Mitochondrial membrane permeabilization: the sine qua non for cell death

Microplastics in the deep: Suspended particles affect the model species Mytilus galloprovincialis under hyperbaric conditions

Microplastics (MPs) are small plastic particles that result from the degradation of bigger fragments or introduced into the environment as primary particles. Their reduced size makes them available for ingestion by marine organisms, particularly in subtidal and deep-sea environments, which represent the largest sinks for MPs in the ocean. However, there is a lack of data regarding the effects of MPs in subtidal and deep-sea ecosystems. Thus, the present study aimed to assess the effects of MPs under hyperbaric conditions. Juvenile mussels, Mytilus galloprovincialis, were exposed to three concentrations of polyethylene MPs: 0.1, 1 and 10 mg/L, in a mixture of sizes (38-45, 75-90 and 180-212 μm), at different pressures: 1, 4 and 50 Bar, for 96 h. After exposure, the filtration rate, biochemical markers of oxidative stress and transcriptomic profile were analyzed to assess the effects of MPs. Results indicate that MPs affected functional endpoints, with a significant decrease in the filtration rate of mussels exposed to MPs at 1 mg/L and higher. Similarly, all tested oxidative stress biomarkers were affected in a treatment, concentration and pressure-dependent manner. RNA-seq analysis performed in organisms exposed to 1 mg/L of MPs at 4 Bar identified several affected signaling pathways (430 differentially expressed genes) including cellular senescence, the MAPK, RAS PI3K-Akt signaling pathways, apoptosis, among others. Overall, the results here presented corroborate the hypothesis that MPs affect exposed organisms under short-term hyperbaric conditions. These findings highlight the need to study MPs effects in subtidal and deep-sea taxa and address, in future studies, combined effects with other stressors such as contaminants that might be sorbed to the surface of the particles. These findings also indicate that improving hazard assessment of MPs under hyperbaric conditions is paramount to support risk assessment and the implementation of mitigation strategies.

The inhibitory effect of Osthole on A549 lung adenocarcinoma cells and its biomarker

Some natural compounds derived from medicinal plants show anti-tumor activity with high efficacy and safety, low toxicity and residual levels etc. The aim of this study was to select natural compounds and biomarkers having high inhibitory effects against A549 adenocarcinoma cells. A total of eight natural compounds having pure plant origin were initially screened, purchased, and their potential anti-cancer activities were comprehensively and systematically evaluated against A549 lung adenocarcinoma cells. The maximum non-cytotoxic concentration (MNTC) and 50% cytotoxic concentration (CC50) of the eight compounds against A549 cells were obtained by cytopathological and MTT assays, respectively. Using Cisplatin as a positive control, the effect of selected compounds were elucidated on the proliferation, migration and invasion of A549 cells by MTT, wound healing and invasion assays, respectively. AnnexinV-FITC/PI, JC-1, ROS and Cell Cycle Kits were used to detect the pro-apoptotic mechanism of A549 cells induced by the tested compounds. qRT-PCR and RNA-seq were used to investigate the effective biomarkers involved in the inhibition process. The results showed that Curcumin, Osthole, Paeonol, Cepharanthine and Cisplatin significantly reduced the proliferation, migration and invasion abilities of A549 cells in a dose-dependent manner. Post 48 h of treatment, Osthole inhibited the metastatic ability of A549 cells by regulating mitochondrial apoptosis, arresting A549 cell in G1-phase and inhibiting release of ROS, while Curcumin, Paeonol and Cepharanthine did not showed the same response. It was therefore elucidated that Osthole was the optimal natural compound showing powerful anti-inhibitory properties against A549 cells. Moreover, the expressions of EGF, IL-2 and IL-10 genes were significantly decreased in Osthole treated group, while IL-6 gene was significantly increased. This study suggested that EGF gene has the potential to be used as a biomarker for Osthole treatment against A549 cells, involved in mitochondrial apoptosis and ROS down-regulation, inhibiting proliferation and epithelial mesenchymal transition (EMT), inflammation and immune processes in A549 cells providing a foundation to develop Osthole as a potential target drug to prevent the occurrence and development of lung adenocarcinoma.

Naringin alleviates fluoride-induced neurological impairment: A focus on the regulation of energy metabolism mediated by mitochondrial permeability transition pore

The neurological impairment induced by fluoride is associated with mitochondrial dysfunction. Normal mitochondrial permeability transition pore (mPTP) opening plays a pivotal role in mitochondrial function. However, it remains unclear whether p53-dependent mPTP-related mitochondrial apoptosis is associated with fluoride-induced neurological impairment, and the alleviation of naringin on those. In vivo, NaF-treated rats had impaired learning and memory abilities, damaged hippocampal structure, and higher respiratory exchange rates (RER). In vitro, the increased apoptosis rates, excessive opening of mPTP, and decreased mitochondrial membrane potential (MMP) were observed in PC12 cells treated with NaF. The protein expressions of p53, CytoC, and cleaved caspase 3 were significantly increased in hippocampi of rats treated with 50 mg/L and 100 mg/L NaF and in 40 mg/L and 80 mg/L NaF-treated PC12 cells, while the protein expression of CypD remains stable. And the changes of p53 and CypD were also confirmed by the immunofluorescence staining in vivo. After inhibiting the expression of p53 with pifithrin-α and p53-siRNA, the decreased apoptosis rates and mPTP opening, increased MMP, and decreased protein expressions of p53, CytoC, and cleaved caspase 3 were observed in NaF-treated PC12 cells. Rats, treated with NaF and naringin, had alleviated impaired neurological function, and had lower RER than rats treated with NaF alone. And compared with those in the NaF group, the decreased apoptosis rates and mPTP opening, and increased MMP were also found in PC12 cells treated with NaF and naringin. Furthermore, hippocampi of rats and PC12 cells treated with NaF and naringin had decreased protein expressions of p53, CytoC, and cleaved caspase 3. Our results indicate that fluoride activates the p53-dependent mPTP-related mitochondrial apoptosis, which then affects energy metabolism, resulting in neurological impairment. Additionally, naringin can alleviate this damage, and further studies on the potential health benefits of naringin are needed.

Commentary on 'Development and validation of a minimally invasive protocol for assessing oxidative stress markers in exfoliated oral cells'

The assessment of reactive oxygen species (ROS) offers immense prospects for the diagnosis of chronic diseases. A protocol to assess redox imbalance in exfoliated cells can prove beneficial in our understanding of the role of ROS in the diagnosis of these diseases. Further studies on the development of such protocols are needed.

Implications of p53 in mitochondrial dysfunction and Parkinson's disease

Purpose: To study the underlying molecular mechanisms of p53 in the mitochondrial dysfunction and the pathogenesis of Parkinson's disease (PD), and provide a potential therapeutic target for PD treatment.

Methods: We review the contributions of p53 to mitochondrial changes leading to apoptosis and the subsequent degeneration of dopaminergic neurons in PD.

Results: P53 is a multifunctional protein implicated in the regulation of diverse cellular processes via transcription-dependent and transcription-independent mechanisms. Mitochondria are vital subcellular organelles for that maintain cellular function, and mitochondrial defect and impairment are primary causes of dopaminergic neuron degeneration in PD. Increasing evidence has revealed that mitochondrial dysfunction-associated dopaminergic neuron degeneration is tightly regulated by p53 in PD pathogenesis. Neurodegenerative stress triggers p53 activation, which induces mitochondrial changes, including transmembrane permeability, reactive oxygen species production, Ca2+ overload, electron transport chain defects and other dynamic alterations, and these changes contribute to neurodegeneration and are linked closely with PD occurrence and development. P53 inhibition has been shown to attenuate mitochondrial dysfunction and protect dopaminergic neurons from degeneration under conditions of neurodegenerative stress.

Conclusions: p53 appears to be a potential target for neuroprotective therapy of PD.

