Novel Dihydrocoumarins Induced by Radiolysis as Potent Tyrosinase Inhibitors.

A representative naturally occurring coumarin, 4-methylumbelliferone (5), was exposed to 50 kGy of gamma ray, resulting in four newly generated dihydrocoumarin products 1-4 induced by the gamma irradiation. The structures of these new products were elucidated by interpretation of spectroscopic data (NMR, MS, [α]D, and UV). The unusual bisdihydrocoumarin 4 exhibited improved tyrosinase inhibitory capacity toward mushroom tyrosinase with IC50 values of 19.8 ± 0.5 µM as compared to the original 4-methylumbelliferone (5). A kinetic analysis also exhibited that the potent metabolite 4 had non-competitive modes of action. Linkage of the hydroxymethyl group in the C-3 and C-4 positions on the lactone ring probably enhances the tyrosinase inhibitory effect of 4-methylumbelliferone (5). Thus, the novel coumarin analog 4 is an interesting new class of tyrosinase inhibitory candidates that requires further examination.

The Next Generation COVID-19 Antiviral; Niclosamide-Based Inorganic Nanohybrid System Kills SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic is a serious global threat with surging new variants of concern. Although global vaccinations have slowed the pandemic, their longevity is still unknown. Therefore, new orally administrable antiviral agents are highly demanded. Among various repurposed drugs, niclosamide (NIC) is the most potential one for various viral diseases such as COVID-19, SARS (severe acute respiratory syndrome), MERS (middle east respiratory syndrome), influenza, RSV (respiratory syncytial virus), etc. Since NIC cannot be effectively absorbed, a required plasma concentration for antiviral potency is hard to maintain, thereby restricting its entry into the infected cells. Such a 60-year-old bioavailability challenging issue has been overcome by engineering with MgO and hydroxypropyl methylcellulose (HPMC), forming hydrophilic NIC-MgO-HPMC, with improved intestinal permeability without altering NIC metabolism as confirmed by parallel artificial membrane permeability assay. The inhibitory effect on SARS-CoV-2  replication is confirmed in the Syrian hamster model to reduce lung injury. Clinical studies reveal that the bioavailability of NIC hybrid drug can go 4 times higher than the intact NIC. The phase II clinical trial shows a dose-dependent bioavailability of NIC from hybrid drug  suggesting its potential applicability as a game changer in achieving the much-anticipated endemic phase.

Myristica fragrans Extract Inhibits Platelet Desialylation and Activation to Ameliorate Sepsis-Associated Thrombocytopenia in a Murine CLP-Induced Sepsis Model.

Sepsis, characterized by an uncontrolled host inflammatory response to infections, remains a leading cause of death in critically ill patients worldwide. Sepsis-associated thrombocytopenia (SAT), a common disease in patients with sepsis, is an indicator of disease severity. Therefore, alleviating SAT is an important aspect of sepsis treatment; however, platelet transfusion is the only available treatment strategy for SAT. The pathogenesis of SAT involves increased platelet desialylation and activation. In this study, we investigated the effects of Myristica fragrans ethanol extract (MF) on sepsis and SAT. Desialylation and activation of platelets treated with sialidase and adenosine diphosphate (platelet agonist) were assessed using flow cytometry. The extract inhibited platelet desialylation and activation via inhibiting bacterial sialidase activity in washed platelets. Moreover, MF improved survival and reduced organ damage and inflammation in a mouse model of cecal ligation and puncture (CLP)-induced sepsis. It also prevented platelet desialylation and activation via inhibiting circulating sialidase activity, while maintaining platelet count. Inhibition of platelet desialylation reduces hepatic Ashwell-Morell receptor-mediated platelet clearance, thereby reducing hepatic JAK2/STAT3 phosphorylation and thrombopoietin mRNA expression. This study lays a foundation for the development of plant-derived therapeutics for sepsis and SAT and provides insights into sialidase-inhibition-based sepsis treatment strategies.

