Surfactin induces apoptosis in human breast cancer MCF-7 cells through a ROS/JNK-mediated mitochondrial/caspase pathway

Isolation of a surfactin-producing strain of Bacillus subtilis and evaluation of the probiotic potential and antioxidant activity of surfactin from fermented soybean meal

BACKGROUND

Surfactin, usually produced by microbial metabolism, has many advantages including low toxicity, high biodegradability, and stability at extreme pH levels and temperatures, making it suitable for industry. However, its commercial production has not yet been achieved.

RESULTS

A strain with a strong surfactin-producing ability was isolated and identified as Bacillus subtilis SOPC5, based on the appearance of colonies, microscopic observation, and 16S rDNA sequencing. The isolate exhibited significant tolerance to acid, bile, gastric, and intestinal juices, and was sufficiently susceptible to antibiotics. Bacillus subtilis SOPC5 showed high levels of auto-aggregation and surface hydrophobicity, and a strong capacity to secrete protease, amylase, and cellulase. The strain also exhibited antibacterial activity against Staphylococcus aureus 10 306 with a antibacterial circle diameter of 18.0 ± 1.1 mm. The maximal yield of surfactin (1.32 mg mL-1) was obtained by fermenting soybean meal (SBM) using the isolate under the following conditions: SBM 86 g L-1, inoculation 1.5 × 107 CFU mL-1, FeSO4 1.2 mg L-1, MnSO4 2.6 mg L-1, MgSO4 0.5 mg mL-1, L-Glu 4 mg L-1, temperature 33 °C, duration 120 h, and shaking at 210 rpm. The purity of surfactin was 97.42% as measured by high-performance liquid chromatography (HPLC). The half inhibitory concentration (IC50) values for surfactin to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS·+) were 1.275 ± 0.11 and 0.73 ± 0.08 mg mL-1, respectively.

CONCLUSION

This study provides a scientific basis for the application of B. subtilis SOPC5 (as a potential probiotic) and the preparation of its metabolic product (surfactin). © 2024 Society of Chemical Industry.

Application of Biosurfactants in Medical Sciences

Biosurfactants derived from microorganisms have attracted widespread attention in scientific research due to their unique surface activity, low toxicity, biodegradability, antibacterial properties, and stability under extreme conditions. Biosurfactants are widely used in many fields, such as medicine, agriculture, and environmental protection. Therefore, this review aims to comprehensively review and analyze the various applications of biosurfactants in the medical field. The central roles of biosurfactants in crucial medical areas are explored, like drug delivery, induction of tumor cell differentiation or death, treating bacterial and viral effects, healing wounds, and immune regulation. Moreover, a new outlook is introduced on optimizing the capabilities of biosurfactants through modification and gene recombination for better use in medicine. The current research challenges and future research directions are described, aiming to provide valuable insights for continuous study of biosurfactants in medicine.

The Physicochemical and Functional Properties of Biosurfactants: A Review

Surfactants, also known as surface-active agents, have emerged as an important class of compounds with a wide range of applications. However, the use of chemical-derived surfactants must be restricted due to their potential adverse impact on the ecosystem and the health of human and other living organisms. In the past few years, there has been a growing inclination towards natural-derived alternatives, particularly microbial surfactants, as substitutes for synthetic or chemical-based counterparts. Microbial biosurfactants are abundantly found in bacterial species, predominantly Bacillus spp. and Pseudomonas spp. The chemical structures of biosurfactants involve the complexation of lipids with carbohydrates (glycolipoproteins and glycolipids), peptides (lipopeptides), and phosphates (phospholipids). Lipopeptides, in particular, have been the subject of extensive research due to their versatile properties, including emulsifying, antimicrobial, anticancer, and anti-inflammatory properties. This review provides an update on research progress in the classification of surfactants. Furthermore, it explores various bacterial biosurfactants and their functionalities, along with their advantages over synthetic surfactants. Finally, the potential applications of these biosurfactants in many industries and insights into future research directions are discussed.

A comprehensive review of biosurfactant production and its uses in the pharmaceutical industry

Biosurfactants are naturally occurring, surface-active chemicals generated by microorganisms and have attracted interest recently because of their numerous industrial uses. Compared to their chemical equivalents, they exhibit qualities that include lower toxic levels, increased biodegradable properties, and unique physiochemical properties. Due to these traits, biosurfactants have become attractive substitutes for synthetic surfactants in the pharmaceutical industry. In-depth research has been done in the last few decades, demonstrating their vast use in various industries. This review article includes a thorough description of the various types of biosurfactants and their production processes. The production process discussed here is from oil-contaminated waste, agro-industrial waste, dairy, and sugar industry waste, and also how biosurfactants can be produced from animal fat. Various purification methods such as ultrafiltration, liquid-liquid extraction, acid precipitation, foam fraction, and adsorption are required to acquire a purified product, which is necessary in the pharmaceutical industry, are also discussed here. Alternative ways for large-scale production of biosurfactants using different statistical experimental designs such as CCD, ANN, and RSM are described here. Several uses of biosurfactants, including drug delivery systems, antibacterial and antifungal agents, wound healing, and cancer therapy, are discussed. Additionally, in this review, the future challenges and aspects of biosurfactant utilization in the pharmaceutical industry and how to overcome them are also discussed.

The Secondary Metabolites of Bacillus subtilis Strain Z15 Induce Apoptosis in Hepatocellular Carcinoma Cells

The lipopeptides produced by Bacillus subtilis have anti-cancer potential. We had previously identified a secondary metabolite of B. subtilis strain Z15 (BS-Z15), which has an operon that regulates lipopeptide synthesis, and also demonstrated that the fermentation products of this strain exerted antioxidant and pro-immune effects. The purpose of this study was to investigate in vitro and in vivo the anticancer effects of BS-Z15 secondary metabolites (BS-Z15 SMs) on hepatocellular carcinoma (HCC) cells. BS-Z15 SMs significantly inhibited H22 cell-derived murine xenograft tumor growth without any systemic toxicity. In addition, BS-Z15 SMs decreased the viability of H22 cells and BEL-7404 cells in vitro with respective IC50 values of 33.83 and 27.26 µg/mL. Consistent with this, BS-Z15 SMs induced apoptosis and G0/G1 phase arrest in the BEL-7404 cells, and the mitochondrial membrane potential was also significantly reduced in a dose-dependent manner. Mechanistically, BS-Z15 SMs upregulated the pro-apoptotic p53, Bax, cytochrome C, and cleaved-caspase-3/9 proteins and downregulated the anti-apoptotic Bcl-2. These findings suggest that the induction of apoptosis in HCC cells by BS-Z15 SMs may be related to the mitochondrial pathway. Thus, the secondary metabolites of B. subtilis strain Z15 are promising to become new anti-cancer drugs for the clinical treatment of liver cancer.

