ANTICANCER EFFECT OF SALIVA EXTRACT OF THE NIGERIAN LEECH (Aliolimnatis michaelseni)

Abstract

Leeches are haematophagous creatures widely distributed all over the world, and have found application in medicine for over three millennia. Leech saliva extract (LSE) contains proteins and peptides that have wide range of potential applications in life threatening and other diseases, such as cancer metastasis. The aim of this study was to demonstrate the anticancer effects of the saliva extract of the Nigerian leech, Aliolimnatis michaelseni, against human breast cancer cells (MCF-7), in vitro. Leech samples were collected from freshwater bodies in Minna, Nigeria. MTT [3-4-5 dimthylthiazolyl-2]-2, 5-diphenyltetrazolium bromide] and Comet assays were deployed to study the cytotoxic and genotoxic potentials of these leech extracts. Results of the MTT assay showed that the saliva extract exacted a dose-dependent cytotoxic effect on the MCF-7 cells, with LC50 of 0.61% (v/v) or 1.55µg/ml. Comet assay results showed that the LSE had a significantly more potent genotoxic effect (P<0.05) than Cisplatin (standard drug for human breast cancer) 5%. LSE had a tail DNA of 9.74%±2.51 while 5% Cisplatin had a tail DNA of 2.7%±0.70. The study revealed that the protein contents of the saliva of Aliolimnatis michaelseni have a promising anticancer potential against human breast cancer cells.