Effects of vegetation type differences induced by human disturbance on the nutrition strategy and gut microbiota of Siberian roe deer.

The Siberian roe deer (Capreolus pygargus) is a widely distributed ungulate in northeast China. Due to a series of human disturbance activities such as large-scale forest cutting, deforestation and reclamation, road construction in the past, the appearance and internal structure of forest vegetation in the habitat of Siberian roe have changed significantly. At the same time, Siberian roe population had a series of ecological adaptation responses in the face of such habitat changes. Therefore, two typical vegetation types with differences were selected in the Muling Forest, China. We used nutritional ecology and microbial metagenomic analysis techniques to compare the nutritional selection strategy and the structure and functional characteristics of faecal microbiota of Siberian roe groups in two vegetation types. The results showed that the α diversity of dietary and gut microbes of deer in Natural Forest was higher than that in Plantation Forest. However, the gut microbes of the Plantation Forest group contained more unique enzymes in the functional pathways of carbon metabolism and biosynthesis of amino acids. This study suggests that habitat type is associated with plant community composition, and contributes to changes in the intake proportions of major macronutrients by altering the availability, quality, and composition of certain edible plants. Feeding behaviour may be an important regulatory factor of gut microbiota structure and function of deer. The metabolic function of gut microbiota to different nutrients may affect the microbial community structure. Therefore, our results suggest that the gut microbes of Siberian roe may have coevolved with their diets, and reflect the adaptability of deer populations to environmental changes (e.g., vegetation type). Our study provides new insights into how spatial heterogeneity affects nutrition and microecosystems by describing the interactions among the environment, diet, and symbiotic gut microbes in wild ungulates.

Vascular protective effects of aqueous extracts of Tribulus terrestris on hypertensive endothelial injury.

Angiotensin II (Ang II) is involved in endothelium injury during the development of hypertension. Tribulus terrestris (TT) is used to treat hypertension, arteriosclerosis, and post-stroke syndrome in China. The present study aimed to determine the effects of aqueous TT extracts on endothelial injury in spontaneously hypertensive rats (SHRs) and its protective effects against Ang II-induced injury in human umbilical vein endothelial cells (HUVECs). SHRs were administered intragastrically with TT (17.2 or 8.6 g·kg-1·d-1) for 6 weeks, using valsartan (13.5 mg·kg-1·d-1) as positive control. Blood pressure, heart rate, endothelial morphology of the thoracic aorta, serum levels of Ang II, endothelin-1 (ET-1), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured. The endothelial injury of HUVECs was induced by 2 × 10-6 mol·L-1 Ang II. Cell Apoptosisapoptosis, intracellular reactive oxygen species (ROS) was assessed. Endothelial nitric oxide synthase (eNOS), ET-1, SOD, and MDA in the cell culture supernatant and cell migration were assayed. The expression of hypertension-linked genes and proteins were analyzed. TT decreased systolic pressure, diastolic pressure, mean arterial pressure and heart rate, improved endothelial integrity of thoracic aorta, and decreased serum leptin, Ang II, ET-1, NPY, and Hcy, while increased NO in SHRs. TT suppressed Ang II-induced HUVEC proliferation and apoptosis and prolonged the survival, and increased cell migration. TT regulated the ROS, and decreased mRNA expression of Akt1, JAK2, PI3Kα, Erk2, FAK, and NF-κB p65 and protein expression of Erk2, FAK, and NF-κB p65. In conclusion, TT demonstrated anti-hypertensive and endothelial protective effects by regulating Erk2, FAK and NF-κB p65.