Surfactin inhibits Fusarium graminearum by accumulating intracellular ROS and inducing apoptosis mechanisms

Fusarium graminearum, a devastating fungal pathogen, is the main pathogen of Fusarium head blight (FHB) in wheat globally; it results in significant yield loss and mycotoxin contamination that severely threatens global wheat production and food safety. However, despite ongoing efforts, controlling this pathogen still remains a major challenge. Surfactin, primarily synthesized by Bacillus sp. via non-ribosomal peptide synthetases, exhibits potent surfactant and antibacterial properties, but its antifungal mechanism has yet to be fully elucidated. We found that the EC50 of surfactin against hyphal growth of F. graminearum was 102.1 µg/mL, and control efficacy against wheat FHB under field conditions achieved 86.38% in wheat cultivar Huaimai 40 and 81.60% in wheat cultivar Zhoumai 36, indicating that surfactin has potential antifungal activity against F. graminearum. Accumulated intracellular ROS, decreased mitochondrial membrane potential (MMP), activated metacaspase activity and condensed chromatin, were induced by surfactin in F. graminearum hyphae, suggesting that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Furthermore, accumulated intracellular ROS was evidenced to act as a key mediator of surfactin-induced apoptosis. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that surfactin induces caspase-independent apoptosis in F. graminearum. Collectively, this study provides evidence that surfactin induces a ROS-mediated mitochondrial apoptosis in F. graminearum hyphae, and may exert its antifungal activity against F. graminearum by activating apoptosis. This study demonstrates the potential of surfactin as an antifungal agent for FHB biocontrol, provides a new perspective on the antifungal mechanism of surfactin against filamentous fungi, and contributes to the application of surfactin-producing microbes in the biocontrol of plant diseases.

In Vivo Investigation of Supportive Immunotherapeutic Combination of Bifidobacterium infantis 35624 and Doxorubicin in Murine Breast Cancer

The aim of the study is to investigate the anti-tumor effect of Bifidobacterium infantis 35624 in a xenograft model in BALB/c mice injected with 4T1 cells as a support for chemotherapeutic treatments of doxorubicin in vivo. The MTT assay was used to determine the cytotoxicity of doxorubicin against cancer cells, and apoptosis was analyzed by using flow cytometry. 4T1 cells (2 × 104 cells/mouse) were injected to BALB/c mice, and mice were fed with/without gavage B. infantis milk (108 CFU/mL) for 14 days and treated with doxorubicin on 5th and 10th days. The weights of the mice were recorded during the study, and the tumor sizes were measured by caliper at the 14th day. CD8 + T cell response was analyzed by using flow cytometer, and the results were compared to control and tumor control groups. The IC50 value for doxorubicin on 4T1 cell lines was determined as 0.053 ± 0.012 µg/mL. The apoptotic effect of doxorubicin at IC50 concentration was determined as 82.3% of cells to late apoptosis, 3.6% of cells to pro-apoptosis, and 6.2% of cells to necrosis. The treatment of doxorubicin, B. infantis milk, and the combination of them inhibited the tumor volumes by 55.50%, 40.69%, and 75.95%, respectively. B. infantis administration significantly enhanced the PHA-induced splenocyte proliferation (P < 0.05). It was shown that IFN-γ was effective in tumor growth and regression of metastasis. Consequently, the combination of B. infantis milk and doxorubicin showed the best anti-tumor effect.

Garcinone E triggers apoptosis and cell cycle arrest in human colorectal cancer cells by mediating a reactive oxygen species–dependent JNK signaling pathway

Despite various therapeutic approaches, colorectal cancer is among the most fatal diseases globally. Hence, developing novel and more effective methods for colorectal cancer treatment is essential. Recently, reactive oxygen species (ROS)/JNK signaling pathway has been proposed as the potential target for the anticancer drug discovery. The present study investigated the anticancer effects of the bioactive xanthone garcinone E (GAR E) in mangosteen and explored its underlying mechanism of action. HT-29 and Caco-2 cancer cells were used as in vitro models to study the anticancer effect of GAR E. The findings demonstrated that GAR E inhibited colony formation and wound healing, whereas triggered the production of ROS, which induced mitochondrial dysfunction and apoptosis, causing cell cycle arrest at the Sub G1 phase. Additionally, GAR E treatment elevated the ratio of Bax/Bcl-2 and activated PARP, caspases 3 and 9, and JNK1/2. These GAR E-induced cytotoxic activities and expression of signaling proteins were reversed by the antioxidant N-acetyl-L-cysteine and JNK inhibitor SP600125, indicating the involvement of ROS/JNK signaling pathways. In vivo experiments using an HT-29 xenograft nude mouse model also demonstrated the antitumor effect of GAR E. In conclusion, our findings showed that GAR E might be potentially effective in treating colorectal cancer and provided insights into the development of xanthones as novel chemotherapeutic agents.

Green Surfactants (Biosurfactants): A Petroleum-Free Substitute for Sustainability-Comparison, Applications, Market, and Future Prospects

Surfactants are a group of amphiphilic molecules (i.e., having both hydrophobic and hydrophilic domains) that are a vital part of nearly every contemporary industrial process such as in agriculture, medicine, personal care, food, and petroleum. In general surfactants can be derived from (i) petroleum-based sources or (ii) microbial/plant origins. Petroleum-based surfactants are obvious results from petroleum products, which lead to petroleum pollution and thus pose severe problems to the environment leading to various ecological damages. Thus, newer techniques have been suggested for deriving surfactant molecules and maintaining environmental sustainability. Biosurfactants are surfactants of microbial or plant origins and offer much added advantages such as high biodegradability, lesser toxicity, ease of raw material availability, and easy applicability. Thus, they are also termed "green surfactants". In this regard, this review focused on the advantages of biosurfactants over the synthetic surfactants produced from petroleum-based products along with their potential applications in different industries. We also provided their market aspects and future directions that can be considered with selections of biosurfactants. This would open up new avenues for surfactant research by overcoming the existing bottlenecks in this field.

Surfactin induces autophagy, apoptosis, and cell cycle arrest in human oral squamous cell carcinoma

OBJECTIVES

To investigate the anticancer effects and underlying mechanisms of surfactin on human oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

The capacity of surfactin to induce apoptosis, autophagy, and cell cycle arrest of two different human OSCC cell lines was investigated by cell viability, acridine orange staining, and cell cycle regulatory protein expression, respectively. The signaling network underlying these processes were determined by the analysis of reactive oxygen species (ROS) generation, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, endoplasmic reticulum (ER) stress-related protein levels, calcium release, mitogen-activated protein kinases activation, and cell cycle regulatory protein expression through corresponding reagents and experiments under various experimental conditions using specific pharmaceutical inhibitors or small interfering RNAs.

