Antinociceptive activity of Helicteres isora

Helicteres isora root extracts were studied for antinociceptive activity on acetic acid-induced writhing test in mice, at a dose of 250 mg/kg. Petroleum ether, chloroform and aqueous ethanol extracts have shown significant activity.     

Pharmacokinetics and relative bioavailability of tiamulin in broiler chicken as influenced by different routes of administration

The bioavailability and pharmacokinetic disposition of tiamulin in broiler chicken were investigated after administration through the crop, drinking water, and feed at 40 mg/kg body weight. Residues of tiamulin in tissues of broiler chicken were also assessed. Plasma and tissue concentrations of tiamulin were analyzed by reverse‐phase high‐performance liquid chromatography (HPLC) method. Plasma concentration–time data were described by the non‐compartmental model for all three routes, and pharmacokinetic parameters were calculated. There were no significant differences (p > 0.05) in pharmacokinetic parameters and mean plasma concentrations of tiamulin between three routes tested (crop, water, and feed), indicating equal efficacy. Tiamulin residues in edible tissues (muscles, skin, and fat) were lower than the advocated maximum residue limit (MRL of 0.1 µg/g and that of liver was 1 µg/g) on the 3rd day. No traces were found on the 5th day after drug administration. This indicated that the withdrawal period (less than 5 days) is very short, which makes it safer. This study shows that tiamulin can be used with equal efficacy through all routes of administration in broiler chicken (crop, water, and feed).     

Hepatic endogenous defense potential of propolis after mercury intoxication

Exposure to mercuric chloride (HgCl₂; 5 mg kg^?1 body weight; i.p.) induced oxidative stress in mice and substantially increased lipid peroxidation (LPO) and oxidized glutathione (GSSG) levels, decreased the level of reduced glutathione (GSH) and various antioxidant enzymes in liver and also increased the activities of liver marker enzymes in serum. Therapy with propolis extract, a resinous wax‐like beehive product (200 mg kg^?1 orally, after mercury administration), for 3 days inhibited LPO and the formation of GSSG and increased the level of GSH in the liver. Release of serum transaminases, alkaline phosphatase, lactate dehydrogenase and γ‐glutamyl transpeptidase were significantly restored after propolis treatment. The activities of antioxidant enzymes, that is, superoxide dismutase, catalase, glutathione‐S‐transferase and glucose‐6‐phosphate dehydrogenase, were also concomitantly restored towards normal levels after propolis administration. These observations clearly demonstrate that propolis treatment augments antioxidant defense against mercury‐induced toxicity and provide evidence that propolis has therapeutic potential as a hepatoprotective agent.     

Nitrous oxide dynamics during denitrification along a hydrological gradient of subtropical grasslands

Nitrous oxide (N₂O) dynamics during denitrification, including N₂O production and reduction, particularly as related to soil depth, are poorly understood. The objective of this study was to investigate the rates of N₂O production and reduction processes at various soil depths along a hydrological gradient in grazed subtropical grasslands. A batch incubation study was conducted on soils collected along a hydrological gradient representing isolated wetland (Center), transient edge (Edge) and pasture upland (Upland) in south-central Florida. Significantly different N₂O production and reduction rates between hydrological zones were observed for surface soils (0–10 cm) under ambient conditions, with average N₂O production rates of 0.368, 0.178 and 0.003 N₂O-N kg⁻¹ dry soil h⁻¹ for Center, Edge and Upland, respectively, and average N₂O reduction rates of 0.063, 0.132 and 0.002 N₂O-N kg⁻¹ dry soil h⁻¹. Nitrous oxide production and reduction in subsurface soils maintained low rates and showed small variations between depths and hydrological zones. Our results suggest that N₂O dynamics were affected by depth, mainly through labile organic carbon (C) and microbial biomass C, being influenced by hydrological zone primarily through soil NO₃^- content. The spatial distribution of N₂O fluxes from denitrification along the hydrological gradient is likely attributed to the differences in N₂O production and reduction in surface soils.     

