Ultrasonic-Assisted Extraction and Characterization of Natural Colorants from Plants and Evaluation of Their Therapeutic Properties and Cytotoxicity

Abstract

Natural colorants as substituents for synthetic colors have gained popularity in the food, textile, pharmaceutical, and cosmetic industry. This study aimed to document the cytotoxicity and bioactivities of the natural pigment extracts from five different plant sources i.e. Rosa indica L., Brassica oleracea, Lawsonia inermis, Daucus carota L. and Calendula officinalis. Different activities were measured in this study, like antifungal and antibacterial (through disc diffusion method), antioxidant (through DPPH free radical scavenging % inhibition), and cytotoxicity (through hemolytic activity). We used the carrageenan-induced inflammation model for the determination of anti-inflammatory activity. Extracts were analyzed for the determination of main coloring constitutions by reverse phase HPLC-DAD analysis. Separation was performed on the Zorbax SB-C18 column 150 mm 4.6 mm ID, 5 um. Best antioxidant activity was shown by Daucus carota L. with IC50 (µg/mL) 9.15±0.5 µg/mL. The best antibacterial activity was shown by Calendula officinalis L. is 20±1.5 mm against gram (+ve) and for the gram (-ve) is 10.3±1.5 mm. Calendula officinalis L. showed high anti-inflammatory activity i.e. 75.33±1.20% and the lowest value of cytotoxicity i.e.3.4±0.05%. HPLC-DAD analysis showed the presence of cyanidin derivatives in Rosa indica L. and Brassica oleracea, carotenoids like lutein as a major component in Calendula officinalis L. Major colorant in Daucus carota was β-carotene and, 2-hydroxy-1,4-naphthoquinone in Lawsonia inermis. The results showed that the natural pigments are non-cytotoxic, and they have good potential to act as multipurpose active agents for various applications in the food, pharmaceutical, and cosmetic industries.