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1.
(R)-3-Hydroxybutyl (R)-3-hydroxybutyrate (ketone monoester) has been developed as an oral source of ketones, which may be utilized for energy. In a 28-day toxicity study, Crl:WI (Wistar) rats received diets containing, as 30% of the calories, ketone monoester (12 and 15 g/kg body weight/day for male and female rats, respectively). Control groups received either carbohydrate- or fat-based diets. Rats in the test group consumed less feed and gained less weight than control animals; similar findings have been documented in studies of ketogenic diets. Between-group differences were noted in selected hematology, coagulation, and serum chemistry parameters; however, values were within normal physiological ranges and/or were not accompanied by other changes indicative of toxicity. Upon gross and microscopic evaluation, there were no findings associated with the ketone monoester. In a developmental toxicity study, pregnant Crl:WI (Han) rats were administered 2 g/kg body weight/day ketone monoester or water (control) via gavage on days 6 through 20 of gestation. No Caesarean-sectioning or litter parameters were affected by the test article. The overall incidence of fetal alterations was higher in the test group; however, there were no specific alterations attributable to the test substance. The results of these studies support the safety of ketone monoester.  相似文献   

2.
The chemotherapeutic drug cisplatin is associated with severe gastrointestinal toxicity that can last for several days. A recent strategy to treat the nausea and emesis includes the combination of a 5-HT3 receptor antagonist, a glucocorticoid, and an NK1 receptor antagonist. The present studies explore the use of the selective noradrenaline reuptake inhibitors, (R)-sila-venlafaxine, (R,R)-reboxetine and (S,S)-reboxetine to prevent cisplatin (5 mg/kg, i.p.)-induced acute (0-24 h) and delayed (24-72 h) emesis in ferrets. The positive control regimen of ondansetron and dexamethasone, both at 1 mg/kg/8 h, reduced acute and delayed emesis by 100 (P < 0.001) and 61% (P < 0.05). (R)-sila-venlafaxine at 5 and 15 mg/kg/4 h reduced acute emesis by 86 (P < 0.01) and 66% (P < 0.05), respectively and both enantiomers of reboxetine at 1 mg/kg/12 h also reduced the response by ∼ 70-90% (P < 0.05). Out of the reuptake inhibitors, only (R)-sila-venlafaxine at 15 mg/kg/4 h was active to reduce delayed emesis (a 57% reduction was observed (P < 0.05)); its terminal plasma levels were positively correlated with an inhibition of emesis during the delayed phase (P < 0.05). (R)-sila-venlafaxine was also examined against a higher dose of cisplatin 10 mg/kg, i.p. (3 h test) and it dose-dependently antagonized the response (maximum reduction was 94% at 10 mg/kg, p.o.; P < 0.01) but it was ineffective against apomorphine (0.125 mg/kg, s.c.) and ipecacuanha (2 mg/kg, p.o.)-induced emesis (P > 0.05). In conclusion, the studies provide the first evidence for an anti-emetic potential of noradrenaline reuptake inhibitors to reduce chemotherapy-induced acute and delayed emesis.  相似文献   

3.
4.
The antiviral effect of the acyclic nucleoside phosphonate tenofovir (R)-PMPA on double-stranded DNA Cauliflower mosaic virus (CaMV) in Brassica pekinensis plants grown in vitro on liquid medium was evaluated. Double antibody sandwich ELISA and PCR were used for relative quantification of viral protein and detecting nucleic acid in plants. (R)-PMPA at concentrations of 25 and 50 mg/l significantly reduced CaMV titers in plants within 6-9 weeks to levels detectable neither by ELISA nor by PCR. Virus-free plants were obtained after 3-month cultivation of meristem tips on semisolid medium containing 50 mg/l (R)-PMPA and their regeneration to whole plants in the greenhouse. Studying the metabolism of (R)-PMPA in B. pekinensis revealed that mono- and diphosphate, structural analogs of NDP and/or NTP, are the only metabolites formed. The data indicate very low substrate activity of the enzymes toward (R)-PMPA as substrate. The extent of phosphorylation in the plant’s leaves represents only 4.5% of applied labeled (R)-PMPA. In roots, we detected no radioactive peaks of phosphorylated metabolites of (R)-PMPAp or (R)-PMPApp.  相似文献   