RESULTS

Surfactin was able to induce apoptosis through NADPH oxidase/ROS/ER stress/calcium-downregulated extracellular signal-regulated kinases 1/2 pathway. Surfactin could also lead to autophagy that shared the common regulatory signals with apoptosis pathway until calcium node. Cell cycle arrest at G₂ /M phase caused by surfactin was demonstrated through p53 and p21 accumulation combined p34^cdc2 , phosphorylated p34^cdc2 , and cyclin B1 inhibition, which was regulated by NADPH oxidase-derived ROS.

CONCLUSION

Surfactin could induce apoptosis, autophagy, and cell cycle arrest in ROS-dependent manner, suggesting a multifaced anticancer agent for OSCC.

Cassava wastewater valorization for the production of biosurfactants: surfactin, rhamnolipids, and mannosileritritol lipids

The global production of cassava was estimated at ca. 303 million tons. Due to this high production, the cassava processing industry (cassava flour and starch) generates approximately ca. 0.65 kg of solid residue and ca. 25.3 l of wastewater per kg of fresh processed cassava root. The composition of the liquid effluent varies according to its origin; for example, the effluent from cassava flour production, when compared to the wastewater from the starch processing, presents a higher organic load (ca. 12 times) and total cyanide (ca. 29 times). It is worthy to highlight the toxicity of cassava residues regarding cyanide presence, which could generate disorders with acute or chronic symptoms in humans and animals. In this sense, the development of simple and low-cost eco-friendly methods for the proper treatment or reuse of cassava wastewater is a challenging, but promising path. Cassava wastewater is rich in macro-nutrients (proteins, starch, sugars) and micro-nutrients (iron, magnesium), enabling its use as a low-cost culture medium for biotechnological processes, such as the production of biosurfactants. These compounds are amphipathic molecules synthesized by living cells and can be widely used in industries as pharmaceutical agents, for microbial-enhanced oil recovery, among others. Amongst these biosurfactants, surfactin, rhamnolipids, and mannosileritritol lipids show remarkable properties such as antimicrobial, biodegradability, demulsifying and emulsifying capacity. However, the high production cost restricts the massive biosurfactant applications. Therefore, this study aims to present the state of the art and challenges in the production of biosurfactants using cassava wastewater as an alternative culture medium.

Added Value of Biophysics to Study Lipid-Driven Biological Processes: The Case of Surfactins, a Class of Natural Amphiphile Molecules

The role of membrane lipids is increasingly claimed to explain biological activities of natural amphiphile molecules. To decipher this role, biophysical studies with biomimetic membrane models are often helpful to obtain insights at the molecular and atomic levels. In this review, the added value of biophysics to study lipid-driven biological processes is illustrated using the case of surfactins, a class of natural lipopeptides produced by Bacillus sp. showing a broad range of biological activities. The mechanism of interaction of surfactins with biomimetic models showed to be dependent on the surfactins-to-lipid ratio with action as membrane disturber without membrane lysis at low and intermediate ratios and a membrane permeabilizing effect at higher ratios. These two mechanisms are relevant to explain surfactins' biological activities occurring without membrane lysis, such as their antiviral and plant immunity-eliciting activities, and the one involving cell lysis, such as their antibacterial and hemolytic activities. In both biological and biophysical studies, influence of surfactin structure and membrane lipids on the mechanisms was observed with a similar trend. Hence, biomimetic models represent interesting tools to elucidate the biological mechanisms targeting membrane lipids and can contribute to the development of new molecules for pharmaceutical or agronomic applications.

Anti-proliferative activity of surfactins on human cancer cells and their potential use in therapeutics

Surfactins are cyclic lipopeptides that are isolated from various Bacillus strains. They are made up of heptapeptides and β-hydroxy fatty acids of variable chain lengths of carbon atoms. Therapeutically they are known to inhibit invasion, migration, and colony formation of human breast carcinoma cells. The role of surfactins is also known as anti-proliferative agents against human cancer cells through induction of apoptosis, arrest of the cell cycle, or suppression of survival signaling. The cytotoxic activity of surfactins is also perceived against human chronic myelogenous leukemia cells, human colon cancer cells, and hepatic carcinoma cells. Considering the wide spectrum of targets, the molecular effects of surfactins are diverse in different cancer cells and they can serve as promising chemotherapeutic agents for the treatment of cancer. Surfactins are being delivered to the targeted cancer cells through nano-carriers or nano-formulations. The present review article provides insight on different types and variations of surfactins, their molecular effect on different cancer cells, and their therapeutic use in the treatment of human cancer.

The natural compound from Garcinia bracteata mainly induces GSDME-mediated pyroptosis in esophageal cancer cells

BACKGROUND

Pyroptosis, an inflammatory form of programmed cell death (PCD), is reported to play important roles in the treatment of tumors. In our previous studies, we found that neobractatin (NBT), a caged prenylxanthone isolated from edible fruits of Garcinia bracteata C. Y. Wu ex Y. H. Li, showed anticancer effects against different cancer cells. However, the effect of NBT on pyroptosis is not well understood.

PURPOSE

This study aims to investigate whether and how GSDME-mediated pyroptosis contributes to NBT-induced antitumor effects in esophageal cancer (EC) cells.

METHODS

Cell viability assay and colony formation assay were used to determine the anticancer effects of NBT in esophageal cancer cells. Lactate dehydrogenase (LDH) release assay and microscopy imaging were used to detect the main characteristic of pyroptosis. CRISPR-Cas9 knockout and siRNA knockdown were performed to verify the roles of GSDME and caspase-3 in NBT-induced pyroptosis. Flow cytometry was used to measure the reactive oxygen species (ROS) level and cell apoptosis. The changes of related protein level were detected by Western blot. Furthermore, animal experiments were used to verify the in vivo effect of NBT.

RESULTS

The results showed that NBT reduced the viability of EC cells mainly through GSDME-mediated pyroptosis. Morphologically, NBT induced cell swelling and formed large bubbles emerging from plasma membrane in wild type EC cells. Furthermore, NBT induced the cleavage of GSDME by activating caspase-3 in EC cells. On the other hand, caspase-3 activated by NBT also induced apoptosis especially at high dosage. Knocking down GSDME switched NBT-induced cell death from mainly pyroptosis to apoptosis in vivo and in vitro. Mechanistic studies indicated that NBT led to accumulation of ROS, which then regulated the phosphorylation of both JNK and MEK/ERK. In the absence of ROS or caspase-3, NBT-induced pyroptosis and apoptosis were completely reversed. Moreover, NBT showed a significant antitumor effect in both the KYSE150 and GSDME knockout KYSE150-/- xenograft models by inducing pyroptosis and apoptosis, respectively.