WGA-M001, a Mixture of Total Extracts of Tagetes erecta and Ocimum basilicum, Synergistically Alleviates Cartilage Destruction by Inhibiting ERK and NF-κB Signaling.

Tagetes erecta and Ocimum basilicum are medicinal plants that exhibit anti-inflammatory effects against various diseases. However, their individual and combined effects on osteoarthritis (OA) are unknown. Herein, we aimed to demonstrate the effects of T. erecta, O. basilicum, and their mixture, WGA-M001, on OA pathogenesis. The administration of total extracts of T. erecta and O. basilicum reduced cartilage degradation and inflammation without causing cytotoxicity. Although WGA-M001 contained lower concentrations of the individual extracts, it strongly inhibited the expression of pathogenic factors. In vivo OA studies also supported that WGA-M001 had protective effects against cartilage destruction at lower doses than those of T. erecta and O. basilicum. Moreover, its effects were stronger than those observed using Boswellia and Perna canaliculus. WGA-M001 effectively inhibited the interleukin (IL)-1ß-induced nuclear factor kappa-light-chain-enhancer of the activated B cell (NF-κB) pathway and ERK phosphorylation. Furthermore, RNA-sequence analysis also showed that WGA-M001 decreased the expression of genes related to the IL-1ß-induced NF-κB and ERK signaling pathways. Therefore, WGA-M001 is more effective than the single total extracts of T. erecta and O. basilicum in attenuating OA progression by regulating ERK and NF-κB signaling. Our results open new possibilities for WGA-M001 as a potential therapeutic agent for OA treatment.

Genotoxicity evaluation of self-assembled-micelle inhibitory RNA-targeting amphiregulin (SAMiRNA-AREG), a novel siRNA nanoparticle for the treatment of fibrotic disease.

The self-assembled-micelle inhibitory RNA-targeting amphiregulin (SAMiRNA-AREG) is a novel small-interfering RNA (siRNA) nanoparticle that is used for treatment of pulmonary fibrosis. We investigated the potential genotoxicity of SAMiRNA-AREG based on the guidelines published by the Organization for Economic Cooperation and Development. In the bacterial reverse mutation assay (Ames test), SAMiRNA-AREG did not induce mutations in Salmonella typhimurium TA100, TA1535, TA98, and TA1537 and Escherichia coli WP2uvrA at concentrations of up to 3000 µg/plate with or without metabolic activation. The SAMiRNA-AREG (concentrations up to 500 µg/mL) did not induce chromosomal aberrations in cultured Chinese hamster lung cells with or without metabolic activation. In the in vivo mouse bone marrow micronucleus assay, the SAMiRNA-AREG (concentrations up to 300 mg/kg body weight) did not affect the proportions of polychromatic erythrocytes and total erythrocytes, nor did it increase the number of micronucleated polychromatic erythrocytes in ICR mice. Collectively, these results suggest that SAMiRNA-AREG is safe with regard to genotoxicity such as mutagenesis or clastogenesis under the present experimental conditions. These results might support the safety of SAMiRNA-AREG as a potential therapeutic agent for pharmaceutical development.

Inhibitory effects of aloin on lipopolysaccharide-induced severe inflammatory responses.

Aloin is the main anthraquinone glycoside from Aloe species. Here, the anti-inflammatory functions of aloin against lipopolysaccharide (LPS)-induced vascular inflammatory responses were tested in endothelial cells or mice such as permeability, expressions of cell adhesion molecule (CAM), migration of leukocytes and lethality. Aloin was found to inhibit LPS-induced barrier disruption, CAM expression, and neutrophil adhesion/transendothelial migration to endothelial cells. Furthermore, aloin inhibited LPS-induced hyperpermeability, leukocyte migration, lethality in vivo. These results suggest that aloin has anti-inflammatory activities against LPS, thereby supporting its usefulness as a treatment for vascular inflammatory.

