Glutathione Biosynthesis in the Postimplantation Rat Conceptus in Vitro

Glutathione (GSH) biosynthesis in Day 10 rat conceptuses was characterized in whole embryo culture by evaluation of net rates of GSH replenishment in whole conceptuses, embryos. and visceral yolk sacs (VYS); uptake and distribution of [³⁵S]cysteine and [³⁵S]methionine from the culture medium; incorporation of ³⁵S-labeled amino acids into GSH; and efflux of [³⁵S]GSH into the culture medium. Diethyl maleate (DEM, 500 μM) depleted intracellular GSH pools in embryo and VYS to 30% of control values within 45 min. Restoration of GSH pools in VYS began immediately and continued at a rate of 295 pmol/ conceptus/hr until GSH concentrations exceeded initial control levels at 4 hr. GSH pools in the embryo remained depleted for over 2 hr, followed by resynthesis at initial rates of 118 pmol/ conceptus/hr. [³⁵S]Cysteine (0.2 mM) uptake from the culture medium resulted in whole conceptus accumulations that reached 1.6 nmol/conceptus. The portion of intracellular free cysteine obtained through uptake of extraconceptal amino acid was 40-90 pmol/conceptus and represented less than 20% of the total free intracellular cysteine. [³⁵S]Methionine (0.2 mM) accumulation surpassed that of cysteine at all time points by two- to threefold. [³⁵S]Cysteine, added 2 hr after DEM, was incorporated into GSH at rates of 126 pmol/conceptus/hr during the first hour. By 4 hr, rates of incorporation had declined to 22 pmol/conceptusfhr. L-Buthionine-[S,R]-sulfoximine (1 mM) completely eliminated incorporation of [³⁵S]cysteinc into GSH. Net efflux of [³⁵S]GSH into the culture medium accounted for less than 40 pmol of total GSH when measured 5 hr after DEM addition. Although effectively transported into the conceptus and readily utilized in protein synthesis, ³⁵S from methionine was not incorporated into GSH under any conditions tested. After chemical depletion, de novo GSH synthesis occurs exclusively in the VYS. Embryonic recovery begins only after GSH pools in the VYS are replete. Prolonged embryonic GSH depletion and slower recovery rates indicate that the embryo may be selectively susceptible to chemical insult following depletion of GSH.     

温度胁迫下泽泻中三萜类成分及其生物合成酶基因的相关性研究

目的 研究温度胁迫下泽泻中三萜类成分及其生物合成酶基因表达的相关性。方法 以不同温度（0℃、6℃、16℃,26℃）栽培下的泽泻为研究对象,采用UPLC-MS/MS法检测泽泻叶片中8种三萜类成分泽泻醇A、泽泻醇B、泽泻醇F、泽泻醇G、24-乙酰泽泻醇A、23-乙酰泽泻醇B、23-乙酰泽泻醇C、24-乙酰泽泻醇F的含量及总量,并采用qRT-PCR技术检测三萜类合成途径中生物合酶HMGR、SQS、FPPS、MVD的mRNA水平。结果 泽泻叶片中23-乙酰泽泻醇B及8种三萜类成分总量与SQS、HMGR基因的mRNA水平呈正相关（P <0.05）;而FPPS及MVD基因在不同温度干预下mRNA水平无显著性变化（P >0.05）。结论 SQS、HMGR可能是泽泻中三萜类成分合成的限速酶,且其表达受到环境温度的调节,为泽泻药材质量的调控提供了理论依据。     

The Acute Toxicity of 2,3,4,7,8-Pentachlorodibenzofuran (4PeCDF) in the Male Fischer Rat