CONCLUSION

Our results indicated that natural compound NBT could induce GSDME-mediated pyroptosis and apoptosis in esophageal cancer cells, making it a potential therapeutic drug in clinical treatment.

Comprehensive Review on Applications of Surfactants in Vaccine Formulation, Therapeutic and Cosmetic Pharmacy and Prevention of Pulmonary Failure due to COVID-19

Our world is under serious threat of environmental degradation, climate change and in association with this the out breaks of diseases as pandemics. The devastating impact of the very recent COVID-19, The sharp increase in cases of Cancer, Pulmonary failure, Heart health has triggered questions for the sustainable development of pharmaceutical and medical sciences. In the search of inclusive and effective strategies to meet today’s demand, improvised methodologies and alternative green chemical, bio-based precursors are being introduced by scientists around the globe. In this extensive review we have presented the potentiality and Realtime applications of both synthetic and bio-based surfactants in bio-medical and pharmaceutical fields. For their excellent unique amphoteric nature and ability to solubilise in both organic and inorganic drugs, surfactants are one of the most potential candidates for bio-medicinal fields such as dermatology, drug delivery, anticancer treatment, surfactant therapy, vaccine formulation, personal hygiene care and many more. The self-assembly property of surfactants is a very powerful function for drug delivery systems that increases the bio-availability of the poorly aqueous soluble pharmaceutical products by influencing their solubility. Over the decades many researchers have reported the antimicrobial, anti-adhesive, antibiofilm, anti-inflammatory, antioxidant activities of surfactants regarding its utility in medicinal purposes. In some reports surfactants are found to have spermicidal and laxative activity too. This comprehensive report is targeted to enlighten the versatile applications of Surfactants in drug delivery, vaccine formulation, Cancer Treatment, Therapeutic and cosmetic Pharmaceutical Sciences and prevention of pulmonary failure due to COVID-19.

The new mitochondrial uncoupler BAM15 induces ROS production for treatment of acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant proliferative disease of myeloid hematopoietic origin and cannot be treated appropriately at present. This is due to the fact that leukemia cells are not sensitive to some of the traditional chemotherapy drugs. Or some chemotherapeutic drugs are too toxic to normal cells, affecting their wide clinical application. In this study, we identified BAM15 as a novel mitochondrial uncoupling agent by screening a library of small molecule compounds that inhibit AML cell activity. BAM15 significantly inhibited proliferation and promoted apoptosis in AML cells while at the same time being less cytotoxic to normal cells. The mechanism may be related to the disturbance of the ROS production balance. In vivo investigations revealed that BAM15 effectively suppressed AML progression and prolonged the survival time of mice. In addition, we found that BAM15 can be used in combination with cytarabine to enhance its anti-cancer activity and inhibit the activity of primary cells in AML. Therefore, we identified BAM15 as a potential drug candidate for the treatment of AML.

Bugs as drugs: neglected but a promising future therapeutic strategy in cancer

Effective cancer treatment is an urgent need due to the rising incidence of cancer. One of the most promising future strategies in cancer treatment is using microorganisms as cancer indicators, prophylactic agents, immune activators, vaccines or vectors in antitumor therapy. The success of bacteria-mediated chemotherapy will be dependent on the balance of therapeutic benefit and the control of bacterial infection in the body. Additionally, protozoans and viruses have the potential to be used in cancer therapy. This review summarizes how these microorganisms interact with tumor microenvironments and the challenges of a 'bugs as drugs' approach in cancer therapy. Several standpoints are discussed, such as bacteria as vectors for gene therapy that shuttle therapeutic compounds into tumor tissues, their intrinsic antitumor activities and their combination with chemotherapy or radiotherapy. Bug-based cancer therapy is a two-edged sword and we need to find the opportunities by overcoming the challenges.

Venom of Viperidae: A Perspective of its Antibacterial and Antitumor Potential

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The emergence of multi-drug resistant bacteria and limitations on cancer treatment represent two important challenges in modern medicine. Biological compounds have been explored with a particular focus on venoms. Although they can be lethal or cause considerable damage to humans, venom is also a source rich in components with high therapeutic potential.

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Viperidae family is one of the most emblematic venomous snake families and several studies highlighted the antibacterial and antitumor potential of viper toxins. According to the literature, these activities are mainly associated to five protein families - svLAAO, Disintegrins, PLA2, SVMPs and C-type lectins- that act through different mechanisms leading to the inhibition of the growth of bacteria, as well as, cytotoxic effects and inhibition of metastasis process. In this review, we provide an overview of the venom toxins produced by species belonging to the Viperidae family, exploring their roles during the envenoming and their pharmacological properties, in order to demonstrate its antibacterial and antitumor potential.

Discrepancy of apoptotic events in mouse hepatocytes and catalase performance: Size-dependent cellular and molecular toxicity of ultrafine carbon black

The diversification of the production process and application of ultrafine carbon black (UFCB), one of the nanomaterials, make the difference in particle sizes that exposed to environment. Currently, few size-dependent toxicity studies of UFCB pay attention to targeted effects on detoxification organs. And there is a research gap in the size-dependent molecular toxicity of UFCB. Based on this, mouse hepatocytes and catalase (CAT) were used as targeted receptors for UFCB size-dependent cellular and molecular toxicity studies. Results indicate that UFCB_13 nm induced higher ROS and lipid peroxidation levels. And the cell viability decreased to 22.5%, which is sharp contrast to UFCB_50 nm (45.3%) and UFCB_95 nm (55.1%). Mitochondrial dysfunction and a 25.2% early apoptosis rate are the further manifestation of the stronger cytotoxicity of UFCB_13 nm. At the molecular level, the exposure of UFCB with better dispersity resulted in more significant changes in the CAT backbone and secondary structure, fluorescence sensitization and enzyme function inhibition. The combined experiments show that the cellular uptake and dispersity of UFCB are the dominating factors for the discrepancy in size-dependent cellular and molecular toxicity, respectively. This study provides a theoretical basis for the necessary circumvention and substitution of UFCB in engineering applications.

