Evaluation of Moisturizing Effect of Methanolic Extract of Five Medicinal Plants Incorporated Into Cream Bases Using Impedance and Extensiometry Methods

October 2011 | Volume 10 | Issue 10 | Original Article | 1116 | Copyright © October 2011


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.

J Drugs Dermatol. 2011;10(10):1116-1121.


Protection of the body from unwanted influences from the environment is the natural function of the skin.1 Water is an important factor on the appearance and function of the skin and, when dehydrated, it becomes rough and flaky and its functions may be impaired.2 The stratum corneum (SC) is the main barrier of the skin which is located in the outmost layer of the skin. Although, SC has only a 10–20 mm thickness, it provides the primary barrier to the percutaneous absorption of compounds and water loss.1 It has been suggested that SC architecture, especially the lipid and natural moisturizing factor (NMF) components and the level of corneocyte maturation, is the most important factor in water flux and retention in the skin, and thus, on the level of moisturization.3 The biosensor function of the SC responds to variable environmental conditions, including humidity causes optimal moisturization of the skin. SC dysfunction due to advanced age, abnormal hydration levels, and pH therefore results in dry skin.3
Since dry skin influences quality of life for many individuals, moisturization is an important issue. In the majority of cases, dry skin can be adequately addressed by topical application of moisturizing products.4 Simple moisturizers are combinations of occlusives and humectants to increase the water-holding ability of the skin. To improve aesthetic properties of the moisturizer and the stability of the active ingredients, a cautiously selected emollient can be added to this regimen.5 Although efficacious moisturizers can cause several unwanted side effects—such as occlusive folliculitis, irritation, allergic contact