Riboflavin and thiamine content in extracts of wild-grown plants for medicinal and cosmetic use

Products derived from wild-grown plants represent a growing segment of the modern pharmaceutical industry. In recent years, particular attention has been paid to their application in the cosmetic industry. The content of B group vitamins in these products is important because they affect the quality of the skin, hair and nails. The determination of thiamine and riboflavin in natural products is not so simple, as it requires complex sample preparation procedures and very sensitive analytical methods. In this paper, the HPLC method with fluorescence detection was applied to the determination of riboflavin and thiamine in the aqueous, ethanol and methanol extracts of elderberry, rosehip, rowanberry, wild garlic and blackthorn. Also, the influence of the extraction solvents on the vitamin’s concentration in obtained extracts was examined. It was found that the content of these vitamins in aqueous extracts is higher than that in alcoholic extracts. Riboflavin concentrations were in the range of 0.84–20.4 μg/g of the dry extract, while thiamine levels were from 0.06 to 0.67 μg/g of the dry extract. The highest riboflavin concentration was found in wild garlic extract followed by rosehip and elderberry extracts. On the other hand, thiamine content was higher in elderberry extract, while in rosehip it was not detected. In this work, the content of riboflavin and thiamine was determined for the first time in extracts of wild garlic, elderberry and rowanberry.