Microbial Lipopeptide Supramolecular Self-Assemblies as a Methuosis-Like Cell Death Inducer with In Vivo Antitumor Activity

Discovering new drugs and improving action mechanisms is a promising strategy to overcome chemotherapy ineffectiveness caused by cancer cell apoptosis resistance. Natural products (like cyclic lipopeptides, CLPs) are potential sources of nonapoptotic cell death inducers and can form diverse supramolecular structures, closely relating to their bioactivities. Herein, it is found for the first time that fatty chain is the key to maintain self-assembled form and antitumor activity of microbial-derived amphiphilic CLP bacillomycin Lb (B-Lb). Compared with B-Lb analogues assemblies without antitumor activity, B-Lb supramolecular self-assemblies (including nanomicelles, nanofibers, giant micrometer rods) can be generated in a multilevel and cross-scale manner and served as a methuosis-like cell death inducer triggered by cytoplasmic vacuolation through macropinocytosis in MDA-MB-231-Luc and MCF-7 cells and in vivo tumor-bearing mice. This study will promote constructing of customized CLP micro-/nanostructures with multipurposes and functions, and boost designing of new antitumor drugs as nonapoptotic cell death modulators based on structure-activity relationship.

Surfactin cyclic lipopeptides change the plasma membrane composition and lateral organization in mammalian cells

The specific structure and composition of the cell plasma membrane (PM) is crucial for many cellular processes and can be targeted by various substances with potential medical applications. In this context, biosurfactants (BS) constitute a promising group of natural compounds that possess several biological functions, including anticancer activity. Despite the efficiency of BS, their mode of action had never been elucidated before. Here, we demonstrate the influence of cyclic lipopeptide surfactin (SU) on the PM of CHO-K1 cells. Both FLIM and svFCS experiments show that even a low concentration of SU causes significant changes in the membrane fluidity and dynamic molecular organization. Further, we demonstrate that SU causes a relevant dose-dependent reduction of cellular cholesterol by extracting it from the PM. Finally, we show that CHO-25RA cells characterized by increased cholesterol levels are more sensitive to SU treatment than CHO-K1 cells. We propose that sterols organizing the PM raft nanodomains, constitute a potential target for SU and other biosurfactants. In our opinion, the anticancer activity of biosurfactants is directly related with the higher cholesterol content found in many cancer cells.

Fluorescent probes for visualizing ROS-associated proteins in disease

Abnormal expression of proteins, including catalytic and expression dysfunction, is directly related to the development of various diseases in living organisms. Reactive oxygen species (ROS) could regulate protein expression by redox modification or cellular signal pathway and thus influence the development of disease. Determining the expression level and activity of these ROS-associated proteins is of considerable importance in early-stage disease diagnosis and the identification of new drug targets. Fluorescence imaging technology has emerged as a powerful tool for specific in situ imaging of target proteins by virtue of its non-invasiveness, high sensitivity and good spatiotemporal resolution. In this review, we summarize advances made in the past decade for the design of fluorescent probes that have contributed to tracking ROS-associated proteins in disease. We envision that this review will attract significant attention from a wide range of researchers in their utilization of fluorescent probes for in situ investigation of pathological processes synergistically regulated by both ROS and proteins.

Biocontrol Potential of Bacillus amyloliquefaciens LYZ69 Against Anthracnose of Alfalfa (Medicago sativa)

Anthracnose is a destructive disease of alfalfa (Medicago sativa) that causes severe yield losses. Biological control can be an effective and eco-friendly approach to control this alfalfa disease. In the present study, Bacillus amyloliquefaciens LYZ69, previously isolated from healthy alfalfa roots, showed a strong in vitro antifungal activity against Colletotrichum truncatum, an important causal agent of anthracnose of alfalfa. The strain LYZ69 protected alfalfa plants (biocontrol efficacy of 82.59%) from anthracnose under greenhouse conditions. The cell-free culture (CFC) of LYZ69 (20%, vol/vol) caused 60 and 100% inhibition of mycelial growth and conidial germination, respectively. High-performance liquid chromatography tandem mass spectrometry separated and identified cyclic lipopeptides (LPs) such as bacillomycin D and fengycin in the CFC of LYZ69. Light microscopy and scanning electron microscopy revealed that the mixture of cyclic LPs produced by LYZ69 caused drastic changes in mycelial morphology. Fluorescence microscopy showed that the LPs induced reactive oxygen species accumulation and caused apoptosis-like cell death in C. truncatum hyphae. In summary, our findings provide evidence to support B. amyloliquefaciens LYZ69 as a promising candidate for the biological control of anthracnose in alfalfa.

Five Surfactin Isomers Produced during Cheonggukjang Fermentation by Bacillus pumilus HY1 and Their Properties

The cyclic lipopeptide produced from Bacillus pumilus strain HY1 was isolated from Korean soybean sauce cheonggukjang. The chemical structures of the surfactin isomers were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The five potential surfactin isoforms were detected with protonated masses of m/z 994.7, 1008.7, 1022.7, 1036.7, and 1050.7 and different structures in combination with Na+, K+, and Ca2+ ions. ESI-MS/MS analysis revealed that the isolated surfactin possessed the precise amino acid sequence LLVDLL and hydroxyl fatty acids with 12 to 16 carbons. The surfactin content during cheonggukjang fermentation increased from 0.3 to 51.2 mg/kg over 60 h of fermentation. The mixture of five surfactin isoforms of cheonggukjang inhibited the growth of two cancer cell lines. The growth of both MCF-7 and Caco-2 cells was strongly inhibited with 100 μg/μL of surfactin. This study is the first-time report of five surfactin isomers of Bacillus pumilus strain HY1 during Korean soybean sauce cheonggukjang fermentation, which has cytotoxic properties.

The Anti-Cancer Effect of Linusorb B3 from Flaxseed Oil through the Promotion of Apoptosis, Inhibition of Actin Polymerization, and Suppression of Src Activity in Glioblastoma Cells

Linusorbs (LOs) are natural peptides found in flaxseed oil that exert various biological activities. Of LOs, LOB3 ([1–9-NαC]-linusorb B3) was reported to have antioxidative and anti-inflammatory activities; however, its anti-cancer activity has been poorly understood. Therefore, this study investigated the anti-cancer effect of LOB3 and its underlying mechanism in glioblastoma cells. LOB3 induced apoptosis and suppressed the proliferation of C6 cells by inhibiting the expression of anti-apoptotic genes, B cell lymphoma 2 (Bcl-2) and p53, as well as promoting the activation of pro-apoptotic caspases, caspase-3 and -9. LOB3 also retarded the migration of C6 cells, which was achieved by suppressing the formation of the actin cytoskeleton critical for the progression, invasion, and metastasis of cancer. Moreover, LOB3 inhibited the activation of the proto-oncogene, Src, and the downstream effector, signal transducer and activator of transcription 3 (STAT3), in C6 cells. Taken together, these results suggest that LOB3 plays an anti-cancer role by inducing apoptosis and inhibiting the migration of C6 cells through the regulation of apoptosis-related molecules, actin polymerization, and proto-oncogenes.

Zeaxanthin Induces Apoptosis via ROS-Regulated MAPK and AKT Signaling Pathway in Human Gastric Cancer Cells

BACKGROUND

Zeaxanthin, a carotenoid commonly found in plants, has a variety of biological functions including anti-cancer activity.