The Acute Toxicity of 2,3,4,7,8-Pentachlorodibenzofuran (4PeCDF)in the Male Fischer Rat. Brewster, D. W., Uraih, L. C, and Birnbaum,L. S. Fundam. Appl. Toxicol. 11, 236-249 Polychlorinated dibenzofuransare ubiquitous environmental pollutants which have great potentialfor human exposure. To characterize the toxicity of 2,3,4,7,8-pentachlorodibenzofuran(4PeCDF), male F344 rats were administered a single oral doseof 0, 100, 250, 500, 1000, or 2000 µg 4PeCDF/kg. A progressiveand dose-dependent loss of body weight was evident by 3 daysafter treatment. Signs of toxicity included piloerection, hairloss, hypoactivity, morbidity, and death. Death occurred assoon as 14 days after treatment and continued throughout the35-day observation period. The LD5O/35 was estimated to be 916µgAg with a 95% confidence interval of 565–1484µgAg. Dose-dependent increases were observed in serumcholesterol, tri-glyceride, and bile acid concentrations andin sorbitol dehydrogenase and aspartate aminotrans-ferase activities.The hematocrit, hemoglobin, mean corpuscular volume, and meancorpuscular hemoglobin concentrations were depressed in a dose-dependentfashion. Hepatic ethoxyresoru-fin-O-deethylase (EROD) activitywas increased in all treatment groups approximately 25 timesabove that of control animals. Lymphoid depletion in the thymusand spleen was observed in the three highest doses and thymicatrophy was present at all dose levels. Absolute liver weightand the livenbody weight ratio were significantly increasedabove controls. Hepatotoxicity was dose-dependent and was characterizedby lipid accumulation resulting in hepatocytomegaly. Epithelialhyperplasia and focal ulcerations of the forestomach was observedin animals administered 500 µg 4PeCDF/kg. Spontaneouscardiomyopathy was exacerbated by treatment with 2000 µgKg.Since 4PeCDFand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) producea similiar spectrum of toxic effects, the biochemical mechanism(s)of toxicity for these chemicals may be Similar.     

Carcinogenicity of Oral Cadmium in the Male Wistar (WF/NCr) Rat: Effect of Chronic Dietary Zinc Deficiency

The effect of chronic dietary zinc deficiency on the carcinogenicpotential of dietary cadmium was assessed in male Wistar (WF/NCr)rats. Groups (n=28) of rats were fed diets adequate (60 ppm)or marginally deficient (7 ppm) in zinc and containing cadmiumat various levels (0, 25, 50, 100, or 200 ppm). Lesions wereassessed over the following 77 weeks. Zinc deficiency alonehad no effect on survival, growth, or food consumption. Cadmiumtreatment did not reduce survival or food consumption and onlyat the highest doses of cadmium (100 and 200 ppm) was body weightreduced (maximum 17%). The incidence of prostatic proliferativelesions, both hyperplasias and adenomas, was increased overthat seen in controls (1.8%) in both zinc-adequate (20%) andzinc-deficient rats (14%) fed 50 ppm cadmium. The overall incidencefor prostatic lesions for all cadmium treatment groups was,however, much lower in zinc-deficient rats, possibly becauseof a marked increase in prostatic atrophy that was associatedwith reduced zinc intake. Cadmium treatment resulted in an elevatedleukemia incidence (maximum 4.8-fold over control) in both zinc-adequateand zinc-deficient groups, although zinc deficiency reducedthe potency of cadmium in this respect. Testicular tumors weresignificantly elevated only in rats receiving 200 ppm cadmiumand diets adequate in zinc. Both zinc-deficient and zinc-adequategroups showed significant positive trends for development oftesticular neoplasia with increasing cadmium dosage. Thus, oralcadmium exposure is clearly associated with tumors of the prostate,testes, and he matopoietic system in rats, while dietary zincdeficiency has complex, apparently inhibitory, effects on cadmiumcarcinogenesis by this route.     

Evaluation of Pharmacokinetic Drug Interactions Between Gemigliptin (Dipeptidylpeptidase-4 Inhibitor) and Glimepiride (Sulfonylurea) in Healthy Volunteers

Purpose

Gemigliptin is approved for the treatment of type II diabetes mellitus. Sulfonylureas are commonly used in combination with other antidiabetic drugs to improve glycemic control. The objective of this study was to evaluate the pharmacokinetics, safety, and tolerability of gemigliptin and glimepiride combination therapy compared with those of monotherapies.