PSTPIP2 protects against alcoholic liver injury and invokes STAT3-mediated suppression of apoptosis

Alcoholic liver injury (ALI) stands as a prevalent affliction within the spectrum of complex liver diseases. Prolonged and excessive alcohol consumption can pave the way for liver fibrosis, cirrhosis, and even hepatocellular carcinoma. Recent findings have unveiled the protective role of proline serine-threonine phosphatase interacting protein 2 (PSTPIP2) in combating liver ailments. However, the role of PSTPIP2 in ALI remains mostly unknown. This study aimed to determine the expression profile of PSTPIP2 in ALI and to uncover the mechanism through which PSTPIP2 affects the survival and apoptosis of hepatocytes in ALI, using both ethyl alcohol (EtOH)-fed mice and an EtOH-induced AML-12 cell model. We observed a consistent decrease in PSTPIP2 expression both in vivo and in vitro. Functionally, we assessed the impact of PSTPIP2 overexpression on ALI by administering adeno-associated virus 9 (AAV9)-PSTPIP2 into mice. The results demonstrated that augmenting PSTPIP2 expression significantly shielded against liver parenchymal distortion and curbed caspase-dependent hepatocyte apoptosis in EtOH-induced ALI mice. Furthermore, enforcing PSTPIP2 expression reduced hepatocyte apoptosis in a stable PSTPIP2-overexpressing AML-12 cell line established through lentivirus-PSTPIP2 transfection in vitro. Mechanistically, this study also identified signal transducer and activator of transcription 3 (STAT3) as a direct signaling pathway regulated by PSTPIP2 in ALI. In conclusion, our findings provide compelling evidence that PSTPIP2 has a regulatory role in hepatocyte apoptosis via the STAT3 pathway in ALI, suggesting PSTPIP2 as a promising therapeutic target for ALI.

A genetically encoded fluorescent protein sensor for mitochondrial membrane damage detection

Mitochondria are essential cellular organelles; detecting mitochondrial damage is crucial in cellular biology and toxicology. Compared with existing chemical probe detection methods, genetically encoded fluorescent protein sensors can directly indicate cellular and molecular events without involving exogenous reagents. In this study, we introduced a molecular sensor system, MMD-Sensor, for monitoring mitochondrial membrane damage. The sensor consists of two molecular modules. Module I is a fusion structure of the mitochondrial localization sequence (MLS), AIF cleavage site sequence (CSS), nuclear localization sequence (NLS), N-terminus of mNeonGreen and mCherry. Module II is a fusion structure of the C-terminus of mNeonGreen, NLS sequence, and mtagBFP2. Under normal condition, Module I is constrained in the inner mitochondrial membrane anchored by MLS, while Module II is restricted to the nucleus by its NLS fusion component. If the mitochondrial membrane is damaged, CSS is cut from the inner membrane, causing Module I to shift into the nucleus guided by the NLS fusion component. After Module I enters the nucleus, the N- and C-terminus of mNeonGreen meet each other and rebuild its intact 3D structure through fragment complementation and thus generates green fluorescence in the nucleus. Dynamic migration of red fluorescence from mitochondria to the nucleus and generation of green fluorescence in the nucleus indicate mitochondrial membrane damage. Using the MMD-Sensor, mitochondrial membrane damage induced by various reagents, such as uncoupling agents, ATP synthase inhibitors, monovalent cationic carriers, and ROS, in HeLa and 293T cells are directly observed and evaluated.

Development and validation of a minimally invasive protocol for assessing oxidative stress markers in exfoliated oral cells

OBJECTIVES

This study aimed to develop and validate a minimally invasive protocol for characterizing oxidative stress markers in exfoliated oral cells.

MATERIALS AND METHODS

Exfoliated oral cells were collected from healthy volunteers. The protocol included the utilization of specific fluorescent probes to measure intracellular reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) and reduced glutathione (GSH). Cells from each volunteer were divided into the positive and negative control groups, which were, respectively, exposed or not to hydrogen peroxide (H2 O2 ) aiming to induce the oxidative stress. Measurements of cell fluorescence were performed using a microscope equipped with epifluorescence.

RESULTS

The results showed that cells exposed to H2 O2 exhibited significantly higher intracellular expression of ROS compared to unexposed cells (positive control: 3851.25 ± 1227.0 vs, negative control: 1106.07 ± 249.6; p = 0.0338). On the contrary, cells exposed to H2 O2 displayed decreased expression of ΔΨm (p = 0.0226) and GSH (p = 0.0289) when compared to the negative control group (ΔΨm positive control: 14634.39 ± 1529.0 vs, negative control: 18897.60 ± 2338.0; and GSH positive control: 9011.08 ± 1900.0 vs, negative control: 15901.79 ± 2745.0).

CONCLUSIONS

The developed protocol proved to be effective in detecting and quantifying oxidative stress biomarkers, such as ROS, ΔΨm and GSH, in exfoliated oral cells. This minimally invasive approach offers a promising method to assess oxidative stress expression and may be clinically relevant in the evaluation of oral diseases associated with oxidative stress.

Metformin enhanced the effect of pirfenidone on pulmonary fibrosis in mice

BACKGROUND

The aim of the study is to observe the anti-inflammatory and antioxidative stress effects of metformin on bleomycin (BLM)-induced pulmonary fibrosis in mice.

METHODS

Mice with BLM-induced pulmonary fibrosis were treated with pirfenidone, metformin, pirfenidone plus metformin and the NADPH oxidase 4 (NOX4) inhibitor diphenyleneiodonium chloride (DPI). Pathological changes and hydroxyproline (HPO) levels were examined in the lung tissue of mice with pulmonary fibrosis. Superoxide dismutase (SOD) activity and malonaldehyde (MDA) levels in lung tissue were determined.

RESULTS

Compared with pirfenidone, pirfenidone plus metformin could reduce alveolar damage and collagen fibre deposition and alleviate BLM-induced pulmonary fibrosis. Lung HPO levels were significantly lower in the PFD + MET group than in the BLM group (p < 0.05). SOD levels in the lungs of mice were increased in the PFD + MET group than in the BLM group (p < 0.05). Metformin and pirfenidone plus metformin can reduce MDA levels (p < 0.05). Pirfenidone plus metformin could reduce HPO levels, increase SOD levels, and reduce MDA levels in the lungs of mice. There was a significant correlation between the HPO level and the Ashcroft score (r = 0.520, p < 0.001).

CONCLUSION

Metformin enhanced the antifibrotic effects of pirfenidone on BLM-treated mice. Moreover, these findings provide an experimental basis for examining whether metformin can improve the antifibrotic effects of pirfenidone on patients with idiopathic pulmonary fibrosis (IPF). It has broad therapeutic prospects for patients with IPF.

Chemical composition and biological activities of the essential oil from Eugenia stipitata McVaugh leaves

In the present study, the volatile components and cytotoxic, antibacterial, antioxidant, and antiprotozoal activities of the essential oil obtained from the leaves of Eugenia stipitata McVaugh (Myrtaceae) grown in the Brazilian Northeast region (Araripe) were investigated. The essential oil was obtained by hydrodistillation. The leaves of E. stipitata provided an oil yield of 0.13 ± 0.01% (w/w). The volatile compounds in the essential oil of E. stipitata were analysed using gas chromatography, and the volatile chemical composition was mainly composed of β-eudesmol (15.28%), γ-eudesmol (10.85%), elemol (10.21%) and caryophyllene oxide (6.65%). The essential oil of E. stipitata was highly selective against Leishmania braziliensis and L. infantum promastigotes. The essential oil exhibited good antibacterial activity. E. stipitata essential oil showed low free-radical scavenging activity. Our results suggest that the E. stipitata essential oil is a relevant source of the primary compounds required for the development of antibacterial and antiprotozoal drugs.

Pathophysiology of Acute Kidney Frailty

Acute kidney frailty is a premorbid condition of diminished renal functional reserve that predisposes to acute kidney injury; this condition results from subclinical wear or distortion of renal homeostatic responses that protect the renal excretory function. Knowledge of its pathophysiological basis is critical for the development of diagnostic and therapeutic strategies that allow for prophylactic intervention and disease prevention.

Reduction of oral pathogens and oxidative damage in the CAL 27 cell line by Rosmarinus officinalis L. and Taraxacum officinale Web. Extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Dandelion (Taraxacum officinale Web.) and rosemary (Rosmarinus officinalis L.) are treasured botanicals with a long usage history in traditional herbal practices worldwide. Dandelion was used to treat kidney, spleen, and liver disease, as well as cardiovascular disease, diabetes, and bacterial infections, whereas rosemary was used to treat pain, spasms, and to improve blood circulation.

AIM OF THE STUDY

The aim of this study was to determine the influence of rosemary and dandelion leaves aqueous extracts on the human tongue epithelial carcinoma cell line (CAL 27) at the level of interaction between oral microbiota and tongue epithelial cells, genomic damage, and H₂O₂ - induced oxidative damage protection.