PURPOSE

This study aimed to investigate the potential mechanisms of zeaxanthin in human gastric cancer cells.

METHODS

CCK-8 assay was used to examine the cytotoxic effect of zeaxanthin on human gastric cancer cells. Flow cytometry was used to analyse AGS cell cycle distribution and apoptosis status. Western blot analysis was used to detect the expression levels of cycle-related proteins (Cyclin A, Cyclin B1, CDK1/2, p21, and p27), apoptosis-related proteins (Bcl-2, Bad, caspase-3, PARP), MAPK, AKT, STAT3, and NF-κB.

RESULTS

CCK-8 assay showed that zeaxanthin has obvious cytotoxic effects on 12 types of human gastric cancer cells, but no obvious toxic effect on normal cells. In addition, flow cytometry and Western blotting results showed that zeaxanthin induces apoptosis by reducing mitochondrial membrane potential; increasing Cytochrome C, Bax, cleaved-caspase-3 (cle-cas-3), and cleaved-PARP (cle-PARP) expression levels; and decreasing Bcl-2, pro-caspase-3 (pro-cas-3), and pro-PARP expression levels. Additionally, zeaxanthin caused cell cycle arrest at the G2/M phase by increasing the levels of p21 and p27 and reduced the levels of AKT, Cyclin A, Cyclin B1, and Cyclin-dependent kinase 1/2 (CDK1/2). Furthermore, after zeaxanthin treatment, the expression levels of reactive oxygen species (ROS), p-JNK, p-p38, and I-κB increased, and the expression levels of p-ERK, p-AKT, STAT3, and NF-κB decreased. However, the ROS scavenger N-acetylcysteine (NAC) and MAPK inhibitors inhibited zeaxanthin-induced apoptosis, and under the action of zeaxanthin, MAPK regulated NF-κB and STAT3, and reduced their protein expression levels.

CONCLUSION

Zeaxanthin has a potential effect against gastric cancer cells through the ROS-mediated MAPK, AKT, NF-κB, and STAT3 signaling pathways, and it is expected to become a new drug for the treatment of human gastric cancer.

Silver Nanotriangles and Chemotherapeutics Synergistically Induce Apoptosis in Glioma Cells via a ROS-Dependent Mitochondrial Pathway

Background

The synergistic effect of nanomaterials and chemotherapeutics provides a novel strategy for the treatment of tumors. Silver nanotriangles (AgNTs) exhibited some unique properties in nanomedicine. Studies on the synergy of silver-based nanomaterials and anti-tumor drugs against gliomas are rare.

Materials and Methods

Chitosan-coated AgNTs were prepared, followed by characterization using transmission electron microscopy, ultraviolet-visible spectroscopy and X-ray diffraction. The anti-glioma effect of cyclophosphamide (CTX), 5-fluorouracil (5-FU), oxaliplatin (OXA), doxorubicin (DOX) or gemcitabine (GEM) combined with AgNTs in different glioma cell lines (U87, U251 and C6) was assessed by the MTT assay to screen out a drug with the most broad-spectrum and strongest synergistic anti-glioma activity. The intracellular reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP) and cell apoptosis were detected by flow cytometry. The possible underlying mechanisms of the synergy were further investigated with ROS scavenger and specific inhibitors of C-jun N-terminal kinase (JNK), p38 and extracellular signal-regulated kinase 1/2 pathways.

Results

The synthesized AgNTs were mainly triangular and truncated triangular with an average edge length of 125 nm. A synergistic anti-glioma effect of AgNTs combined with CTX was not observed, and the synergism between AgNTs and 5-FU was cell type-specific. AgNTs combined with OXA, DOX or GEM displayed synergistic effects in various glioma cell lines, and the combination of AgNTs and GEM showed the strongest synergistic activity. A decrease in cell viability, loss of the MMP and an increase in apoptosis rate induced by this synergy could be significantly attenuated by the ROS scavenger N-acetylcysteine and JNK inhibitor SP600125.

Conclusion

Our results suggested that the combination of AgNTs and GEM possessed broad-spectrum and potent synergistic anti-glioma activity, resulting from cell apoptosis mediated by a ROS-dependent mitochondrial pathway in which JNK might be involved.

Immunomodulatory Role of Microbial Surfactants, with Special Emphasis on Fish

Microbial surfactants (biosurfactants) are a broad category of surface-active biomolecules with multifunctional properties. They self-assemble in aqueous solutions and are adsorbed on various interfaces, causing a decrease in surface tension, as well as interfacial tension, solubilization of hydrophobic compounds, and low critical micellization concentrations. Microbial biosurfactants have been investigated and applied in several fields, including bioremediation, biodegradation, food industry, and cosmetics. Biosurfactants also exhibit anti-microbial, anti-biofilm, anti-cancer, anti-inflammatory, wound healing, and immunomodulatory activities. Recently, it has been reported that biosurfactants can increase the immune responses and disease resistance of fish. Among various microbial surfactants, lipopeptides, glycolipids, and phospholipids are predominantly investigated. This review presents the various immunological activities of biosurfactants, mainly glycolipids and lipopeptides. The applications of biosurfactants in aquaculture, as well as their immunomodulatory activities, that make them novel therapeutic candidates have been also discussed in this review.

Sulphamoylated Estradiol Analogue Induces Reactive Oxygen Species Generation to Exert Its Antiproliferative Activity in Breast Cancer Cell Lines

2-Methoxyestradiol (2ME), a 17β-estradiol metabolite, exerts anticancer properties in vitro and in vivo. To address 2ME’s low bioavailability, research led to the in silico design of sulphamoylated 2ME analogues. However, the role of oxidative stress induced in the activity exerted by sulphamoylated compounds remains elusive. In the current study, the influence of 2-Ethyl-17-oxoestra-1,3,5(10)-trien-3-yl sulphamate (ESE-one) on reactive oxygen species (ROS) induction and its effect on cell proliferation, as well as morphology, were assessed in breast tumorigenic cells (MCF-7 and MDA-MB-231). Fluorescent microscopy showed that sulphamoylated estradiol analogues induced hydrogen peroxide and superoxide anion, correlating with decreased cell growth demonstrated by spectrophotometry data. ESE-one exposure resulted in antiproliferation which was repressed by tiron (superoxide inhibitor), trolox (peroxyl inhibitor) and N,N′-dimethylthiourea (DMTU) (hydrogen peroxide inhibitor). Morphological studies demonstrated that tiron, trolox and DMTU significantly decreased the number of rounded cells and shrunken cells in MCF-7 and MDA-MB-231 cells induced by ESE-one. This in vitro study suggests that ESE-one induces growth inhibition and cell rounding by production of superoxide anion, peroxyl radical and hydrogen peroxide. Identification of these biological changes in cancer cells caused by sulphamoylated compounds hugely contributes towards improvement of anticancer strategies and the ROS-dependent cell death pathways in tumorigenic breast cells.

