Eurecat, Centre Tecnològic de Catalunya, Technological Unit of Nutrition and Health, Reus, Spain.
Universitat Rovira i Virgili, Department of Biochemistry and Biotechnology, Nutrigenomics Research Group, Tarragona, Spain.
J Nutr Biochem. 2019 Jan;63:72-86. doi: 10.1016/j.jnutbio.2018.09.013. Epub 2018 Sep 21.
The xenohormesis theory postulates that animals, through the consumption of chemical cues, mainly polyphenols, synthetized by plants, are able to favorably adapt to changing environmental conditions. We hypothesized that the intake of fruits with a seasonally distinctive phenotype (in terms of bioactive compounds) produced a metabolic response that depends on mammals' circannual rhythms and that fruit intake out of season can lead to a disruption in characteristic seasonal metabolism. Fischer 344 rats were chronically exposed to short (L6, 6 h light/day) and long (L18, 18 h light/day) photoperiods in order to simulate autumn and spring seasons, respectively, and were fed either a standard diet (STD) or an obesogenic cafeteria diet (CAF) and orally treated with either vehicle or 100 mg kg day of lyophilized sweet cherry (Prunus avium L.), a fruit consumed during long-day seasons. Cherry consumption exerted a marked photoperiod-dependent effect, inducing more changes when it was consumed out of season, which was apparent in the following observations: (a) in L6 STD-fed rats, a down-regulation of the phosphorylated (p) levels of the downstream postreceptor target of insulin Akt2 in the soleus muscle and an enhancement of fatty acid transport and β-oxidation-related pathways, which was evidenced by increased Had gene expression (soleus) and pAMPK levels (soleus and gastrocnemius) and (b) an increase in whole-body fat oxidation and circulating levels of glucose and insulin in L6-CAF-fed obese rats. Although the pathophysiological significance of these results requires further research, our findings could contribute to highlighting the importance of the consumption of seasonal fruits to maintain optimal health.
异种外激假说认为，动物通过摄入植物合成的化学信号（主要是多酚类物质），能够适应不断变化的环境条件。我们假设，摄入具有季节性表型特征（就生物活性化合物而言）的水果会产生一种代谢反应，这种反应取决于哺乳动物的年周期节律，而在非季节时摄入水果可能会导致特征性季节性代谢紊乱。我们用短光照（L6，每天 6 小时光照）和长光照（L18，每天 18 小时光照）分别模拟秋季和春季，慢性暴露于 Fischer 344 大鼠中，并分别用标准饮食（STD）或肥胖症 cafeteria 饮食（CAF）喂养，并用载体或 100mgkg 天冻干甜樱桃（Prunus avium L.）口服处理，这种水果在长日照季节食用。樱桃的摄入表现出明显的光周期依赖性效应，在非季节摄入时会引起更多的变化，以下观察结果明显：（a）在 L6 STD 喂养的大鼠中，比目鱼肌中胰岛素下游受体后靶标 Akt2 的磷酸化（p）水平下调，脂肪酸转运和β氧化相关途径增强，表现为 Had 基因表达（比目鱼肌）和 pAMPK 水平（比目鱼肌和腓肠肌）增加；（b）L6-CAF 喂养肥胖大鼠的全身脂肪氧化和循环葡萄糖和胰岛素水平增加。尽管这些结果的病理生理意义需要进一步研究，但我们的发现可能有助于强调食用季节性水果对维持最佳健康的重要性。
