25.24% through phosphorylation of ERK, JNK, and p38 kinase (p<0.05). Hence, antioxidant peptide P3 from Hanwoo beef extract can be used as an antioxidative and anti-cancer agent in the functional food industry.

Inhibition of Prostate Cancer DU-145 Cells Proliferation by Anthopleura anjunae Oligopeptide (YVPGP) via PI3K/AKT/mTOR Signaling Pathway

We investigated the antitumor mechanism of Anthopleura anjunae oligopeptide (AAP-H, YVPGP) in prostate cancer DU-145 cells in vitro and in vivo. Results indicated that AAP-H was nontoxic and exhibited antitumor activities. Cell cycle analysis indicated that AAP-H may arrest DU-145 cells in the S phase. The role of the phosphatidylinositol 3-kinase/protein kinase B/mammalian rapamycin target protein (PI3K/AKT/mTOR) signaling pathway in the antitumor mechanism of APP-H was investigated. Results showed that AAP-H treatment led to dose-dependent reduction in the levels of p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448), whereas t-AKT and t-PI3K levels remained unaltered compared to the untreated DU-145 cells. Inhibition of PI3K/AKT/mTOR signaling pathway in the DU-145 cells by employing inhibitor LY294002 (10 μM) or rapamycin (20 nM) effectively attenuated AAP-H-induced phosphorylation of AKT and mTOR. At the same time, inhibitor addition further elevated AAP-H-induced cleaved-caspase-3 levels. Furthermore, the effect of AAP-H on tumor growth and the role of the PI3K/AKT/mTOR signaling pathway in nude mouse model were also investigated. Immunohistochemical analysis showed that activated AKT, PI3K, and mTOR levels were reduced in DU-145 xenografts. Western blotting showed that AAP-H treatment resulted in dose-dependent reduction in p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448) levels, whereas t-AKT and t-PI3K levels remained unaltered. Similarly, Bcl-xL levels decreased, whereas that of Bax increased after AAP-H treatment. AAP-H also increased initiator (caspase 8 and 9) and executor caspase (caspase 3 and 7) levels. Therefore, the antitumor mechanism of APP-H on DU-145 cells may involve regulation of the PI3K/AKT/mTOR signaling pathway, which eventually promotes apoptosis via mitochondrial and death receptor pathways. Thus, the hydrophobic oligopeptide (YVPGP) can be developed as an adjuvant for the prevention or treatment of prostate cancer in the future.

A novel anti‑proliferative pentapeptide (ILYMP) isolated from Cyclina sinensis protein hydrolysate induces apoptosis of DU‑145 prostate cancer cells

Prostate cancer is the main causes of cancer associated mortality in men worldwide, cancer patients often suffer serious side effects when treated with chemotherapy or radiotherapy, therefore novel drugs are in high demand to treat prostate cancer. In the present study, a pentapeptide (Ile‑Leu‑Tyr‑Met‑Pro; ILYMP) with a molecular weight of 635.71 Da was isolated from the protein hydrolysate of Cyclina sinensis via ultrafiltration and chromatographic methods, and subsequently named Cyclina sinensis pentapeptide (CSP). The activity of CSP was first investigated in prostate cancer (PCa) DU‑145 cells. CSP was demonstrated to significantly inhibit DU‑145 cell proliferation at a half‑maximal inhibitory concentration of 11.25 mM at a 72 h time interval. In addition, the results of acridine orange/ethidium bromide double staining, scanning electron microscopy and flow cytometry analyses suggested that CSP inhibited DU‑145 cell proliferation via the induction of apoptosis. Following treatment with CSP, Bcl‑2‑associated X (Bax), cleaved caspase‑3 and cleaved caspase‑9 protein expression levels were enhanced in DU‑145 cells; whereas B‑cell lymphoma 2 expression was suppressed in DU‑145 cells. In conclusion, to the best of the authors' knowledge, this is the first study to investigate the effects of an anti‑proliferative peptide derived from Cyclina sinensis on DU‑145 cells, and the results suggested that CSP may represent a therapeutic nutraceutical agent for the treatment of patients with PCa.

