Phytochemical evaluation and solar photoprotection analysis of Leonurus sibiricus L.

Currently, sunscreens have been developed with a greater number of components of natural origin, especially those of vegetable origin. Within this reality, UV-VIS spectrophotometry has great application in the prediction of FPS. The objective of this work was to evaluate the phytochemical composition and the spectral profiles of the photoprotective activity of Leonurus sibiricus L extracts, envisioning the development of photoprotective formulations. In the methodology, leaves, flowers and stems of L. sibiricus L. were collected, washed, dried, ground, crushed and subjected to ultrasonification (60 minutes at 30°C), and three extracts were formulated: aqueous, ethanolic and hydroalcoholic, all at 1 :10 (m/v). Then, photochemical analyzes were carried out through qualitative chemical tests with the use of precipitation reagents and/or color change, identifying the presence of photoprotective compounds. Subsequently, solutions of each extract (0.1%- m/v) were prepared and evaluated by spectrophotometry and, based on the results, the SPF values were calculated. The phytochemical evaluation detected secondary metabolites with photoprotective activity, such as flavonoids, tannins, alkaloids, reducing sugars, phenolic compounds, cardiotonic heterosides and triterpenes and steroids. ) It is concluded that the aqueous extract of L. sibiricus at 3% (w/v) was the best candidate for the development of photoprotective formulations, with an estimated SPF of 8, being considered a good candidate for adjuvant or active in ultraviolet filters. However, more in vivo and in vitro tests are needed to confirm the results and the possibility of safe use.