Nordihydroguaiaretic Acid from Creosote Bush (Larrea tridentata) Mitigates 12-O-Tetradecanoylphorbol-13-Acetate-Induced Inflammatory and Oxidative Stress Responses of Tumor Promotion Cascade in Mouse Skin

Table 1

Anti-inflammatory effect of topically applied NDGA on TPA-induced morphological changes in skin as measured by number of epidermal layers, leukocyte infiltration and intercellular edema.

Group	Observation
	No. of epidermal layers	Leukocyte infiltration	Intercellular edema
I (Ac/Ac)	2-3	−	−
II (Ac/TPA)	4–6	+++	+++
III [NDGA [15]/TPA]	3-4	+	+
IV [NDGA [25]/TPA]	3-4	+/−	−
V [NDGA [15]/Ac]	2-3	−	−
VI [NDGA [25]/Ac]	2-3	−	−

Leukocytes infiltration and intensity of edema are indicated by slight (+), moderate (++), severe (+++), equivocal (+/−) while (−) indicates absence of any significant change. Ac: acetone; NDGA: nordihydroguaiaretic acid; TPA: 12-O-tetradecanoylphorbol-13-acetate.