572
enoids, such as α– and β–carotenes and cryptoxanthins, and non–provitamin A
carotenoids, such as lutein, zeaxanthin, capsanthin, and carotenoids are lipid–soluble plant pigments found in photosynthetic plants and animal tissues, human blood
have a variety of functions. Provitamin A carotenoids are an important source of
dietary vitamin A that are found primarily in dark green leafy vegetables, such as
spinach, yellow vegetables and in fruit, such as orange carrots, mango, and papaya.
Their bioavailability is significantly more variable than that of preformed vitamin A
(retinol) (Schönfeldt et al. 2016; Ravisankar et al. 2015).
Alkaloids Alkaloids are heterocyclic nitrogen containing natural products named
due to their alkaline nature. Caffeine (1,3,7–trimethylxanthine) is the most consumed
alkaloidal phytochemical in a large number of beverages in the world. Caffeine can
be extracted from coffee, tea, cola, and cacao, or synthesised from uric acid. It is used
in the preparation of beverages like coffee, tea, chocolate, cola drinks, as well as
constituent in analgesic and diet pills. Caffeine acts as a stimulant of
the central nervous system (CNS), heart muscles, and relaxes muscle structures
including the coronary arteries and the bronchi. The beneficial effects of caffeine
include prevention of cardiovascular and respiratory disease, inflammatory disorders,
and as an agent that promotes kidney dieresis (Howes 2018; O’Keefe et al. 2018).
Phenolics, Phenolic Acids and Flavonoids Polyphenolics and flavonoids are the
secondary metabolites present in plants having defensive mechanisms against oxidative stress, ultraviolet radiations, and other pathogens. Some of these are the most
profuse antioxidants in the diet that modulates the activity of many enzymes and
cell receptors. More than 4000 phenolics, stilbenes, phenolic acids, flavonoids, coumarins, tannins, lignans, and lignins have been recognized in plant foods like vegetables and fruits, grains, nuts, cereals, oilseeds, legumes, spices, chocolate, tea, and
beverages (Scalbert et al. 2005). Among them, flavonoids are the most abundant
polyphenols and are classified into flavonols, flavanones, flavones, flavanols, isoflavones, and anthocyanins (Afreen et al. 2018; Vauzour 2012; Yeh et al. 2017). Dietary
fruits rich in polyphenolic compounds reduce the occurrence of cancer by inhibiting
some enzymes that promote cell proliferation.
Some prominent phenolics with health benefitting effects include curcumins and
resveratrol. Curcumin–I (1,7–bis–(4–hydroxy–3–methoxyphenyl)–1,6–heptadiene–3,5–dione) is a hydrophobic polyphenolic compound present in the rhizomes of
Curcuma longa (turmeric). Among three curcuminoids (C–I, C–II, C–III), the more
polar curcumin–III (demethoxylated curcumin, C–III) showed better activity than
curcumin–I and II due to higher solubility and better bioavailability (Yadav et al.
2017). They exhibit significant antioxidative, anti–inflammatory, anti–angiogenic,
pro–apoptotic, anti–cancer (Ghosh et al. 2015; Lu and Yen 2015; Pulido–Moran
et al. 2016), anti–viral, anti–diabetes, and anti–neurodegenerative activities, as well
as wound–healing properties. It is also used for the treatment of aging–related diseases like cardiovascular and neurodegenerative diseases, diabetes, atherosclerosis,
rheumatoid arthritis, and hypertension. Another potent role of curcumin is as a
nutraceutical to manage obesity and metabolic disorders (Howes 2018; Mobasheri
K. Sharma et al.
enoids, such as α– and β–carotenes and cryptoxanthins, and non–provitamin A
carotenoids, such as lutein, zeaxanthin, capsanthin, and carotenoids are lipid–soluble plant pigments found in photosynthetic plants and animal tissues, human blood
have a variety of functions. Provitamin A carotenoids are an important source of
dietary vitamin A that are found primarily in dark green leafy vegetables, such as
spinach, yellow vegetables and in fruit, such as orange carrots, mango, and papaya.
Their bioavailability is significantly more variable than that of preformed vitamin A
(retinol) (Schönfeldt et al. 2016; Ravisankar et al. 2015).
Alkaloids Alkaloids are heterocyclic nitrogen containing natural products named
due to their alkaline nature. Caffeine (1,3,7–trimethylxanthine) is the most consumed
alkaloidal phytochemical in a large number of beverages in the world. Caffeine can
be extracted from coffee, tea, cola, and cacao, or synthesised from uric acid. It is used
in the preparation of beverages like coffee, tea, chocolate, cola drinks, as well as
constituent in analgesic and diet pills. Caffeine acts as a stimulant of
the central nervous system (CNS), heart muscles, and relaxes muscle structures
including the coronary arteries and the bronchi. The beneficial effects of caffeine
include prevention of cardiovascular and respiratory disease, inflammatory disorders,
and as an agent that promotes kidney dieresis (Howes 2018; O’Keefe et al. 2018).
Phenolics, Phenolic Acids and Flavonoids Polyphenolics and flavonoids are the
secondary metabolites present in plants having defensive mechanisms against oxidative stress, ultraviolet radiations, and other pathogens. Some of these are the most
profuse antioxidants in the diet that modulates the activity of many enzymes and
cell receptors. More than 4000 phenolics, stilbenes, phenolic acids, flavonoids, coumarins, tannins, lignans, and lignins have been recognized in plant foods like vegetables and fruits, grains, nuts, cereals, oilseeds, legumes, spices, chocolate, tea, and
beverages (Scalbert et al. 2005). Among them, flavonoids are the most abundant
polyphenols and are classified into flavonols, flavanones, flavones, flavanols, isoflavones, and anthocyanins (Afreen et al. 2018; Vauzour 2012; Yeh et al. 2017). Dietary
fruits rich in polyphenolic compounds reduce the occurrence of cancer by inhibiting
some enzymes that promote cell proliferation.
Some prominent phenolics with health benefitting effects include curcumins and
resveratrol. Curcumin–I (1,7–bis–(4–hydroxy–3–methoxyphenyl)–1,6–heptadiene–3,5–dione) is a hydrophobic polyphenolic compound present in the rhizomes of
Curcuma longa (turmeric). Among three curcuminoids (C–I, C–II, C–III), the more
polar curcumin–III (demethoxylated curcumin, C–III) showed better activity than
curcumin–I and II due to higher solubility and better bioavailability (Yadav et al.
2017). They exhibit significant antioxidative, anti–inflammatory, anti–angiogenic,
pro–apoptotic, anti–cancer (Ghosh et al. 2015; Lu and Yen 2015; Pulido–Moran
et al. 2016), anti–viral, anti–diabetes, and anti–neurodegenerative activities, as well
as wound–healing properties. It is also used for the treatment of aging–related diseases like cardiovascular and neurodegenerative diseases, diabetes, atherosclerosis,
rheumatoid arthritis, and hypertension. Another potent role of curcumin is as a
nutraceutical to manage obesity and metabolic disorders (Howes 2018; Mobasheri
K. Sharma et al.