Methods

A randomized, open-label, crossover study was performed on healthy Korean male volunteers. Each subject received the following treatments (A and B) with a 7-day washout period: treatment A consisted of gemigliptin 50 mg once daily administered orally for 6 days, followed by concomitant oral dosing of glimepiride 4 mg and gemigliptin 50 mg on day 7; treatment B consisted of a single dose of glimepiride 4 mg. Blood samples were collected up to 24-h postdose on day 6 (gemigliptin) and day 7 (gemigliptin and glimepiride) following treatment A, and on day 1 (glimepiride) following treatment B. Concentrations of gemigliptin, glimepiride, and metabolites were determined using validated liquid chromatography–tandem mass spectrometry (LC–MS/MS). Safety assessments were performed throughout the study.

Results

Twenty-three subjects completed the study. The geometric mean ratios (GMRs) of C_max,ss and AUC_τ,ss for gemigliptin were 1.0097 [90 % confidence interval (CI) 0.924–1.103] and 0.9997 (90 % CI 0.976–1.024), respectively. For glimepiride, the GMRs of C_max and AUC_last were 1.031 (90 % CI 0.908–1.172) and 0.995 (90 % CI 0.902–1.097), respectively. Both combination and monotherapy were well tolerated, and no serious adverse events were reported.

Conclusion

Gemigliptin and glimepiride did not alter the pharmacokinetic properties of each other when they were co-administered in healthy volunteers, and were generally tolerated.     

Evaluation of the Pharmacokinetic Interaction Between Diazepam and ACC-9653 (a Phenytoin Prodrug) in Healthy Male Volunteers

The protein binding and pharmacokinetics of diazepam, ACC-9653 (a phenytoin prodrug), and phenytoin were evaluated in nine healthy male volunteers following administration of diazepam and ACC-9653, alone or concomitantly, in a randomized crossover design. No significant differences were observed in the fraction unbound or pharmacokinetic parameters of ACC-9653, phenytoin, or diazepam when ACC-9653 was administered alone compared to concomitant administration with diazepam. The phenytoin fraction unbound increased significantly with increased concentrations of ACC-9653, indicating displacement of phenytoin from its binding sites by ACC-9653. ACC-9653 also demonstrated concentration dependent binding. The lack of a significant pharmacokinetic drug interaction between ACC-9653 and diazepam suggests that these drugs may be safely administered together, although this conclusion should be confirmed in the intended patient population.     

高效液相色谱荧光光谱法测定虎杖中的白藜芦醇及其苷的顺、反异构体

目的建立高效液相色谱法，分离和测定虎杖中的白藜芦醇及其苷的顺、反异构体的含量。方法采用Nucleodur 100-5 C₁₈柱(250 mm×4.6 mm ID, 5 μm)；流动相为异丙醇和水二元梯度洗脱系统；流速0.6 mL·min^-1；荧光检测器激发波长为334 nm，发射波长为404 nm。结果在选定色谱条件下白藜芦醇及其苷的顺、反异构体线性关系良好。样品加样平均回收率：反式白藜芦醇及其苷分别为96.7%和99.1%；顺式白藜芦醇及其苷分别为91.1%和93.7%。相对标准偏差：反式白藜芦醇及其苷分别为1.34%和0.72%；顺式白藜芦醇及其苷分别为1.27%和2.08%。结论本方法精密度好、结果可靠，适合虎杖中白藜芦醇及其苷的顺、反异构体定量分析。     

国产列当科肉苁蓉属的分类学研究

本文在详细回顾肉苁蓉属分类历史的基础上 ,对中国列当科肉苁蓉属进行了分类学研究 ,共记载 5种该属植物 ,并澄清了一些混淆的属的中文名称和错误鉴定。     

Differential responses to copper-induced oxidative stress in the marine macroalgae Lessonia nigrescens and Scytosiphon lomentaria (Phaeophyceae)