Antioxidant and Skin Whitening Activities of Sub- and Super-Critical Water Treated Rutin.

We focused on the functional components, antioxidant activity, skin-whitening, and anti-wrinkle properties of subcritical and supercritical water (SCW)-treated rutin. Rutin treatments were performed at the following temperature and pressure conditions: 200 °C/15 bar, 300 °C/100 bar, and 400 °C/250 bar. ABTS and DPPH radical scavenging activities and reducing power presented their highest values (1193.72 mg AAE/g, 728.73 mg AAE/g, and 0.65, respectively) at 300 °C/100 bar. The tyrosinase inhibitory activity of SCW-treated rutin was 21.72-60.05% at 1 mg/mL. The ethyl acetate fraction showed 14.91% melanin inhibitory activity at a concentration of 10 µg/mL compared to the α-MSH treatment group. The protein expression inhibition rates of MITF, tyrosinase, TRP-1, and TRP-2 in the ethyl acetate fractions were 14.05%, 72%, 93.05%, and 53.44%, respectively, at a concentration of 10 µg/mL, compared to the control. These results indicate that SCW treatment could be used to develop cosmetic materials and functional food with physiological activity, and that SCW-treated rutin can be used as a skin-whitening cosmetic material.

Four-Week Repeated Intravenous Dose Toxicity of Self-Assembled-Micelle Inhibitory RNA-Targeting Amphiregulin in Mice.

The present study investigated the potential subchronic toxicity of self-assembled-micelle inhibitory RNA-targeting amphiregulin (SAMiRNA-AREG) in mice. The test reagent was administered once-daily by intravenous injection for 4 weeks at 0, 100, 200, or 300 mg/kg/day doses. Additional recovery groups (vehicle control and high dose groups) were observed for a 2-week recovery period. During the test period, mortality, clinical signs, body weight, food consumption, ophthalmology, urinalysis, hematology, serum biochemistry, gross pathology, organ weight, and histopathology were examined. An increase in the percentages of basophil and large unstained cells was observed in the 200 and 300 mg/kg/day groups of both sexes. In addition, the absolute and relative weights of the spleen were higher in males given 300 mg/kg/day relative to the concurrent controls. However, these findings were considered of no toxicological significance because the changes were minimal, were not accompanied by other relevant results (eg, correlating microscopic changes), and were not observed at the end of the 2-week recovery period indicating recovery of the findings. Based on the results, SAMiRNA-AREG did not cause treatment-related adverse effects at dose levels of up to 300 mg/kg/day in mice after 4-week repeated intravenous doses. Under these conditions, the no-observed-adverse-effect level of the SAMiRNA-AREG was ≥300 mg/kg/day in both sexes and no target organs were identified.

Inhibitory effects of aloin on TGFBIp-mediated septic responses.

Aloin is the major anthraquinone glycoside obtained from the Aloe species. Transforming growth factor ß-induced protein (TGFBIp) is an extracellular matrix protein and released by primary human umbilical vein endothelial cells (HUVECs) and functions as a mediator of experimental sepsis. We hypothesized that aloin could reduce TGFBIp-mediated severe inflammatory responses in HUVECs and mice. Aloin effectively inhibited lipopolysaccharide (LPS)-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. Aloin suppressed TGFBIp-induced sepsis lethality and pulmonary injury. Therefore, aloin is a potential therapeutic agent for various severe vascular inflammatory diseases, with inhibition of the TGFBIp signaling pathway as the mechanism of action. [Formula: see text].

Suppressive effects of aloin on polyphosphate-mediated vascular inflammatory responses.

