Ornithodoros brasiliensis (mouro tick) salivary gland homogenates inhibit in vivo wound healing and in vitro endothelial cell proliferation

• Published in: Parasitology research (1987) Vol. 112; no. 4; pp. 1749 - 1753
• Main Authors: Reck, José, Marks, Fernanda S., Termignoni, Carlos, Guimarães, Jorge A., Martins, João Ricardo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-04-2013; Springer
• Subjects: Animals; Biomedical and Life Sciences; Biomedicine; Cell Extracts - isolation & purification; Cell Extracts - toxicity; Cell Line; Cell Proliferation - drug effects; Cell Survival - drug effects; Disease Models, Animal; Endothelial Cells - drug effects; Host-parasite relationships; Humans; Immunology; Inhibitory Concentration 50; Ixodidae; Male; Medical Microbiology; Microbiology; Original Paper; Ornithodoros; Ornithodoros - chemistry; Properties; Rats; Rats, Wistar; Saliva; Salivary glands; Salivary Glands - chemistry; secretions; Skin - injuries; Wound healing; Wound Healing - drug effects; Brazil; Endothelial Cell Proliferation; Salivary Secretion; Hard Tick; Salivary Gland; Cutaneous Wound Healing
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-013-3333-3

Ornithodoros brasiliensis
is a nidicolous tick only found in the southern Brazilian highlands region.
O
.
brasiliensis
parasitism is frequently associated with toxicosis syndrome, which can lead to severe reactions, ranging from local pruritus and pain to systemic disturbances both in humans and dogs. One of the most frequent findings associated with an
O
.
brasiliensis
bite is a slow healing lesion at the site of tick attachment, which can take several weeks to heal. This work tested the hypothesis that an
O
.
brasiliensis
salivary gland homogenate is able to modulate the skin wound-healing process in vivo, using a model of excisional skin lesion in rats, which are divided into two groups: (1) control group and (2) treated group, which topically received salivary gland homogenate equivalent to the protein amount of one whole salivary gland (≈5 μg protein). The hypothesis that
O
.
brasiliensis
salivary gland homogenates interfere with endothelial cell proliferation, a key role phenomenon in wound healing, was also tested.
O
.
brasiliensis
salivary gland homogenates significantly delay skin wound healing. The time to full healing of skin lesions in control rats was 15 days, contrasting with 24 days in rats topically treated with
O
.
brasiliensis
salivary gland homogenates. The calculated HT
50
(healing time to recover 50 % of the wound area) for control groups was 3.6 days (95 % CI, 3.2–3.9) and for salivary gland treated rats was 7.7 days (95 % CI, 7.0–8.4). Salivary gland homogenates have a strong cytotoxic activity on cultured endothelial cells (LC
50
, 13.6 mg/ml). Also, at sublethal concentrations (≤3 mg/ml), salivary gland homogenates have a remarkable anti-proliferative activity (IC
50
0.7 mg/ml) on endothelial cells, equivalent to ≈0.03 salivary gland pairs, an activity which seems to be much greater than reported for any other tick species. This is the first report about the biological activities of
O
.
brasiliensis
salivary compounds and provides the first in vivo evidence to support the concept of wound-healing modulation by tick salivary secretions. Results shown here contribute to an understanding of
O
.
brasiliensis
tick toxicosis syndrome, and also increase our knowledge of tick salivary bioactive compounds.