Understanding apoptotic signaling pathways in cytosine deaminase-uracil phosphoribosyl transferase-mediated suicide gene therapy in vitro

The present work was carried out to evaluate the antioxidant activity of hesperidin and to study its protective effect on H₂O₂ induced oxidative damage on pBR322 DNA and RBC cellular membrane. The in vitro assays were performed with different concentrations (2, 4, 6, 8, and 10 μg/ml, which were equivalent to 3.27, 6.55, 9.83, 13.10, and 16.38 μM) of hesperidin and the results clearly indicate that hesperidin at 10 μg/ml exhibited radical scavenging activity greater than that of standards like ascorbic acid and trolox. The protective effect of hesperidin on pBR322 DNA and RBC cellular membrane on treatment with different concentrations of H₂O₂ shows that hesperidin at 2.5 mM converts the open circular form (oc) of pBR322 DNA that is an indication of damage to super coiled (ccc) form and at 10 μg/ml it prevents membrane damage. Thus, our result proves hesperidin to be a valuable antioxidant that protects pBR322 DNA and RBC cellular membrane from free radical induced oxidative damage.     

Evaluation of the DNA damaging effects of amitraz on human lymphocytes in the Comet assay

Amitraz is formamidine pesticide widely used as insecticide and acaricide. In veterinary medicine, amitraz has important uses against ticks, mites and lice on animals. Also, amitraz is used in apiculture to control Varroa destructor. It this study, the alkaline Comet assay was used to evaluate DNA damaging effects of amitraz in human lymphocytes. Isolated human lymphocytes were incubated with varying concentrations of amitraz (0.035, 0.35, 3.5, 35 and 350 μg/mL). The Comet assay demonstrated that all concentrations of amitraz caused statistically significant increase in the level of DNA damage, thus indicating that amitraz possesses genotoxic potential. The concentration of amitraz that produced the highest DNA damage (3.5 μg/mL) was chosen for further analysis with the antioxidant catalase. The obtained results showed that co-treatment with antioxidant catalase (100 IU/mL or 500 IU/mL) significantly reduced the level of DNA damage, indicating the possible involvement of reactive oxygen species in DNA damaging effects of amitraz. Flow cytometric analysis revealed increase of the apoptotic index following treatment with amitraz. However, co-treatment with catalase reduced the apoptotic index, while treatment with catalase alone reduced the percentage of apoptotoc cells even in comparison with the negative control. Therefore, catalase had protective effects against ROS-mediated DNA damage and apoptosis.     

Antioxidant system activation by mercury in Pfaffia glomerata plantlets

Oxidative stress caused by mercury (Hg) was investigated in Pfaffia glomerata plantlets grown in nutrient solution using sand as substrate. Thirty-day-old acclimated plants were treated for 9 days with four Hg levels (0, 1, 25 and 50 μM) in the substrate. Parameters such as growth, tissue Hg concentration, toxicity indicators (δ-aminolevulinic acid dehidratase, δ-ALA-D, activity), oxidative damage markers (TBARS, lipid peroxidation, and H₂O₂ concentration) and enzymatic (superoxide dismutase, SOD, catalase, CAT, and ascorbate peroxidase, APX) and non-enzymatic (non-protein thiols, NPSH, ascorbic acid, AsA, and proline concentration) antioxidants were investigated. Tissue Hg concentration increased with Hg levels. Root and shoot fresh weight and δ-ALA-D activity were significantly decreased at 50 μM Hg, and chlorophyll and carotenoid concentration were not affected. Shoot H₂O₂ concentration increased curvilinearly with Hg levels, whereas lipid peroxidation increased at 25 and 50 μM Hg, respectively, in roots and shoots. SOD activity showed a straight correlation with H₂O₂ concentration, whereas CAT activity increased only in shoots at 1 and 50 μM Hg. Shoot APX activity was either decreased at 1 μM Hg or increased at 50 μM Hg. Conversely, root APX activity was only increased at 1 μM Hg. In general, AsA, NPSH and proline concentrations increased upon addition of Hg, with the exception of proline in roots, which decreased. These changes in enzymatic and non-enzymatic antioxidants had a significant protective effect on P. glomerata plantlets under mild Hg-stressed conditions.     

