Background: Skin moisturizing is an important issue due to its impact on skin function. Adverse reactions to herbal extracts have been rarely reported and can be used in moisturizers. This study was conduct to evaluate moisturizing effect of a methanolic extract of five medicinal plants incorporated into cream bases.
Methods: Methanolic extract of five medicinal plants including olive, burdock, licorice, mallow and marsh horsetail was prepared. The extracts were dissolved in distilled water completely and freeze-dried to a dry powder. These extracts were added separately to the cream based formulation that has been suggested to be appropriate for adding herbal extracts. Moisturizing effects of these creams with herbal extracts were assessed using the impedance method on 12 rats equally divided into six groups (one control and five cases), as well as the extensiometry method on 25 mice divided into five groups (in each group one cream with herbal extract and control cream were tested concurrently). Obtained results were compared with the control cream based.
Results: The maximum moisturizing effect was observed with the marsh horsetail. Other creams with herbal extracts, except the one with the licorice, also exerted significantly higher moisturizing effect compared to the controls (P<0.05). Regarding the force for skin tearing, the differences were statistically significant in all groups when compared to the control group (P<0.05) and the highest difference was seen in the marsh horsetail group (2.0832 ± 0.6811 kgN).
Conclusions: The highest moisturizing activity was observed using marsh horsetail extract that can be explained by flavonoids content of marsh horsetail.