MATERIALS AND METHODS

The polyphenolic composition of the extracts was determined by spectrophotometric and HPLC analyses. After extract treatment, cytotoxic impact and ROS generation in CAL 27 cells were measured using the MTT assay and the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay, respectively. Microdilutions were applied to investigate the antimicrobial and adhesive properties against representatives of the oral microbiota. The single-cell gel electrophoresis (comet assay) and cytokinesis-blocked micronucleus cytome assay (CBMN cyt) were used to detect induced genomic damages.

RESULTS

Both extracts increased the adhesion of the lactic acid bacteria L. plantarum but decreased the adhesion of the bacterial pathogens S. enterica serovar Typhimurium LT21 and E. coli K-12 MG1655 adhesion onto CAL 27 cells. 1 h treatment with 5x concentrated dandelion extract and 1x, 2.5x, and 5x of rosemary extract caused an increase in comet tail intensity. CBMN cyt results demonstrated a significant increase in micronucleus formation even at concentrations several times lower than the usual bioactive compound concentrations found in a cup of beverage, with higher concentrations also inducing cell apoptosis and necrosis. Rosemary extract showed a protective effect against H₂O₂ - induced oxidative damage by decreasing the apoptotic cell number, probably preventing mutations leading to tumor aggressiveness, invasion, and metastasis.

CONCLUSIONS

Both tested extracts demonstrated their usefulness in maintaining good oral bacteria balance and their protective capability as powerful antitumor agents by causing a protective apoptotic effect in tumor cell line already at the dosage of an average daily cup.

Plant Essential Oils as a Tool in the Control of Bovine Mastitis: An Update

Bovine mastitis is a major concern for the dairy cattle community worldwide. Mastitis, subclinical or clinical, can be caused by contagious or environmental pathogens. Costs related to mastitis include direct and indirect losses, leading to global annual losses of USD 35 billion. The primary treatment of mastitis is represented by antibiotics, even if that results in the presence of residues in milk. The overuse and misuse of antibiotics in livestock is contributing to the development of antimicrobial resistance (AMR), resulting in a limited resolution of mastitis treatments, as well as a serious threat for public health. Novel alternatives, like the use of plant essential oils (EOs), are needed to replace antibiotic therapy when facing multidrug-resistant bacteria. This review aims to provide an updated overview of the in vitro and in vivo studies available on EOs and their main components as an antibacterial treatment against a variety of mastitis causing pathogens. There are many in vitro studies, but only several in vivo. Given the promising results of treatments with EOs, further clinical trials are needed.

Sodium New Houttuyfonate Induces Apoptosis of Breast Cancer Cells via ROS/PDK1/AKT/GSK3β Axis

BACKGROUND

Sodium new houttuyfonate (SNH) has been reported to have anti-inflammatory, anti-fungal, and anti-cancer effects. However, few studies have investigated the effect of SNH on breast cancer. The aim of this study was to investigate whether SNH has therapeutic potential for targeting breast cancer.

METHODS

Immunohistochemistry and Western blot analysis were used to examine the expression of proteins, flow cytometry was used to detect cell apoptosis and ROS levels, and transmission electron microscopy was used to observe mitochondria.

RESULTS

Differentially expressed genes (DEGs) between breast cancer-related gene expression profiles (GSE139038 and GSE109169) from GEO DataSets were mainly involved in the immune signaling pathway and the apoptotic signaling pathway. According to in vitro experiments, SNH significantly inhibited the proliferation, migration, and invasiveness of MCF-7 (human cells) and CMT-1211 (canine cells) and promoted apoptosis. To explore the reason for the above cellular changes, it was found that SNH induced the excessive production of ROS, resulting in mitochondrial impairment, and then promoted apoptosis by inhibiting the activation of the PDK1-AKT-GSK3β pathway. Tumor growth, as well as lung and liver metastases, were suppressed under SNH treatment in a mouse breast tumor model.

CONCLUSIONS

SNH significantly inhibited the proliferation and invasiveness of breast cancer cells and may have significant therapeutic potential in breast cancer.

Effects of mitochondrial dysfunction on bone metabolism and related diseases: a scientometric study from 2003 to 2022

Background

In recent years, mitochondrial dysfunction has been extensively studied and published, but research on the effects of mitochondrial dysfunction on bone metabolism and related diseases is only just beginning. Furthermore, no studies have been carried out to systematically illustrate this area from a scientometric point of view. The goal of this research is to review existing knowledge and identify new trends and possible hotspots in this area.

Methods

All publications related to the relationship between mitochondrial dysfunction and bone metabolism and related diseases from 2003 to 2022 were searched at the Web of Science Core Collection (WoSCC) on May 7, 2022. Four different analytical tools: VOSviewer 1.6.18, CiteSpace V 6.1, HistorCite (12.03.07), and Excel 2021 were used for the scientometric research.

Results

The final analysis included 555 valid records in total. Journal of Biological Chemistry (Co-citations = 916) is the most famous journal in this field. China (Percentage = 37%), the United States (Percentage = 24%), and Korea (Percentage = 12%) are the most productive countries. Blanco FJ and Choi EM are the main researchers with significant academic influence. Current research hotspots are basic research on mitochondrial dysfunction and the prevention or treatment of bone metabolism-related diseases.

Conclusion

The study of the consequences of mitochondrial dysfunction on bone metabolism and associated diseases is advancing rapidly. Several prominent researchers have published extensive literature and are widely cited. Future research in this area will focus on oxidative stress, aging, gene expression, and the pathogenesis of bone metabolism-related diseases.

Mechanisms of Mitochondrial Apoptosis-Mediated Meat Tenderization Based on Quantitative Phosphoproteomic Analysis

This study investigates the mechanism of phosphorylation in the regulation of apoptosis-mediated meat tenderization during postmortem aging. The results found that the pork muscle exhibited apoptotic potential at early postmortem (48 h) and showed more tenderness at late postmortem, as evidenced by the increase in mitochondrial membrane permeability (MMP), Ca2+ level, reactive oxygen species (ROS) content, and caspases activity at 0 h to 48 h, and decreases in ATP level at 0 h to 24 h and shear force at 12 h to 120 h (p < 0.05). Phosphoproteomic analysis revealed that phosphorylation regulated apoptosis by modulating ATP and calcium bindings as well as apoptotic signaling, which occurred within early 12 h and mainly occurred at 12 h to 48 h postmortem. Moreover, differential expression of phosphoproteins demonstrated that phosphorylation regulated oxidative stress-induced apoptosis and rigor mortis, thereby promoting the development of meat tenderness. Our results provide insights into the roles of phosphorylation in various physiological processes that affect meat tenderness.

Essential Oils as Multicomponent Mixtures and Their Potential for Human Health and Well-Being

Essential oils (EOs) and their individual volatile organic constituents have been an inherent part of our civilization for thousands of years. They are widely used as fragrances in perfumes and cosmetics and contribute to a healthy diet, but also act as active ingredients of pharmaceutical products. Their antibacterial, antiviral, and anti-inflammatory properties have qualified EOs early on for both, the causal and symptomatic therapy of a number of diseases, but also for prevention. Obtained from natural, mostly plant materials, EOs constitute a typical example of a multicomponent mixture (more than one constituent substances, MOCS) with up to several hundreds of individual compounds, which in a sophisticated composition make up the property of a particular complete EO. The integrative use of EOs as MOCS will play a major role in human and veterinary medicine now and in the future and is already widely used in some cases, e.g., in aromatherapy for the treatment of psychosomatic complaints, for inhalation in the treatment of respiratory diseases, or topically administered to manage adverse skin diseases. The diversity of molecules with different functionalities exhibits a broad range of multiple physical and chemical properties, which are the base of their multi-target activity as opposed to single isolated compounds. Whether and how such a broad-spectrum effect is reflected in natural mixtures and which kind of pharmacological potential they provide will be considered in the context of ONE Health in more detail in this review.

Protein kinase D: A therapeutic target in experimental alcoholic pancreatitis

BACKGROUND

Alcohol abuse, a main cause of pancreatitis, has been known to augment NF-κB activation and cell necrosis in pancreatitis. However, the underlying mechanisms are unclear. We recently reported that inhibition of protein kinase D (PKD) alleviated NF-κB activation and severity of experimental pancreatitis. Here we investigated whether PKD signaling mediated the modulatory effects of alcohol abuse on pathological responses in alcoholic pancreatitis.

