The aim of present study is to review on hypoglycemic property of Nigella sativa L. hyperglycemic condition occurs either due to non-functioning of pancreatic beta cells or inability of body cells to utilize insulin. Currently diabetes is one of the fast growing diseases which covers nearly 2.8 % of world population and is predicted to increase up to 4.4 % by 2030. Nigella sativa (NS) also known as Black cumin and Kalonji, is an annual herb of Ranunculaceae family which grows up to 20-60cm in height. NS is also referred as miracle herb of century because it holds so many health curing properties. NS seeds has long history for their usage to treat various diseases in Middle East and Indian subcontinent. In traditional folk practice black seeds were used as spice and medicine. The black seeds were traditionally used to treat the ailments like asthma, arthritis, backache, diabetes, diarrhea, dry cough, rhinitis, hair greying, hair loss, dry cough, hypertension, fatigue, memory improvement, muscle aches, anxiety, sexual impotency, Insomnia, toothache, gum disease, amenorrhea and dysmenorrhea, anthelminthic and skin eruptions. However, extensive research on NS seeds were found to contain various bioactive compounds which have therapeutic properties against many diseases. Among all bioactive compounds Thymoquinone (TQ), a volatile mono oxygenated terpene has been found to possess hypoglycemic activity.
NS seed extract and TQ hypoglycemic activity has been studied in many animal models including human clinical trials. All studies revealed that mechanism of hypoglycemic activity mainly occurs to lowering plasma glucose levels and increasing insulin levels. Moreover, some studies also reported loss of appetite, weight loss, and reduction in glyceride levels and partial regeneration of pancreatic beta cells. Randomized Clinical trials of NS in diabetic patients has resulted reduction in levels of fasting blood glucose, postprandial glucose, LDL cholesterol, triglycerides and body weight.