Anti-inflammatory and antinociceptive activities of Rhipicephalus microplus saliva

To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rlhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host.Methods:For saliva collection,engorged ticks were obtained from a controlled bovine infestation and collected by natural fall.The ticks were fixed and injected pilocarpine 0.2%for induction of salivation.Saliva was collected,lyophilized and stored at-80℃.Cytotoxic activity was assessed by the hemolysis method(25,50,100,200 and 300μg/mL)and MTT cell viability assay(2.5,5,10,20 and 40μg/mL)for 24,48 and 72 h.Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of l0,15 and 20 mg/kg;antinociceptive activity was assessed using the acetic acid-induced writhing test,and formalin-induced paw-licking in mice at dose of 15 mg/kg.Results:Saliva did not cause erythrocytes hemolysis at any concentration tested,as well as did not decrease cell viability in the MTT assay.Saliva inhibited neutrophil migration by 87%and 73%at doses of l5 and 20 mg/kg,respectively.In the nociceptive tests,saliva presented analgesic activity of69.96%in the abdominal writhing test,and of 84.41%in the formalin test.The study proves that Rlhipiceplhalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities.The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and,in future,to develop novel anti-inflammatory and analgesic drugs.

Effects of Purified Indian Cattle Tick Rhipicephalus microplus Saliva Toxins on Various Enzymes in Blood Serum, Liver and Muscles of Albino Mice

In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and lactic dehydrogenase. For this purpose, sub-lethal doses, 40% and 80% of 24 h LD50 purified saliva toxins of Rhipicephalus microplus (Canestrini, 1888) were injected subcutaneously in the albino mice. In treated mice saliva toxins targeted membrane-bound enzymes i.e. serum acid phosphatase and alkaline phosphatase, its level was increased from 118.30% to 163.63% at the 6th hr in comparison to the control. Besides this, the levels of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) and lactic dehydrogenase (LDH) also increased up to 161.11% (at 6th hr), 148.27 (at 8th hr) and 125.45% (at 6th hr) respectively in comparison to control. An increase in the level of LDH showed insufficient oxygen supply, massive disintegration of cells and leakage of the enzyme into the circulation. It clearly indicated the toxic effects of saliva toxins on the membrane of blood cells, hepatocytes and myocardial muscle cell functions in albino mice. On the other hand activity of acetyl cholinesterase was reduced by 65.51% at the 6th hr of the saliva toxin injection in comparison to the control. This inhibition of acetyl cholinesterase activity caused the accumulation of acetylcholine molecules at the synaptic junctions and led to prolonged activation of acetylcholine receptors. It caused permanent stimulation of nerves and muscle cells that may result in muscular paralysis and finally death of the animal.