5.
Ludwigia octovalvis is an aquatic plant widely distributed in Taiwan. It is traditionally used as a diuretic and is consumed as health drink. In this study, we evaluated the anti-proliferative activity of extracts and active constituent (chlorophyll a; CHL-a) of L. octovalvis in 3T3-L1 adipocytes; its mode of action on apoptosis was also investigated. Results showed that, among the different extracts and fractions, the ethylacetate layer (EAL) possessed the most potent anti-proliferative activity. Activity guided fractionation of the EAL obtained the bioactive constituent CHL-a (IC50: 24.10 ± 0.83 nM). At concentrations 5–30 nM, CHL-a exhibited a dose-dependent accumulation of the Sub-G1 peak and caused cell cycle arrest at the G0/G1 phase. At 30 nM, it significantly reduced the cell viability, induced the appearance of DNA fragments, and enhanced the activation of caspase-3. Western blot data revealed that CHL-a decreased the level of Bcl-2, and increased the expression of CD95 (APO-1/CD95) and Bax. Furthermore, CHL-a up-regulated the AMPK and p-AMPK levels, and down-regulated the expression of PPAR-γ. These results conclude that CHL-a possesses potent anti-proliferative activity, and its apoptotic effects on 3T3-L1 adipocytes are mediated through the activation of CD95 (APO-1/CD95) system and the AMPK signaling pathway.  相似文献   

6.
Many plant species are used for medicinal purposes without the knowledge of their possible toxic effect. The ethnopharmacologically renowned genus Achillea L. (Asteraceae) is even more troublesome in this respect since different taxa are believed to have the same beneficial properties as A. millefolium. According to the median lethal i.p. dose (LD50 = 853 mg/kg, mice), the volatiles of Achillea umbellata Sibth. et Sm. are more toxic than the thujone-containing essential oils (LD50 > 960 mg/kg). A GC–MS analysis of A. umbellata oil revealed the presence of a series of fragranyl esters (six new natural products). The major constituents of this oil, the rare monoterpene alcohol fragranol and fragranyl acetate, and one more ester (benzoate), as well as the oil itself, showed antianxiety, analgesic and, in some instances, paralyzing properties at 50–150 mg/kg but these are very likely sign of intoxication and not of possible beneficial effects of the plant volatiles. Testing of antimicrobial activity demonstrated that the oil possesses moderate activity against pathogenic microorganisms, but the effect of the oil differs in pro- and eukaryotic cells. According to the results obtained, fragranol may be considered as the main active principle responsible for the observed activity/toxicity.  相似文献   

7.
This study was undertaken to examine the anticandidal effects of microbially bioconverted product of cabbage, obtained from the microbial conversion of cabbage (Brassica oleracea var. capitata) by a bacterial strain Pectobacterium carotovorum pv. carotovorum 21 (Pcc 21) against various isolates of Candida species including a clinical isolate. The bioconverted product (10 μl, corresponding to 500 μg/disc) displayed potential anticandidal effect against Candida albicans KACC 30062, Candida geochares KACC 30061, Candida albicans KACC 30003, Candida saitoana KACC 41238 and Candida glabrata P00368 (clinical isolate) as a diameter of zones of inhibition, found in the range of 14 ± 0.9 to 19 ± 1.1 mm. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of bioconverted product against the tested isolates were found in the range of 62.5–250 and 125–250 μg/ml, respectively. Also the bioconverted product had remarkable anticandidal effect on the viable counts of the tested Candida isolates. Further, scanning electron microscopic study revealed potential detrimental effect of bioconverted product on the morphology of C. albicans KACC 30062 at MIC concentration. All these findings together indicate that bioconverted product of cabbage has potential therapeutic value of medicinal significance to control Candida species including clinical isolates.  相似文献   