Phytochemical and antimicrobial studies on Drynaria quercifolia

Friedelin, epifriedelinol, beta-amyrin, beta-sitosterol, beta-sitosterol 3-beta-D-glucopyranoside, and naringin were isolated from the dried rhizome of Drynaria quercifolia. The methanol extract showed broad and concentration-dependent antibacterial activity.     

Distribution of anticancer drug camptothecin in Nothapodytes foetida

The topoisomerase I-DNA inhibitor alkaloid camptothecin has been evaluated from the various parts of Nothapodytes foetida. The bark contained 0.27% dry wt of camptothecin and 0.11% dry wt 9-methoxycamptothecin followed by the root, stem, and leaves. Immature seeds contained higher concentrations of camptothecin (0.32% dry wt) and 9-methoxycamptothecin (0.16% dry wt) compared to mature seeds. Various parts of mature and immature seeds were analysed to determine the content of the major alkaloids. Zygotic embryos of immature seeds contained 0.11% dry wt of camptothecin and 0.04% dry wt of 9-methoxycamptothecin. The highest concentration of camptothecin (0.42% dry wt) and 9-methoxycamptothecin (0.18% dry wt) were accumulated in the cotyledons of immature seeds.     

Antihyperglycemic activity of Caralluma attenuata

Extracts of Caralluma attenuata are screened for their antihyperglycemic activity. Ethanol, chloroform and butanol extracts were tested on glucose loaded and alloxan-induced diabetic rats. In both tests, the butanol extract, at the oral dose of 250 mg/kg, has shown statistically significant and considerable antihyperglycemic activity.     

Effect of handling and water stress on water status and rooting of loblolly pine stem cuttings

Two experiments were conducted to determine theeffect of handling, short-term storage, andinitial water stress on cutting water potential (_W) and rooting of loblolly pine(Pinus taeda L.) stem cuttings. First,stock plants and cuttings were measured for_W at predawn (04:00 a.m.) and earlymorning (09:00 a.m.). Cuttings were thensevered, wrapped in wet paper towels, andplaced in insulated containers for 2 or 7 h atapproximately 30 °C or for 21 h in coldstorage (4 °C). Water potentials ofcuttings were measured at the end of eachstorage period. Second, effects of initialwater stress on rooting performance of cuttingswere tested by withholding water from dormant(winter) and succulent (summer) cuttings forvarying periods of time. After each dryingtreatment, _W was measured on asample of cuttings and the remainder of thecuttings were transferred to a greenhouse withintermittent mist for 12 weeks.Storage of cuttings for long periods (7 to 21h) of time under low vapor pressure deficitconditions resulted in less negative waterpotentials of the cuttings. Dormant cuttingsrooted at higher percentages, even after beingexposed to lower values of _W Thelower values of _W in dormantcuttings could be attributed to higher ambientvapor pressure deficit during the drying phase. Results suggest that subjecting cuttings tomoderate water stress for a short period oftime does not adversely affect the rooting ofcuttings. Cutting water potentials below –1.7MPa appeared to reduce rooting of succulentcuttings and water potentials below –2.0 MPaaffected rooting in dormant cuttings.     

Prevalence and molecular detection of Anaplasma marginale, Babesia bovis and Babesia bigemina in cattle from Puntarenas Province, Costa Rica

A study was conducted in 2008 to determine the prevalence of Anaplasma and Babesia infections in cattle in the Puntarenas Province of Costa Rica. Blood samples were taken from a total of 449 cattle during the month of March at 30 farms in the region of Espiritu Santu, Costa Rica. Commercially available enzyme-linked immunosorbent assays (ELISA) were used to determine presence of antibodies to Babesia bigemina and Anaplasma marginale, and real-time PCR was used to determine the presence of DNA from the disease-causing organisms. The ELISA results indicated that 87.5% of the cattle sampled were positive for antibodies to A. marginale, while 59.1% were positive for antibodies to B. bigemina. The real-time PCR results showed that 235 cattle were carrying A. marginale DNA (56.9%), 6 with B. bigemina DNA (1.34%), and 2 with B. bovis DNA (0.45%).