This was the key finding from a clinical study conducted by researchers from Kochi Gakuen University, Mz Science Co Ltd, Shinyamato Kanpoh Pharmaceutical Co Ltd, and Kindai University.
They set out to evaluate the effects of the test cream, dubbed “Gold Hakuyo all-in-one cream”, on 14 healthy female subjects aged 31 to 59.
The results highlighted the potential of a multi-ingredient approach, which is characteristic of Kampo, for addressing the complex, varied causes of skin ageing.
The study employed the “split-face method”, a rigorous trial design where subjects applied the test cream to only one side of their face (test side) and not the other (untreated side) twice daily for 28 days.
Expert inspectors, who were kept blinded to which side of the face received the treatment, evaluated the wrinkle grade from photographs taken before and after the four-week period. Their assessment showed a statistically significant difference in wrinkle grade reduction on the test side.
Older subjects saw greater wrinkle reduction
Another key finding was that the cream’s anti-wrinkle effect appeared more pronounced in relatively older subjects.
The authors explained that no changes in wrinkle grade were observed in subjects under 40 years of age after using the test product, whereas in many subjects over 40 years of age, a decrease in wrinkle grade was observed only on the test side of the face.
This led the team to conclude that the product proved “effective in reducing wrinkles in relatively elderly subjects with a high wrinkle grade”.
However, they also stated that the cream was not necessarily ineffective for younger users. Instead, their initial wrinkles were so shallow that any improvement was too small to be detected by the current evaluation method.
Skin condition improvements
Beyond the objective wrinkle grading, the subjects themselves reported significant improvements in their facial skin conditions via a follow-up questionnaire.
The researchers assessed 14 parameters, including skin softness, makeup adhesion, smoothness, moisture, and overall satisfaction. On the untreated side, no parameter showed marked changes, while nearly all parameters improved on the test side.
Specifically, statistically significant differences were observed in the scores before and after the four-week trial for skin softness, makeup adhesion, smoothness, tightness after face wash, moisture, and overall satisfaction of the test cream.
Moreover, the team found a strong positive correlation between a decrease in wrinkle grade and improvements in skin softness, smoothness, and moisture. These results suggested that in addition to the condition of the epidermis, maintaining moisture was important for reducing shallow wrinkles.
Power of combined ingredients in Kampo
The test cream is classified as a quasi-drug in Japan, containing active ingredients such as tranexamic acid and dipotassium glycyrrhizate, alongside a complex blend of Japanese and Chinese plant extracts.
Kampo medicines are characterised by combining multiple natural compounds to achieve a wide range of pharmacological effects, making them particularly relevant for ageing, which is driven by multiple mechanisms.
The researchers speculated that the combined action of ingredients like dipotassium glycyrrhizate (which may promote wound healing and increase collagen content), alongside components in the plant extracts, contributed to the anti-wrinkle efficacy.
For instance, hydrolysed egg shell has been shown to increase the expression of type III collagen, which helps maintain dermal elasticity. Additionally, apigenin from chamomile extract stimulates type I and type III collagen synthesis.
All-in-one approach
The authors acknowledged study limitations, primarily the difficulty in isolating the effect and mechanism of a single component, since the cream was a complex blend of Kampo ingredients.
They called for future research to include larger-scale trials targeting a more general population to demonstrate the definitive efficacy beyond the small group of subjects who were already interested in beauty products, as well as to further verify the efficacy for deeper wrinkles.
As the test cream was designed to be an all-in-one product, the researchers concluded that there was “no need to use multiple cosmetic products other than the test cream”.
This simplification of the skin care routine, coupled with the cream’s proven efficacy, may appeal to consumers seeking streamlined, multifunctional products that address various age-related skin symptoms effectively.
Source: Cosmetics
“Anti-Wrinkle Effect on the Outer Corners of the Eyes of a Cosmetic Cream Containing Various Bioactive Ingredients of Kampo Medicines: A Preliminary Clinical Trial with the Split-Face Method”
https://doi.org/10.3390/cosmetics12060271
Authors: Kenji Kikushima, et al.