8.
Extracts of Citrus aurantium L. (Rutaceae) unripe fruits have gained popularity for the treatment of obesity. Due to the wide use of C. aurantium/p-synephrine-containing products, this research was undertaken to evaluate its subchronic toxicity in mice and their actions in oxidative stress biomarkers. Groups of 9–10 mice received for 28 consecutive days a commercial C. aurantium dried extract (containing 7.5% p-synephrine) 400, 2000 or 4000 mg/kg and p-synephrine 30 or 300 mg/kg by oral gavage. There was a reduction in body weight gain of animals treated with both doses of p-synephrine. Organs relative weight, biochemical and hematological parameters were not altered in all treated mice. There was an increase in reduced glutathione (GSH) concentration in groups treated with C. aurantium 4000 mg/kg and p-synephrine 30 and 300 mg/kg. In glutathione peroxidase (GPx), there were an inhibition of the activity in C. aurantium 400 and 2000 mg/kg and p-synephrine 30 and 300 mg/kg treated animals, respectively, and was no alteration in malondialdehyde (MDA) levels. Thus, the results indicate a low subchronic toxicity of the tested materials in mice and a possible alteration in the oxidative metabolism. However, further tests are required to better elucidate the effects of these compounds in the antioxidant system.  相似文献   

9.
The objective of this study was to obtain data on the safety-in-use of yeast hydrolysate in 10–30 kDa molecular weight as a dietary supplement by assessing its acute and subacute oral toxicity in female and male Sprague–Dawley (SD) rats. The single oral dose of the hydrolysate at 5000 mg/kg did not produce mortality or significant changes in the general behavior and gross appearance of the internal organs of rats. In subacute toxicity study, the hydrolysate was administered orally at a dose of 1000 mg/kg/day for a period of 14 days. The satellite group was treated with the hydrolysate at the same dose and the same period and kept for another 14 days after treatment. There were no significant differences in organ weights between control and treated group of both sexes. Hematological analysis and blood chemistry revealed no toxicity effects of Saccharomyces cerevisiae hydrolysate. Pathologically, neither gross abnormalities nor histopathological changes were observed. These results show that the hydrolysate possesses very low toxicity as indicated in SD rat model.  相似文献   

10.
Phorbol esters are the main toxins in Jatropha curcas seed and oil. The aim of this study was to assess the acute toxicity of phorbol esters given by intragastric administration and to determine the LD50 for Swiss Hauschka mice. The LD50 and 95% confidence limits for male mice were 27.34 mg/kg body mass and 24.90–29.89 mg/kg body mass; and the LD5 and LD95 were 18.87 and 39.62 mg/kg body mass, respectively. The regression equations between the probits of mortalities (Y) and the log of doses (D) was Y = −9.67 + 10.21 log (D). Histopathological studies on the organs from the dead mice showed: (1) no significant abnormal changes in the organs at the lowest dose (21.26 mg/kg body mass) studied, (2) prominent lesions mainly found in lung and kidney, with diffused haemorrhages in lung, and glomerular sclerosis and atrophy in kidney at doses ?32.40 mg/kg body mass, and (3) multiple abruption of cardiac muscle fibres and anachromasis of cortical neurons at the highest dose of 36.00 mg/kg body mass. The results obtained would aid in developing safety measures for the Jatropha based biofuel industry and in exploiting the pharmaceutical and agricultural applications of phorbol esters.  相似文献   

11.
This study was carried out to investigate the chemopreventive effects of immature plum extracts. The methanol extract of immature plums (plum 1), that are picked at 20–40 days before final harvest, has remarkably inhibited the growth of hepatoma HepG2 cells. The effects of immature plum extracts on hepatotoxicity in benzo(α)pyrene (B(α)P, carcinogen)-treated mice were investigated. Male ICR mice were pretreated with immature plum extracts (2.5 or 5 g/kg bw/day, for 5 days, i.p.) before treatment with B(α)P(0.5 mg/kg bw, i.p., single dose). The activities of serum aminotransferase, cytochrome P450 (CYPs) and the hepatic content of lipid peroxide were increased on B(α)P-treatment group than control, but those levels were significantly decreased by the pretreatment of immature plum extracts. The primary CYPs involved in the metabolism and bioactivation of B(α)P are CYP1A1. The pretreatment of immature plum extracts inhibited the induction of CYP1A1 expression. The activities of glutathione peroxidase, superoxide dismutase and catalase were decreased by the pretreatment of immature plum extracts more than with B(α)P alone. Whereas, the hepatic content of glutathione and glutathione S-transferase activity depleted by B(α)P was significantly increased (p > 0.05). These results suggest that immature plum extracts may counteract toxic effects of carcinogens, such as B(α)P, and therefore possess the chemopreventive efficacy.  相似文献   