METHODS

Alcoholic pancreatitis was provoked in two rodent models with pair-feeding control and ethanol-containing Lieber-DeCarli diets for up to 8 weeks followed by up to 7 hourly intraperitoneal injections of cerulein at 1 μg/kg (rats) or 3 μg/kg (mice). Effects of PKD inhibition by PKD inhibitors or genetic deletion of pancreatic PKD isoform (PKD3Δpanc mice) on alcoholic pancreatitis parameters were determined.

RESULTS

Ethanol administration amplified PKD signaling by promoting expression and activation of pancreatic PKD, resulted in augmented/promoted pancreatitis responses. Pharmacological inhibition of PKD or with PKD3Δpanc mice prevented the augmenting/sensitizing effect of ethanol on NF-κB activation and inflammatory responses, cell necrotic death and the severity of disease in alcoholic pancreatitis. PKD inhibition prevented alcohol-enhanced trypsinogen activation, mRNA expression of multiple inflammatory molecules, the receptor-interacting protein kinase activation, ATP depletion, and downregulation of pro-survival Bcl-2 protein in alcoholic pancreatitis. Furthermore, PKD inhibitor CID755673 or CRT0066101, administrated after the induction of pancreatitis in mouse and rat alcoholic pancreatitis models, significantly mitigated the severity of pancreatitis.

CONCLUSION

PKD mediates effect of alcohol abuse on pathological process of pancreatitis and constitutes a novel therapeutic target to treat this disease.

Effects of benzo[a]pyrene exposure on oxidative stress and apoptosis of gill cells of Chlamys farreri in vitro

As a common pollutant in marine environment, benzo[a]pyrene (B[a]P) has high toxicity to economic shellfish. In order to explore the mechanism of oxidative stress and apoptosis, the effects of 0, 2, 4, 8 μg/mL B[a]P on gill cells of C. farreri at 12 and 24 h were studied. The results showed that B[a]P decreased the activity of gill cells, increased the content of reactive oxygen species (ROS) and the expression of antioxidant defense genes. Besides, B[a]P could induce oxidative damage to nucleus and mitochondria. The gene expression and enzyme activity of apoptosis pathway related factors were changed. In conclusion, these results showed that B[a]P could cause oxidative stress and oxidative damage in gill cells of C. farreri, and mediate gill cell apoptosis through mitochondrial pathway and death receptor pathway. This article provides a theoretical basis for clarifying the molecular mechanism of PAHs-included oxidative stress and apoptosis in bivalves.

Guanabenz mitigates the neuropathological alterations and cell death in Alzheimer's disease

Alzheimer's disease (AD) pathology is characterized by cognitive impairment, increased acetylcholinesterase (AChE) activity, and impaired neuronal communication. Clinically, AChE inhibitors are being used to treat AD patients; however, these remain unable to prevent the disease progression. Therefore, further development of new therapeutic molecules is required having broad spectrum effects on AD-related various neurodegenerative events. Since repurposing is a quick mode to search the therapeutic molecules; henceforth, this study was conducted to evaluate the anti-Alzheimer activity of drug guanabenz which is already in use for the management of high blood pressure in clinics. The study was performed employing both cellular and rat models of AD along with donepezil as reference drug. Guanabenz treatment in both the experimental models showed significant protection against AD-specific behavioral and pathological indicators like AChE activity, tau phosphorylation, amyloid precursor protein, and memory retention. In conjunction, guanabenz also attenuated the AD-related oxidative stress, impaired mitochondrial functionality (MMP, cytochrome-c translocation, ATP level, and mitochondrial complex I activity), endoplasmic reticulum stress (GRP78, GADD153, cleaved caspase-12), neuronal apoptosis (Bcl-2, Bax, cleaved caspase-3), and DNA fragmentation. In conclusion, findings suggested the panoptic protective effect of guanabenz on disease-related multiple degenerative markers and signaling. Furthermore, clinical trial may shed light and expedite the availability of new therapeutic anti-Alzheimer's molecule for the wellbeing of AD patients.

Regression Modeling of the Antioxidant-to-Nephroprotective Relation Shows the Pivotal Role of Oxidative Stress in Cisplatin Nephrotoxicity

The clinical utility of the chemotherapeutic drug cisplatin is significantly limited by its nephrotoxicity, which is characterized by electrolytic disorders, glomerular filtration rate decline, and azotemia. These alterations are consequences of a primary tubulopathy causing injury to proximal and distal epithelial cells, and thus tubular dysfunction. Oxidative stress plays a role in cisplatin nephrotoxicity and cytotoxicity, but its relative contribution to overall toxicity remains unknown. We studied the relation between the degree of oxidative reduction (provided by antioxidant treatment) and the extent of nephrotoxicity amelioration (i.e., nephroprotection) by means of a regression analysis of studies in animal models. Our results indicate that a linear relation exists between these two parameters, and that this relation very nearly crosses the value of maximal nephroprotection at maximal antioxidant effect, suggesting that oxidative stress seems to be a pivotal and mandatory mechanism of cisplatin nephrotoxicity, and, hence, an interesting, rationale-based target for clinical use. Our model also serves to identify antioxidants with enhanced effectiveness by comparing their actual nephroprotective power with that predicted by their antioxidant effect. Among those, this study identified nanoceria, erythropoietin, and maltol as highly effective candidates affording more nephroprotection than expected from their antioxidant effect for prospective clinical development.

Oxidative and Nitrosative Stress in Age-Related Macular Degeneration: A Review of Their Role in Different Stages of Disease

Although the exact pathogenetic mechanisms leading to age-related macular degeneration (AMD) have not been clearly identified, oxidative damage in the retina and choroid due to an imbalance between local oxidants/anti-oxidant systems leading to chronic inflammation could represent the trigger event. Different in vitro and in vivo models have demonstrated the involvement of reactive oxygen species generated in a highly oxidative environment in the development of drusen and retinal pigment epithelium (RPE) changes in the initial pathologic processes of AMD; moreover, recent evidence has highlighted the possible association of oxidative stress and neovascular AMD. Nitric oxide (NO), which is known to play a key role in retinal physiological processes and in the regulation of choroidal blood flow, under pathologic conditions could lead to RPE/photoreceptor degeneration due to the generation of peroxynitrite, a potentially cytotoxic tyrosine-nitrating molecule. Furthermore, the altered expression of the different isoforms of NO synthases could be involved in choroidal microvascular changes leading to neovascularization. The purpose of this review was to investigate the different pathways activated by oxidative/nitrosative stress in the pathogenesis of AMD, focusing on the mechanisms leading to neovascularization and on the possible protective role of anti-vascular endothelial growth factor agents in this context.

Mitochondrial dynamics and mitophagy involved in MPA-capped CdTe quantum dots-induced toxicity in the human liver carcinoma (HepG2) cell line

Quantum dots (QDs) are nanoparticles of inorganic semiconductors and have great promise in various applications. Many studies have indicated that mitochondria are the main organelles for the distribution and toxic effects of QDs. However, the underlying mechanism of QDs interacting with mitochondria and affecting their function is unknown. Here, we report the mechanism of toxic effects of 3-mercaptopropionic acid (MPA)-capped CdTe QDs on mitochondria. Human liver carcinoma (HepG2) cells were exposed to 25, 50 and 100 μmol/L of MPA-capped CdTe QDs. The results indicated that MPA-capped CdTe QDs inhibited HepG2 cell proliferation and increased the extracellular release of LDH in a concentration-dependent manner. Furthermore, MPA-capped CdTe QDs caused reactive oxygen species (ROS) generation and cell damage through intrinsic apoptotic pathway. MPA-capped CdTe QDs can also lead to the destruction of mitochondrial cristae, elevation of intracellular Ca²⁺ levels, decreased mitochondrial transmembrane potential and ATP production. Finally, we showed that MPA-capped CdTe QDs inhibited mitochondrial fission, mitochondrial inner membrane fusion and mitophagy. Taken together, MPA-capped CdTe QDs induced significant mitochondrial dysfunction, which may be caused by imbalanced mitochondrial fission/fusion and mitophagy inhibition. These findings provide insights into the regulatory mechanisms involved in MPA-capped CdTe QDs-induced mitochondrial dysfunction.

Bio-guided isolation of anti-leishmanial natural products from Diospyros gracilescens L. (Ebenaceae)

BACKGROUND

Plants represent an intricate and innovative source for the discovery of novel therapeutic remedies for the management of infectious diseases. The current study aimed at discovering new inhibitors of Leishmania spp., using anti-leishmanial activity-guided investigation approach of extracts from Diospyros gracilescens Gürke (1911) (Ebenaceae), targeting the extracellular (promastigotes) and intracellular (amastigotes) forms of Leishmania donovani.