Protective Effect of Selenomethionine on Aflatoxin B1-Induced Oxidative Stress in MDCK Cells

AFB1 is a mycotoxin which exerts their cytotoxicity through increasing oxidative damage in target organ. Kidney is one of target organs vulnerable to damage caused by AFB1. In this study, Madin-Darby canine kidney (MDCK) cells were used to evaluate the AFB1-induced cell damage by the MTT assay. The results revealed that the toxic effect of AFB1 on MDCK cells is both dose and time dependent. Half maximal toxic concentration (IC₅₀) was noted at 0.25 μg/ml of AFB1. Further, protective effect of six different concentrations (0.2, 0.8, 1, 2, 4, and 8 μM) of selenomethionine (SeMet) was observed against 0.25 μg/ml of AFB1-induced damage. The results showed that 0.25 μg/ml of AFB1 caused significant increase in oxidative stress, which was demonstrated by significant increase of malondialdehyde (MDA) level, reduction of intracellular GSH level, as well as GPX1 activity and mRNA level in MDCK cells when compared with control. SeMet protected the cells from AFB1-induced oxidative damage in a dose-dependant manner. Good protection could be achieved between 1 and 4 μM of concentration. Amid this range, MDA level significantly decreased while intracellular GSH level and GPX1 activity in addition to mRNA level significantly increased. Moreover, cell viability was significantly improved. It could be concluded that SeMet is a potential antioxidative agent to alleviate AFB1-induced oxidative stress.     

The Protective Role of Resveratrol in the Sodium Arsenite-Induced Oxidative Damage via Modulation of Intracellular GSH Homeostasis

Sodium arsenite (NaAsO₂) is a well-established environmental carcinogen that has been found to cause various human malignant tumors. Thus, how to prevent the deleterious effects caused by NaAsO₂ has received widely concerns. Resveratrol (3,4′,5-trihydroxystilbene), a polyphenol found in numerous plant species, has recently been known as a natural and powerful antioxidant. However, whether resveratrol could attenuate the toxicity of NaAsO₂ and its detailed mechanisms have not been reported. In this study, the protective effects of resveratrol against NaAsO₂-induced oxidative and genetic damage as well as apoptosis were evaluated for the first time. We demonstrated that cotreatment of human bronchial epithelial cell with 5 μM resveratrol for 24 h effectively reduced the levels of 30 μM NaAsO₂-induced reactive oxygen species, chromosomal and DNA damage, and cell apoptosis. Revseratrol was also showed to significantly elevate the concentration of glutathione (GSH) and the activities of its relevant enzymes as compared with NaAsO₂ alone, indicating that resveratrol ameliorates the toxicity of NaAsO₂ by modulating the process of GSH biosynthesis, recycling and utilization. Our findings further suggest that GSH homeostasis represents one of the detoxification mechanisms responding to NaAsO₂ exposure, and resveratrol plays a protective role in the regulation of oxidative and genetic damage as well as apoptosis through the modulation of GSH homeostasis.

Effects of a Standardized Phenolic-Enriched Maple Syrup Extract on β-Amyloid Aggregation,Neuroinflammation in Microglial and Neuronal Cells,and β-Amyloid Induced Neurotoxicity in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

Published data supports the neuroprotective effects of several phenolic-containing natural products, including certain fruit, berries, spices, nuts, green tea, and olive oil. However, limited data are available for phenolic-containing plant-derived natural sweeteners including maple syrup. Herein, we investigated the neuroprotective effects of a chemically standardized phenolic-enriched maple syrup extract (MSX) using a combination of biophysical, in vitro, and in vivo studies. Based on biophysical data (Thioflavin T assay, transmission electron microscopy, circular dichroism, dynamic light scattering, and zeta potential), MSX reduced amyloid β_1?42 peptide (Aβ_1?42) fibrillation in a concentration-dependent manner (50–500 μg/mL) with similar effects as the neuroprotective polyphenol, resveratrol, at its highest test concentration (63.5?% at 500 μg/mL vs. 77.3?% at 50 μg/mL, respectively). MSX (100 μg/mL) decreased H₂O₂-induced oxidative stress (16.1?% decrease in ROS levels compared to control), and down-regulated the production of lipopolysaccharide (LPS)-stimulated inflammatory markers (22.1, 19.9, 74.8, and 87.6?% decrease in NOS, IL-6, PGE₂, and TNFα levels, respectively, compared to control) in murine BV-2 microglial cells. Moreover, in a non-contact co-culture cell model, differentiated human SH-SY5Y neuronal cells were exposed to conditioned media from BV-2 cells treated with MSX (100 μg/mL) and LPS or LPS alone. MSX-BV-2 media increased SH-SY5Y cell viability by 13.8?% compared to media collected from LPS-BV-2 treated cells. Also, MSX (10 μg/mL) showed protective effects against Aβ_1?42 induced neurotoxicity and paralysis in Caenorhabditis elegans in vivo. These data support the potential neuroprotective effects of MSX warranting further studies on this natural product.     