In order to help explain the absence of the brown kelp Lessonia nigrescens from a coastal environment chronically enriched with copper, we characterized the biochemical responses induced by copper stress in this kelp and compared them with those displayed by the copper tolerant brown alga Scytosiphon lomentaria. These algae were cultivated with increasing concentrations of copper (20, 40 and 100 μg L⁻¹) for 96 h and the temporal production of hydrogen peroxide, superoxide anions and lipoperoxides as well as the activities of antioxidant enzymes catalase (CAT), glutathione peroxidase (GP), ascorbate peroxidase (AP), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) and the activity of the defense enzyme lipoxygenase (LOX) were determined. In L. nigrescens and S. lomentaria, a single peak of hydrogen peroxide was detected, with similar maxima after 3 h of copper exposure, although in L. nigrescens buffering took longer. Superoxide anions, on the other hand, were only detected in L. nigrescens. The production of lipoperoxides in L. nigrescens increased steadily at higher copper levels, in a pattern clearly different to their rapid stabilization in S. lomentaria. We suggest that the accumulation of lipoperoxides might be related to LOX, whose activity also increases with exposure time. Furthermore, activities of the antioxidant enzymes CAT, GP, AP and DHAR were lower in L. nigrescens than in S. lomentaria, and GP and DHAR were completely inhibited at higher copper concentrations. Since these enzymes also detoxify fatty acid hydroperoxides, their inhibition, together with the activation of LOX, may explain the persistent and copper-dependent levels of lipoperoxides in L. nigrescens. Based on terrestrial plant models demonstrating toxic effects of lipoperoxides, and on our results on organellar ultrastructural changes, we suggest that copper toxicity induced an uncontrolled lipoperoxide accumulation which may lead to cell damage and dysfunction in L. nigrescens, explaining at least partially, the absence of this kelp in a copper-enriched coastal environment.     

Isolation and analysis of bioactive diterpenoids in Salvia species (Salvia chionantha and Salvia kronenburgiii) by micellar electrokinetic capillary chromatography

In the present work, we isolated two bioactive diterpenoids, horminone and 7-O-acetylhorminone and developed a micellar electrokinetic chromatography (MEKC) method for the simultaneous quantitative analysis of them in Turkish Salvia species. The optimal separation electrolyte was 50 mmol/L SDS and 25% methanol at pH 11.5. The limits of detection (S/N = 3) were 3.269 and 4.518 μg/mL for horminone and 7-O-acetylhorminone, respectively. The method has been applied successfully to analyze these two components in Salvia chionantha and Salvia kronenburgii acetone extracts.     

Comparative Potencies of Aroclors 1232, 1242, 1248, 1254, and 1260 in Male Wistar Rats--Assessment of the Toxic Equivalency Factor (TEF) Approach for Polychlorinated Biphenyls (PCBs)

Immature male Wistar rats were treated with several differentdoses of the commercial polychlorinated biphenyls (PCBs) Aroclors1232, 1242, 1248, 1254, and 1260 (10, 40, 160, 480, and 2000mg/kg) and the effects on body weight gain, thymic atrophy,and the induction of hepatic microsomal aryl hydrocarbon hydroxylase(AHH), ethoxyresorufin O-deethylase (EROD), and pentoxyresorufin(O-deethylase (PROD) activities were measured 14 days aftertreatment. A significant inhibition in body weight gain wasobserved only in rats treated with high doses of Aroclors 1232and 1248 and thymic atrophy was not observed for any of theAroclors. All the Aroclors caused a dose-dependent increasein hepatic microsomal AHH, EROD, and PROD activities. The correspondingED50 values for the induction of AHH-EROD activities variedfrom 51 to 678 mg/kg. Aroclor 1260 was the least active inducerof the P4501A1-mediated enzyme activities. In contrast, Aroclor1260 was a potent inducer of PROD activity (ED50=37 mg/kg),but Aroclors 1232, 1242,1248, and 1254 did not induce 50% ofthe maximal response at the highest dose used in this experiment(2000 mg/ kg). Previous studies have quantitated the levelsof those PCB congeners which induce AHH or EROD activities inAroclors 1232, 1242, 1254, and 1260 and their potencies or toxicequivalency factors (TEFs) relative to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) have also been estimated or experimentally determined.Using highly conservative TEF values it was demonstrated thatthe calculated ED50s for the Aroclors as inducers of AHH andEROD activity were significantly lower than the observed ED50values. However, if the TEFs were derived directly from therelative potencies of the PCBs (compared to 2,3,7,8-TCDD) asinducers of AHH and EROD activity, then there was a good correspondencebetween the observed and calculated ED50 Values.     