12.
Phenolic and organic acid profiles of aqueous extracts from Pieris brassicae material and the host kale (Brassica oleracea L. var. acephala) leaves were determined by HPLC/UV–DAD/MSn-ESI and HPLC–UV, respectively. The identified phenolics included acylated and nonacylated flavonoid glycosides, hydroxycinnamic acyl gentiobiosides, and sulphate phenolics. Kale exhibited the highest content (11 g/kg lyophilized extract), while no phenolics were identified in the butterflies or exuviae. Nine different organic acids were characterized in the materials, with kale showing the highest amount (112 g/kg lyophilized extract). With the exception of the exuviae extract, the rest were screened for bioactivity. Using spectrophotometric microassays, all exhibited antiradical capacity against DPPH and NO in a concentration-dependent way, whereas only kale and excrement extracts were active against superoxide. All displayed activity on intestinal smooth muscle, albeit with distinct relaxation–contraction profiles. Larvae and butterfly extracts were more efficacious for intestinal relaxation than was kale extract, whereas excrement extract evoked only contractions, thus evidencing their different compositions. Collectively, these results show that P. brassicae sequesters and metabolizes kale’s phenolic compounds. Moreover, the extract’s bioactivities suggest that they may constitute an interesting source of bioactive compounds whose complex chemical structures preclude either synthesis or isolation.  相似文献   

13.
A disease causing anorexia and ruminal indigestion in cattle and goats, and also edema of the lips, tongue and face in goats, was associated with the ingestion of Centratherum brachylepis in pastures containing large amounts of the plant. On 3 farms with a total of 217 cattle and 140 goats, 57 (26%) cattle and 56 (40%) goats were affected, and 11 (5%) cattle and 34 (24%) goats died. In one cow that died there were widespread and severe histologic lesions in the rumen that consisted of vacuolation and ballooning degeneration of keratinocytes, and vesicle and pustule formation in the epithelium. C. brachylepis was administered orally to 3 sheep and 11 goats. Clinical signs similar to those observed in spontaneous field cases in goats were reproduced in 2 sheep and 3 goats that ingested 30-50 g/kg body weight of the plant when administered within 48 h of it being collected. C. brachylepis collected between 2 and 13 days prior to being administered caused no clinical signs in 1 sheep and 8 goats at dose rates of 30-300 g/kg body weight of the plant. These feeding studies provide evidence that C. brachylepis is the cause of the field disease observed and that the plant loses toxicity after harvesting.  相似文献   

14.
Snake venoms have demonstrated antinociceptive activity, and certain isolated neurotoxins have demonstrated significant analgesia in animal models. Here we report a novel analgesic toxin which was isolated from Naja naja atra and was given the name ‘najanalgesin’. The LD50 of the crude venom and najanalgesin were 0.89 mg/kg and 2.69 mg/kg, respectively. We used the writhing test and hot plate test to evaluate the antinociceptive properties of the crude venom and najanalgesin after intraperitoneal (ip) administration. The analgesic mechanism of najanalgesin was also studied. The response latency time was significantly prolonged in the hot plate test after ip administration of the crude venom of Naja naja atra (0.111-0.445 mg/kg) in a dose-dependent manner. Najanalgesin (1 mg/kg) elicited almost the same antinociceptive effect as that of the crude venom of Naja naja atra at the dose of 0.445 mg/kg and remained for 6 h after intraperitoneal injection, shown by hot plate test. The percentage of increase in the latency time for the venom and the najanalgesin 3 h after drug administration was 96.2% and 112%, respectively. The number of writhes decreased to almost 1/3, 1/6, and 1/12 of the NS (physiological saline) group after intraperitoneal administration of najanalgesin at 0.25, 0.5, and 1.0 mg/kg, respectively. Pretreatment with atropine (1 mg/kg) or naloxone (3 mg/kg) blocked the antinociception of najanalgesin in the hot plate test. Based on the sequence information, najanalgesin is found to be highly homologous with the conventional CTXs (cardiotoxins). To our knowledge, no study had previously reported that a toxin which was homologous with CTXs possessed the antinociceptive activity. Thus, this is the first report that the antinociceptive effect induced by najanalgesin is mediated by cholinergic and opioidergic mechanisms.  相似文献   