Human endothelial cells-derived polyphosphate (PolyP) is one of the pro-inflammatory mediators as suggested by the previous reports. Aloin is the major anthraquinone glycoside obtained from the Aloe species and exhibits anti-inflammatory and anti-oxidative activities. Aloin inhibits PolyP-mediated barrier disruption, the expressions of cell adhesion molecules, and adhesion/migration of leukocyte to HUVEC. PolyP-induced NF-κB activation and the productions of TNF-α and IL-6 were inhibited by aloin in HUVECs. These anti-inflammatory functions of aloin were confirmed in PolyP-injected mice. In conclusion, based on the anti-inflammatory effects of aloin in PolyP-mediated septic response, aloin has therapeutic potential for various systemic inflammatory diseases.

Design, synthesis, and evaluation of curcumin analogues as potential inhibitors of bacterial sialidase.

Sialidases are key virulence factors that remove sialic acid from the host cell surface glycan, unmasking receptors that facilitate bacterial adherence and colonisation. In this study, we developed potential agents for treating bacterial infections caused by Streptococcus pneumoniae Nan A that inhibit bacterial sialidase using Turmeric and curcumin analogues. Design, synthesis, and structure analysis relationship (SAR) studies have been also described. Evaluation of the synthesised derivatives demonstrated that compound 5e was the most potent inhibitor of S. pneumoniae sialidase (IC50 = 0.2 ± 0.1 µM). This compound exhibited a 3.0-fold improvement in inhibitory activity over that of curcumin and displayed competitive inhibition. These results warrant further studies confirming the antipneumococcal activity 5e and indicated that curcumin derivatives could be potentially used to treat sepsis by bacterial infections.

Anti-inflammatory effects of dabrafenib in vitro and in vivo.

The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new treatments for human diseases (drug repositioning). Drug repositioning refers to the development of existing drugs for new indications. Dabrafenib (DAB) is a B-Raf inhibitor and initially used for the treatment of metastatic melanoma therapy. Here, we tested the possible use of DAB in the treatment of lipopolysaccharide (LPS)-mediated vascular inflammatory responses. The anti-inflammatory activities of DAB were determined by measuring permeability, neutrophils adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated human umbilical vein endothelial cells (HUVECs) and mice. We found that DAB inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs), and adhesion and transendothelial migration of neutrophils to human endothelial cells. DAB also suppressed LPS-induced hyperpermeability and leukocytes migration in vivo. Furthermore, DAB suppressed the production of tumor necrosis factor-α (TNF-α) or interleukin (IL)-6 and the activation of nuclear factor-κB (NF-κB) or extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, treatment with DAB resulted in reduced LPS-induced lethal endotoxemia. These results suggest that DAB possesses anti-inflammatory functions by inhibiting hyperpermeability, expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.

Ameliorative effects of pine bark extract on cisplatin-induced acute kidney injury in rats.

OBJECTIVE: This study investigated the dose-response effects of pine bark extract (PBE, pycnogenol®) on oxidative stress-mediated apoptotic changes induced by cisplatin (Csp) in rats. MATERIALS AND METHODS: The ameliorating potential of PBE was evaluated after orally administering PBE at doses of 10 or 20 mg/kg for 10 days. Acute kidney injury was induced by a single intraperitoneal injection of Csp at 7 mg/kg on test day 5. RESULTS: Csp treatment caused acute kidney injury manifested by elevated levels of serum blood urea nitrogen (BUN) and creatinine (CRE) with corresponding histopathological changes, including degeneration of tubular epithelial cells, hyaline casts in the tubular lumen, and inflammatory cell infiltration (interstitial nephritis). Csp also induced significant apoptotic changes in renal tubular cells. In addition, Csp treatment induced high levels of oxidative stress, as evidenced by an increased level of malondialdehyde, depletion of the reduced glutathione (GSH) content, and decreased activities of glutathione S-transferase, superoxide dismutase, and catalase in kidney tissues. On the contrary, PBE treatment lowered BUN and CRE levels and effectively attenuated histopathological alterations and apoptotic changes induced by Csp. Additionally, treatment with PBE suppressed lipid peroxidation, prevented depletion of GSH, and enhanced activities of the antioxidant enzymes in kidney tissue. CONCLUSIONS: These results indicate that PBE has a cytoprotective effect against oxidative stress-mediated apoptotic changes caused by Csp in the rat kidney, which may be attributed to both increase of antioxidant enzyme activities and inhibition of lipid peroxidation.

