Shahrekord University of Medical Sciences Journal of Herbmed Pharmacology 2345-5004 11 4 2022 10 01 Effect of ethyl acetate fraction of Costus afer on glycaemic control and essential haematological and biochemical indices of streptozotocin-induced diabetic rats 575 584 10.34172/jhp.2022.66 EN Obiajulu Christian Ezeigwe https://orcid.org/0000-0002-5416-6079 Daniel Nnaemeka Onwusulu https://orcid.org/0000-0003-2031-304X Chukwuemeka Steve Adindu https://orcid.org/0000-0003-2639-8304 Chukwudi Onyeaghana Okani https://orcid.org/0000-0002-9517-9300 Maryclare Ebubechukwu Onuegbu https://orcid.org/0000-0002-0097-6295 Journal Article 10.34172/jhp.2022.66 2022 06 15 2022 07 21 Introduction: Diabetes mellitus is a common global cause of sudden unpredictable death if undiagnosed and untreated. Costus afer (Costaceae) is a tropical plant with quite a lot of pharmacological properties. This study investigated the prophylactic and antidiabetic properties of ethyl acetate fraction of C. afer in streptozotocin-induced diabetic rats. Methods: Acute toxicity (LD50) test was done using Lorke’s method. Haematological indices were determined using haematology autoanalyser. The biochemical assays were done using standard diagnostic methods. Results: The lethal dose was 3807.9 mg/kg. There was a significant reduction (P < 0.05) in the fasting blood glucose concentration from week one to week four in the group that was pre-treated and later post-treated with 200 mg/kg body weight (bw) of the ethyl acetate fraction of C. afer leaves compared with the untreated diabetic control. The result of the hematological parameters revealed a significant increase (P < 0.05) in the hemoglobin, packed cell volume (PCV), and platelet count of the group pretreated and treated with 200 mg/kg of the fraction compared with the untreated diabetic control. The result of the biochemical assays revealed a far much better recovery from the disruptions caused by the induction of experimental diabetes as seen in the groups that were initially pretreated with 100 and 200 mg/kg before the induction of diabetes compared with the groups treated with the same dose but without pretreatment. Conclusion: C. afer might be used for the prevention and management of diabetes mellitus. Its safety is evidenced by its effects on the hematological and biochemical indices.