Lesson from Ecotoxicity: Revisiting the Microbial Lipopeptides for the Management of Emerging Diseases for Crop Protection

Microorganisms area treasure in terms of theproduction of various bioactive compounds which are being explored in different arenas of applied sciences. In agriculture, microbes and their bioactive compounds are being utilized in growth promotion and health promotion withnutrient fortification and its acquisition. Exhaustive explorations are unraveling the vast diversity of microbialcompounds with their potential usage in solving multiferous problems incrop production. Lipopeptides are one of such microbial compounds which havestrong antimicrobial properties against different plant pathogens. These compounds are reported to be produced by bacteria, cyanobacteria, fungi, and few other microorganisms; however, genus Bacillus alone produces a majority of diverse lipopeptides. Lipopeptides are low molecular weight compounds which havemultiple industrial roles apart from being usedas biosurfactants and antimicrobials. In plant protection, lipopeptides have wide prospects owing totheirpore-forming ability in pathogens, siderophore activity, biofilm inhibition, and dislodging activity, preventing colonization bypathogens, antiviral activity, etc. Microbes with lipopeptides that haveall these actions are good biocontrol agents. Exploring these antimicrobial compounds could widen the vistasof biological pest control for existing and emerging plant pathogens. The broader diversity and strong antimicrobial behavior of lipopeptides could be a boon for dealing withcomplex pathosystems and controlling diseases of greater economic importance. Understanding which and how these compounds modulate the synthesis and production of defense-related biomolecules in the plants is a key question—the answer of whichneeds in-depth investigation. The present reviewprovides a comprehensive picture of important lipopeptides produced by plant microbiome, their isolation, characterization, mechanisms of disease control, behavior against phytopathogens to understand different aspects of antagonism, and potential prospects for future explorations as antimicrobial agents. Understanding and exploring the antimicrobial lipopeptides from bacteria and fungi could also open upan entire new arena of biopesticides for effective control of devastating plant diseases.

Apoptosis of Leukemia Cells by Ocimum basilicum Fractions Following TNF alpha Induced Activation of JNK and Caspase 3

Purpose:

Leukemia, one of the major cancers, affects a large proportion of people around the world. Better treatment options for leukemia are required due to a large number of side effects associated with current therapeutic regimens. In the present study, we sought to determine the pathway of triggering apoptosis of leukemic cells by Ocimum basilicum (O. basilicum) plant extract.

Materials/Methods:

Methanolic extract of the O. basilicum plant material was prepared. The crude extract was fractionated into several fractions through column chromatography using ethyl acetate and n-hexane as eluting solvents. Cell viability of leukemic cells was assessed via Cell titer GLO assay and apoptosis was measured through Annexin V/PI staining. Two apoptotic molecules JNK and caspases were analyzed through western blotting while pro-inflammatory cytokines TNFα, CCL2 and CXCL8 using qPCR. Fractions were characterized through LC-MS.

Results:

The most potent with lowest IC50 values among the fractions were BF2 (2:8 n-hexane:ethyl acetate) and BF3 (3:7 n-hexane:ethyl acetate). Cytotoxicity was associated with apoptosis. Apoptosis was found caspasedependent and P-JNK activation was detected sustained. A significant increase in the level of TNF α and a decrease in the level of CXCL8 were observed in BF2 and BF3 treated cells.

Conclusion:

The fractions of O. basilicum extract were found to kill cells following JNK pathway activation. Excellent results were obtained with BF2 and BF3 probably due to predominant Epicatechin and Cinnamic acid derivatives in these fractions.

Met-enkephalin inhibits ROS production through Wnt/β-catenin signaling in the ZF4 cells of zebrafish

Opioid neuropeptides are developed early in the course of a long evolutionary process. As the endogenous messengers of immune system, opioid neuropeptides participate in regulating immune response. In this study, the mechanism that Met-enkephalin (M-ENK) inhibits ROS production through Wnt/β-catenin signaling was investigated in the ZF4 cells of zebrafish. ZF4 cells were exposed to 0, 10, 20, 40, 80, and 160 μM Met-enkephalin (M-ENK) for 24 h, and the cell viability was detected with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The cell viability was significantly increased by 10, 20, 40, 80, and 160 μM M-ENK. After ZF4 cells were exposed to 0, 20, 40, and 80 μM M-ENK for 24 h, the mRNA expression of Wnt10b, β-catenin, and CCAAT/enhancer binding protein α (C/EBPα) was significantly increased by 40 and 80 μM M-ENK. However, the mRNA and protein expression of GSK-3β was significantly decreased by 40 and 80 μM M-ENK. The protein expression of β-catenin was significantly induced by 40 and 80 μM M-ENK, while the protein expression of p-β-catenin was significantly decreased by 20, 40, and 80 μM M-ENK. In addition, the mRNA expression of CAT, SOD, and GSH-PX was significantly increased by 40 and 80 μM M-ENK. The levels of H₂O₂, ·OH, and O₂^·- were significantly decreased, but the activity of CAT, SOD, and GSH-PX was significantly increased by 40 and 80 μM M-ENK. The fluorescence intensity of reactive oxygen species (ROS) was decreased, and that of mitochondrial membrane potential (MMP) was increased with the increase of M-ENK concentration in ZF4 cells. The results showed that M-ENK could induce Wnt/β-catenin signaling, which further inhibited ROS production through the induction of C/EBPα, MMP, and the activities of antioxidant enzymes.

Microbial biosurfactants: current trends and applications in agricultural and biomedical industries

Synthetic surfactants are becoming increasingly unpopular in many applications due to previously disregarded effects on biological systems and this has led to a new focus on replacing such products with biosurfactants that are biodegradable and produced from renewal resources. Microbially derived biosurfactants have been investigated in numerous studies in areas including: increasing feed digestibility in an agricultural context, improving seed protection and fertility, plant pathogen control, antimicrobial activity, antibiofilm activity, wound healing and dermatological care, improved oral cavity care, drug delivery systems and anticancer treatments. The development of the potential of biosurfactants has been hindered somewhat by the myriad of approaches taken in their investigations, the focus on pathogens as source species and the costs associated with large-scale production. Here, we focus on various microbial sources of biosurfactants and the current trends in terms of agricultural and biomedical applications.

