众所周知，UVB辐射会引起多种不良的皮肤变化，从简单的光老化到皮肤癌。此外，研究表明活性氧自由基（ROS）与癌症的发展和进展有关。本研究的目的是检查是否经过亚慢性UVB辐射的SKH-1（无毛雄性）小鼠（Mus musculus）出现了日光性角化病变（AK）和鳞状细胞癌病变，并且乳胶C精华霜的处理显著预防了异常皮肤发育。数据首次表明从巴西橡胶树（Hevea brasiliensis var. subconcolor Ducke）中提取的乳胶C精华霜具有光保护活性。乳胶C精华霜阻止了AK向鳞状细胞癌的进展，表明用乳胶C精华霜进行局部治疗的小鼠只出现AK病变，并且使用最高浓度（10%）的处理显著降低了表皮厚度，暗示细胞增殖减少。乳胶C精华霜保护了小鼠皮肤免受氧化应激损伤，增加了过氧化氢酶（CAT）活性，再生了谷胱甘肽（GSH）水平，降低了硫代巴比妥酸反应活性物质（TBARS）的产生，并恢复了皮肤的总抗氧化能力（TAC）。证据表明，皮肤中的UV辐射引起了全身性变化和红细胞分析，表明乳胶C精华霜增加了CAT活性和GSH水平。综上所述，这些数据表明乳胶C精华霜在UVB辐射暴露后对皮肤起到重要的抗氧化和光保护作用，预防了严重的皮肤损伤。

It is known that UVB radiation induces several adverse skin alterations starting from simple photoaging to skin cancer. In addition, it was demonstrated that reactive oxygen species (ROS) were found to be related to cancer development and progression. The aim of study was to examine whether male hairless (SKH-1) mice (Mus musculus) that were subchronically exposed to UVB radiation presented with actinic keratosis (AK) and squamous cell carcinoma lesions, and that treatment with latex C-serum cream significantly prevented abnormal skin development. Data demonstrated for the first time the photoprotective activity of latex C-serum extracted from the rubber tree Hevea brasiliensis var. subconcolor Ducke. Latex C-serum prevented the progression of AK to squamous cell carcinoma in SKH-1 mice, indicating that mice topically treated with latex C-serum presented only AK lesions and treatment with the highest concentration (10%) significantly reduced epidermal thickness, suggesting diminished cell proliferation. Latex C-serum protected the skin of mice against oxidative stress damage, increasing catalase (CAT) activity, regenerating glutathione (GSH) levels, lowering thiobarbituric acid-reactive species (TBARS) production and regenerating the total antioxidant capacity (TAC) of the skin. Evidence that UV radiation in skin induced systemic alterations and erythrocytic analysis indicated that latex C-serum increased CAT activity and GSH levels. Taken together these data indicate that latex C-serum plays an important antioxidant and photoprotective role, preventing serious damage to the skin following exposure to UVB radiation.