METHODS

The plant extracts were prepared by maceration using H20: EtOH (30:70, v/v) and further fractionated using a bio-guided approach. Different concentrations of D. gracilescens extracts, fractions and isolated compounds were tested in triplicate against L. donovani promastigotes and amastigotes in vitro. The antileishmanial potency and cytotoxicity on RAW 264.7 cells were determined using the resazurin colorimetric assay. The time kill kinetic profile of the most active sample was also investigated. The structures of all compounds were elucidated on the basis of extensive spectroscopic analyses, including 1D and 2D NMR, and HR-ESI-MS and by comparison of their data with those reported in the literature.

RESULTS

The hydroethanolic crude extract of D. gracilescens trunk showed the most potent antileishmanial activity (IC50 = 5.84 μg/mL). Further fractionation of this extract led to four (4) fractions of which, the hexane fraction showed the most potent activity (IC50 = 0.79 μg/mL), and seven (07) compounds that exhibited moderate potency (IC50 = 13.69-241.71 μM) against L. donovani. Compound 1-deoxyinositol (7) inhibited the promastigote and amastigote forms of L. donovani with IC50 values of 241.71 μM and 120 μM respectively and also showed the highest selectivity against L. donovani promastigotes (SI > 5.04). To the best of our knowledge, the antileishmanial activity of this compound is being reported here for the first time. The promising hexane fraction showed significant inhibition of parasites growth at different concentrations, but with no evidence of cidal effect over an exposure period of 120 h.

CONCLUSIONS

The results obtained indicated that the hydroethanolic extract from the D. gracilescens trunk and the derived hexane fraction have very potent inhibitory effect on cultivated promastigotes and amastigotes of L. donovani parasite. The isolated compounds showed a lesser extent of potency and selectivity. However, further structure-activity-relationship studies of 1-deoxyinositol could lead to more potent and selective hit derivatives of interest for detailed drug discovery program against visceral leishmaniasis.

Possible Mechanisms of Liver Injury Induced by Cadmium Sulfide Nanoparticles in Rat

Cadmium is primarily utilized in the construction of particles known as quantum dots. Hepatotoxicity caused by microparticles of cadmium is very well known; however, toxicity of nanoparticles of cadmium is not well understood. The present study describes the toxicity of cadmium sulfide nanoparticles (CdSNPs) in the liver of rat. Adult Wistar rats were administered CdSNPs (10 mg/kg) on alternate days for 45 days. Serum enzymes (ALT, AST, ALP), biomarkers of lipid peroxidation (MDA, H₂O₂, and NO), and metallothionein concentration were determined. Histopathological and TEM observations were also made to record morphological changes. CdSNPs (10 mg/kg) induced significant changes in the structure and function of liver. Values of serum enzymes and reactive species increased significantly in rats treated with CdSNPs in comparison to CdS-treated rats. Histopathological observations showed extensive parenchymal degeneration. Ultrastructural studies exhibited proliferation of endoplasmic reticulum, microsomes, and lysosomes. It is concluded that NP-membrane interaction leads to the generation of reactive species that alter membrane integrity and induce oxidative stress. These events may activate cell death pathways in hepatocytes.

Pancreas-specific deletion of protein kinase D attenuates inflammation, necrosis, and severity of acute pancreatitis

BACKGROUND

Protein kinase D (PKD) family, which includes PKD/PKD1, PKD2, and PKD3, has been increasingly implicated in the regulation of multiple cellular functions and human diseases. We recently reported that pharmacologic inhibition of PKD ameliorated the pathologic responses and severity of pancreatitis. However, to further investigate the importance of PKD family members in pancreatitis, it is necessary to explore the effects of pancreas-specific genetic inhibition of PKD isoform on pathology of pancreatitis.

METHODS

We generated a mouse model (referred as PKD3Δpanc mice) with pancreas-specific deletion of PKD3, the predominant PKD isoform in mouse pancreatic acinar cells, by crossing Pkd3flox/flox mice with Pdx1-Cre transgenic mice which express Cre recombinase under the control of the mouse Pdx1 promoter. Pancreas-specific deletion of the PKD3 gene and PKD3 protein was confirmed by PCR and Western blot analysis. Experimental pancreatitis was induced in PKD3Δpanc and Pkd3flox/flox (control mice) littermates by intraperitoneal injections of cerulein or L-arginine.

RESULTS

Compared to the control mice, PKD3Δpanc mice displayed significant attenuation in inflammation, necrosis, and severity of pancreatitis in both experimental models. PKD3Δpanc mice had markedly decreased NF-κB and trypsinogen activation, pancreatic mRNA expression of multiple inflammatory molecules, and the receptor-interacting protein kinase 1 (RIP1) activation in pancreatitis. PKD3Δpanc mice also had less pancreatic ATP depletion, increased pro-survival Bcl-2 family protein expression, and autophagy promotion.

CONCLUSION

With PKD3Δpanc mouse model, we further demonstrated that PKD plays a critical role in pathobiological process of pancreatitis and PKD constitutes a novel therapeutic target to treat this disorder.

Assessment of cytotoxic and antimicrobial activities of two components of Cymbopogon citratus essential oil

Background

There is a continuing search for compuounds to improve the chemical plaque inhibitory action of oral hygiene products. Although the antibacterial effects of chlorhexidine (CHX) and essential oils components, citral/myrcene, have been described, there is contradictory information regarding their cytotoxic effects in host tissues. This study aimed to evaluate the cytotoxic activity of the major components of the oil C. citratus, citral and myrcene on human periodontal ligament fibroblast (HPLF) cultures and their antimicrobial effect on different bacterial species present in supragingival biofilm.

Material and Methods

Cytotoxicity of the compounds to HPLF was determined by MTT assay. Antimicrobial activity was tested against reference strains of Enterococcus faecalis, Streptococcus mutans and Lactobacillus rhamnosus and for S. mutans clinical strains by broth microdilution assay. One-way analysis of variance (ANOVA) with Games-Howell post-hoc multiple comparison or unpaired t tests were used for inter- and intragroup comparisons.

Results

Overall, all of the compounds under study showed a cytotoxic effect to HPLF which varied in a dose-dependant manner. Whilst myrcene did not show bacteriostatic activity at tested concentrations, both citral and CHX exhibited bacteriostatic/bactericidal effects to all strains at specific concentrations, being CHX most effective to inhibit bacterial growth at lower concentrations than what observed for citral.

Conclusions

Based on these findings, it would possible to conclude that whereas myrcene might be ineffective to control bacterial growth, citral could have a promising antimicrobial activity against dental colonizers with low cytotoxicity, and may be useful for preventing the onset and progression of oral diseases. Key words:Antimicrobial activity, citral, cytotoxicity, chlorhexidine, myrcene.

The role of mitochondrial reactive oxygen species, NO and H2 S in ischaemia/reperfusion injury and cardioprotection

Redox signalling in mitochondria plays an important role in myocardial ischaemia/reperfusion (I/R) injury and in cardioprotection. Reactive oxygen and nitrogen species (ROS/RNS) modify cellular structures and functions by means of covalent changes in proteins including among others S‐nitros(yl)ation by nitric oxide (NO) and its derivatives, and S‐sulphydration by hydrogen sulphide (H₂S). Many enzymes are involved in the mitochondrial formation and handling of ROS, NO and H₂S under physiological and pathological conditions. In particular, the balance between formation and removal of reactive species is impaired during I/R favouring their accumulation. Therefore, various interventions aimed at decreasing mitochondrial ROS accumulation have been developed and have shown cardioprotective effects in experimental settings. However, ROS, NO and H₂S play also a role in endogenous cardioprotection, as in the case of ischaemic pre‐conditioning, so that preventing their increase might hamper self‐defence mechanisms. The aim of the present review was to provide a critical analysis of formation and role of reactive species, NO and H₂S in mitochondria, with a special emphasis on mechanisms of injury and protection that determine the fate of hearts subjected to I/R. The elucidation of the signalling pathways of ROS, NO and H₂S is likely to reveal novel molecular targets for cardioprotection that could be modulated by pharmacological agents to prevent I/R injury.

