ABSTRACT
Azadirachta indica leaves have been reported to possess anticarcinogenic, antimutagenic, antiviral, antioxidant, antimalarial, immunomodulatory, anti inflammatory and antihyperglycemic abilities. Antibacterial, antifungal, hepatoprotective, anti-ulcer, anti-fertility and anti-nociceptive,anti-stress, antihelminthiasis and contraceptive properties have also been associated with A. indica. This study aimed to determine the comparative changes between granulocyte-macrophage colony-stimulating factor and aqueous extract of A. indicaleaf on cisplatin-induced bone marrow toxicity on adult Wistar rats. Cisplatin toxicity was induced by the intraperitoneal injection of 2.5mg/kg body weight of cisplatin for five (5) days, every three (3) weeks, for ninety (90) days. The effects of the extract, cisplatin and GM-CSF on body weight, histological, immunohistological, haematological and biochemical indices were investigated. Phytochemical screening and acute toxicity study of the extract were executed using standard procedures. Ten (10) kilograms of air-dried and coarsely powdered A. indica leaf was subjected to maceration method for twenty-four (24) hours inside glass jars that contained tap water at room temperaturebefore being subjected to filtration using Whatman’s paper. The filtrate was then taken to soxlet extractor for extraction. Lorke's method was adopted for acute toxicity testing, with little modification. Fifty-six (56) adult Wistar rats were allotted into eight (8) groups of seven (7) animals each. Group 1 received distilled water only for ninety (90) days; group 2 received 5 ng/ml of GM-CSF only, subcutaneously, once weekly for ninety (90) days;Group3 received 2.5mg/kg body weight of cisplatin for five (5) days, every three (3) weeks via intraperitoneal injection for ninety (90) days. Group 4 received 300mg/kg body weight (low dose) day of A. indica extract for ninety (90) days via orogastric tube;Group 5 received 1200mg/kg body weight (high dose) day of A. indica extract for ninety (90) days via orogastric tube; group 6 received 5 ng/ml of GM-CSF, subcutaneously, once weekly for ninety (90) days; and 2.5mg/kg body weight of cisplatin for five (5) days, every three (3)weeks via intraperitoneal injection for ninety (90) days. Group 7 received 300mg/kg body weight (low dose) day of A. indica extract for ninety (90) days via orogastric tube and 2.5mg/kg body weight of cisplatin for five (5) days, every three (3) weeks via intraperitoneal injection for ninety (90) days while Group 8 received 1200mg/kg body weight (high dose) day of A. indica extract for ninety (90) days via orogastric tube and 2.5mg/kg body weight of cisplatin for five (5) days, every three (3) weeks via intraperitoneal injection for ninety (90) days. The bone marrows of the sternums were excised and harvested using a midline abdominal incision that was extended into the chest region. The following investigations were carried out: full blood count (mean corpuscular haemoglobin concentration, mean corpuscular haemoglobin, packed cell volume, haemoglobin, red blood cells, white blood cells, monocytes, neutrophils, eosinophilsand lymphocytes), antioxidant assays (superoxide dismutase, malondialdehyde, glutathione peroxidase), immunohistochemistry and histology. From the phytochemical screening, results showed that the aqueous leaves extract of A. indicacontains alkaloids, cardiac glycosides, saponins, tannins, flavonoids, carbohydrates and terpenoids. The sternums were harvested and subjected to the following stains: haematoxylin and eosin, E-cadherin and CD 68. Blood was collected for haematological evaluation. The body weights of the animals administered with cisplatin also reduced significantly, while the administration of A. indica in the treatment groups prevented such occurrence. Results of the full blood count and antioxidant assay showed that cisplatin administration had deleterious effects on different blood cells and caused oxidative stress while treatment with A. indica reversed those changes. The histology and immunohistochemistry followed a similar pattern of results where cisplatin-induced fat vacuolation was prevented by the administration of A. indica in both low and high doses, although better results were obtained in the low dose administration of A. indica. In conclusion, cisplatin causes phospholipidosis (vacuolation) and bone marrow damage, while A. indica leaves were not cytotoxic and were able to protect the bone marrow from the myelosuppressive, anaemic and immunosuppressive effects of cisplatin when both were given together. The cellular integrity of the bone marrow was also maintained afteraqueous leaf extract ofA. indicawas administered. The researchers recommend that the extract can act as an adjuvant for patient on chemotherapy since it has both antineoplastic and immunostimulatory activities. However, leaves extract of A. indica should pass through all the stages of clinical trial before it can be given to patients on chemotherapy.
