Determinación de las actividades fotoprotectora, genotóxica y de irritación ocular in vitro del extracto hidroalcohólico de Buddleja incana.

Abstract

This dissertation work aims at determining the photoprotective effect in vitro of the hydroalcoholic extract of Buddleja incana leaves at 20, 200 and 2000 ppm of concentration; as well as, complement the study with the genotoxicity and eye irritation tests. Previously, conditioning and control of the crude drug were effectuated. In phytochemical screening, the presence of phenolic compounds and flavonoids was qualitatively revealed. The extract was subjected to physical-chemical tests to standardize it, to then be concentrated in an evaporator followed by lyophilization. The content of flavonoids, phenols and antioxidant capacity were determined by spectrophotometric techniques, as well as the SPF in vitro, through the Mansur equation. The photoprotective activity was checked through the method of cell death induced by exposure of Escherichia coli (ATCC 25922) to ultraviolet radiation, the number of UFC survivors was detected at 30-minute intervals during 3 hours. To verify the ocular irritation in vitro of the extract, the horioallantoic membrane test and its variant that includes trypan blue as an indicator of injury were used. The genotoxicity test in vitro was carried out by submitting the roots of Vicia faba to the extract of B. incana, to observe them under a microscope then and identify dividing cells and those with the presence of micronuclei as indicators of genotoxicity. The results disclose the content of phenols of 27.9 GAE / 100 g lyophilized and flavonoids of 6.5 QE / g. The extract of B. incana presents a photoprotective effect very similar to the controls ethylhelix methoxycinnamate and octyl dimethyl-PABA at the same concentrations when comparing the survival level, employing the Tukey statistical analysis from which it is concluded that there is no significant difference, reaching the bacterial survival until 90 min. The extract shows no signs of neither genotoxicity nor eye irritation at any of the tested concentrations. It is recommended to structurally identify the responsible compounds of the photoprotective activity for its application as new sunscreens.