CEES-induced ROS accumulation regulates mitochondrial complications and inflammatory response in keratinocytes

Reactive oxygen species (ROS) is mainly produced as a by-product from electron transport chain (ETC) of mitochondria and effectively eliminated by cellular antioxidants. However, 2-chloroethyl ethyl sulfide (CEES) exposure to keratinocytes declined antioxidant capacity and increased accumulation of ROS triggered alteration of mitochondrial activity and apoptosis is lacking. Our findings demonstrated that the electron leakage from the impaired ETC, leading to the accumulation of ROS was gradually elevating with increasing concentration of CEES exposure, which decline the activity of superoxide dismutase (SOD), manganese SOD (MnSOD) and copper-zinc SOD (Cu-ZnSOD) in keratinocytes. Further, excess accumulation of ROS, decreased the mitochondrial membrane potential (ΔΨm) and increased the mitochondrial mass with increasing dose of CEES. CEES exposure provoked the decrease in expression of transcription factor A mitochondrial (TFAM), augmented mitochondrial DNA (mtDNA) damage and altered the mtDNA-encoded oxidative phosphorylation (OXPHOS) subunits. Moreover, fragmented mtDNA translocated into cytosol, where it activated cGAS-STING and interferon regulatory factor3 (IRF3), coinciding with the increased expression of inflammatory mediators and alteration of cell-to-cell communication markers. Pre-treatment of N-acetyl-l-cysteine (NAC) or L-Nω-nitroarginine methyl ester (NAME), hydralazine hydrochloride (Hyd·HCl) or ERK1/2 or phosphoinositide3-kinase (PI3-K)/Akt inhibitors in keratinocyte cells significantly restored the CEES effect. Our findings suggest that CEES-induced mitochondrial ROS production and accumulation leads to mitochondrial dysfunction and inflammatory response in keratinocytes. However, treatment of antioxidants or ERK1/2 or PI3-K/Akt inhibitors is a novel therapeutic option for the keratinocytes complication.

High glucose augments ROS generation regulates mitochondrial dysfunction and apoptosis via stress signalling cascades in keratinocytes

Mitochondria are fascinating structures of the cellular compartments that generate energy to run the cells. However, inherent disorders of mitochondria due to diabetes can cause major disruption of metabolism that produces huge amount of reactive oxygen species (ROS). Here we study the elevated level of ROS provoked by high glucose (HG) environment triggered mitochondrial dysfunction, inflammatory response and apoptosis via stress signalling pathway in keratinocytes. Our results demonstrated that elevated glucose level in keratinoctes, increase the accumulations of ROS and decrease in cellular antioxidant capacities. Moreover, excess production of ROS was associated with mitochondrial dysfunction, characterized by loss of mitochondrial membrane potential (ΔΨm), increase in mitochondrial mass, alteration of mitochondrial respiratory complexes, cytochrome c (Cyt c) release, decrease in mitochondrial transcription factor A (TFAM) and increase in mitochondrial DNA (mtDNA) fragmentation. Damaged mtDNA escaped into the cytosol, where it engaged the activation of ERK1/2, PI3K/Akt, tuberin and mTOR via cGAS-STING leading to IRF3 activation. Pre-treatment of pharmacological inhibitors, ERK1/2 or PI3K/Akt suppressed the IRF3 activation. Furthermore, our results demonstrated that activation of IRF3 in HG environment coinciding with increased expression of inflammatory mediators. Excess production of ROS interfered with decreased in cell viability, increased lysosomal content and expression of FoxOs, leading to cell cycle deregulation and apoptosis. Pre-treatment of N-acetyl-l-cysteine (NAC) significantly reduced the HG-induced cell cycle deregulation and apoptosis in keratinocytes. In conclusion, increased oxidative stress underlies the decrease in antioxidant capacities and mitochondrial dysfunction in HG environment correlate with inflammation response and apoptosis via ERK1/2-PI3K/Akt-IRF3 pathway in keratinoctes.

Comparison of antifungal activity of essential oils from different plants against three fungi

The antifungal activity of plant essential oils (EOs) extracted by steam distillation from seven different species (Cinnamon, Anise, Clove, Citronella, Peppermint, Pepper, and Camphor) was investigated. Three common fungi were isolated from moldy wheat bread, which were identified as Aspergillus niger, A. oryzae, and A. ochraceus. The antifungal activity of anise, peppermint, clove, cinnamon, pepper, citronella, and camphor EOs from seven different spices was confirmed by agar diffusion assay against three fungi. Among all the EOs, the cinnamon EO showed the highest antifungal activity for all the fungi strains with the largest inhibition zone at the concentration of 800 mg/mL and lowest MIC ranging from 0.0625 to 0.125 mg/mL, followed by clove EO. The remaining EOs exerted moderate inhibitory effects. Further research indicated the substantial inhibitory activities of cinnamon and clove EOs on mycelial growth and spore germination in a dose-dependent manner. Further, the in vivo inhibitory activity of selected EOs on naturally infected bread demonstrated that cinnamon and clove EOs can as be used as natural antifungal agents.

Effects of siRNA-Mediated Knockdown of GSK3β on Retinal Ganglion Cell Survival and Neurite/Axon Growth

There are contradictory reports on the role of the serine/threonine kinase isoform glycogen synthase kinase-3β (GSK3β) after injury to the central nervous system (CNS). Some report that GSK3 activity promotes axonal growth or myelin disinhibition, whilst others report that GSK3 activity prevents axon regeneration. In this study, we sought to clarify if suppression of GSK3β alone and in combination with the cellular-stress-induced factor RTP801 (also known as REDD1: regulated in development and DNA damage response protein), using translationally relevant siRNAs, promotes retinal ganglion cell (RGC) survival and neurite outgrowth/axon regeneration. Adult mixed retinal cell cultures, prepared from rats at five days after optic nerve crush (ONC) to activate retinal glia, were treated with siRNA to GSK3β (siGSK3β) alone or in combination with siRTP801 and RGC survival and neurite outgrowth were quantified in the presence and absence of Rapamycin or inhibitory Nogo-A peptides. In in vivo experiments, either siGSK3β alone or in combination with siRTP801 were intravitreally injected every eight days after ONC and RGC survival and axon regeneration was assessed at 24 days. Optimal doses of siGSK3β alone promoted significant RGC survival, increasing the number of RGC with neurites without affecting neurite length, an effect that was sensitive to Rapamycin. In addition, knockdown of GSK3β overcame Nogo-A-mediated neurite growth inhibition. Knockdown of GSK3β after ONC in vivo enhanced RGC survival but not axon number or length, without potentiating glial activation. Knockdown of RTP801 increased both RGC survival and axon regeneration, whilst the combined knockdown of GSK3β and RTP801 significantly increased RGC survival, neurite outgrowth, and axon regeneration over and above that observed for siGSK3β or siRTP801 alone. These results suggest that GSK3β suppression promotes RGC survival and axon initiation whilst, when in combination with RTP801, it also enhanced disinhibited axon elongation.

Antileishmanial activity of Melampodium divaricatum and Casearia sylvestris essential oils on Leishmania amazonensis

Leishmaniasis is a disease that affects millions of people and it is an important public health problem. The drugs currently used for the treatment of leishmaniasis present undesirable side effects and low efficacy. In this study, we evaluated the in vitro activity of Melampodium divaricatum (MD-EO) and Casearia sylvestris (CS-EO) essential oils (EO) against promastigote and amastigote forms of Leishmania amazonensis. Sesquiterpenes E-caryophyllene (56.0%), germacrene D (12.7%) and bicyclogermacrene (9.2%) were identified as the main components of MD-EO, whereas E-caryophyllene (22.2%), germacrene D (19.6%) and bicyclogermacrene (12.2%) were the main constituents of CS-EO. CS-EO and E-caryophyllene were active against promastigote forms of L. amazonensis (IC50 24.2, 29.8 and 49.9 µg/mL, respectively). However, MD-EO, CS-EO and E-caryophyllene were more active against amastigote forms, with IC50 values of 10.7, 14.0, and 10.7 µg/mL, respectively. E-caryophyllene presented lower cytotoxicity against macrophages J774-A1 (CC50 of 62.1 µg/mL) than the EO. The EOs and E-caryophyllene should be further studied for the development of new antileishmanial drugs.

