Investigation of erythropoietic and nutritive properties of Achatina achatina snail lectin in albino Wistar rats

Myeloid stem cells divide to form cell committed progenitor cells which differentiate through a series of cell divisions to form the various precursor cells which produce red cells (Erythrocytes), White cells (Leucocytes) and Platelets (Thrombocytes) in a general process referred to as haemopoiesis. The specific process for formation of red cells is known as erythropoiesis. Red cell indices include: Mean cell haemoglobin concentration (MCHC), Mean cell haemoglobin (MCH), Mean cell volume (MCV), and are calculated from red blood cells (RBC) count, haemoglobin (Hb) contents and packed cell volume (PCV)/Haematocrit (HCT) and the deduced information provides valuable guide for classification of anaemias. Achatina achatina snail species are considered by many people in various West African counties to be the most prized delicious snail for eating.  Lectins are glyco-proteins with haemagglutinating activity capable of eliciting diverse physiological responses including stimulation of Haemopoiesis and toxicity to cells, making them useful in biotechnology and biomedical applications. This research therefore aimed to deduce if A. achatina snail lectin is toxic or nutritive and whether it possesses erythropoietic properties in experimental animals. A total of 120 samples of local Achatina Achatina snail specie were collected, authenticated at the Zoology Department of the University of Nigeria, Nsukka and a pooled crude Lectin extract was obtained. Purifications were performed on the crude extract using three approaches: Ammonium sulphate precipitation, Dialysis (partial purifications) and Con A Sepharose 4B affinity chromatography column (complete purification). The affinity purified lectin was used for all the tests conducted in this research. The crude, partially and complete/affinity purified lectin extracts were subjected to Haemagglutination tests and their protein contents were assayed using Pierce BCA Protein Assay Kit method (Thermo Scientific). The lectin was further assessed to determine its Erythropoietic or toxic properties using a total of Thirty-five (35) male Albino Wistar Rats weighing 101-180g and aged 2-3 months obtained from the Animal house of University of Nigeria, Nsukka. The animals were divided into 5 groups (A-E) and allowed to acclimatize for 2 weeks. Graded doses of 0.04ml, 0.05ml and 0.06ml of the affinity purified lectin were administered intra-peritoneally to each of the rats in Groups A-D (test groups) according to their body weights at intervals of 2 days for 1 week. Group E served as the control. One (1) ml of blood was collected from each of the rats before and 24 hours after the last day of lectin administration for the following tests: HB, PCV, RBC count, MCHC, MCH, MCV, using Sysmex auto analyzer. Post lectin administration changes in the weight (WT) of the rats were also assessed. The results of the research showed as follows: On complete/affinity purification, 15mls of pure sample containing only the high molecular weight lectin was obtained. The respective haemagglutination tests on the crude, partially and affinity purified lectin showed preferential agglutination with blood group A type. The Protein contents of the lectin show as follows: The crude extract contains 13.5mg/dl, dialyzed precipitate – 5.7mg/dl, dialyzed supernatant – 5.0mg/dl and the Affinity purified lectin – 0.422mg/dl.  The activity of the lectin in the assessed erythropoietic parameters gave the following findings: The mean difference of the pre and post lectin administration values of the test groups versus the control values in the Rats’ blood levels of HB, PCV, RBC, and WT gain were deduced to be statistically significant (p < 0.05) in more than one of the test groups, while the mean difference values of MCH was deduced to be statistically significant only in the test group A. The mean difference values of MCHC and MCV were found to be statistically insignificant in all the test groups (A-D). Hence, this research shows the lectin to be non-toxic, an effective inducer of erythropoiesis and of nutritive value as a food stuff since there were statistically significant increases in the Rats’ blood levels of HB, PCV, RBC, and WT gain including that the increase in values of MCH and MCV and the decrease in MCHC values were not statistically significant. This research has therefore succeeded in determination of activities of A. achatina snail lectin in erythropoietic parameters indicating the lectin to be of nutritive value as a food stuff, non-toxic and have positive effects on erythropoiesis.