Anticancer Activity of Anthopleura anjunae Oligopeptides in Prostate Cancer DU-145 Cells

Anthopleura anjunae anti-tumor peptide (AAP-H) is a pentapeptide from the sea anemone Anthopleura anjunae with an amino acid sequence of Tyr-Val-Pro-Gly-Pro that is obtained by alkaline protease enzymatic hydrolysis extraction. In this study, we investigated the inhibitory effects of AAP-H on prostate cancer DU-145 cell proliferation using a methylthiazolyldiphenyl-tetrazolium bromide assay. Cell morphology was analyzed by hematoxylin-eosin staining, acridine orange/ethidium bromide fluorescence staining, Hoechst 33258 fluorescence staining, and scanning electron microscopy. The mitochondrial membrane potential was determined by flow cytometry following JC-1 staining. The cell apoptosis rate was measured by Annexin V-fluorescein isothiocyanate and propidium iodide staining followed by flow cytometric analysis, and the expression of apoptosis-associated proteins was assayed by Western blotting. The results demonstrated that AAP-H induced significant reductions in the number of viable cells and increased cell death in both a dose-dependent and time-dependent manner, with an IC₅₀ of approximately 9.605 mM, 7.910 mM, and 2.298 mM at 24 h, 48 h, and 72 h, respectively. The morphologic characteristics of apoptotic cells were observed after treatment with AAP-H. The mitochondrial membrane potential was markedly decreased, and apoptosis increased after AAP-H treatment. Pro-apoptotic proteins, such as Bax, cytochrome-C, caspase-3, and caspase-9 were increased, but Bcl-2 was decreased. These findings suggest that AAP-H has moderate inhibitory effects on prostate cancer DU-145 cells, and the mechanism might involve the mitochondria-mediated apoptotic pathway. Therefore, AAP-H is a candidate anti-prostate cancer drug or health-care food.

A Potential Adjuvant Agent of Chemotherapy: Sepia Ink Polysaccharides

Sepia ink polysaccharide (SIP) isolated from squid and cuttlefish ink is a kind of acid mucopolysaccharide that has been identified in three types of primary structures from squid (Illex argentinus and Ommastrephes bartrami), cuttlefish Sepiella maindroni, and cuttlefish Sepia esculenta ink. Although SIP has been proved to be multifaceted, most of the reported evidence has illuminated its chemopreventive and antineoplastic activities. As a natural product playing a role in cancer treatment, SIP may be used as chemotherapeutic ancillary agent or functional food. Based on the current findings on SIP, we have summarized four topics in this review, including: chemopreventive, antineoplastic, chemosensitive, and procoagulant and anticoagulant activities, which are correlative closely with the actions of anticancer agents on cancer patients, such as anticancer, toxicity and thrombogenesis, with the latter two actions being common causes of death in cancer cases exposed to chemotherapeutic agents.

Taurine attenuates acrylamide-induced apoptosis via a PI3K/AKT-dependent manner

As a potent neurotoxic agent, acrylamide (ACR) is formed in food processing at higher temperature. Taurine (TAU), a nonessential amino acid, is used to cure neurodegenerative disorders, followed by activation of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway. In this article, we certified that antiapoptotic efficacy of TAU in vivo and vitro. ACR-treated rats received TAU by drinking water 2 weeks after ACR intoxication. The results showed that in treated rats, TAU alleviated ACR-induced neuronal apoptosis, which was associated with the activation of PI3K/AKT signaling pathway. TAU attenuated apoptosis caused by ACR through observing terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells, measure of protein expression of Bcl-2, Bax, and caspase 3 activity. TAU-induced antiapoptotic effect is PI3K/AKT-dependent, which was proved in ACR-intoxicated ventral spinal cord 4.1 cells in the presence of AKT inhibitor, MK-2206. Therefore, our results demonstrated that TAU-attenuated ACR-induced apoptosis in vivo through a PI3K/AKT-dependent manner provided new sights in the molecular mechanism of TAU protection against ACR-induced neurotoxicity.

