Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.
Discoloration are symptoms of skin aging. They are connected with presence of melanin and lipofuscin, whose excess and abnormal distribution in the skin cause dark spots to appear. Melanin is formed under the influence of tyrosinase during melanogenesis. Its content changes with age, which may be a result of menopause. Lipofuscin is another example of the age pigment. It is composed of proteins, lipids and carbohydrates. It is described as an age pigment because its content increases with age. The formation and accumulation of lipofuscin is inevitable and leads to cell and homeostasis dysfunction because it reduces the proteasome activity.
Current literature data indicate that progerin, which is a mutant of lamin A, may be one of several previously known physiological biomarkers of the aging process which begins at the age of 30. Lamins belong to the family of intermediate filaments type V and are an important component of the nuclear envelope (NE). The physiological processes of an alternative splicing of LMNA (lamin A/C) gene and posttranslational processing result in the formation of different variants of this gene. Prelamin A is generated in cytosol and modified by respective enzymes. In the final step, 15-aa peptide is released at the C-terminus, resulting in mature lamin A. Point mutation of cytosine to thymine at position 1824 in exon 11 of LMNA gene causes a truncated form of lamin A, which is defined as progerin. In the course of time, progerin is mainly found in skin fibroblasts and reticular layers of terminally differentiated keratinocytes. Changes take place in the nucleus and they are similar to those observed in patients with Hutchinson-Gilford progeria syndrome and refer mainly to an increase in the amount of reactive oxygen species which reduce the level of antioxidant enzymes, DNA damage and histone modification. There are still pending studies on working out new anti-aging strategies and the skin is the main area of research. Biomimetic peptides (analogues of elafin) are used in cosmetics to reduce the formation of progerin.
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