15.
Clinically used anticoagulant warfarin is usually available as a racemic mixture of S- and R-warfarin that are both metabolized mainly by cytochrome P450 isoenzymes. Determination of warfarin enantiomers and their enantiomeric 7-hydroxywarfarin (7-OH-warfarin) metabolites in the human plasma sample allows probing of cytochrome P450 isoenzyme activities and detection of ingestion of warfarin-containing products for the investigation of unexplained bleeding. The present study aims to develop a sensitive and specific liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for simultaneous detection of S-warfarin, R-warfarin, S-7-OH-warfarin and R-7-OH-warfarin in human plasma. Plasma samples were extracted with mixed-mode cation-exchange (MCX) cartridge with recoveries of greater than 87.0% for all four analytes. The selectivity of 7-OH-warfarin from other monohydroxylated warfarin metabolites such as 4′-, 6-, 8- and 10-hydroxywarfarins using a Chirobiotic V chiral column and multiple reaction monitoring (MRM) was addressed. The developed LC–MS/MS method is simple, specific and has been fully validated with satisfactory accuracy and adequate reproducibility with limit of quantification (LOQ) of 5 ng/ml for all four analytes. The method was successfully applied to analyze the steady state plasma concentrations of the four analytes in 30 patients.  相似文献   

16.
The flower buds of Syzygium aromaticum (clove), a common food flavor, have been used as indigenous medicine for the treatment of male sexual disorders in Asian countries. However, the possible mechanism(s) by which it acts at testicular level remain obscure. Therefore, to investigate its effect on testicular function, chronic oral exposure of hexane extract of flower buds of Syzygium aromaticum in three doses (15 mg, 30 mg, and 60 mg/kg BW) were evaluated for a single spermatogenic cycle (35 days) in Parkes (P) strain mice. The treatment did not induce systemic toxicity at the doses tested. Lower dose (15 mg) of the extract increased the activities of Δ5 3 β-HSD and 17 β-HSD, and serum level of testosterone. The higher doses (30 and 60 mg) of extract inhibited these parameters and induced non-uniform degenerative changes in the seminiferous tubules associated with decrease in daily sperm production and depletion of 1C (round and elongated spermatids) population. Taken together these results suggest biphasic action of hexane extract of Syzygium aromaticum flower bud on testicular function, thereby advocating a cautious use of the flower bud as an aphrodisiac in indigenous systems of medicine in Asian countries.  相似文献   

17.
Chlorella are traditionally freshwater green algae that have been evaluated for dietary purposes because of their nutritional value. This study investigates the safety of Chlorella protothecoides in a 28-day study. Sprague–Dawley rats were administered 0 (control), 2.5, 5.0, or 10% of their diet for 28 days using an FDA Redbook protocol. The average daily dietary intake of algal biomass was determined to be 0, 1794, 3667, and 7557 mg/kg body weight for males and 0, 1867, 3918, and 8068 mg/kg body weight for females. Hematological and biochemical analyses were conducted, and upon completion, gross and microscopic evaluations were performed. No signs of toxicity were observed. Although statistically significant alterations were noted in several parameters among males and females, these changes were deemed to be of no toxicological significance due to the lack of dose–response relationships, the fact that they occurred in only one sex, and the lack of any supporting gross or microscopic alterations. The no-observed-adverse-effect level for the algal biomass under the conditions of this study was considered to be 10% in the diet, the highest dose tested.  相似文献   

