Nigella sativa, a cure for every disease: Phytochemistry, biological activities, and clinical trials

Nigella sativa plant from Ranunculaceae family has been commonly used as traditional remedies by the ancient world such as Greeks, Romans, and Egyptians. The plant is also known black seed or black cumin. The plant is highly valued by Muslims all over the world as it has been mentioned by the Islamic Prophet Muhammad that the black seed has the capability of curing all diseases except death. The purpose of this chapter is to provide updated and categorized information on the traditional uses, chemical composition, biological activities, bioavailability, safety, toxicity, and clinical trials of N. sativa in order to explore their therapeutic potential and evaluate future research opportunities. Every part of this plant contains a valuable medicinal feature. It contains different types of active phytoconstituents like carbohydrates, volatiles, alkaloids, saponins, flavonoids, phenolics, glycoside, coumarins, fixed oils, proteins, vitamins, and minerals are present. The use of its seeds, whole plant, and oil is common for treatment of many diseases like hepatoprotective, antidiabetic, antiasthmatic, cardioprotective, analgesic, neuroprotective, antiinflammatory, antioxidant, antimicrobial, and anticancer effects. N. sativa has potential for the treatment of a wide range of diseases and has been well studied for its phytochemical properties. However, further scientific studies are needed to explore mechanisms of actions, adverse effects of the extracts, the effective therapeutic dose, and the therapeutic effect of major secondary metabolites.