Secretion and regeneration of tetrodotoxin in the rough-skin newt (Taricha granulosa)

Rough-skin newts (Taricha granulosa) released tetrodotoxin (TTX) in their skin secretions in response to mild electric stimulation. This release resulted in a large (21% to almost 90% of the pre-stimulation levels) reduction in the amount of TTX present in the dorsal skin of individual newts. Over the next 9 months newts significantly regenerated the levels of TTX in their skin. These data, in combination with previously published results, are consistent with the hypothesis that these newts produce their own TTX.     

Toxicity of Methylenedioxymethamphetamine (MDMA) in the Dog and the Rat

Toxicity of Methylenedioxymethamphetamine (MDMA) in the Dogand the Rat. FRITH, C. H., CHANG, L. W., LATTIN, D. L., WALLS,R. C., HAMM, J., AND DOBLIN, R. (1987). Fundam. Appl Toxicol.9, 110–119. Methylenedioxymethamphetamine (MDMA) was administeredto dogs and rats orally once a day for a 28-day period to evaluatethe morphological and neuropathological effects. Major clinicalsigns associated with the administration of MDMA in the dogincluded circling, depression, dilated pupils, hyperactivity,rapid breathing, and salivation. Major clinical signs in therat included hyperactivity, excitability, piloerection, exophthalmos,and salivation. Gross observations at necropsy in the dog possiblyrelated to administration of the test article included reducedtesticular size (one high and one medium dose) and prostaticenlargement in two high-dose animals. No gross lesions wereseen in the rats at necropsy. The medium-and the high-dose groupsin both sexes in both the rats and the dogs gained significantlyless weight than the control and low-dose groups. Food consumptiondecreased the first week for the high-and medium-dose groups,but a significant reversal toward more normal consumption wasnoted in the following weeks in both the rats and the dogs.Hematologic, clinical chemistry, and urinalysis values did notappear to be affected by the administration of the test articlein the dog. in the rat clinical pathology variables showinga trend to decrease with dose included urinary pH, blood ureanitrogen, glucose, creatinine (females), lactate dehydrogenase(LDH) (females), and chloride. Clinical pathology variablesshowing a trend to increase with dose included total white bloodcell count and phosphorus. Microscopically, testicular atrophywas present in one medium-dose and two high-dose male dogs.Prostatic hyperplasia was present in two high-dose male dogs.No test article-related lesions were seen in the brains of eitherspecies.     

Arsenic species and leaching characters in tea (Camellia sinensis)

Tea is one of the most popular non-alcoholic beverages consumed in the world. Arsenic including species totalling to 47 Chinese tea samples from 18 tea-producing provinces in China were analyzed. By simulating the infusion process, leaching characters, effects of extraction time and temperature on arsenic extraction were investigated. Total amount of arsenic in tea leaf samples was in the range below the detection limit to 4.81 μg/g. Leaching of arsenic was strongly affected by extraction time and temperature. Because arsenic leaching ability by hot water was low and most of the arsenic was left in tea leaf residues after infusion, the concentration of arsenic in tea infusion was low even when some original tea leaf samples contained high level of arsenic. The major species in tea infusion were inorganic arsenic form (arsenite As^III and arsenate As^V). Compared with the amount of arsenic in infusion, more organic arsenic species were found in the original tea leaf samples. The contents of extractable inorganic arsenic in tea leaf samples were in the range below the detection limit to 226 ng/g. Considering ingestion dose and assuming one person (60 kg body weight) consumes 10 g of Chinese tea per day, the maximum inorganic arsenic contribution from tea infusion is 2.26 μg, which is equal to 0.038 μg/kg/d excluding water contribution. This value only accounts for 1.8% of provisional tolerable weekly intake (PTWI) (2.1 μg/kg/d) recommended by the Food and Agriculture Organization/World Health Organization [FAO/WHO, 1989. Evaluation of certain food additives and contaminants. Thirty-third Report of the Joint FAO/WHO Expert Committee on Food Additives. WHO Technical Report Series No. 776, Geneva, World Health Organization].     