Anti-inflammatory effects of vicenin-2 and scolymoside on polyphosphate-mediated vascular inflammatory responses.

AIM AND OBJECTIVE: Recent results indicate that polyphosphate (polyP) released by human endothelial cells can function as a pro-inflammatory mediator. Cyclopia subternata is a medicinal plant commonly used in traditional medicine to relieve pain in biological processes. This study was undertaken to investigate whether two structurally related active compounds found in C. subternata, namely vicenin-2 and scolymoside, can modulate polyP-mediated inflammatory responses in human umbilical vein endothelial cells (HUVECs) and in mice. METHODS: The anti-inflammatory activities of vicenin-2 and scolymoside were determined by measuring permeability, leukocytes adhesion and migration, and activation of pro-inflammatory proteins in polyP-activated HUVECs and mice. In addition, the beneficial effects of vicenin-2 and scolymoside on survival rate in polyP-injected mice were determined. RESULTS: We found that vicenin-2 and scolymoside inhibits polyP-mediated barrier disruption, the expressions of cell adhesion molecules, and leukocyte to HUVEC adhesion/migration. Interestingly, polyP-induced NF-κB activation and the productions of TNF-α and IL-6 were inhibited by vicenin-2 and scolymoside in HUVECs. These anti-inflammatory functions of vicenin-2 and scolymoside were confirmed in polyP-injected mice. CONCLUSIONS: These results suggest that vicenin-2 and scolymoside have therapeutic potential for various systemic inflammatory diseases.

NORE1/SAUL1 integrates temperature-dependent defense programs involving SGT1b and PAD4 pathways and leaf senescence in Arabidopsis.

Leaf senescence is not only primarily governed by developmental age but also influenced by various internal and external factors. Although some genes that control leaf senescence have been identified, the detailed regulatory mechanisms underlying integration of diverse senescence-associated signals into the senescence programs remain to be elucidated. To dissect the regulatory pathways involved in leaf senescence, we isolated the not oresara1-1 (nore1-1) mutant showing accelerated leaf senescence phenotypes from an EMS-mutagenized Arabidopsis thaliana population. We found that altered transcriptional programs in defense response-related processes were associated with the accelerated leaf senescence phenotypes observed in nore1-1 through microarray analysis. The nore1-1 mutation activated defense program, leading to enhanced disease resistance. Intriguingly, high ambient temperature effectively suppresses the early senescence and death phenotypes of nore1-1. The gene responsible for the phenotypes of nore1-1 contains a missense mutation in SENESCENCE-ASSOCIATED E3 UBIQUITIN LIGASE 1 (SAUL1), which was reported as a negative regulator of premature senescence in the light intensity- and PHYTOALEXIN DEFICIENT 4 (PAD4)-dependent manner. Through extensive double mutant analyses, we recently identified suppressor of the G2 Allele of SKP1b (SGT1b), one of the positive regulators for disease resistance conferred by many resistance (R) proteins, as a downstream signaling component in NORE1-mediated senescence and cell death pathways. In conclusion, NORE1/SAUL1 is a key factor integrating signals from temperature-dependent defense programs and leaf senescence in Arabidopsis. These findings provide a new insight that plants might utilize defense response program in regulating leaf senescence process, possibly through recruiting the related genes during the evolution of the leaf senescence program.

Comparative toxicity and biodistribution assessments in rats following subchronic oral exposure to copper nanoparticles and microparticles.

