TNF and skin aging: Gavaged NTP at a dose of 100 mg/day considerably mitigated skin aging characterized by the reduced loss of hydroxyproline and hyaluronic acid; reduced oxidative stress, as evidenced by the increased activities of antioxidant enzymes and decreased levels of MDA; and decreased inflammatory levels, as evidenced by the decreased levels of IL-1β and TNF-α in d-Galactose-induced aging mice.