Saponin mixture, obtained from Astragalus monspessulanus subsp. monspessulanus (Fabaceae) was investigated for possible protective effect on tert-butyl hydroperoxide (t-BuOOH)-induced cytotoxicity using primary isolat...Saponin mixture, obtained from Astragalus monspessulanus subsp. monspessulanus (Fabaceae) was investigated for possible protective effect on tert-butyl hydroperoxide (t-BuOOH)-induced cytotoxicity using primary isolated rat hepatocytes. The cells were isolated by two-stepped col-lagenase perfusion. Liver damage was induced by one hour incubation with t-BuOOH (75 μmol·L-1) and discerned by decreased cell viability, increased lactate dehydrogenase (LDH) leakage into the medium, increased production of malondialdehyde (MDA) and depletion of the cell protector glutathione (GSH). Cell pre-incubation with the saponin mixture (1 mg/mL and 5 mg/mL) significantly (p < 0.05) ameliorated t-BuOOH-induced liver damage, judged by preserved cell viability, decreased activity of LDH, decreased MDA production and restoration of GSH. The effect was concentration-dependent, more pronounced in the highest concentration and comparable with those of silymarin, used as a positive control. The observed cytoprotective effect could be explained by the influence of the saponins on the mitochondrial function, disturbed by t-BuOOH toxic metabolites.展开更多
The effects of climate change on organisms are now being extensively studied in many different taxa. However, the variation in body size, usually shrinkage in response to increasing temperature, has received little at...The effects of climate change on organisms are now being extensively studied in many different taxa. However, the variation in body size, usually shrinkage in response to increasing temperature, has received little attention regarding to reptiles. During past periods of global warming, many organisms shrank in size, and current evidence and experiments manipulating temperature have shown a biomass decrease in some organisms with increasing temperatures. Here we test whether the body size of the Montpellier snake Malpolon rnonspessulanus from the southeastern Iberian Peninsula is changing and correlated with the increasing temperature in this region during a 39- year period （1976-2014）. We measured the snout-vent length （SVL） of vouchers in scientific collections to check for trends in adult body size at the population level in relation with temperature, while controlling for the age of the individuals （estimated by skeletochronology, n =141）. Given the great ontogenetic variation in body size of the study species, we categorized age in 3 classes： ＂young adults＂ （under 5 years old）, ＂intermediate adults＂ （from 5 to 7 years old）, and ＂old adults＂ （from 8 to 14 years old）. By means of linear mixed models, we found a negative relationship between SVL of ＂old adults＂ and average annual temperature in the region during the lifetime of each individual. Our results indicate that largest and oldest individuals of the Montpellier Snake, that is, males because of strong sexual size dimorphism in this species, disappeared from the study population, and suggest that it occurred in response to rising environmental temperature.展开更多
文摘Saponin mixture, obtained from Astragalus monspessulanus subsp. monspessulanus (Fabaceae) was investigated for possible protective effect on tert-butyl hydroperoxide (t-BuOOH)-induced cytotoxicity using primary isolated rat hepatocytes. The cells were isolated by two-stepped col-lagenase perfusion. Liver damage was induced by one hour incubation with t-BuOOH (75 μmol·L-1) and discerned by decreased cell viability, increased lactate dehydrogenase (LDH) leakage into the medium, increased production of malondialdehyde (MDA) and depletion of the cell protector glutathione (GSH). Cell pre-incubation with the saponin mixture (1 mg/mL and 5 mg/mL) significantly (p < 0.05) ameliorated t-BuOOH-induced liver damage, judged by preserved cell viability, decreased activity of LDH, decreased MDA production and restoration of GSH. The effect was concentration-dependent, more pronounced in the highest concentration and comparable with those of silymarin, used as a positive control. The observed cytoprotective effect could be explained by the influence of the saponins on the mitochondrial function, disturbed by t-BuOOH toxic metabolites.
文摘The effects of climate change on organisms are now being extensively studied in many different taxa. However, the variation in body size, usually shrinkage in response to increasing temperature, has received little attention regarding to reptiles. During past periods of global warming, many organisms shrank in size, and current evidence and experiments manipulating temperature have shown a biomass decrease in some organisms with increasing temperatures. Here we test whether the body size of the Montpellier snake Malpolon rnonspessulanus from the southeastern Iberian Peninsula is changing and correlated with the increasing temperature in this region during a 39- year period （1976-2014）. We measured the snout-vent length （SVL） of vouchers in scientific collections to check for trends in adult body size at the population level in relation with temperature, while controlling for the age of the individuals （estimated by skeletochronology, n =141）. Given the great ontogenetic variation in body size of the study species, we categorized age in 3 classes： ＂young adults＂ （under 5 years old）, ＂intermediate adults＂ （from 5 to 7 years old）, and ＂old adults＂ （from 8 to 14 years old）. By means of linear mixed models, we found a negative relationship between SVL of ＂old adults＂ and average annual temperature in the region during the lifetime of each individual. Our results indicate that largest and oldest individuals of the Montpellier Snake, that is, males because of strong sexual size dimorphism in this species, disappeared from the study population, and suggest that it occurred in response to rising environmental temperature.