BACKGROUND: Copper nanoparticles (Cu NPs) have great potential in electronics and biomedical fields because of their efficient thermodynamic and anti-microbial properties. However, their potential toxic effects and kinetic data following repeated exposure are still unclear. METHODS: We evaluated the physicochemical properties of Cu NPs (25 nm) and copper microparticles (Cu MPs, 14-25 µm). Comparative in vivo toxicity of Cu NPs and Cu MPs was evaluated by conducting a 28-day repeated oral dose study at equivalent dose levels of 0, 100, 200, and 400 mg/kg/day (vehicle, 1 % hydroxypropyl methylcellulose). We determined Cu levels in the blood, tissues, urine, and feces by using inductively coupled plasma mass spectrometry. RESULTS: The solubility of Cu NPs and Cu MPs was 84.5 and 17.2 %, respectively, in an acidic milieu; however, they scarcely dissolved in vehicle or intestinal milieus. The specific surface area of Cu NPs and Cu MPs was determined to be 14.7 and 0.16 m2/g, respectively. Cu NPs exhibited a dose-dependent increase of Cu content in the blood and tested organs, with particularly high levels of Cu in the liver, kidney, and spleen. Only for liver and kidney increased Cu levels were found in Cu MPs-treated rats. Cu NPs caused a dose-related increase in Cu levels in urine, whereas Cu MPs did not affect the urine Cu levels. Extremely high levels of Cu were detected in the feces of Cu MPs-treated rats, whereas much lower levels were detected in the feces of Cu NPs-treated rats. A comparative in vivo toxicity study showed that Cu NPs caused damages to red blood cells, thymus, spleen, liver, and kidney at ≥200 mg/kg/days, but Cu MPs did not cause any adverse effects even at the highest dose. CONCLUSIONS: Overall, the in vivo repeated dose toxicity study of Cu NPs and Cu MPs demonstrated that large surface area and high solubility in physiological milieus could directly influence the toxicological responses and biodistribution of Cu particles when administered orally. Under these experimental conditions, the no-observed-adverse-effect levels of Cu NPs and Cu MPs were determined to be 100 and ≥400 mg/kg/day, respectively.

Withaferin-A--A Natural Anticancer Agent with Pleitropic Mechanisms of Action.

Cancer, being the second leading cause of mortality, exists as a formidable health challenge. In spite of our enormous efforts, the emerging complexities in the molecular nature of disease progression limit the real success in finding an effective cancer cure. It is now conceivable that cancer is, in fact, a progressive illness, and the morbidity and mortality from cancer can be reduced by interfering with various oncogenic signaling pathways. A wide variety of structurally diverse classes of bioactive phytochemicals have been shown to exert anticancer effects in a large number of preclinical studies. Multiple lines of evidence suggest that withaferin-A can prevent the development of cancers of various histotypes. Accumulating data from different rodent models and cell culture experiments have revealed that withaferin-A suppresses experimentally induced carcinogenesis, largely by virtue of its potent anti-oxidative, anti-inflammatory, anti-proliferative and apoptosis-inducing properties. Moreover, withaferin-A sensitizes resistant cancer cells to existing chemotherapeutic agents. The purpose of this review is to highlight the mechanistic aspects underlying anticancer effects of withaferin-A.

Melatonin attenuates neutrophil inflammation and mucus secretion in cigarette smoke-induced chronic obstructive pulmonary diseases via the suppression of Erk-Sp1 signaling.

