The collagen enhancement by Spirulina extract in intrinsic and extrinsic skin aging in albino rat

Abstract Background The aging of the skin is considered a cumulative process that is classed as intrinsic or extrinsic. Environmental factors like sun exposure and air pollution are considered the main cause of extrinsic aging. Mainly, intrinsic aging reflects the genetic background and depends on time. Spirulina platensis unicellular blue–green algae have a variety of biological and nutritional activities because of their high level of nutrients. The current study aims to investigate the mechanism by which spirulina extract (SE) may act anti-aging in female albino rats. Spirulina extract (20 mg/mL) was injected subcutaneously before UVA irradiation (2.16 J/cm 2 ), daily for 7 days. The epidermal thickness and the collagen fibers layer were stained utilizing hematoxylin and eosin and Masson. Results SE induced significant improvements in the activities of antioxidants including superoxide dismutase and reduced glutathione, down-regulating in expressions of inflammatory cytokines: interleukin-1β and tumor necrosis factor-α and reverses excessive ROS levels. As well as , the recovery of collagen density and reduction in the production of matrix metalloproteinases were presented. Conclusions The results found that spirulina extract may delay the signs of skin aging by enhancing collagen as well as antioxidant activities and inhibiting collagen degradation and inflammation.