Antigenotoxic effects of quercetin, rutin and ursolic acid on HepG2 cells: evaluation by the comet assay

In the present study, the chemoprotective effects of quercetin, rutin and ursolic acid on tert-butyl hydroperoxide (t-BHP)-induced DNA damage in a human hepatoma cell line (HepG2) were investigated by the comet assay. To determine whether protection was due to direct chemical interactions alone or to cellular-mediated responses three different types of treatments were used: simultaneous incubation of cells with individual test compounds and the toxicant; pre-treatment with test compound before addition of the toxicant followed or not by a recovery period. The expression of Hsp70 was quantified by Western blotting to test the involvement of heat shock proteins in the cellular responses to the test compounds. In addition, effects on proliferation were evaluated by the MTT assay. The results show that quercetin and ursolic acid prevented DNA damage and had antiproliferative properties in HepG2 cells suggesting an anticarcinogenic potential for these compounds. The protective effects of quercetin against t-BHP-induced DNA damage seem to be due to both direct effects on t-BHP toxicity and to cellularly mediated indirect effects which reflect the potentiation of the cellular antioxidant defenses. Ursolic acid seems to exert effects only through cellularly mediated mechanisms since it was not protective in simultaneous incubation. Quercetin and ursolic acid also showed to increase the rate of DNA repair. Rutin did not have effects at any level. These results, obtained with liver cells, emphasize and confirm the chemopreventive potential of quercetin and ursolic acid, which may help explain the lower cancer incidence in human population with high dietary intakes of fruits and vegetables. These results also demonstrate that Hsp70 is not involved in the observed effects in HepG2.

Developmental competence and expression of the Hsp 70.1 gene in oocytes obtained from Bos indicus and Bos taurus dairy cows in a tropical environment

Bos indicus cows usually have better reproductive performance in tropical and subtropical regions than Bos taurus cows, presumably due to their better adaptation to tropical environments. The aim of this study was to evaluate the developmental competence and expression of the Hsp 70.1 gene in immature oocytes from B. taurus (Holstein) and B. indicus (Gyr) dairy cows raised in a tropical region. Cumulus-oocyte complexes were obtained by transvaginal ultrasound-guided follicle aspiration between spring and early autumn, and subjected to in vitro maturation and fertilization. Presumptive zygotes were co-cultured with their own cumulus cells in CR2aa media with 10% fetal calf serum; Grade 1 blastocysts were transferred to synchronized crossbred recipients. The total RNA was extracted from immature Holstein and Gyr oocytes (three pools for each breed) and relative quantification of the Hsp 70.1 transcripts was performed by real time PCR after reverse transcription. Cleavage and blastocyst rates were greater (P<0.05) for Gyr (n=390 oocytes) than Holstein (n=505) breed (66.7% versus 53.1% of cleavage and 19.6% versus 10.8% of blastocysts, respectively), but pregnancy rates were not significantly different following transfer to recipients (44.5% for 36 Gyr embryos; 60% for 10 Holstein embryos). Holstein immature oocytes had a higher level (P<0.05) of Hsp 70.1 relative expression (1.82+/-0.22; mean+/-S.E.M.) than Gyr oocytes (1.12+/-0.11). In conclusion, Gyr oocytes obtained in a tropical region were less subject to stress and more likely to develop (after IVF) than Holstein oocytes.

