title: Extracts from Calendula officinalis offer in vitro protection against H2 O2 induced oxidative stress cell killing of human skin cells.
abstract: The in vitro safety and antioxidant potential of Calendula officinalis flower head extracts was investigated. The effect of different concentrations (0.125, 0.5, 1.0, 2.0 and 5.0% (v/v)) of Calendula extracts on human skin cells HaCaT in vitro was explored. Doses of 1.0% (v/v) (0.88 mg dry weight/mL) or less showed no toxicity. Cells were also exposed to the Calendula extracts for either 4, 24 or 48 h before being exposed to an oxidative insult (hydrogen peroxide H2 O2 ) for 1 h. Using the MTT cytotoxicity assay, it was observed that two independent extracts of C. officinalis gave time-dependent and concentration-dependent H2 O2 protection against induced oxidative stress in vitro using human skin cells. Pre-incubation with the Calendula extracts for 24 and 48 h increased survival relative to the population without extract by 20% and 40% respectively following oxidative challenge. The antioxidant potential of the Calendula extracts was confirmed using a complimentary chemical technique, the DPPH(●) assay. Calendula extracts exhibited free radical scavenging abilities. This study demonstrates that Calendula flower extracts contain bioactive and free radical scavenging compounds that significantly protect against oxidative stress in a human skin cell culture model.
authors.affiliation: Medical Biotechnology, School of Medicine, Faculty of Medicine, Nursing and Health Sciences, Flinders University, Australia.
authors.forename: Abdullah M
authors.initials: AM
authors.lastname: Alnuqaydan
authors.forename: Claire E
authors.initials: CE
authors.lastname: Lenehan
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Hughes
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Sanderson
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D020838:Calendula / Q000737:chemistry*; D002460:Cell Line; D035264:Flowers / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000009:adverse effects; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D012867:Skin / Q000166:cytology / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D006861:Hydrogen Peroxide
keywords: Calendula officinalis; antioxidants; cytotoxicity; flower extracts; human cells; oxidative stress