Basini Giuseppina, Bianco Federico, Grasselli Francesca
Dipartimento di Produzioni Animali, Biotecnologie Veterinarie, Qualità e Sicurezza degli Alimenti--Sezione di Fisiologia Veterinaria, Università di Parma, 43100 Parma, Italy.
Biofactors. 2005;23(1):25-33. doi: 10.1002/biof.5520230104.
Vascular Endothelial Growth Factor (VEGF) plays a pivotal role in the physiological ovarian angiogenic process: its production appears to be stimulated by the hypoxic environment which takes place during follicle development. Recently, epigallocatechin-3-gallate (EGCG) from green tea has been used in livestock nutrition as an alternative to antibiotics. However, despite many potential benefits of EGCG consumption, it is also important to get an insight on the possible reproductive-related consequences of feeding supplementation: in fact this substance has been found to inhibit angiogenesis, a process fundamental for follicle development. Therefore, we evaluated the effect of EGCG (5 and 50 microg/ml) on the production of the main angiogenetic factor, VEGF, by swine granulosa cells cultured in normoxia (19% O2), partial (5% O2) or total hypoxia (1% O2). In addition, we studied the effect of the catechin on cell proliferation. Our data demonstrate that both partial and total hypoxia stimulated VEGF production. EGCG reduced VEGF production independently of the O2 condition: 50 microM was the most effective doses. Granulosa cell proliferation was inhibited by EGCG even if only by the highest concentration. This effect might possibly be due to the decrease induced in VEGF production. Therefore feeding supplementation with EGCG should be carefully considered.
血管内皮生长因子(VEGF)在生理性卵巢血管生成过程中起关键作用:其产生似乎受到卵泡发育过程中出现的低氧环境的刺激。最近,绿茶中的表没食子儿茶素 - 3 - 没食子酸酯(EGCG)已被用作牲畜营养中抗生素的替代品。然而,尽管食用EGCG有许多潜在益处,但了解饲料补充剂可能对生殖产生的相关影响也很重要:事实上,已发现这种物质会抑制血管生成,而血管生成是卵泡发育的一个基本过程。因此,我们评估了EGCG(5和50微克/毫升)对在常氧(19% O₂)、部分低氧(5% O₂)或完全低氧(1% O₂)条件下培养的猪颗粒细胞中主要血管生成因子VEGF产生的影响。此外,我们研究了儿茶素对细胞增殖的影响。我们的数据表明,部分低氧和完全低氧均刺激了VEGF的产生。EGCG在不依赖于氧气条件的情况下降低了VEGF的产生:50微摩尔是最有效的剂量。EGCG即使仅在最高浓度下也抑制颗粒细胞增殖。这种作用可能是由于VEGF产生的减少所致。因此,应谨慎考虑用EGCG进行饲料补充。