Naturally, vitamin K exists in two bioactive forms mainly phylloquinone (vitamin K1) and menaquinones (vitamin K2). Phylloquinone is mostly found in green leafy vegetables such as kale, spinach, broccoli, and vegetable oils. However, menaquinones abundantly occurs in fermented vegetable products as menaquinones‐7 (MK‐7) and in animal‐based products as menaquinone‐4 (MK‐4). Diverse concentrations of menaquinones are present in various dietary sources such as fermented pulses and milk‐based products, cheese, meat, and animal organs. Presently, MK‐7 and MK‐4 contribute about 24 and 7%, respectively, of the total vitamin K dietary intake in the population consuming fermented products regularly. However, about 10% of menaquinones are pooled in the liver out of total intake of vitamin K. Conclusively, fermented soybean products and fermented milk‐based products such as cheese and soured milk contain ample amount of MK‐7, whereas animal organs, meat, fish, and egg contain appreciable amount of MK‐4.
Part of the book: Vitamin K2
Polyphenols have credentials to tackle the oxidative stress. Oxidative stress is the imbalance between free radicals production and antioxidant enzymes ability to tackle these radicals resulting the onset various metabolic related disorders. Polyphenols based foods have credential as a shield against these glitches mainly owing to their antioxidant potential. In this context, tea polyphenols have gained paramount attention of scientific community as therapeutic agents for the prevention and treatment of various oxidative stress induce maladies owing to their structural diversity, strong antioxidant ability and capacity to modulate various expression involved in the pathogenesis of these maladies. The notable polyphenols are catechins which are mainly present in green tea and further subdivided into various compounds like ECG, EGC, EGCG which has their unique therapeutic potential. The catechins undergo various structural changes and transformed into theaflavins and thearubigins in the process of black tea formation. These are high molecular weight polyphenols and promising candidates in obesity, diabetes and cancer treatment. Mechanistically, these polyphenols ameliorate oxidative stress by trapping the noxious radicals like superoxide and peroxyl, promote the activity of glutathione, suppressing the malondialdehyde (MDA) activity. The current chapter is an attempt to highlight the therapeutic potential of tea polyphenols.
Part of the book: Polyphenols