Sepia ink oligopeptide induces apoptosis and growth inhibition in human lung cancer cells

Sepia ink oligopeptide (SIO), as a tripeptide extracted from Sepia ink, could be used as an inducer of apoptosis in human prostate cancer cells. We designed a cyclo-mimetic peptide of SIO by introducing a disulfide bond to stabilize the native peptide into beta turn structure, and produced a peptide with higher cell permeability and stability. Through labeling an FITC to the N-terminus of the peptide, the cell permeability was examined. Stabilized peptide showed enhanced cellular uptake than linear tripeptide as indicated by flow cytometry and cell fluorescent imaging. The high intracellular delivery of stable SIO could more efficiently inhibit cell proliferation and induce apoptosis. Furthermore, the expression of the anti-apoptotic protein Bcl-2 was down-regulated, whereas pro-apoptotic proteins P53 and caspase-3 were up-regulated by stable SIO. In conclusion, our study is the first to use stable SIO to induce apoptosis in two lung cancer cells A549 and H1299.

Two novel peptides derived from Sinonovacula constricta inhibit the proliferation and induce apoptosis of human prostate cancer cells

In China, the incidence of prostate cancer has been increasing. Toxicity, drug resistance and limited transient benefits in patients are the main problems associated with standard chemotherapeutic regimens, and new drugs are therefore required to treat prostate cancer. SCH‑P9 and SCH‑P10 proteins were obtained from Sinonovacula constricta hydrolysates. The amino acid sequences of SCH‑P9 and SCH‑P10 were identified as Leu‑Pro‑Gly‑Pro and Asp‑Tyr‑Val‑Pro, with molecular weights of 382.46 Da and 492.53 Da, respectively. An MTT assay, annexin V‑fluorescein isothiocyanate (FITC) staining and cell cycle analysis were applied to identify the viability of cells, stages of apoptosis, and cell cycle distribution, respectively. SCH‑P9 and SCH‑P10 inhibited the growth of DU‑145 and PC‑3 cells in a dose‑ and time‑dependent manner. Annexin V‑FITC staining and flow cytometry analysis were employed to measure apoptosis and cell cycle arrest, respectively. SCH‑P9 and SCH‑P10 inhibited the growth of DU‑145 cells by reducing the number of cells in G0/G1 phase, increasing the number in subG1 phase and inducing apoptosis. SCH‑P9 reduced the number of PC‑3 cells in subG1 and G0/G1 phases, increased the number of cells in G2/M phase and induced apoptosis. SCH‑P10 reduced the number of PC‑3 cells in G2/M phase, increased the number of cells in G0/G1 phase and induced apoptosis. In conclusion, the results demonstrated that SCH‑P9 and SCH‑P10 induced apoptosis in DU‑145 and PC‑3 cells and may, therefore, exhibit potential for application in the treatment of prostate cancer.

Isolation and purification of novel peptides derived from Sepia ink: Effects on apoptosis of prostate cancer cell PC‑3

Novel prostate cancer therapeutics are in high demand. In order to identify potential therapeutic targets, protein from sepia ink was hydrolyzed by utilizing pepsin in an orthogonal array design. Pepsin hydrolysate (SH) obtained at optimal conditions exhibited the highest antitumor activity. Subsequently, a novel antitumor peptide, which was termed SHP, was isolated through ultrafiltration, gel filtration chromatography and reversed phase high‑performance liquid chromatography. The amino acid sequence of SHP was identified as Leu‑Lys‑Glu‑Glu‑Asn‑Arg‑Arg‑Arg‑Arg‑Asp with a molecular mass of 1371.53 Da. The results of the proliferation assay revealed that SHP significantly inhibited the proliferation of PC‑3 cells in a time‑ and dose‑dependent manner. Acridine orange/ethidium bromide staining indicated significant SHP‑induced apoptosis. Furthermore, Annexin V/PI double‑staining assays revealed that the percentage of early‑ stage apoptotic cells increased from 8.85 to 29% following PC‑3 exposure to 5, 10 and 15 mg/ml SHP for 24 h. SHP‑induced apoptosis was accompanied by the activation of cellular tumor antigen p53 and caspase‑3, the upregulation of apoptosis regulator BAX, and the downregulation of apoptosis regulator Bcl‑2. These findings suggest that SHP is a novel inducer of apoptosis in vitro and merits further investigation as a possible therapeutic agent for the treatment of cancer.