A Comprehensive Review on Linum usitatissimum Medicinal Plant: Its Phytochemistry, Pharmacology, and Ethnomedicinal Uses

Background: Linum usitatissimum or flax has been broadly utilized in numerous milieus worldwide as a primeval medicinal plant because of its health benefits in diverse types of diseases. Objective: The objective of this review is to assemble the latest information on the botanical description, distribution, conventional uses, and biochemical constituents, along with the pharmacological activities and toxicity of flax. Methods: For this purpose, data on Linum was accumulated from scientific journals, books, and worldwide acknowledged scientific databases via a library and electronic search. Results: Phytochemical analysis showed that the major chemical constituents of L. usitatissimum are ω-3 fatty acid, phytoestrogenic-lignans (secoisolariciresinol diglucoside-SDG), phenols, flavonoids, sterols, proteins, antioxidants as well as various soluble and insoluble fibres. Among them, secoisolariciresinol diglucosides (SDG) are the major bioactive compounds of L. usitatissimum with prospective pharmacological accomplishments. Pure compounds and crude extracts isolated from L. usitatissimum exhibited significant anti-cancer, antioxidant, anti-microbial, anti-inflammatory, anti-obesity, antidiabetic, anti-diarrheal, anti-malarial, hepato-protective, reno-protective, immunosuppressive, antiarrhythmic, and cognitive effects. Studies indicated that the toxicological effect from the consumption of flaxseed is because of its cyanogenic glycosides, linatine, and cadmium, but the level does not seem to be adequately concentrated to contribute to any physiological impact. Conclusions: Further studies are expected to comprehend the detailed mode of action of its dynamic constituents as potent therapeutics and to completely reveal its preventive and healing potentials.