The incidence of chronic obstructive pulmonary disease (COPD) has substantially increased in recent decade. Cigarette smoke (CS) is the most important risk factor in the development of COPD. In this study, we investigated the effects of melatonin on the development of COPD using a CS and lipopolysaccharide (LPS)-induced COPD model and cigarette smoke condensate (CSC)-stimulated NCI-H292 cells, a human mucoepidermoid carcinoma cell. On day 4, the mice were treated intranasally with LPS. The mice were exposed to CS for 1 hr per day (8 cigarettes per day) from day 1 to day 7. Melatonin (10 or 20 mg/kg) was injected intraperitoneally 1 hr before CS exposure. Melatonin markedly decreased the neutrophil count in the BALF, with reduction in the proinflammatory mediators and MUC5AC. Melatonin inhibited Erk phosphorylation and Sp1 expression induced by CS and LPS treatment. Additionally, melatonin decreased airway inflammation with a reduction in myeloperoxidase expression in lung tissue. In in vitro experiments, melatonin suppressed the elevated expression of proinflammatory mediators induced by CSC treatment. Melatonin reduced Erk phosphorylation and Sp1 expression in CSC-stimulated H292 cells. In addition, cotreatment of melatonin and Erk inhibitors significantly limited the proinflammatory mediators with greater reductions in Erk phosphorylation and Sp1 expression than that observed in H292 cells treated with Erk inhibitor alone. Taken together, melatonin effectively inhibited the neutrophil airway inflammation induced by CS and LPS treatment, which was closely related to downregulation of Erk phosphorylation. These findings suggest that melatonin has a therapeutic potential for the treatment of COPD.

Protective effects of diallyl disulfide on carbon tetrachloride-induced hepatotoxicity through activation of Nrf2.

This study was conducted to investigate the potential effects of diallyl disulfide (DADS) on carbon tetrachloride (CCl4 )-induced acute hepatotoxicity and to determine the molecular mechanisms of protection offered by DADS in rats. DADS was administered orally at 50 and 100 mg/kg/day once daily for 5 consecutive days prior to CCl4 administration. The single oral dose of CCl4 (2 mL/kg) caused a significant elevation in serum aspartate and alanine aminotransferase activities, which decreased upon pretreatment with DADS. Histopathological examinations showed extensive liver injury, characterized by extensive hepatocellular degeneration/necrosis, fatty changes, inflammatory cell infiltration, and congestion, which were reversed following pretreatment with DADS. The effects of DADS on cytochrome P450 2E1 (CYP2E1), the major isozyme involved in CCl4 bioactivation, were also investigated. DADS pretreatment resulted in a significant decrease in CYP2E1 protein levels in dose-dependent manner. In addition, CCl4 caused a decrease in protein level of cytoplasmic nuclear factor E2-related factor 2 (Nrf2) and suppression of nuclear translocation of Nrf2 concurrent with downregulation of detoxifying phase II enzymes and a decrease in antioxidant enzyme activities. In contrast, DADS prevented the depletion of cytoplasmic Nrf2 and enhanced nuclear translocation of Nrf2, which, in turn, upregulated antioxidant and/or phase II enzymes. These results indicate that the protective effects of DADS against CCl4 -induced hepatotoxicity possibly involve mechanisms related to its ability to induce antioxidant or detoxifying enzymes by activating Nrf2 and block metabolic activation of CCl4 by suppressing CYP2E1.

Ameliorative effects of pine bark extract on spermatotoxicity by α-chlorohydrin in rats.

We investigated the protective effects of pine bark extract (Pycnogenol®, PYC, Horphag Research Ltd., Route de Belis, France) against α-chlorohydrin (ACH)-induced spermatotoxicity in rats. Rats were orally administered ACH (30 mg/kg/day) with or without PYC (20 mg/kg/day) for 7 days. Administration of ACH significantly decreased sperm motility. α-Chlorohydrin also caused histopathological alterations and apoptotic changes in caput epididymides. An increased malondialdehyde concentration and decreased glutathione content, as well as catalase and glutathione peroxidase activities were also found. In contrast, PYC treatment significantly prevented ACH-induced spermatotoxicity, including decreased sperm motility, histopathological lesions, and apoptotic changes in the caput epididymis. Pycnogenol® also had an antioxidant benefit by decreasing malondialdehyde and increasing levels of the antioxidant glutathione and the activities of the antioxidant enzymes catalase and peroxidase in epididymal tissues. These results indicate that PYC treatment attenuated ACH-induced spermatotoxicity through antioxidant and antiapoptotic effects.