Antioxidant,Anti-Skin-Aging,Anti-Inflammatory,and Anti-Acetylcholinesterase Activities of Rourea oligophlebia Extracts

The objective of this study was to evaluate the antioxidant, anti-skin-aging, anti-inflammatory, and anti-acetylcholinesterase activities of the hexane (n-hex), AcOEt, BuOH, MeOH, and aqueous extracts from R. oligophlebia roots. The total phenolic and flavonoid contents (TPC and TFC) were determined using Folin-Ciocalteu and AlCl₃ colorimetric assays. The antioxidant capacity was examined by reducing power (RP), ferric reducing antioxidant power (FRAP), ABTS⋅⁺, and DPPH⋅⁺ radical cation assays. All extracts potentially exhibited antioxidant activity with IC₅₀ values ranging from 2.93 to 5.73 μg/mL for ABTS⋅⁺ and from 5.69 to 7.65 μg/mL for DPPH⋅⁺ except the n-hex extract. The BuOH, MeOH, and aqueous extract possess promising anti-skin-aging activities, as observed by an attenuation of UV-A toxicity on human keratinocytes. We proposed that these anti-skin-aging properties are possibly due to direct scavenging activity against reactive oxygen species and upregulate cellular antioxidant machinery. Moreover, we found that the antioxidant capacity was well correlated with anti-inflammatory capacity against nitric oxide (NO) production in terms of the n-hex, AcOEt, and BuOH extracts with IC₅₀ values from 23.21 to 47.1 μg/mL. In contrast, these activities were found to be poorly correlated with AchE activity. To the best of our knowledge, this is the first report of the antioxidant, anti-skin-aging, anti-inflammatory, and anti-acetylcholinesterase activities of the extracts of R. oligophlebia roots. These findings indicated that this species could be a potential source of natural antioxidant, anti-aging, and anti-inflammatory agents. Consequently, it may be suggested as a medicinal plant that prevents diseases related to oxidative stress and inflammatory responses.     

Integration of physical and genetic maps in apple confirms whole-genome and segmental duplications in the apple genome

A total of 355 simple sequence repeat (SSR) markers were developed, based on expressed sequence tag (EST) and bacterial artificial chromosome (BAC)-end sequence databases, and successfully used to construct an SSR-based genetic linkage map of the apple. The consensus linkage map spanned 1143 cM, with an average density of 2.5 cM per marker. Newly developed SSR markers along with 279 SSR markers previously published by the HiDRAS project were further used to integrate physical and genetic maps of the apple using a PCR-based BAC library screening approach. A total of 470 contigs were unambiguously anchored onto all 17 linkage groups of the apple genome, and 158 contigs contained two or more molecular markers. The genetically mapped contigs spanned ～421 Mb in cumulative physical length, representing 60.0% of the genome. The sizes of anchored contigs ranged from 97 kb to 4.0 Mb, with an average of 995 kb. The average physical length of anchored contigs on each linkage group was ～24.8 Mb, ranging from 17.0 Mb to 37.73 Mb. Using BAC DNA as templates, PCR screening of the BAC library amplified fragments of highly homologous sequences from homoeologous chromosomes. Upon integrating physical and genetic maps of the apple, the presence of not only homoeologous chromosome pairs, but also of multiple locus markers mapped to adjacent sites on the same chromosome was detected. These findings demonstrated the presence of both genome-wide and segmental duplications in the apple genome and provided further insights into the complex polyploid ancestral origin of the apple.     

Yeast extract elicited isoflavonoid accumulation and biosynthetic gene expression in Pueraria candollei var. mirifica cell cultures

Plant Cell, Tissue and Organ Culture (PCTOC) - Yeast extract (YE) has emerged as a potent biotic elicitor that can induce plant defense responses, leading to enhanced phytoalexin accumulation....     

Transient expression of the homogentisate phytyltransferase gene from <Emphasis Type="Italic">Clitoria ternatea</Emphasis> causes metabolic enhancement of α-tocopherol biosynthesis and chlorophyll degradation in tomato leaves

Homogentisate prenyltransferase (HPT) is an important enzyme involved in the α-tocopherol (vitamin E) biosynthetic pathway of all plant taxa. Tocopherol biosynthesis and chlorophyll degradation are related, but more information is needed to explain their relationship. In this study, a candidate gene for HPT from Clitoria ternatea (CtHPT) was isolated and identified via a phylogeny-based approach, and its hypothetical protein sequence was analyzed. Transient expression of CtHPT with Agrobacterium-mediated infiltration into tomato leaves was then performed and observed for the metabolic relationship between the α-tocopherol biosynthesis and chlorophyll degradation by gas chromatography–mass spectrometry. In silico analysis showed that CtHPT contained a chloroplast signal peptide and nine-transmembrane α-helixes. The results showed that, the content of α-tocopherol increased in transient expression of CtHPT, with the increased pool sizes of its biosynthetic intermediates: 2-methyl-6-phythylbenzoquinol and 2,3-dimethyl-5-phythylbenzoquinol, and the increased levels of phytol and various fatty acids. Moreover, the CtHPT transient expression was observed to cause chlorophyll deficiency in the tomato leaves with simultaneous increase of phytol and fatty acids, presumably the degradative products of chlorophyll and chloroplast membranes, respectively. It was concluded that the overexpression of CtHPT may enhance the metabolic flow of the α-tocopherol biosynthetic pathway, causing the degradation of chlorophylls, thereby increasing the supply of the precursor phytol for the α-tocopherol biosynthetic pathway.