Citrus hassaku Extract Powder Increases Mitochondrial Content and Oxidative Muscle Fibers by Upregulation of PGC-1α in Skeletal Muscle

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is expressed in skeletal muscles and regulates systemic metabolism. Thus, nutraceuticals targeting skeletal muscle PGC-1α have attracted attention to modulate systemic metabolism. As auraptene contained in citrus fruits promotes lipid metabolism and improves mitochondrial respiration, it could increase mitochondrial function through PGC-1α. Therefore, we hypothesized that PGC-1α is activated by auraptene and investigated its effect using Citrus hassaku extract powder (CHEP) containing >80% of auraptene. C2C12 myotubes were incubated with vehicle or CHEP for 24 h; C57BL/6J mice were fed a control diet or a 0.25% (w/w) CHEP-containing diet for 5 weeks. PGC-1α protein level and mitochondrial content increased following CHEP treatment in cultured myotubes and skeletal muscles. In addition, the number of oxidative fibers increased in CHEP-fed mice. These findings suggest that CHEP-mediated PGC-1α upregulation induced mitochondrial biogenesis and fiber transformation to oxidative fibers. Furthermore, as CHEP increased the expression of the protein sirtuin 3 and of phosphorylated AMP-activated protein kinase (AMPK) and the transcriptional activity of PGC-1α, these molecules might be involved in CHEP-induced effects in skeletal muscles. Collectively, our findings indicate that CHEP mediates PGC-1α expression in skeletal muscles and may serve as a dietary supplement to prevent metabolic disorders.

Henderson Altıntopu ve Bazı Şadok Çeşitlerinin Adana Ekolojik Koşullarında Verim ve Meyve Kalite Özelliklerinin Belirlenmesi

Pomelo [Citrus grandis (L.) Osbeck] has the largest fruit size among citrus species. There are several cultivars for pomelo species which is sensitive to low temperatures thus its cultivation is possible in relatively preserved areas in subtropical regions. The interest to pomelo production has increased due to several reasons such as, its has a little or no bitterness in fruit flesh conversaly to grapefruit, avaibility of pigmented varieties, high concentration of vitamin C, total phenolics and carotenoids in fruit flesh, as well as its efficiency in destroying free radicals such as superoxide anion and hydrogen peroxide. Several pomelo varieties have been introduced to Turkey and adaptation studies have been established. In the present study, Reinking, Pomelo WN, Kao Panne and Citrus hassaku which is a spontaneous hybrid between pomelo and mandarin were investigated in terms of fruit yield and pomological characteristics. In addition, Henderson grapefruit was included in this study in order to obtain a comparasion between pomelo and grapefruit. A large variation was observed in fruit yield of cultivars established in 2011 and 2012. In 2011, the highest yield was determined in Henderson whereas it was obtained from Citrus hassaku in 2012. Pomelo varieties yielded between 5-60 kg fruit per tree and 8.6-50 kg fruit per tree in 2011 and 2012, respectively. In terms of pomological traits, Citrus hassaku had the highest fruit weight; Pink, Kao Panne and Reinking pomelos had the highest peel thickness and Pomelo WN yielded the highest TSS/TA ratio.

Distinguishing grapefruit and pummelo accessions using ISSR markers

Grapefruit is the fourth economically most important citrus fruit in the world. In this research Inter-Simple Sequence Repeat (ISSR) markers were used to distinguish twenty-nine grapefruit (Citrus paradisi Macf.), five pummelo (Citrus maxima (Burm.) Merr.) and one Citrus hassaku Hort. Ex Tanaka accessions. Twelve ISSR primers produced a total of 100 fragments and 62 of them were polymorphic. The number of average polymorphic fragments per primer was 5.2. The mean polymorphism information content (PIC) was 0.37. The unweighted pair group method arithmetic average (UPGMA) analysis demonstrated that the accessions had a similarity range from 0.79 to 1.00. The accessions were separated into two main clusters; group A with five pummelos and group B with grapefruits. In the pummelo cluster, all pummelos were distinguished whereas in the grapefruit cluster some accessions were not clearly separated. There was a low level of variation in the grapefruits due to their mutation origin.