Antioxidant and Cellular Protective Effects against Oxidative Stress of Calendula officinalis Flowers Extracts in Human Skin Cells

Suspension culture of stem cells established of Calendula officinalis L

Plant stem cell cultures have so far been established in only a few plant species using cambial meristematic cells. The presence of stem cells or stem cell-like cells in other organs and tissues of the plant body, as well as the possibility of de novo generation of meristematic cells from differentiated cells, allow to consider the establishment of stem cell cultures in a broader range of species. This study aimed to establish a stem cell culture of the medicinal plant Calendula officinalis L. Callus tissues were induced from leaf and root explants, and already at this stage, stem and dedifferentiated cells could be identified. The cell suspension cultures established both from the root- and leaf-derived calli contained a high proportion of stem cells (92-93% and 72-73%, respectively). The most effective combination of growth regulators for the development of stem cells in calli as well as cell cultures was 1.0 mg/L 2,4-D and 0.5 mg/L BAP. The highest amount of stem cells (5.60-5.72 × 105) was in cell suspension derived from the roots. An effective protocol for the establishment of marigold stem cell suspension culture was developed. The ratio of root-derived stem cells against dedifferentiated cells exceeded 90%.

Antimelanogenic and Antimigration Properties of the Ethyl Acetate Fraction of Calendula officinalis Flowers on Melanoma Cells

Calendula officinalis L., commonly known as marigold, is not only cultivated for ornamental purposes but is also used as a traditional medicinal herb. Its flowers have been used to treat various skin diseases, including rashes, burns, cuts and bruises, since ancient times. However, to our knowledge, the impact of C. officinalis L. on melanoma and its mechanism have not been clarified. The aim of this work was to investigate the chemical characterization and antimelanogenic and antimigration activities of the ethyl acetate fraction of C. officinalis flowers (EFC), as well as elucidate the potential mechanism. The obtained results showed that EFC markedly decreased α-MSH-induced melanin production and the cell migration ability of melanoma cells in a dose-dependent manner. Additionally, EFC significantly inhibited the activity and expression of matrix metalloproteinase 2 (MMP-2) via suppressing the mitogen-activated protein kinase (MAPK) signaling pathway. Taken together, the present study demonstrated that C. officinalis flowers can be used as a natural source of antimelanogenisis and antimigration regent to treatment or prevent skin diseases.