Synthesis of thiazolidine-2,4-dione derivatives: anticancer,antimicrobial and DNA cleavage studies

In the search of efficient anticancer agents, here, new 5-(4-alkylbenzyledene)thiazolidine-2,4-dione derivatives (5a–g) have been successfully synthesized and characterized and are evaluated for anticancer and antimicrobial activities using DNA cleavage studies. In vitro studies on anticancer activity of compound 5d (NSC: 768619/1) was done against the full panel of 60 human tumor cell lines. The five-level dose activity results revealed that, the compound 5d was active against all the cell lines, it has shown potential activity against leukemia SR (GI₅₀: 2.04 μM), non-small cell lung cancer NCI-H522 (GI₅₀: 1.36 μM), colon cancer COLO 205 (GI₅₀: 1.64 μM), CNS cancer SF-539 (GI₅₀: 1.87 μM), melanoma SK-MEL-2 (GI₅₀: 1.64 μM), ovarian cancer OVCAR-3 (GI₅₀: 1.87 μM), renal cancer RXF 393 (GI₅₀: 1.15 μM), prostate cancer PC-3 (GI₅₀: 1.90 μM), and breast cancer MDA-MB-468(GI₅₀: 1.11 μM). DNA cleavage studies revealed that at 50 μg/mL concentration, partial DNA digestion was observed and when the concentration is increasing to threefold (150 μg/mL), complete linear DNA digestion and partial supercoiled DNA digestion was observed. Further antimicrobial studies indicate that all the synthesized compounds except compound 5a possess prominent activity against all the screened microbial species. This study throws a ray of light in the field of anticancer drugs.     

Protective effect of esculin against prooxidant aflatoxin B1-induced nephrotoxicity in mice

The study was designed to investigate the protective effect of esculin against pro-oxidant aflatoxin B₁ (AFB₁)-induced nephrotoxicity in mice. In this study toxicity was developed by oral administration of AFB₁ at a dose of 66.60 μg/kg bw/day for 90 days in male Swiss albino mice. Esculin (150 mg/kg bw/0.2 ml/day) and standard compound ascorbic acid (300 mg/kg bw/0.2 ml/day) was given after 30 min of AFB₁ administration for 90 days. Protective efficacy was assessed by measuring the levels of lipid peroxidation (LPO) and non-enzymatic antioxidants such as reduced glutathione (GSH) and also by measuring activities of enzymatic antioxidants such as glutathione peroxidase (GPX), glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) in kidney. Results were analysed at the 30^th, 60^th and 90^th day of the daily treatments, which showed a decrease in the level of LPO and an increase in the levels of enzymatic and non-enzymatic antioxidants. The protective effect of esculin was further proved by histopathological findings as it exhibited regenerative activities in mice renal tubules against AFB₁-induced nephrotoxicity. The results obtained clearly demonstrate that the protective efficacy of esculin against pro-oxidant AFB₁-induced nephrotoxicity in mice might be due to its antioxidants and free radical scavenging properties.     

Carbon-Mercaptooctadecane/Carboxylated Multi-walled Carbon Nanotubes Composite Based Genosensor for Detection of Bacterial Meningitis