Flaxseed extract induces apoptosis in human breast cancer MCF-7 cells

Significant evidence indicated that flaxseed (Linum usitatissimum) possesses various positive health aspects such as reducing the risk of cancer and cardiovascular diseases. The fatty acids are considered to be responsible for these benefits of flaxseed. Herein, the in vitro effects of flaxseed extract on the growth and apoptosis of human breast cancer MCF-7 cells were investigated. The MCF-7 cells treated with flaxseed extract showed a dose-dependent decrease in cell viability. The flaxseed extract induced reactive oxygen species and the flow cytometric analysis demonstrated that flaxseed fatty acids triggered apoptosis of MCF-7 cells, which was also shown by the loss of mitochondrial membrane potential and caspase cascade reaction. Thus, the flaxseed extract regulated the growth of MCF-7 cells and induced apoptosis. Eventually, the flaxseed could be used as a dietary supplement to prevent breast cancer.

Focus on Cdc42 in Breast Cancer: New Insights, Target Therapy Development and Non-Coding RNAs

Breast cancer is the most common malignant tumors in females. Although the conventional treatment has demonstrated a certain effect, some limitations still exist. The Rho guanosine triphosphatase (GTPase) Cdc42 (Cell division control protein 42 homolog) is often upregulated by some cell surface receptors and oncogenes in breast cancer. Cdc42 switches from inactive guanosine diphosphate (GDP)-bound to active GTP-bound though guanine-nucleotide-exchange factors (GEFs), results in activation of signaling cascades that regulate various cellular processes such as cytoskeletal changes, proliferation and polarity establishment. Targeting Cdc42 also provides a strategy for precise breast cancer therapy. In addition, Cdc42 is a potential target for several types of non-coding RNAs including microRNAs and lncRNAs. These non-coding RNAs is extensively involved in Cdc42-induced tumor processes, while many of them are aberrantly expressed. Here, we focus on the role of Cdc42 in cell morphogenesis, proliferation, motility, angiogenesis and survival, introduce the Cdc42-targeted non-coding RNAs, as well as present current development of effective Cdc42-targeted inhibitors in breast cancer.

Scandenolone from Cudrania tricuspidata fruit extract suppresses the viability of breast cancer cells (MCF-7) in vitro and in vivo

Scandenolone, an isoflavone, has shown anti-cancer potential. In this study, we extracted scandenolone from Cudrania tricuspidata fruit and evaluated its anti-breast cancer effects as well as toxicity in cell and animal models. In cell model, scandenolone suppressed the breast cancer MCF-7 cells viability, ceased mitotic cell cycle, decreased mitochondrial membrane potential, up-regulated cleaved caspase-3 and promoted the phosphorylation of p53. Additionally, this isoflavone promoted cell apoptosis and induced a sustained activation of the phosphorylation of p38 and ERK, but not JNK and Akt. The effects were further verified in a human MCF-7 breast cancer xenograft model, where scandenolone efficiently suppressed the cancer growth and increased apoptotic cells in tumor tissue. However scandenolone has also shown certain toxicity to normal hepatocytes and breast epithelial cells. It could be concluded that scandenolone suppressed the growth of breast cancer cells, but its toxicity towards normal cells might limit its potential clinical use.

In Silico Discovery of Novel Ligands for Antimicrobial Lipopeptides for Computer-Aided Drug Design

The increase in antibiotic-resistant strains of pathogens has created havoc worldwide. These antibiotic-resistant pathogens require potent drugs for their inhibition. Lipopeptides, which are produced as secondary metabolites by many microorganisms, have the ability to act as potent safe drugs. Lipopeptides are amphiphilic molecules containing a lipid chain bound to the peptide. They exhibit broad-spectrum activities against both bacteria and fungi. Other than their antimicrobial properties, they have displayed anti-cancer properties as well, but their mechanism of action is not understood. In silico drug design uses computer simulation to discover and develop new drugs. This technique reduces the need of expensive and tedious lab work and clinical trials, but this method becomes a challenge due to complex structures of lipopeptides. Specific agonists (ligands) must be identified to initiate a physiological response when combined with a receptor (lipopeptide). In silico drug design and homology modeling talks about the interaction between ligands and the binding sites. This review summarizes the mechanism of selected lipopeptides, their respective ligands, and in silico drug design.

Toxicity and applications of surfactin for health and environmental biotechnology

Characterized as one of the most potent biosurfactants, surfactin is a cyclic lipopeptide synthesized by several strains of Bacillus genus. The aim of this review was to present the physicochemical and structural properties of surfactin and to demonstrate advances and applications of this biosurfactant for health and environmental biotechnology. Further, this review also focused on toxicological effects of surfactin on in vivo and in in vitro systems. The hydrophobic nature of surfactin enables interaction with membrane-bound phospholipids and indicates the ability of the molecule to act as a new weapon with respect to therapeutic and environmental properties. Seeking to avoid environmental contamination produced by widespread use of synthetic surfactants, surfactin emerges as a biological control agent against pathogen species owing to its antibacterial and antiviral properties. In addition, the mosquitocidal activity of surfactin was suggested as new strategy to control disease vectors. The current findings warrant future research to assess the toxicity of surfactin to enable an optimizing anticancer therapy and to seek refined methodologies, including nanotechnology techniques, to allow for an improved delivery of the biogenic molecule on target cells.

Proviral insertion in murine lymphomas 2 promotes stomach cancer progression by regulating apoptosis via reactive oxygen species-triggered endoplasmic reticulum stress

Gastric cancer is one of the most fatal cancers worldwide. The incidence and death rates are still increasing for gastric cancer. Increasing studies have shown that proviral insertion in murine lymphomas 2 (PIM2) functions as critical regulator of multiple cancers. However, it remains unknown whether and how PIM2 regulates gastric cancer progression. In this study, PIM2 was increased in the gastric cancer tissues of patients. Patients with high PIM2 expression levels had significantly shorter survival than those with low PIM2 expression. PIM2 knockdown reduced proliferation, migration and invasion in vitro by up-regulating E-cadherin, and down-regulating N-cadherin and Vimentin. Knockdown of PIM2 induced apoptosis in gastric cancer cells, which was regulated by endoplasmic reticulum (ER) stress, as evidenced by the increased expression levels of Activating transcription factor (ATF) 6, ATF4, X-box- binding protein-1 (XBP-1) and C/EBP homologous protein (CHOP). In addition, our data showed that PIM2 silence induced reactive oxygen species (ROS) production, leading to the activation of c-Jun N-terminal kinase (JNK). Importantly, we found that PIM2 knockdown-induced apoptosis and ER stress could be abolished by reducing reactive oxygen species (ROS) generation. In vivo, PIM2 knockdown showed a significant reduction in SGC-7901 xenograft tumor size. In summary, our findings provided experimental evidence that PIM2 might function as an important oncogene in gastric cancer, which supplied promising target for developing new therapeutic strategy in gastric cancer.