Determination and comparison of sun protection factors (SPF) of main anthraquinones and their glycosides

Sun protection factor (SPF) is a value, shows effectiveness of sunscreen and a higher SPF means more protection from UV radiation [1]. UV-A and UV-B are mainly responsible for skin hazards such as sunburn, cutaneous degeneration, photosensitivity and skin cancer in intense exposure [2]. The aim of the present study was to determine SPF values of main anthraquinones emodin, aloe-emodin, rhein, physcion, chrysophanol and their glycoside forms.

The SPF's of main anthranoids were determined according to the in vitro spectrophotometric method described by Mansur et al [3]. All anthranoids were prepared at 100 µg/mL and 200 µg/mL concentrations with ethanol, scanned at wavelength 290 – 320nm and three replicates were made. SPF values calculated by Mansur equation. All of the anthranoids showed high UV protection capability between SPF 4.408 – 30.6, indicating that they have potentially protective against UV rays. Emodin showed highest UV capability with SPF 20.23 (100 µg/mL) and SPF 30.59 (200 µg/mL). SPF's of the glycosides were found lower than aglycones. Therefore, the sun protection effect decreased as the polarity increased. These results have shown that anthranoids can be used as sunscreen agents in formulations for various skin types.

This study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) (Project No: SBAG-214S147)

[1] Kaur CD, Saraf S. Pharmacognosy Res 2010, 2: 22 – 25

[2] D'orazio J, Jarrett S, Amaro-Ortiz A, Scott T. Int J Mol Sci 2013, 14:12222 – 48

[3] Mansur JS, Breder MN, Mansur MC, Azulay RD. An Bras Dermatol 1986, 61: 121 – 124