Effects of L-Carnitine and Ginkgo Biloba Extract (EG b 761) in Experimental Bleomycin-Induced Lung Fibrosis

The effects of Ginkgo biloba extract (EGb 761) and L-carnitine on bleomycin (BLM)-induced lung fibrosis were studied in rats. BLM (cumulative dose of 180 mgkg(-1)) was given intraperitoneally (i.p.) three times weekly for 4 consecutive weeks. Treatment with BLM enhanced the responsiveness of isolated pulmonary arterial rings to serotonin (5-HT), significantly increased the normal serum level of tumour necrosis factor (TNF-alpha) by approximately 105% and markedly elevated the level of lipid peroxide (LPO) and collagen content in the lung homogenates by 34 and 83%, respectively. EGb 761 (100 mgkg(-1) ), given in drinking water for the whole study period, totally abolished the BLM-induced alterations in the measured biochemical and pharmacological parameters. Meanwhile, L-carnitine (500 mg kg(-1) ), administered in drinking water, significantly decreased the BLM-induced elevations of serum TNF-alpha, LPO level in lung tissues and the enhanced responsiveness of pulmonary arterial rings to 5-HT. However,L-carnitine did not reduce the increase in the collagen content produced by BLM. The results of the present study indicate the beneficial effects of EGb 761 and L-carnitine against lung toxicity induced by BLM treatment. Furthermore, the present data shows the advantageous use of EGb 761 as a protective agent in BLM-induced lung fibrosis under the experimental circumstances.     

Prenylated flavonoids and related compounds of the Indonesian Artocarpus (Moraceae)

Several species of the genus Artocarpus (Moraceae) have been investigated in our laboratories during the last decade. Over 60 phenolic constituents have been discovered and characterized, including 27 new compounds from 13 Indonesian taxa of Artocarpus, namely A. champeden, A. lanceifolius, A. teysmanii, A. scortechinii, A. rotunda, A. maingayi, A. kemando, A. bracteata, A. altilis, A. fretessi, A. gomezianus, A. reticulatus and A. glaucus. The principal and the most pronounced features of these phenolic constituents are the assembly of an isoprenyl substituent at C-3 of a flavone skeleton by closure of an ether bridge or a carbon–carbon linkage with the B ring of the skeleton, which may further rearrange into xanthone to produce various classes of natural products. The structures of the new and unusual natural products are presented. Many of the metabolites also exhibit cytotoxic effect against murine leukemia P388 cells.     

Study on the Correlation Between the Microstructure Quantification and the Content of Quality Markers of Cultivated Astragalus Membranaceus(Fisch.)Bge.var.Mongholicus(Bge.)Hsiao in Gansu Province

研究蒙古黄芪横切面组织显微定量与质量标志物含量的相关性,为蒙古黄芪商品等级划分和质量评价提供依据。

测量13批蒙古黄芪药材横切面7个组织显微定量参数,HPLC测量质量标志物中7个化学成分;对13批蒙古黄芪药材的7个组织显微定量参数和7个质量标志物及其相加相除运算的8个结果(以下简称“运算结果”),分别运用SPSS 26.0软件进行Spearman相关性分析和聚类分析,Graphpad Prism 8.0对显著相关变量进行多元线性回归,SIMCA 14.1进行主成分分析。

木射线数、木质部宽度、木栓层宽度、韧皮部宽度/木质部宽度与质量标志物及其运算结果存在多对显著相关关系,蒙古黄芪横切面组织形态可以描述质量标志物含量。主成分分析提取了2个主成分,对主成分贡献较大的6个变量分别是毛蕊异黄酮苷、芒柄花苷、韧皮部宽度/木质部宽度、黄芪甲苷、黄芪皂苷I、黄芪皂苷II,其将13批蒙古黄芪药材分为2类,结果与聚类分析一致。

本研究基于横切面组织显微定量与质量标志物含量的相关性,以蒙古黄芪横切面组织显微定量参数间接表征质量标志物的含量,为蒙古黄芪药材商品等级划分的综合依据提供新的科学基础,对于蒙古黄芪药材质量现代化评价模式的形成具有参考价值。