Human brain bacterial meningitis is a life-threatening disease mainly caused by Neisseria meningitidis, lead to several complications including damage of brain or even death. The present available methods for diagnosis of meningitis have one or more limitations. A rmpM gene based genosensor was fabricated by immobilizing 5′-amino modified 19-mer single stranded DNA probe onto carbon-mercaptooctadecane/carboxylated multi-walled carbon nanotubes composite electrode and hybridized with 2.5–40 ng/6 μL of single stranded genomic DNA (ssG-DNA) of N. meningitidis from cerebrospinal fluid (CSF) of the suspected meningitis patients. The electrochemical response was measured by using cyclic voltammetry and differential pulse voltammetry (DPV) using 1 mM methylene blue as redox indicator in 30 min (including a response time of 1 min) at 25 °C. The sensitivity of the genosensor was 3.762 (μA/cm²)/ng and limit of detection was 2 ng of ssG-DNA of N. meningitidis with DPV. The genosensor has specificity only to N. meningitidis and does not hybridize with the genomic DNA of any other possible pathogen in human CSF. The immobilization of the probe and hybridization of the ssG-DNA were characterized by using electrochemical impedance in presence of 5 mM potassium ferricyanide and scanning electron microscopy. The genosensor loses only 12 % of its original DPV current on storage at 4 °C for 6 months. Carbon composite based electrochemical array can be constructed to detect multiple bacterial meningitis suspected patient CSF samples during an outbreak of the disease.     

Salt tolerance of a cash crop halophyte Suaeda fruticosa: biochemical responses to salt and exogenous chemical treatments

Suaeda fruticosa Forssk is a leaf succulent obligate halophyte that produces numerous seeds under saline conditions. Seeds are a good source of high quality edible oil and leaves are capable of removing substantial amount of salt from the saline soil besides many other economic usages. Little is known about the biochemical basis of salt tolerance in this species. We studied some biochemical responses of S. fruticosa to different exogenous treatments under non-saline (0 mM), moderate (300 mM) or high (600 mM) NaCl levels. Eight-week-old seedlings were sprayed twice a week with distilled water, hydrogen peroxide (H₂O₂, 100 μM), glycine betaine (GB, 10 mM), or ascorbic acid (AsA, 20 mM) for 30 days. At moderate (300 mM) NaCl, leaf Na⁺, Ca²⁺ and osmolality increased, along with unchanged ROS and antioxidant enzyme activities, possibly causing a better plant growth. Plants grew slowly at 600 mM NaCl to avoid leaf Na⁺ buildup relative to those at 300 mM NaCl. Exogenous application of distilled water and H₂O₂ improved ROS scavenging mechanisms, although growth was unaffected. ASA and GB alleviated salt-induced growth inhibition at 600 mM NaCl through enhancing the antioxidant defense system and osmotic and ion homeostasis, respectively.     

The Antioxidant Activity of Copper(II) (3,5-Diisopropyl Salicylate)4 and Its Protective Effect Against Streptozotocin-Induced Diabetes Mellitus in Rats

Oxidative stress has been suggested as a potential contributor to the development of diabetic complications. In this study, we investigated the protective effect of a strong antioxidant copper complex against streptozotocin (STZ)-induced diabetes in animals. Out of four copper complexes used, copper(II) (3,5-diisopropyl salicylate)₄ (Cu(II)DIPS) was found to be the most potent antioxidant–copper complex. Pretreatment with Cu(II)DIPS (5 mg/kg) twice a week prior to the injection of streptozotocin (50 mg/kg) has reduced the level of hyperglycemia by 34 % and the mortality rate by 29 %. Injection of the same dosage of the ligand 3,5-diisopropyl salicylate has no effect on streptozotocin-induced hyperglycemia. The same copper complex has neither hypoglycemic activity when injected in normal rats nor antidiabetic activity when injected in STZ-induced diabetic rats. The protective effect of Cu(II)DIPS could be related to its strong antioxidant activity compared to other copper complexes median effective concentration (MEC)?=?23.84 μg/ml and to Trolox MEC?=?29.30 μg/ml. In addition, it reduced serum 8-hydroxy-2′-deoxyguanosine, a biomarker of oxidative DNA damage, by 29 %. This effect may explain why it was not effective against diabetic rats, when β Langerhans cells were already destroyed. Similar protective activities were reported by other antioxidants like Trolox.     

