Catechins are a type of flavonoid known for their beneficial functions as antioxidants and antibacterials. Recent research indicates the antioxidant potential of catechins on the skin. Catechin and epigallocatechin are reported to have significant potential in preventing ageing. Epigallocatechin gallate, gallocatechin gallate, and epigallocatechin can inhibit hyperpigmentation processes. Additionally, catechins exhibit potential in UV protection and inflammation inhibition in acne. Consequently, catechins are now being used in the cosmetics industry, with formulations containing catechins as the active ingredient developed to produce various products such as soap, sunscreen, creams, etc. Herein, this paper reviews the antioxidant potential of catechins for use in cosmetic formulations and the current status of clinical trials of catechins in cosmetics.

Gambir (Uncaria gambir, Roxb.) contains catechins that is often empirically used to treat various diseases. Catechins can reduce cholesterol levels by inhibiting coenzyme HMG-CoA reductase that plays a role in cholesterol metabolism. Research has been carried out covering the optimization of transethosomal catechins, the formulation of Transethosomal Catechin Gel (TCG) and Non-Transethosomal Catechin Gel (NTCG), which were then tested for catechin permeation from these gel preparations in vitro using Franz’s diffusion cell with PTFE membranes. The anti-hypercholesterol activity test was carried out with Simvastatin orally as a positive control using 25 male Wistar rats (Rattus norvegicus). The catechin transetosomes have a size of 176.1 ± 5.8 nm, Zeta potential −11.6 ± 5.28, and Entrapment Efficacy of 96.77% ± 0.05. The result of cumulative catechins that permeated from TCG and NTCG were and 172.454 ± 5.287 and 112.741 ± 2.241 μg respectively. Permeation test graphs showed similar permeation and flux profiles. TCG can reduce total cholesterol and LDL (Low Density Lipoprotein) values in rats by 39.77% and 51.52% respectively during 14 days of use.

Natural ingredients are an important source of bioactive compounds. Among these bioactive compounds, polyphenols are the most interesting because of their health benefits. Catechins are a class of polyphenol compounds that exhibit a range of activities, with applications in the pharmaceutical and cosmetic industries. These include antimicrobial, antioxidant, anti-inflammatory, and other therapeutic effects. In cosmetic formulations, catechins can be used as anti-acne agents. Reducing the particle size of catechins affects several of their physicochemical properties and can also increase their absorption rates and solubility. This article discusses the physicochemical properties of catechins and their potential applications as antimicrobial agents.

Exposure to ultraviolet (UV) radiation from the sun significantly damages the skin, leading to premature aging, hyperpigmentation, and oxidative stress that disrupts skin homeostasis. UV radiation increases the production of reactive oxygen species (ROS), accelerating skin deterioration. Although sunscreens remain the primary method for UV protection, chemical-based formulations are often associated with side effects, such as allergic reactions and acne. To address these concerns, the inclusion of natural ingredients in sunscreen formulations has gained attention. Curcumin, an active compound found in turmeric (Curcuma longa) and Java turmeric (Curcuma xanthorrhiza), is well-known for its antioxidant and anti-inflammatory properties. This review explores the potential of curcumin as a natural ingredient for enhancing the Sun Protection Factor (SPF) of sunscreen products. A systematic literature review was conducted, analyzing 200 articles sourced from Google Scholar and PubMed using keywords such as “Curcumin”, “Curcuma”, “Antioxidant”, “Anti-Inflammatory”, and “Sun Protection Factor”. Studies unrelated to UV protection were excluded. The findings, presented in tabular form, indicate that curcumin and Curcuma exhibit significant potential to enhance SPF values due to their antioxidant, anti-inflammatory, and UV-absorbing properties. Additionally, curcumin may aid in skin repair following UV-induced damage. However, the specific concentration of curcumin in various Curcuma species remains unknown, and further research is necessary to determine its optimal use. Consideration of additional excipients in sunscreen formulations is also required to maximize efficacy. In conclusion, curcumin demonstrates considerable promise as a sustainable and effective natural ingredient for protecting the skin from UV radiation, offering a safer alternative to conventional chemical-based sunscreens.

Free radicals can cause damage to the structure of the dermis layer, which makes skin lose its elasticity and leads to the formation of wrinkles. A strategy to prevent this problem is by using antioxidants. A plant that has been reported to contain good antioxidant activity is sacha inchi seed (Plukenetia volubilis L.); apart from that, its oil has quite a high omega-3 content and potentially can act as an anti-aging agent stimulating the skin-cell-regeneration process, maintaining skin moisture and elasticity and stimulating collagen production. This research aims to analyze the physicochemical characteristics and determine the fatty acid profile, the levels of vitamins A, D, and E, and the antioxidant activity of sacha inchi seed oil. This research was conducted through eight main stages: sacha inchi seed extraction, quality parameters checking, phytochemical screening, determining fatty acid profiles, vitamin analysis, antioxidant activity tests, microbiological contamination tests, and heavy-metal contamination tests. In this study, quality inspection results were obtained: organoleptic form (liquid), color (yellow), odor (typical), relative density value (0.91 g/cm³), acid number (0.38 ± 0.02 mg/g), peroxide value (11.01 mEq/Kg), iodine value (179.32 g/100 g), and refractive index (1.479). The phytochemical screening results of sacha inchi seed oil were positive for containing flavonoids, triterpenoids, and steroids. The results of the fatty acid profile were omega-3 (48.5%), omega-6 (34.8%), and omega-9 (7.7%). The results of the vitamin contents analysis were vitamin A (123.42 mg/100 g), vitamin D (899.46 mg/100 g), and vitamin E (145.06 mg/100 g). The antioxidant activity test showed an IC₅₀ value of 8.859 ppm (very strong), and the microbial and heavy-metal contamination tests were negative.

Bromelain, a natural enzyme derived from pineapple, is known for its antioxidant properties, and its potential as a photoprotective agent has garnered interest in skincare applications. The primary objective of this research was to evaluate and optimize the effectiveness of bromelain-based creams in providing antioxidant and photoprotective protection against ultraviolet (UV) radiation. Antioxidant activity was assessed using the DPPH radical scavenging assay, and the Sun Protection Factor (SPF) was determined in vitro and in vivo to evaluate photoprotective activity. The results revealed that bromelain exhibited strong antioxidant activity. Photoprotection, as measured by SPF, the formulation F3, which combined bromelain with other UV filters, exhibited the highest SPF values of 22.043 ± 0.277 (in vitro) and 21.3 ± 2.901 (in vivo), indicating enhanced photoprotective efficacy. This improvement in SPF was likely due to the synergistic effect of bromelain with the UV filters Octyl Methoxycinnamate (OMC). The findings suggest a positive correlation between antioxidant activity and photoprotection, with bromelain’s antioxidant properties contributing to its overall photoprotective effect. Bromelain may be used on people without causing skin or eye irritation. This study supports the potential of bromelain-based creams as dual-action skincare formulations, offering both antioxidant and UV protection.