Eating More and Fighting Less: Social Foraging Is a Potential Advantage for Successful Expansion of Bird Source Populations.

Animals can expand distributions in response to climatic and environmental changes, but the potential expansive ability of a source population is rarely evaluated using designed experiments. Group foraging can increase survival in new environments, but it also increases intraspecific competition. The trade-off between benefit and conflict needs to be determined. The expanding Light-vented Bulbul Pycnonotus sinensis was used as a model to test mechanisms promoting successful expansion. Social foraging and its advantages were evaluated using lab-designed feeding trials. Consuming novel foods was compared between bulbuls and a sympatric, nonexpansive relative species, the finchbill Spizixos semitorques, from native areas at both solitary and social levels. Bulbuls increased their eating times when transferred from solitary to group, whereas social context did not affect finchbills. Bulbuls were significantly more likely to eat with their companions than finchbills when in a group. Thus, exploring food resources in a bulbul source population was facilitated by social context, indicating that social foraging is an important means by which birds successfully expand and respond to environmental changes. This research increases understanding of successful expansion mechanisms and will consequently help predict invasive potentials of alien species.

Oxymatrine and its metabolite matrine contribute to the hepatotoxicity induced by radix Sophorae tonkinensis in mice.

Previous studies by our group demonstrated that radix Sophorae tonkinensis could induce hepatotoxicity. However, it remains unclear which components of this herb may be responsible for its hepatotoxicity. The present study aimed to investigate the hepatic toxicity of treatment with matrine (MT) and oxymatrine (OMT) alone or simultaneously. Furthermore, the current study aimed to identify whether the hepatotoxicity induced by OMT is actually the toxic characterization of its metabolite MT. Hepatotoxicity was evaluated by biochemical and histopathological approaches in subchronic toxicity in mice, as well as via evaluation of cytotoxicity and enzyme leakage in AML12 liver cells. The results indicated that treatment of mice with OMT and MT individually or simultaneously resulted in centrilobular hypertrophy in the liver at doses equivalent to that contained in radix S. tonkinensis at a hepatotoxic dose, suggesting that MT and OMT are likely hepatotoxic components of this herb. OMT-induced hepatotoxicity may be primarily exerted via its metabolite MT in mice. Furthermore, OMT combined with MT was observed to be more toxic compared with OMT or MT alone. These results extend our understanding of the hepatotoxicity of radix S. tonkinensis and its active ingredients.

Hepatotoxicity induced by radix Sophorae tonkinensis in mice and increased serum cholinesterase as a potential supplemental biomarker for liver injury.

Radix Sophorae tonkinensis (S. tonkinensis) is used in Chinese folk medicine to treat sore throats, viral hepatitis, and jaundice. However, little is known about the hepatotoxicity induced by it. This study is to investigate hepatotoxicity induced by radix S. tonkinensis and a potential supplemental biomarker for liver injury through acute toxicity, accumulative toxicity, tolerance test, and sub-chronic toxicity. The contents of cytisine (CYT), matrine (MT), and oxymatrine (OMT) in radix S. tonkinensis extracts were determined simultaneously by the method we developed. In the acute toxicity study, mice were scheduled for single oral gavage at doses of 0, 2.4, 3.2, 4.2, 5.6, 7.5g/kg of radix S. tonkinensis extracts respectively. Another three groups of mice received radix S. tonkinensis extracts orally in single doses of 0, 4.3, 5.6g/kg, while the two groups of the hepatic injury model were induced by intraperitoneal injection with 0.1% and 0.2% carbon tetrachloride (CCl4). Mortality rate, analysis of serum biochemistry, and histopathological examination were used to assess the acute toxicity. In the accumulative toxicity study, mice were treated radix S. tonkinensis extracts orally by the method of dose escalation for 20days respectively. Accumulative toxicity was assessed by mortality rate. In the tolerance test, half of the mice of test group in the accumulative toxicity were administered the dose of 4.3g/kg radix S. tonkinensis extracts, and the rest of the mice in the test group were assigned to receive the dose of 5.6g/kg radix S. tonkinensis extracts. In the sub-chronic toxicity study, mice were treated with daily doses of 0, 0.25, 1.0, 2.5g/kg radix S. tonkinensis extracts for 90days. Assessments of body weights, serum biochemical analysis, and histopathological examination were performed. An enzyme-inhibition assay for butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) of CYT, MT, and OMT was also carried out. The contents of CYT, MT, and OMT in radix S. tonkinensis extracts were 5.63mg/g, 27.63mg/g, and 16.20mg/g respectively. In the acute toxicity study, LD50 of radix S. tonkinensis extracts was 4.3g/kg. No mice were found dead in the accumulative toxicity study. In the acute toxicity and tolerance test, increased ALT, AST, and CHE levels were observed in a dose-response manner, while the severity of histological changes in liver was shown in a dose-dependent mode. In the sub-chronic toxicity, though there was a decline trend of ALT and AST levels found in 0.25g/kg, 1.0g/kg, and 2.5g/kg radix S. tonkinensis extracts as compared to control, which might be related to weight loss, the severity of histopathological changes in the liver and the increased serum CHE level was shown in a dose-response manner. MT, OMT, and CYT showed inhibitory effects on BuChE and AChE in the enzyme-inhibition assay. The results of this study indicate that radix S. tonkinensis should have hepatotoxicity, and increased serum CHE is a potential supplemental biomarker for liver injury.

Complete mitochondrial genome of the Mongolian lark, Melanocorypha mongolica (Aves: Passeriformes).

We sequenced the entire mitochondrial genome of Melanocorypha mongolica for the first time. The mitogenome is 17,358 bp in length, which includes 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA (rRNA) genes, the control region (CR1), and the control region 2 (CR2). Gene order follows a pattern similar to those of Eurasian Skylark. Using mitochondrial genomes of Melanocorypha mongolica and other seven reference birds in Sylvioidea, we preformed Bayesian analysis based on concatenated protein-coding genes. The results reveal that Alaudidae and Acroccphalidae are clustered together, which is sister to the branches included Sylviidae and Leiothrichidae. Further sequencing of mitochondrial genomes in Alaudidae is useful to advance phylogenetic relationship of species in the family.