318 EFFECT OF MATERNAL HEAT STRESS ON OOCYTE QUALITY AND IN VITRO COMPETENCE IN BOS INDICUS CATTLE

High temperatures can be harmful to the competence of cumulus–oocyte complexes and to embryo development (Al-Katanani et al. 2002 J. Dairy Sci. 85, 390–396). The aim of this study was to evaluate the effect of maternal heat stress on in vitro embryo yield. Ten multiparous nonlactating Gir (Bos indicus) cows were kept in tie stalls for an adaptive period of 28 days [pre-heat-stress period (PRE-HS)/Days -28 to -1]. Cows were subjected to 2 OPU (ovum pickup) sessions (Days -14 and -7). In the heat-stress period (HS; Days 0 to 28), cows were divided into control (C: n = 5) and heat-stressed (HS: n = 5) groups. During this period, OPU sessions were performed once a week from Days 0 to 28. The C group remained in a thermo-neutral environment, and the HS group was kept in a climatic chamber with controlled temperature and humidity (38�C and 80% during the day and 30�C and 80% during the night). In the post-heat-stress period (POST-HS; Days 28 to 147), all cows returned to thermo-neutral conditions. Then 17 OPU sessions were performed once a week from Days 35 to 147. In all periods, blood samples were collected weekly for progesterone (P4) analysis, and ovarian follicles were counted, measured, and aspirated. The COCs were evaluated and selected for the IVF procedure. Data were analyzed by ANOVA (PROC MIXED of SAS) and a chi-squared test. The luteal phase was defined as the period between 2 samples with P4 below 1.0 ng mL-1. A handling accident caused the exclusion of an HS cow after the sixth session. The C and HS groups were subjected to 125 and 107 OPU sessions, respectively. Means � SEM for the C vs. HS groups, in the PRE-HS, HS, and POST-HS periods, respectively, were visualized follicles: 25.5 � 2.5 vs. 28.5 � 2.8, 24.2 � 1.1 vs. 24.0 � 1.9, and 15.3 � 0.6 vs. 15.8 � 0.8; largest follicle diameter: 12.1 � 1.5 vs. 11.1 � 1.7, 13.3 � 0.8 vs. 13.0 � 0.6, and 11.4 � 0.4b vs. 14.0 � 0.4a; P &lt; 0.05; 2nd largest follicle diameter: 6.2 � 1.3 vs. 6.0 � 1.2, 5.9 � 0.6 vs. 7.1 � 0.8, and 6.3 � 0.3b vs. 8.7 � 0.5a; recovered COCs: 11.2 � 2.8 vs. 14.3 � 2.5, 9.6 � 1.0 vs. 11.0 � 1.3, and 8.6 � 0.7 vs. 7.9 � 0.6; COCs selected for IVF: 69/112 (61.6%)b vs. 108/143 (75.5%)a, 164/241 (68%) vs. 172/265 (64.9%), and 426/712 (59.8%) vs. 305/535 (75.0%); cleavage: 44/59 (74.5%) vs. 87/105 (82.9%), 72/101 (71.3%) vs. 74/121 (61.2%), and 226/317 (71.3%) vs. 159/230 (69.1%); embryos per cow/OPU: 2.1 � 1.1y vs. 4.1 � 1.0x, 0.4 � 0.3 vs. 0.5 � 0.3, and 0.9 � 0.2x vs. 0.4 � 0.1y; P &lt; 0.1; and blastocyst yield: 16/59 (27.1%) vs. 33/105 (31.5%), 11/31 (35.5%) vs. 13/52 (25.0%), and 76/279 (27.2%)a vs. 25/188 (13.3%)b. In conclusion, maternal heat stress increased the percentage of short estrous cycles, decreased the P4 concentrations, and decreased the number of embryos produced by Bos indicus cows, mainly from 28 to 147 days post-heat-stress, showing long-term deleterious effects on blastocyst development.