Establishment and characterization of Stevia rebaudiana (Bertoni) cell suspension culture: an in vitro approach for production of stevioside

A protocol has been standardized for establishment and characterization of cell suspension cultures of Stevia rebaudiana in shake flasks, as a strategy to obtain an in vitro stevioside producing cell line. The effect of growth regulators, inoculum density and various concentrations of macro salts have been analyzed, to optimize the biomass growth. Dynamics of stevioside production has been investigated with culture growth in liquid suspensions. The callus used for this purpose was obtained from leaves of 15-day-old in vitro propagated plantlets, on MS medium fortified with benzyl aminopurine (8.9 μM) and naphthalene acetic acid (10.7 μM). The optimal conditions for biomass growth in suspension cultures were found to be 10 g l^?1 of inoculum density on fresh weight basis in full strength MS liquid basal medium of initial pH 5.8, augmented with 2,4-dichlorophenoxy acetic acid (0.27 μM), benzyl aminopurine (0.27 μM) and ascorbic acid (0.06 μM), 1.0× NH₄NO₃ (24.7 mM), 3.0× KNO₃ (56.4 mM), 3.0× MgSO₄ (4.5 mM) and 3.0× KH₂PO₄ (3.75 mM), in 150 ml Erlenmeyer flask with 50 ml media and incubated in dark at 110 rpm. The growth kinetics of the cell suspension culture has shown a maximum specific cell growth rate of 3.26 day^?1, doubling time of 26.35 h and cell viability of 75 %, respectively. Stevioside content in cell suspension was high during exponential growth phase and decreased subsequently at the stationary phase. The results of present study are useful to scale-up process and augment the S. rebaudiana biological research.     

Antifungal activity of alkanols: inhibition of growth of spoilage yeasts

Primary aliphatic alkanols from C₆ to C₁₃ were tested for their antifungal activity against Saccharomyces cerevisiae using a broth dilution method. Undecanol (C₁₁) was found to be the most potent fungicide against this yeast with the minimum fungicidal concentration (MFC) of 25 μg/ml (0.14 mM), followed by decanol (C₁₀) with the minimum inhibitory concentration (MIC) of 50 μg/ml (0.31 mM). The time-kill curve study showed that undecanol was fungicidal against S. cerevisiae at any growth stages. This fungicidal activity was not influenced by pH values. Dodecanol (C₁₂) was the most effective fungistatic but did not show any fungicidal activity up to 1600 μg/mL. Fungistatic dodecanol quickly reduced cell viability, but the cell viability recovered shortly after and then finally became no longer different from the control indicating that the effect of dodecanol on S. cerevisiae was classified as a sublethal damage. However, fungistatic dodecanol combined with sublethal amount of anethole showed a fungicidal activity against this yeast. Anethole completely restricted the recovery of cell viability. Therefore expression of the synergistic effect was probably due to the blockade of the recovering process from dodecanol induced-stress. The alkanols tested inhibited glucose-induced acidification by inhibiting the plasma membrane H⁺-ATPase. Octanol (C₈) increased plasma membrane fluidity in the spheroplast cells of S. cerevisiae. The same series of aliphatic primary alkanols was also tested against a food spoilage fungus Zygosaccharomyces bailii and compared with their effects against S. cerevisiae. Decanol was found to be the most potent fungicide against Z. bailii with an MFC of 50 μg/ml (0.31 mM), whereas undecanol was found to be the most potent fungistatic with an MIC of 25 μg/ml (0.14 mM). The time-kill curve study showed that decanol was fungicidal against Z. bailii at any growth stage. This antifungal activity was slightly enhanced in combination with anethole. The primary antifungal action of medium-chain (C₉–C₁₂) alkanols comes from their ability as nonionic surfactants to disrupt the native membrane-associated function of the integral proteins. Hence, the antifungal activity of alkanols is mediated by biophysical process, and the maximum activity can be obtained when balance between hydrophilic and hydrophobic portions becomes the most appropriate.     

The ameliorating effect of Acadian marine plant extract against ionic liquids-induced oxidative stress and DNA damage in marine macroalga Ulva lactuca

