Science
Mechanism of Action
This ingredient operates through a multifaceted mechanism, combining the distinct benefits of its two botanical origins. As a potent antioxidant, it effectively combats free radicals, thereby protecting skin cells from oxidative stress and premature aging. Its robust anti-inflammatory action helps to significantly reduce redness, irritation, and discomfort, making it beneficial for conditions like eczema, rosacea, and atopic dermatitis. Key compounds from licorice, such as glabridin and liquiritin, precisely inhibit tyrosinase enzyme activity, which is crucial for melanin production, leading to a visible reduction in hyperpigmentation and dark spots and an overall brighter skin tone. Glycyrrhetic acid in licorice provides corticosteroid-like activity for enhanced soothing. Reynoutria japonica, rich in resveratrol, amplifies these antioxidant and anti-inflammatory effects and also contributes antimicrobial properties. Furthermore, Reynoutria japonica actively supports wound healing by shielding skin fibroblasts, minimizing inflammation, and promoting organized collagen synthesis. It can also alleviate symptoms akin to atopic dermatitis and improve skin barrier integrity by modulating JAK/STAT signaling pathways and suppressing proinflammatory immune responses. Licochalcone A, another licorice compound, may inhibit the proliferation of acne-causing bacteria, while Reynoutria japonica also exhibits anti-collagenase and moderate anti-hyaluronidase activity, supporting skin structure.
Research
Clinical Evidence
Medium confidenceN/A
Key findings
- 01 Topical application of 2% glycyrrhizin, a licorice component, has been clinically used to manage skin and oral conditions such as eczema and herpes simplex infection.
- 02 Licorice root formulated in a hydrogel significantly accelerated the healing process of second-degree burns when applied topically.
- 03 Glycyrrhiza glabra roots demonstrated antimicrobial potential in vitro at a concentration of 500 µg/mL.
- 04 An acetone extract of Reynoutria japonica exhibited a strong inhibitory effect against Streptococcus mutans in vitro, with a minimum inhibitory concentration (MIC) of 0.15 mg/mL.
- 05 This Reynoutria japonica acetone extract also showed bactericidal activity against Streptococcus mutans in vitro, with a minimum bactericidal concentration (MBC) of 0.60 mg/mL.
- 06 Reynoutria japonica extract, when used in higher, yet unspecified, amounts, has shown efficacy in visibly improving hyperpigmentation.
Transparency
Dusting Analysis
Insufficient data to determine dusting patterns or thresholds for this specific blend.
The Formula
Formulation
Stability
Licorice extract components, specifically glycyrrhizin, demonstrate high thermal stability, tolerating temperatures between 100°C and 121°C across a broad pH range of 4.5 to 9.5. Reynoutria Japonica Extract is chemically stable under typical ambient room temperature conditions. For optimal formulation integrity, this extract should be incorporated into formulations when the temperature is below 50°C.
Safety
Safety Profile
Glycyrrhiza Glabra (Licorice) Root Extract and its derivatives are deemed safe for cosmetic applications by the CIR Expert Panel, having been found non-irritating and non-sensitizing dermally. Licorice also holds a Generally Recognized as Safe (GRAS) status from the FDA for direct food use. However, prolonged oral intake of licorice (specifically glycyrrhizin) can induce hypokalemia and hypertension, effects reversible upon discontinuation. Polygonum Cuspidatum Root Extract (Reynoutria Japonica) is currently under review by the CIR Expert Panel (2024 Final Priorities List). While generally recognized as gentle and non-irritating in cosmetics, individual allergic reactions, such as rashes or itching, can occur in sensitive skin types, necessitating patch testing. Furthermore, oral consumption of Japanese knotweed is contraindicated during pregnancy due to reported abortifacient effects. Safety assessments regarding dermal or inhalation toxicity for Polygonum Cuspidatum Root Extract remain undetermined in some sources. Given the oral contraindication, Moumoujus recommends avoiding use during pregnancy.
Your Skin
Skin Compatibility
Our Assessment
Verdict
This combined licorice and reynoutria japonica extract is a valuable multi-functional ingredient, offering significant antioxidant, anti-inflammatory, and skin brightening benefits suitable for a wide range of skin types, particularly for addressing hyperpigmentation and soothing irritation.
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