Hirudin alleviates acute ischemic stroke by inhibiting NLRP3 inflammasome-mediated neuroinflammation: In vivo and in vitro approaches.

Acute ischemic stroke is a severe condition that a vessel supplying blood to the brain is abruptly blocked mostly due to cerebral thrombosis and embolism. There is a dearth of the effective prevention and early intervention strategies. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated neuroinflammation plays a crucial role in the pathophysiology of ischemic stroke. Hirudin is a secretion from the salivary glands of the leech Hirudo medicinalis and has a role in regulating inflammation. In this study, hirudin with a dose of 10-40 mg/kg was given to middle cerebral artery occlusion/reperfusion mice. Hirudin markedly constrained cerebral infarct area in a dose-dependent manner, and significantly improved locomotor disability at 40 mg/kg dose. Similar to MCC950, a selective NLRP3 inflammasome inhibitor, hirudin inhibited M1 polarization and promoted M2 polarization. It also strikingly suppressed the ischemia-induced overexpression of NLRP3 and its downstream components, caspase-1, apoptosis-associated speck-like protein (ASC), and interleukin-1ß (IL-1ß). Hirudin and MCC950 equivalently protected viability and death of BV-2 microglia cells against oxygen-glucose deprivation/reperfusion (OGD/R), an in vitro cell model of brain ischemia. Both agents had similar effects in normalizing the OGD/R-evoked aberrant microglial profiles and NLRP3 pathway dysregulation as observed in the mice. These results demonstrated anti-ischemic effects of hirudin and its association with the inhibition of microglial NLRP3 inflammasome-mediated neuroinflammation. Hirudin is a promising agent for the early intervention of acute ischemic stroke.

[Study on Oxygen Consumption, Oxygen Consumption Rate and Asphyxiation Point of Poecilobdella manillensis].

OBJECTIVE: To investigate the oxygen consumption, oxygen consumption rate and asphyxiation point of Poecilobdella ma- nillensis. METHODS: Oxygen consumption, oxygen consumption rate and asphyxiation point on juvenile (the average weight of 0. 29 g) and adult leech (the average weight of 2.89 g) of Poecilobdella manillensis were measured at water temperature conditions of 20. 2 and 30. 4 °C respectively using an airtight container with flowing water. RESULTS: Oxygen consumptions of Poecilobdella manillensis were increased with the increase of temperature and body weight respectively; However, their oxygen consumption rates circadian variation and the aver- age oxygen consumption rate at daytime were higher than those at night. In addition, their asphyxiation point was declined accordingly with the increase of temperature and body weight respectively. CONCLUSIONS: Oxygen consumption and oxygen consumption rate of Poeci- lobdella manillensis were closely associated with their activities and influenced by circadian variation, the preferable feeding time were the period of 6:00-10:00 in the morning or 17:00-19:00 in the afternoon; Meanwhile, Poecilobdella manillensis had a higher ability of the hypoxia tolerance for high density or factory farming, the long time living preservation and the long distance transport.

[The standard operating procedure of the standardization breeding for Poecilobdella manillensis].

OBJECTIVE: To prepare Standard Operating Procedure (SOP) for the artificial breeding technology of Poecilobdella manillensi. METHODS: The environment of producing area and breeding technology, the control of diseases, reserving seeds for breeding, harvesting and processing,the standard of the product quality and supervision for the standardization breeding of Poecilobdella Manillensis was studied. RESULTS: The average yield of vital specimen of Poecilobdella Manillensis was 420.88 kg/mu, the natural hirudin in 1kg of the living specimen of Poecilobdella Manillensis contained 430,000 AT-U, and the quality index and hygienic standard of all products complied with the regulations and standards of the State. CONCLUSION: SOP is applicable for the breeding of Poecilobdella manillensi for Guangxi district.

[Experiment on the hibernation of Poecilobdella manillensis].

Poecilobdetla manillensis were divided into different groups with dissimilar number in the wet rice field soil and kept hibernating at room temperature. The results showed that the survival rates decreased along with the increase of the number in different groups. When the number of P. manillensis over 1 800 leech per square meter, the survival rate decreased significantly. However, it wasn't different from the rate of the group which number was below 1500 leech per square meter (P > 0.05). The net weight of various groups decreased about 10.4%-15.6% respectively after hibernation and there was no significant difference among groups (P > 0.05). It is concluded that rice field soil is suitable for the hibernation of P. manillensis.