Ionic liquids (ILs) are generally considered as the green replacement for conventional volatile organic solvents. Nonetheless, their high solubility in water with proven toxic effects on aquatic biota has questioned their green credentials. In the present study, the detoxification potential of Acadian marine plant extract powder (AMPEP) prepared from the brown alga Ascophyllum nodosum was investigated against the 1-alkyl-3-methylimidazolium bromide [C₁₂mim]Br ionic liquid-induced toxicity and oxidative stress in marine macroalga Ulva lactuca. The IL ([C₁₂mim]Br) at LC₅₀ (70 μM) exposure triggered the generation of reactive oxygen species (ROS) such as O ₂ ^·? , H₂O₂ and OH· causing membrane and DNA damage together with inhibition of antioxidant systems in the alga. The supplementation of AMPEP (150 μg mL^?1) to the culture medium significantly reduced the accumulation of ROS and lipid peroxidation together with the inhibition of lipoxygenase (LOX) activity specially LOX-2 and LOX-3 isoforms. This is for the first time wherein comet assay was performed to ascertain the protective role of AMPEP against DNA damage in algal tissue grown in medium supplemented with IL and AMPEP. The AMPEP showed protective role against DNA damage (5–45 % tail DNA) when compared to those of grown in IL alone (45–70 % tail DNA). Further, specific isomorphs of different antioxidant enzymes such as superoxide dismutase (Mn-SOD-1, ~150 kDa), ascorbate peroxidase (APX-4, ~55 kDa), glutathione peroxidase (GSH-Px-2, ~55 kDa) and glutathione reductase (GR-1, ~180 kDa) responded specifically to AMPEP supplementation. It is evident from these findings that AMPEP could possibly be used for circumventing the negative effects arising from ILs-induced toxicity in marine ecosystem.     

Genomic instability related to zinc deficiency and excess in an in vitro model: is the upper estimate of the physiological requirements recommended for children safe?

Micronutrients are important for the prevention of degenerative diseases due to their role in maintaining genomic stability. Therefore, there is international concern about the need to redefine the optimal mineral and vitamin requirements to prevent DNA damage. We analyzed the cytostatic, cytotoxic, and genotoxic effect of in vitro zinc supplementation to determine the effects of zinc deficiency and excess and whether the upper estimate of the physiological requirement recommended for children is safe. To achieve zinc deficiency, DMEM/Ham’s F12 medium (HF12) was chelated (HF12Q). Lymphocytes were isolated from healthy female donors (age range, 5–10 yr) and cultured for 7 d as follows: negative control (HF12, 60 μg/dl ZnSO₄); deficient (HF12Q, 12 μg/dl ZnSO₄); lower level (HF12Q + 80 μg/dl ZnSO₄); average level (HF12Q + 180 μg/dl ZnSO₄); upper limit (HF12Q + 280 μg/dl ZnSO₄); and excess (HF12Q + 380 μg/dl ZnSO₄). The comet (quantitative analysis) and cytokinesis-block micronucleus cytome assays were used. Differences were evaluated with Kruskal-Wallis and ANOVA (p < 0.05). Olive tail moment, tail length, micronuclei frequency, and apoptotic and necrotic percentages were significantly higher in the deficient, upper limit, and excess cultures compared with the negative control, lower, and average limit ones. In vitro zinc supplementation at the lower and average limit (80 and 180 μg/dl ZnSO₄) of the physiological requirement recommended for children proved to be the most beneficial in avoiding genomic instability, whereas the deficient, upper limit, and excess (12, 280, and 380 μg/dl) cultures increased DNA and chromosomal damage and apoptotic and necrotic frequencies.     

Antioxidant Activity of Purified Protein Hydrolysates from Northern Whiting Fish (Sillago sihama) Muscle

In the present study, northern whiting fish (Sillago sihama) muscle was hydrolyzed with gastrointestinal enzymes (pepsin, trypsin and α-chymotrypsin) separately and the resulted protein hydrolysates were tested for antioxidant activities using DPPH radical scavenging activity and reducing power assays. The protein hydrolysate obtained from trypsin exhibited highest antioxidant activity. Further, it was fractionated by consecutive chromatography using anion exchange and gel filtration chromatography; the separated fractions were collected and evaluated for antioxidant activity. The results showed that fraction 2 exhibited high chelating activity (73.15 % at 0.5 mg/mL) and best radical scavenging activity for DPPH radical (55.16 % at 0.5 mg/mL), ABTS radical (57.98 % at 50 μg/mL), superoxide radical (39.55 % at 200 μg/mL) and hydroxyl radical (51.33 % at 100 μg/mL). In addition, the active fraction showed strong antioxidant activity in the inhibition of linoleic acid autooxidation (60 % at 0.5 mg/mL) and also it exhibited significant protective effect on DNA damage caused by hydroxyl radicals. The size of the active fraction was found to be <360.2 Da using mass spectroscopy. These results demonstrate that muscle protein hydrolysate from northern whiting fish could be a best alternative to produce natural antioxidant peptides.     