18.
Water-soluble crude polysaccharide from a brown alga Turbinaria ornata (TCP) was screened for its antioxidant and anti-inflammatory potential. The major functional groups of polysaccharide were analyzed by Fourier Transmission-Infra Red (FT-IR). In vitro free radical quenching and total antioxidant activity of TCP was investigated by 1, 1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide (NO) scavenging, lipid peroxidation (LPO) inhibition and ABTS radical assay. Evaluation of anti-inflammatory activity of TCP was performed using carrageenan-induced paw edema in rats and vascular permeability test in mice. Phytochemical analysis of TCP showed the presence of carbohydrates, proteins and polyphenols further, the FT-IR analysis of TCP showed the presence of functional groups of sugar moiety, uronic acids and sulfate groups. TCP showed maximum LPO, NO and DPPH inhibition of 78.04%, 38.82% and 80.21% at a concentration of 1000, 125 and 500 μg/ml respectively. Oral administration of TCP (2.5, 5, 10, 20 mg/kg) reduced the paw edema considerably (p < 0.05) in a dose dependent manner compared to carrageenan induced rats. Similarly, oral administration of TCP (3, 10, 30 mg/kg) evoked a significant (p < 0.05) dose dependent inhibitory effect on vascular permeability in mice. Altogether, these results suggest that the crude polysaccharide of T.ornata could be considered as a potential antioxidant and anti-inflammatory agent.  相似文献   

19.
Exposure to benzene, toluene and xylene in the human population may pose a health risk. We tested a working hypothesis that these test chemicals cause cellular toxicity to a non-target organism, Drosophila melanogaster. Third instar larvae of D. melanogaster transgenic for hsp70, hsp83 and hsp26 and Oregon R+ strain were exposed to 1.0-100.0 mM benzene, toluene and xylene for 2-48 h to examine the heat shock proteins (hsps), ROS generation, anti-oxidant stress markers and developmental end points. The test chemicals elicited a concentration- and time-dependent significant (p < 0.01) induction of the hsps in the exposed organism in the order of hsp70 hsp83 ≥ hsp26 as evident by β-galactosidase activity after 24 h. RT-PCR amplification studies in Oregon R+ larvae revealed a similar induction pattern of these genes along with hsp60 in the order of hsp70 hsp60 hsp26 ≥ hsp83. Under similar experimental conditions, a significant induction of ROS generation and oxidative stress markers viz. superoxide dismutase, catalase, glutathione S-transferase, thioredoxin reductase, glutathione, malondialdehyde and protein carbonyl content was observed. Sub-organismal response was propagated towards organismal response i.e., a delay in the emergence of flies and their reproductive performance. While hsp70 was predominantly induced in the organism till 24 h of treatment with the test chemicals, a significant or insignificant regression of Hsp70 after 48 h was concurrent with a significant induction (p < 0.01) of hsp60 hsp83 ≥ hsp26 in comparison to the former. A significant positive correlation was observed between ROS generation and these hsps in the exposed organism till 24 h and a negative correlation between ROS generation and hsp70 in them after 48 h indicating a modulatory role of ROS in the induction of hsps. The study suggests that among the tested hsps, hsp70 may be used as an early bioindicator of cellular toxicity against benzene, toluene and xylene and D. melanogaster as an alternative animal model for screening the risk posed by environmental chemicals.  相似文献   

20.
This study was carried out to evaluate the anticandidal effects of bioconverted product, obtained from the microbial conversion of cabbage (Brassicaoleracea) by a bacterial strain Pseudomonassyringe pv. T1 (Ps-T1) against various isolates of Candida species. The diameters of zones of inhibition of bioconverted product of cabbage (10 μl, corresponding to 500 μg/disc) against Candidaalbicans KACC 30003 and 30062, Candidageochares KACC 30061, Candidasaitoana KACC 41238 and Candidaglabrata P00368 were found between 10 ± 1 and 16 ± 0.8 mm. The bioconverted product was tested for the minimum inhibitory and minimum fungicidal concentration values against the tested pathogens which were found in the range of 125-500 and 125-500 μg/ml, respectively. On the viable counts of the tested fungal pathogens, the bioconverted product showed a remarkable anticandidal effect. Also the study of using scanning electron microscopy on the morphology of C.albicans KACC 30062 revealed potential detrimental effect of bioconverted product at MIC concentration. The results of this study suggest that bioconverted product of cabbage by Ps-T1 holds potential therapeutic value and medicinal significance to control Candida species.  相似文献   

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