Subcellular targets of zinc oxide nanoparticles during the aging process: role of cross-talk between mitochondrial dysfunction and endoplasmic reticulum stress in the genotoxic response

Zinc oxide nanoparticles (ZnO NPs) are being produced abundantly and applied increasingly in various fields. The special physicochemical characteristics of ZnO NPs makes them incline to undergo physicochemical transformation over time (aging), which modify their bioavailability and toxicity. However, the subcellular targets and the underlying molecular mechanisms involved in the genotoxicity induced by ZnO NPs during aging process are still unknown. The present study found that the acute cytotoxic effects of fresh ZnO NPs was largely regulated by mitochondria-dependent apoptosis, which the level of cleaved Caspase-3 and mitochondria damage were significantly higher than that of 60 day-aged ZnO NPs. In contrast, aged ZnO NPs induced more reactive oxygen species (ROS) production and endoplasmic reticulum (ER) stress marker protein (BIP/GRP78) expression and their genotoxicity could be dramatically suppressed by either ROS scavengers (DMSO, CAT and NaN3) or ER stress inhibitor (4-PBA). Using mitochondrial-DNA deficient (ρ0) AL cells, we further found that ER stress induced by aged ZnO NPs was triggered by ROS generated from mitochondria, which eventually mediated the gentoxicity of aged NPs. Our data provided novel information on better understanding the contribution of subcellular targets to the genotoxic response of ZnO NPs during the aging process.

Phosphorylated Glycogen Synthase Kinase-3β (GSK-3β) Improves Cognition in Rats with Diabetes-Associated Cognitive Decline

Background

The serine/threonine kinase glycogen synthase kinase-3β (GSK-3β) is involved in a broad range of cellular processes, including cell proliferation, apoptosis, and inflammation. GSK-3β has been considered to play an important role in the pathogenesis of T2DM and AD, which is activated in both the periphery and central nervous system. However, the upstream and downstream factors and the underlying regulatory mechanisms of GSK-3β in T2DM and AD are unclear.

Material/Methods

Here, we investigated the production of cytochrome C, Caspase-3, and Caspase-9 in in the hippocampus of DM rats and clarify the role of GSK-3β in these processes. Streptozotocin (STZ)-induced DM rats presented increased GSK-3β activity.

Results

We found that cytochrome C, Caspase-3, and Caspase-9 were overproduced in the hippocampus. Furthermore, the cytochrome C, Caspase-3, and Caspase-9 levels were restored after GSK-3β inhibitors Licl treatment.

Conclusions

Our results show that GSK-3β regulates the production of cytochrome C, Caspase-3, and Caspase-9 in STZ-induced rat brain and may therefore contribute to DM-caused cognitive dysfunction via inhibition of neural cell apoptosis.

Effects of Lysosomal-Mitochondrial Apoptotic Pathway on Tenderness in Post-Mortem Bovine Longissimus Muscle

The objective of this study was to investigate the mechanism underlying lysosome-mediated apoptosis, the cross-talk between the lysosomes and mitochondria, and the effect of the pathway on bovine longissimus muscle tenderness during 7 d post-mortem aging through the observation and analysis of longissimus dorsi (LD) muscles of six crossbred cattle. Results showed that an elevated reactive oxygen species level ( P < 0.05) can damage lysosomal membrane stability ( P < 0.05) through accumulating redox-active iron of bovine muscle during post-mortem aging. In addition, the activities of cathepsins B and D increased with post-mortem aging ( P < 0.05). Moreover, cathepsin B and D activated Bid and Bax in the mitochondria ( P < 0.05). Activated Bid and Bax triggered mitochondrial membrane permeability ( P < 0.05) and further activated caspase-9 and caspase-3 ( P < 0.05), leading to apoptosis. Ultimately, the tenderness of bovine muscle was improved during post-mortem aging ( P < 0.05). Importantly, cathepsin D plays a crucial role in the lysosomal-mitochondrial apoptotic pathway and tenderness in post-mortem muscle. These findings provide new insights into the apoptotic pathway of bovine muscle during post-mortem aging.

The release of cytochrome c and the regulation of the programmed cell death progress in the endosperm of winter wheat (Triticum aestivum L.) under waterlogging

It has been shown in mammalian systems that the mitochondria can play a key role in the regulation of apoptosis by releasing intermembrane proteins (such as cytochrome c) into the cytosol. Cytochrome c released from the mitochondria to the cytoplasm activates proteolytic enzyme cascades, leading to specific nuclear DNA degradation and cell death. This pathway is considered to be one of the important regulatory mechanisms of apoptosis. Previous studies have shown that endosperm cell development in wheat undergoes specialized programmed cell death (PCD) and that waterlogging stress accelerates the PCD process; however, little is known regarding the associated molecular mechanism. In this study, changes in mitochondrial structure, the release of cytochrome c, and gene expression were studied in the endosperm cells of the wheat (Triticum aestivum L.) cultivar "huamai 8" during PCD under different waterlogging durations. The results showed that waterlogging aggravated the degradation of mitochondrial structure, increased the mitochondrial permeability transition (MPT), and decreased mitochondrial transmembrane potential (ΔΨm), resulting in the advancement of the endosperm PCD process. In situ localization and western blotting of cytochrome c indicated that with the development of the endosperm cell, cytochrome c was gradually released from the mitochondria to the cytoplasm, and waterlogging stress led to an advancement and increase in the release of cytochrome c. In addition, waterlogging stress resulted in the increased expression of the voltage-dependent anion channel (VDAC) and adenine nucleotide translocator (ANT), suggesting that the mitochondrial permeability transition pore (MPTP) may be involved in endosperm PCD under waterlogging stress. The MPTP inhibitor cyclosporine A effectively suppressed cell death and cytochrome c release during wheat endosperm PCD. Our results indicate that the mitochondria play important roles in the PCD of endosperm cells and that the increase in mitochondrial damage and corresponding release of cytochrome c may be one of the major causes of endosperm PCD advancement under waterlogging.

Antioxidant, Antifungal, Antibiofilm, and Cytotoxic Activities of Mentha spp. Essential Oils

Since ancient times, plants have been used to preserve food, or for their health properties. Essential oils are complex mixtures of volatile compounds that are obtained from botanical material, specifically from aromatic plants. Lamiaceae is one of the most important families in the production of essential oils, as it has both antioxidant and antimicrobial properties. The essential oils of Mentha (the Lamiaceae family) have been extensively studied for their biological actions. In this review, we report the antioxidant, antifungal, antibiofilm, and cytotoxic properties of Mentha spp. essential oils. The first objective is to provide comprehensive information about the use of essential oils in the treatment of fungal infections, or as antioxidants and integrative anticancer therapy. The second is to explore the evidence supporting its effectiveness in treating diseases without causing any serious adverse reactions.

Characterization of Nanospheres Containing Zanthoxylum riedelianum Fruit Essential Oil and Their Insecticidal and Deterrent Activities against Bemisia tabaci (Hemiptera: Aleyrodidae)

The aim of our study was to produce and characterize poly-ε-caprolactone (PCL) nanospheres containing essential oils from Zanthoxylum riedelianum fruit and to evaluate their stability gains as well as their insecticidal and deterrent activities against whitefly (Bemisia tabaci). The PCL nanospheres exhibited a homogeneous spherical morphology, with particle diameters between 106.7 nm and 129.2 nm, pH of approximately 6, zeta potential (ZP) lower than −19.0 mV and encapsulation efficiency higher than 98%. Only 43% of the nanoencapsulated essential oil (NSEO) was degraded in response to ultraviolet light, whereas the essential oil (EO) degraded by 76% over the same period. In a free-choice test, the NSEO and EO reduced the number of whitefly eggs by approximately 70%. NSEO and EO at 1.5% killed 82.87% and 91.23% of 2nd-instar nymphs of whitefly, respectively. Although NSEO displayed lower insecticidal activity, it offers a greater advantage over the free EO, due to protection conferred by polymer against photodegradation. Therefore, its usage may optimize the maintenance of essential oils in the field through photoprotection and controlled release. Our results suggest that the EO of Z. riedelianum fruit can be used for B. tabaci management strategy; nevertheless, the benefits of NSEO require further evaluation at the field level.

Toxicological Aspects of the Essential Oil from Cinnamodendron dinisii

The objective of this study was to determine cytotoxic activity, hemolytic activity, and to evaluate the ability of the essential oil from Cinnamodendron dinisii to induce DNA fragmentation of human lymphocytes. The essential oil was obtained by hydrodistillation. Cytotoxic activity was determined by the MTT method. Hemolytic activity was evaluated by spectrophotometric quantification of hemoglobin released by erythrocytes. Damage to lymphocyte DNA molecules was assessed by the Comet assay. The essential oil under study showed high cytotoxic activity on Vero cells (CC₅₀ = 35.72 μg/mL) and induced hemolysis in both hematocrits, besides leading to the oxidation of hemoglobin released. The genotoxic activity of C. dinisii essential oil was also observed, which induced concentration-dependent DNA fragmentation of human lymphocytes and, at 50 μL/mL, it was more active than the positive control. The essential oil from C. dinisii has a toxic action, suggesting a special attention in the application of this oil to health-promoting activities; however, among its components, there are molecules with potential for future application in anticancer therapies.