Resveratrol mitigates genotoxicity induced by iodine-131 in primary human lymphocytes

The purpose of this study was to investigate the radioprotective effects of resveratrol as a natural product that protects against genotoxic actions of ¹³¹I in cultured human lymphocytes. Whole-blood samples from human volunteers were treated with resveratrol at doses of 0.5, 1, 5, and 50 μg/mL for 1 h, after which the lymphocytes were incubated with ¹³¹I (100 μCi/1.5 mL) for 2 h. The lymphocyte cultures were then mitogenically stimulated to enable evaluation of the number of micronuclei in cytokinesis-blocked binucleated cells. Incubation of lymphocytes with ¹³¹I induced genotoxicity, which was reflected by an increase in micronuclei frequency. At the doses tested, resveratrol significantly reduced micronuclei frequency. Maximal protective effects occurred at a dose of 1 μg/mL, with total micronuclei values being reduced by 65 % compared to controls. In conclusion, our results indicate protective effects of resveratrol at low doses against genetic damage and adverse effects induced by ¹³¹I administration.     

Protective effect of the total flavonoids from <Emphasis Type="Italic">Apocynum venetum</Emphasis> L. on carbon tetrachloride-induced hepatotoxicity in vitro and in vivo

Apocynum venetum L., belonging to the family Apocynaceae, is a popular medicinal plant, which is commonly used in the treatment of hypertension, neurasthenia, and hepatitis in China. In the present study, the total flavonoids (TFs) were prepared from the leaves of A. venetum, and its protective effects on carbon tetrachloride (CCl₄)-induced hepatotoxicity in a cultured HepG2 cell line and in mice were investigated. Cell exposed to 0.4% CCl₄ (v/v) for 6 h led to a significant decrease in cell viability, increased LDH leakage, and intracellular reactive oxygen species (ROS). CCl₄ also induced cell marked apoptosis, which was accompanied by the loss of mitochondrial membrane potential (MMP). Pretreatment with TFs at concentrations of 25, 50, and 100 μg/mL effectively relieved CCl₄-induced cellular damage in a dose-dependent manner. In vivo, TFs (100, 200, and 400 mg/kg BW) were administered via gavage daily for 14 days before CCl₄ treatment. The high serum ALT and AST levels induced by CCl₄ were dose-dependently suppressed by pretreatment of TFs (200 and 400 mg/kg BW). Histological analysis also supported the results obtained from serum assays. Furthermore, TFs could prevent CCl₄-caused oxidative damage by decreasing the MDA formation and increasing antioxidant enzymes (CAT, SOD, GSH-Px) activities in liver tissues. In summary, both in vitro and in vivo data suggest that TFs, prepared from A. venetum, showed a remarkable hepatoprotective and antioxidant activity against CCl₄-induced liver damage.     

A natural plant growth promoter,calliterpenone, enhances growth and biomass,carbohydrate, and lipid production in cyanobacterium Synechocystis PCC 6803

Cyanobacteria have evolved photosynthetic mechanisms in which solar energy is used to fix CO₂ into carbohydrates. The lipids from cyanobacteria can be converted to biodiesel by extraction–transesterification methods. The present study demonstrates the usefulness of the natural plant and microbial growth promoter calliterpenone from the plant Callicarpa macrophylla supplemented at three different doses (15, 25, 50 μL of a 0.01 mM solution) per 100 mL BG11⁺ medium for enhancing total biomass, carbohydrate, and lipid yields and reducing the surface-to-volume ratios of cells of Synechocystis PCC 6803. The enhanced total dried biomass, carbohydrate, and lipid production was 316.1, 140.34, and 130.76 %, respectively, higher than the control, and were obtained after 15 days of cultivation at the dose of 15 μL (0.01 mM) of calliterpenone per 100 mL BG11⁺ medium. A decrease in surface-to-volume ratio of cells from 1.19 to 0.84 compared to the control was also observed. Response surface methodology was used to optimize the doses of calliterpenone at different pH of growth media. An increase of 346.95, 187.2, and 134.46 % in biomass, carbohydrate, and lipid yields, respectively, was achieved after 10 days of cultivation in optimized BG11⁺ media at pH 7.5 and with 20 μL (0.01 mM) calliterpenone per 100 mL. Thus, this biomolecule can be exploited for higher yields of Synechocystis PCC 6803 in a relatively shorter culture time making this an attractive strategy for fuel production using this cyanobacterium.