272 DEVELOPMENTAL COMPETENCE OF OOCYTES OBTAINED FROM BOS TAURUS AND BOS INDICUS DAIRY COWS RAISED IN A TROPICAL CLIMATE

The effects of heat stress on Bos taurus reproductive performance in tropical and subtropical regions are well known, and have been associated with lower oocyte developmental capacity. The aim of this study was to evaluate the developmental competence of oocytes from Bos taurus (Holstein) and Bos indicus (Gyr) dairy cows raised in a Brazilian tropical region, located at 21°35′S latitude, 43°51′W longitude, and 435 meters altitude. Cumulus–oocyte complexes (COCs) were recovered by oocyte pickup (OPU) from mature non-lactating Holstein (n = 9) and Gyr (n = 13) donor cows between the end of spring and the beginning of autumn, with at least two OPU sessions/cow. COCs were in vitro-maturated in TCM-199 (GIBCO, Grand Island, NY, USA) with 10% inactivated estrus cow serum for 24 h under 5% CO2 at 38.5°C in air. Bos taurus and Bos indicus semen with similar cleavage rates, previously evaluated by in vitro fertilization with oocytes obtained from slaughterhouse ovaries, were used to reduce bull effect. Holstein and Gyr spermatozoa were obtained through swim-up method and co-incubated with Holstein (n = 390) and Gyr (n = 505) oocytes, respectively, in Fert-TALP medium (Parrish et al. 1988 Biol. Reprod. 38, 1171–1180) supplemented with 10 μg/mL heparin (Sigma-Aldrich, Sao Paulo, Brazil) and 6 mg/mL fatty acid-free bovine albumin (Sigma) for 18 h in 5% CO2 at 38.5°C in air. Presumptive zygotes were co-cultured with their own cumulus cells in CR2aa medium (Wilkinson et al. 1996 Theriogenology 45, 41–49) supplemented with 10% fetal calf serum in humid atmosphere of 5% CO2 at 38.5°C in air. On Day 7 to 8 of co-culture, Gyr and Holstein blastocysts were assessed and those classified as grade 1 (IETS Manual) were transferred to synchronized Bos indicus × Bos taurus crossbred recipients managed under the same nutritional and environmental conditions. Pregnancy diagnosis was performed between 35 and 50 days after estrus. Cleavage, blastocyst, and pregnancy rates were analyzed by chi-square test. Cleavage and blastocyst rates were greater (P < 0.05) in Gyr than in Holstein (66.7% vs. 53.1% for cleavage and 19.6% vs. 10.8% for blastocyst, respectively), but the pregnancy rate was similar (P > 0.05; 44.5% vs. 60% for Gyr and Holstein, respectively). These results show that Gyr oocytes obtained in a tropical region have greater developmental capacity than Holstein oocytes, suggesting an interaction between genotype and environment that influences the success of an in vitro embryo production program; nevertheless, the blastocyst viability after transferring to recipients is similar for both breeds.

Metal contents in Porites corals: Anthropogenic input of river run-off into a coral reef from an urbanized area, Okinawa

In order to monitor pollutants from urban areas to coral reefs, metal contents in Porites coral samples collected from the Hija River mouth and at nearby sites from the estuary were analyzed. The corals were cleaned by oxidative and reductive treatments to effectively eliminate detritus and organic materials. Metal-to-calcium (Me/Ca) ratios in the samples were determined by ICP-MS. Filtered samples of river water were also measured similarly for metal concentrations. The extent of anthropogenic contribution by riverine input was assessed by comparing the Me/Ca values in corals to those of Rukan-sho, an unpolluted coral reef. High riverine inputs of Mn, Cd, Zn and Ag were observed from Me/Ca values in the coral samples. Manganese in the coral samples showed strong dependence on salinity, varying inversely to the distance from terrestrial sources. Considering a lead background of 25.0 nmol/mol measured in the Rukan-sho corals, Pb/Ca in corals of the Hija River estuary that are two and three times higher may indicate lead enrichment in the river mouth. Because Pb is only moderately high in the Hija River water compared to its concentration in surface seawater, lead may have accumulated in the estuarine water and sediments, resulting in an elevated concentration of lead available for coral uptake.

Effectiveness of the ProFile.04 Taper Series 29 files in removal of gutta-percha root fillings during curved root canal retreatment

The purpose of this in vitro study was to evaluate the capacity of ProFile.04 Taper Series 29 files to remove gutta-percha during curved root canal retreatment. Forty-four mandibular molars whose mesial roots presented between 26 and 40 degrees of curvature, determined by Schneider's method, were selected. The root canals were enlarged to ISO size 35 and obturated with laterally condensed gutta-percha using Sealer 26. The teeth were randomly divided into three groups for gutta-percha removal: GI: size 2 Gates Glidden drills; GII: size 6 ProFile.04 Taper Series 29 files; GIII: size 7 ProFile.04 Taper Series 29 files. The penetration of the instruments was measured with millimetered x-rays and clinical observation. The ProFile.04 Taper Series 29 files removed the endodontic filling material better than the Gates Glidden files.

Determination of betamethasone 17-benzoate in lipophylic vehicles by reversed-phase high-performance liquid chromatography

A stability-indicating, reversed-phase HPLC method was developed to assay betamethasone 17-benzoate in lipophylic bases. An on-line precolumn sample clean-up system was used to protect the analytical column from contamination; it consisted of the Waters Guard-Pak Precolumn Module and the muBondapak C18 Precolumn Insert. The method is simple, specific, accurate, and precise. It is also cost effective because it extends the life of the HPLC column.