Selenocysteine inhibits human osteosarcoma cells growth through triggering mitochondrial dysfunction and ROS-mediated p53 phosphorylation

Osteosarcoma represents the most common primary malignant bone tumor in children and adolescents, which shows severe resistance toward standard chemotherapy because of high invasive capacity and growing incidence. Selenocysteine (SeC) is a naturally available Se-containing amino acid that displays splendid anticancer activities against several human tumors. However, little information about SeC-induced growth inhibition against human osteosarcoma is available. Herein, the anticancer efficiency and underlying mechanism of SeC against human osteosarcoma were evaluated in vitro and in vivo. The results revealed that SeC significantly inhibited MG-63 human osteosarcoma cells growth in vitro through induction of S-phase arrest and apoptosis, as reflected by the decrease of cyclin A and CDK-2, PARP cleavage, and caspases activation. SeC treatment also resulted in mitochondrial dysfunction through affecting Bcl-2 family expression. Moreover, SeC triggered p53 phosphorylation by inducing reactive oxygen species (ROS) overproduction. ROS inhibition effectively blocked SeC-induced cytotoxicity and p53 phosphorylation. Importantly, MG-63 human osteosarcoma xenograft growth in nude mice was significantly suppressed in vivo through triggering apoptosis and p53 phosphorylation. These results indicated that SeC had the potential to inhibit human osteosarcoma cells growth in vitro and in vivo through triggering mitochondrial dysfunction and ROS-mediated p53 phosphorylation, which validated the potential application of Se-containing compounds in treatment of human osteosarcoma.

Cytotoxic and anti-kinetoplastid potential of the essential oil of Alpinia speciosa K. Schum

Alpinia speciosa K. Schum, known as colônia (colony), is native to tropical Asia and found in parts of tropical America. Its leaves are used to wrap food, rhizomes for food preparation and seeds for health maintenance, and have been widely used by the population as a diuretic, antihypertensive, antiulcerogenic and sedative. The present study aimed to verify the leishmanicidal and trypanocidal potential, as well as the cytotoxicity, of the A. speciosa essential oil, in vitro. A. speciosa presented 1,8-cineole (28.46%), camphor (17.10%) and sabinene (9.95%) as major constituents. The cytotoxic activity of the essential oil presented a low value, while the antipromastigote and antiepimastigote activity presented values considered clinically relevant, since it had an action below 500 μg/mL. In relation to this study, it can be concluded that this is a pioneer in the potential of the A. speciosa essential oil and in the use against the parasites Trypanosoma cruzi Chagas and Leishmania brasiliensis Vianna, having its importance also rooted in this fact. Still in accordance with the results, A. speciosa was effective because it presented values of clinical relevance and low toxicity. It was also observed that the chemical constitution of the above identified compounds with remarkable antiparasitic activities.

Lonicera japonica Thunb. Induces caspase-dependent apoptosis through death receptors and suppression of AKT in U937 human leukemic cells

Decoctions obtained from the dried flowers of Lonicera japonica Thunb. (Indongcho) have been utilized in folk remedies against inflammatory diseases. Recently, many agents that have used for inflammatory diseases are showing anticancer effects. Here, we have isolated polyphenols extracted from lyophilized Lonicera japonica Thunb (PELJ) and investigated the anticancer effects of PELJ on U937 cells. Here, we demonstrated that PELJ induced apoptosis by upregulation of DR4 and Fas, and further it is augmented by suppression of XIAP. In addition, The PELJ-induced apoptosis is at least in part by blocking PI3K/Akt pathway. These findings suggest that PELJ may provide evidence of anticancer activities on U937 cells. Further study for detailed mechanism and the effects on animal models is warranted to determine whether PELJ provide more conclusive evidence that PELJ which may provide a beneficial effect for treating cancer.

Glucosylceramide synthase regulates the proliferation and apoptosis of liver cells in vitro by Bcl‑2/Bax pathway

Our previous study found that glucosylceramide, a type of sphingolipids, was associated with liver inflammation and fibrosis. Glucosylceramide is generated by glucosylceramide synthase (GCS), which is encoded by the UDP‑glucose ceramide glucosyltransferase (UGCG) gene. GCS is a key enzyme to regulate the physiological activity of cells. However, the role of GCS in hepatic cells remains unclear. The aim of the present study was to explore the mechanism of GCS in the proliferation and apoptosis of liver cells. Following the interference of expression of GCS in vitro by UGCG small interfering (si)RNA, the MTT method was performed to detect the proliferation of HL‑7702 hepatocytes, and ELISA was used to determine the concentration of tumor necrosis factor (TNF) α and cytochrome c in the supernatant of culture system. Fluorescence microscopy was used to observe the apoptosis of liver cells stained by Annexin V‑fluorescein isothiocyanate/propidium iodide. Reverse transcription‑quantitative polymerase chain reaction was used to detect the gene expression apoptosis regulator Bcl‑2 (Bcl‑2), apoptosis regulator Bax (Bax) and caspase-3. Western blot analysis was used to detect the expression of caspase-3 protein in the liver cells. Following treatment with UGCG siRNA for 24 h, the proliferation of HL‑7702 hepatocytes was significantly inhibited when compared with the transfection reagent group. Furthermore, the early and advanced apoptosis of liver cells showed an increasing trend. Additionally, concentrations of TNF α and cytochrome c showed no significant difference between the UGCG siRNA and transfection reagent groups. Compared with the transfection reagent group, Bcl‑2 mRNA expression decreased, and Bax and caspase-3 mRNA expression increased in the UGCG siRNA transfection group. The protein expression level of caspase-3 showed increased in hepatocytes following the treatment with UGCG siRNA. In conclusion, the metabolic changes of sphingolipids caused by the lack of GCS may be involved in the proliferation and apoptosis of liver cells through the Bcl‑2/Bax signaling pathway.

Prostaglandin F2α synthase in Trypanosoma cruzi plays critical roles in oxidative stress and susceptibility to benznidazole

Nifurtimox (Nfx) and benznidazole (Bz) are the current drugs used for the treatment of Chagas disease. The mechanisms of action and resistance to these drugs in this parasite are poorly known. Prostaglandin F2α synthase or old yellow enzyme (OYE), an NAD(P)H flavin oxidoreductase, has been involved in the activation pathway of other trypanocidal drugs such as Nfx; however, its role in the mechanism of action of Bz is uncertain. In this paper, we performed some experiments of functional genomics in the parasite Trypanosoma cruzi with the aim to test the role of this gene in the resistance to Bz. For this, we overexpressed this gene in sensitive parasites and evaluated the resistance level to the drug and other chemical compounds such as hydrogen peroxide, methyl methanesulfonate and gamma radiation. Interestingly, parasites overexpressing OYE showed alteration of enzymes associated with oxidative stress protection such as superoxide dismutase A and trypanothione reductase. Furthermore, transfected parasites were more sensitive to drugs, genetic damage and oxidative stress. Additionally, transfected parasites were less infective than wild-type parasites and they showed higher alteration in mitochondrial membrane potential and cell cycle after treatment with Bz. These results supply essential information to help further the understanding of the mechanism of action of Bz in T. cruzi.

Use of Cymbopogon citratus essential oil in food preservation: Recent advances and future perspectives

The economic burdens and health implications of food spoilage are increasing. Contamination of food sources by fungi, bacteria, yeast, nematodes, insects, and rodents remains a major public health concern. Research has focused on developing safer natural products and innovations to meet consumers' acceptance as alternatives to synthetic food preservatives. Many recent novel preservative techniques and applications of both natural and synthetic origin continue to proliferate in food and chemical industries. In particular, some essential oils of plant origin are potent food preservatives and are thus attractive alternatives to synthetic preservatives. This paper provides an overview of recent advances and future prospects in assessing the efficacy of the use of Cymbopogon citratus (lemongrass) essential oil in food preservation. The possible mechanisms of action and toxicological profile as well as evidence for or against the use of this essential oil as an alternative to synthetic food preservatives in domestic and industrial applications are discussed.