Background: Effective long term management is the key to treatment of diabetes mellitus (DM) and its complications. Aim: To ascertain the ability of Cryptolepine in managing DM and some associated complications. Methodology: Changes in; fasting blood sugar (FBS), body weight, response to thermally-induced pain, and semen quality were assessed in normal and Alloxan-induced diabetic rats treated with Cryptolepine (10, 30, or 100 mg/kg), Glibenclamide (10 mg/kg) or normal saline (2 ml/kg) per os. Hematological profile, liver and kidney function tests, lipid profile, as well as liver, kidney, and pancreas histopathological examinations were also conducted to establish possible effects of Cryptolepine treatment. Results: Cryptolepine treatment reduced (p≤0.001) FBS and body weight, inhibited (p≤0.05-0.001) the latency to tail flick or withdrawal from pain stimulus. It did not alter (p>0.05): hematological parameters, elevated (p≤0.05-0.001) plasma aspartate transaminase, alanine transaminase, and gamma-glutamyl transferase, reduced (p≤0.01) plasma urea, and elevated (p≤0.001) plasma creatinine associated with DM. Cryptolepine however reversed (p≤0.05-0.001) DM-associated elevation (p≤0.05-0.001) of plasma cholesterol, triglycerides, and low-density lipoproteins, and the reduction in high-density lipoproteins. Cryptolepine (10-30 mg/kg) showed dose-dependent regeneration of β-islet cells, but could not repair degenerated liver and kidney tissue. Cryptolepine worsens dose-dependently (p≤0.001) reduced sperm quality associated with DM. Conclusion: Cryptolepine abolishes hyperglycemia, weight loss, cold allodynia, neuropathic pain, hyperlipidaemia, as well as pancreatic β-islet cell damage associated with DM. It however does not improve liver and kidney damage and lowered semen quality.
Key words: Cold allodynia, Tail flick test, Paw withdrawal, Cryptolepine, Glibenclamide, Diabetes mellitus complications