Iranian Journal of Pharmaceutical Research (2004): Supplement 2:
2nd International Congress on Traditional Medicine and Materia Medica
Evaluation of sun protection activity of some medicinal herbs extracts
Khazaeli P., Mehrabani M., Abedini A., Magd Zadeh M.
Department of Pharmaceutics, School of Pharmacy, Kerman University Med. Sci., Kerman, Iran
In vitro evaluation of sun protection activity of some medicinal herbs by SPF determination, to find out which herbal extracts have the best protection activity and can be used as sunscreen agent.
Sun rays are the most environmental harmful factor which affect skin, cause sun burn and photo aging. According to the previous studies the plant’s flavonoids are suitable absorbents for UV rays. In this study twenty plants were selected. These plants have high percent of flavonoids and were: Zizyphus vulgaris, Zizyphus spina-christii, Glycine max, Glycyrrhiza glabra, Matricaria recutita, Achillea wihelmsii, Ruta graveolens, Fumaria parviflora, Lawsonia inermis, Nymphaea alba, Hypericum perforatum, Lavandula officinalis, Viola tricolor, Centurea cyanus, Arnica montana, Melisa officinalis, Trigonella Foenum-graecum, Rosmarinus officinalis, Polygonum avicular, Crataegus monogyna.
The plants were extracted totally by methanol, followed by purification of flavonoids with ethyl acetate. The UV spectrophotometer was used for screening the UV absorbance and transmittance spectrum of the extracts. The plants which have high and broad spectrum were selected. The transmittance percentage between 292.5-337.5 nm, by steps of 5 nm was determined by using solutions with three different concentrations. The SPF was determined in 2 mg/ml by plotting MPF against Ln C. In another procedure, gel bases contains the extracts were prepared. The SPF of the gels was determined by use of transpore tape method and transmittance reading between 290-400 nm. Finally the plants with the highest SPF values were recognized.
Plotting the transmittance percentage and the absorbance of the extracts against wavelength is a useful method to predict the sun protection activity of the samples. Hypericum, Viola and Arnica showed broad and high absorbance spectrums. By purification of flavonoids with ethyl acetate, the spectrums showed higher peaks.
Two In vitro methods were used to determine the SPF values. The higher SPF values also were observed in these three plants; 12.2, 25.6 and 12 respectively.
Results shows that some plant extracts can be used in sun protection preparations as potent UV absorbents with more safety and efficacy than chemicals and also with anti-inflammatory properties.