Green Tea Extract (EGCG)vsVitamin K

EGCG scavenges ROS (superoxide, hydroxyl radical, peroxynitrite) and chelates iron/copper that catalyze Fenton reactions. Inhibits MMP-2 (gelatinase A) and MMP-9 (gelatinase B) that degrade collagen types I, III, IV and elastin in photoaged skin — these enzymes are UV-upregulated via AP-1 and NF-kappa B. Reduces sebum by inhibiting 5-alpha reductase type 1 (testosterone to DHT conversion in sebaceous glands). Anti-inflammatory: NF-kappa B inhibition (I-kappa B degradation prevention), COX-2 suppression, TNF-alpha/IL-1beta reduction. Promotes keratinocyte differentiation via involucrin and filaggrin upregulation. Catechol structure enables dual antioxidant and metal-chelating activity. Topical EGCG reduces UV-induced erythema and prevents collagen degradation when used before sun exposure.

Vitamin K (phytonadione/K1) is cofactor for gamma-glutamyl carboxylase, which carboxylates glutamic acid residues in clotting factors II, VII, IX, X and proteins S, C — essential for calcium binding and coagulation cascade activation. Topically promotes reabsorption of subcutaneous extravasated blood by activating local clotting cascades that convert leaked hemoglobin to biliverdin and bilirubin for clearance. Strengthens capillary walls, reduces vascular permeability. For vascular dark circles: improves vessel wall integrity, reduces hemosiderin deposition. Supports elastic fiber production through matrix Gla protein carboxylation. Has anti-inflammatory effects. Clinical use: bruising, post-procedure ecchymosis, periorbital vascular hyperpigmentation. Results require 4-8 weeks consistent application.