Can Green Tea, Andrographis, and Turmeric Extracts Really Protect and Rejuvenate Your Skin?

🔍 Key Finding

This review examines the antioxidant properties of EGCG (from green tea), andrographolide (from Andrographis paniculata), and curcuminoids (from turmeric) for skin protection and cosmetic applications, finding that while promising, their use is limited by poor bioavailability and instability, which may be improved through pharmacomodulation, co-antioxidants, and novel formulations.

🔬 Methodology Overview

• Design: Narrative review.
• Data Sources: Publications found using specific keywords related to the cosmetic and dermatological uses of Camellia sinensis, Andrographis paniculata, and Curcuma longa extracts on PubMed. Example keywords: “[Camellia sinensis skin effects] and [antioxidant]”, “[EGCG skin effects] and [antioxidant] and [cosmetics]”, “[andrographolide skin effects] and [cosmetics]”, “[curcumin skin effects] and [cosmetics]”.
• Selection Criteria: Focused on cosmetic and dermatological applications of the identified plant extracts.
• Analysis Approach: Qualitative synthesis of findings from selected publications regarding the antioxidant effects, bioavailability, pharmacomodulations, and formulations of the compounds of interest.
• Scope: Review of the current literature on the use of Camellia sinensis (specifically EGCG), Andrographis paniculata (specifically andrographolide), and Curcuma longa (specifically curcuminoids) extracts in cosmetics and dermatology, with an emphasis on improving bioavailability and stability for skin protection.

📊 Results

• Green Tea (Camellia sinensis):

  • Epigallocatechin-3-gallate (EGCG) shows antioxidant and skin-protective effects but suffers from instability and poor skin penetration.
  • Chitosan microparticles improve skin permeability of non-galloylated catechins (EGC and EC) more than galloylated catechins (EGCG and ECG).
  • Methylated EGCG (300Me-EGCG) shows antioxidant and cytoprotective effects in keratinocytes.
  • Vitamin C and α-lipoic acid improve EGCG stability in topical creams, while vitamin E decreases stability.

• Andrographis paniculata:

  • Andrographolide and its derivatives exhibit antioxidant, anti-inflammatory, and anti-aging effects.
  • Methanolic extract (containing 0.87 % andrographolide) and 14-deoxyandrographolide show antioxidant effects in keratinocytes and fibroblasts.
  • Neoandrographolide decreases type I procollagen production in fibroblasts.
  • Andrographolide sodium bisulfate increases SOD and CAT activity in UV-exposed mouse skin.
  • Nanoparticle formulations increase andrographolide bioavailability by 241 % compared to suspension.
  • A gel formulation containing andrographolide showed 92.5 % good tolerance in patients with melasma.

• Turmeric (Curcuma longa):

  • Curcumin and its derivatives, including tetrahydrocurcumin (THC), possess antioxidant, anti-inflammatory, and skin-protective properties.
  • THC shows greater free radical quenching ability at lower concentrations than curcumin, but curcumin may have higher activity in other applications.
  • Few in vivo studies exist for cosmetic applications, and clinical trials for curcuminoids have been disappointing due to instability.

💡 Clinical Impact

This review highlights the antioxidant and anti-inflammatory properties of EGCG, andrographolide, and curcuminoids, suggesting their potential use in cosmetic and dermatological formulations for skin protection and anti-aging; however, further research, including randomized controlled trials, is needed to confirm clinical efficacy and determine optimal formulations and dosages for specific skin conditions.

🤔 Limitations

• EGCG instability affected by pH and UV exposure, reducing effectiveness in some formulations.
• Alkylated gallate esters, showing improved EGCG bioavailability, exhibited cytotoxicity in rats.
• Limited skin penetration of some catechins, especially galloylated forms like EGCG and ECG.
• Inconsistent research findings regarding curcuminoid efficacy.
• Curcumin instability in biological settings, leading to poor clinical trial results.
• Low potency, poor pharmacodynamics, and potential toxicity reported for curcumin in some studies.
• Lack of placebo-controlled, double-blind clinical trials for dermatological preparations using these plant extracts.

✨ What It Means For You

This research reinforces the need for dermatologists to consider natural antioxidants like EGCG, andrographolide, and curcuminoids as potential therapeutic agents for skin protection and treatment of dermatological conditions. However, doctors should be aware of the bioavailability and stability limitations of these compounds and prioritize formulations that enhance delivery and efficacy, such as nanoparticles or co-antioxidant combinations, for optimal patient outcomes.

Reference

Messire, G.; Serreau, R.; Berteina-Raboin, S. Antioxidant Effects of Catechins (EGCG), Andrographolide, and Curcuminoids Compounds for Skin Protection, Cosmetics, and Dermatological Uses: An Update. Antioxidants. 2023;12:1317. https://doi.org/10.3390/antiox12071317