Page 22 - GTM-3-2

Global Translational Medicine Impact of flavonoids on vascular health

pattern) and the B-ring (generally catechol, pyrogalol, or in flavonoids across plants are influenced by factors such as
4’-hydroxylated). 3 species, age, geographical distribution, cultivation method,
The oxidation of the C-ring results in the production plant part used, and storage conditions. In addition, abiotic
of several types of flavonoids, such as flavans, factors such as sunlight exposure, soil type, precipitation,
flavanones, flavones, and flavanols, as well as catechins, and the number of fruits per tree play a role in determining
1
anthocyanidins, and isoflavones. Flavonoids, also known flavonoid content in plants.
as polyphenolic compounds, are classified into six types: Over the last decade, flavonoids have garnered increased
flavonols, flavanones, flavanols, flavones, anthocyanidins, attention for their potential health benefits. Given their
and isoflavonoids. Each type undergoes distinct metabolic heterogeneous structure, studies investigating flavonoids
processes within the human body. 2,4 are usually both long-term and complex. Numerous studies
Flavonoids demonstrate substantial antioxidant activity, suggest that dietary flavonoids may serve as beneficial
contributing to the body’s defense against toxins. Their adjuncts in chronic inflammatory diseases. 17,18 Common
potent antioxidant properties, crucial for protecting plants flavonoid-rich foods, including vegetables and fruits, are
from adverse environmental conditions, have attracted extensively integrated into daily diets. For instance, apples,
considerable scientific attention. These compounds berries, grapes, kale, onions, and tomatoes are rich in
5
have been extensively investigated in epidemiological flavones. In addition, celery, chamomile, mint, red peppers,
and experimental studies for their anti-inflammatory, parsley, citrus fruit peels, and beverages like red wine
6
immunomodulatory, and potent anticancer properties and tea contain abundant flavones. These flavones play
7
both in vitro and in vivo. 8 a pivotal role in the vasodilation process, which involves
the relaxation of smooth muscles in the walls of arteries
Flavonoids play roles in diverse biological activities and veins. This relaxation allows blood vessels to expand,
across animals, bacteria, and plants. In plants, they facilitating increased blood flow and contributing to the
contribute to the color and fragrance of flowers, aid in reduction of BP. The modulation of systemic vascular
19
attracting seed-dispersing agents in fruits, act as a defense resistance and the promotion of increased blood flow are
against oxidative stress, and function as ultraviolet filters. crucial components of vasodilation. The present review
These polyphenolic compounds are found in various extensively discusses the role of flavonoids in vascular
plants, such as roses, and offer several health benefits, such activity.
as antimicrobial, antihypertensive, and bronchodilatory
effects, making flavonoids potentially valuable for 2. Sources and bioavailability of flavonoids
combating microorganisms, managing blood pressure Polyphenolic compounds, including flavonoids, play a
(BP), and easing respiratory discomfort. 9-12 In addition, crucial role in plant flavor and coloration. They serve
flavonoids safeguard plants from environmental stresses, various essential functions in plants, including auxin
serving as signaling agents, detoxifiers, and defensive transport, growth, pollinator attraction, reproduction, seed
molecules against pathogens. Despite the considerable dispersal, protection against abiotic and biotic stresses, and
13
diversity among flavonoids, their low bioavailability and resistance to predators. Flavonoids are abundant in many
20
biological activities, such as vasodilation, anti-atherogenic vegetables (onions and lettuce), fruits (apples, limes, and
modulation of cell signaling, regulation of gene expression cherries), grains, legumes, and tea; they are even present
related to disease development, reduction of hypertension, in processed foods such as wine and dark chocolate.
14
and prevention of platelet aggregation in humans, are The flavonoid content varies depending on the source,
contingent on their chemical nature. Fruits, nuts, seeds, species, sunlight exposure, season of collection, and
vegetables, and beverages such as coffee, wine, and tea are other factors. Physiologically, humans do not synthesize
21
rich sources of flavonoids, exhibiting significant antioxidant flavonoids, relying on plant sources for their intake. In
activity. Flavonoids hold substantial therapeutic value in humans, the small intestine absorbs flavonoids, which
14
conditions such as Alzheimer’s disease, atherosclerosis, then undergo conjugation with glucuronic acid, sulfate,
and cancer. 15 or O-methylation. This process varies significantly among
Flavonoids stand as major antioxidants in the human all classes of flavonoids, but overall, the absorption rate
diet, with intake levels surpassing those of Vitamin C by remains high when flavonoids are consumed as part of
10 times and Vitamin E/carotenoids by 20 times. Their integrated food. 22
antioxidant, anticarcinogenic, anti-inflammatory, and
antimutagenic actions have led to their incorporation 2.1. Flavones
in cosmetic, medicinal, nutritional, and pharmaceutical Flavones comprise a closed pyran ring with a ketone at
applications. The qualitative and quantitative variations position 4, and positions 2 and 3 are linked by a double
16

Volume 3 Issue 2 (2024) 2 doi: 10.36922/gtm.2458