Protective effect of purple sweet potato leaf (Ipomoea batatas Linn Convolvulaceae) against alcohol-induced liver damage in mice

Purpose: To investigate the hepatoprotective effect of Ipomoea batatas extract against alcohol-induced liver damage in mice. Methods: Male C57BL/6 mice were randomly divided into 4 experimental groups (n = 10). Normal Group: The animals received distilled water 5 ml/kg for 7 days; Alcohol Group: The animals received alcohol 5 ml/kg of 40 % w/v alcohol for 7 days; Alcohol + Purple sweet potato leaf extract (PSPE) Group: PSPE 400 mg/kg was for 7 days. The animals received alcohol 5 ml/kg of 40 % w/v alcohol for 7 days; Alcohol + Hovenia dulcis Thunb extract (HDE) Group: HDE 400 mg/kg was for 7 days. To confirmed to the liver protection effect of PSPE, it was calculated, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), and total cholesterol (TC) in serum were detected. To evaluate changes of histological in alcohol-fed mice, liver tissue was determined by H&E staining. Results: Blood alcohol concentration in purple sweet potato leaf extract (PSPE) 200 mg/kg and Hovenia dulcis (H. dulcis) extract (HDE) 200 mg/kg treated group significantly decreased compared to - alcohol with water treated group (p < 0.05). Serum ALT (alanine aminotransferase) and AST (aspartate aminotransferase) were markedly reduced. Liver sections in mice stained with H&E (hematoxylin and eosin) stain to displayed the physiological changes in the liver tissue. Furthermore, the results showed that inflammatory cells increased in the alcohol group compared to the normal group, but spontaneously decreased in the PSPE or HDE-treated group. Conclusion: These results demonstrate that Ipomoea batatas may be therapeutically effective in protecting the liver from alcohol-induced hepatotoxicity and fatty liver.

Development of high fiber rich antioxidant biscuits from purple and orange sweet potato peels

Sweet potato peel (SPP), which consist of various natural bioactive compounds, could play an important role in ameliorating chronic diseases such as cancer, cardiovascular diseases, and other degenerative diseases and yet remained underutilized. The current study investigated the effect of orange or purple SPP powder at different level of substitution (2, 5, 10%) in the production of biscuits on the proximate, antioxidant potentials and consumer acceptance. Dietary fibre increased significantly (P < 0.05) with an increase in SPP powder, ranging from 2 to 2.3 g/100 g. The total phenolic content of the biscuits was between 101.21 and 147.7 GAE/mL, total flavonoid ranged from 22.7 to 42.2 RU/mL, ABTS radical content ranged from 2.7 to 42.2 (µg ascorbic/mL). Acceptable biscuits were obtained by incorporating 2% SPP powder. Thus, SPP powder could be used as a functional and nutraceutical ingredient in biscuit production.

A Novel WRKY Transcription Factor from Ipomoea trifida, ItfWRKY70, Confers Drought Tolerance in Sweet Potato

WRKY transcription factors are one of the important families in plants, and have important roles in plant growth, abiotic stress responses, and defense regulation. In this study, we isolated a WRKY gene, ItfWRKY70, from the wild relative of sweet potato Ipomoea trifida (H.B.K.) G. Don. This gene was highly expressed in leaf tissue and strongly induced by 20% PEG6000 and 100 μM abscisic acid (ABA). Subcellar localization analyses indicated that ItfWRKY70 was localized in the nucleus. Overexpression of ItfWRKY70 significantly increased drought tolerance in transgenic sweet potato plants. The content of ABA and proline, and the activity of SOD and POD were significantly increased, whereas the content of malondialdehyde (MDA) and H2O2 were decreased in transgenic plants under drought stress. Overexpression of ItfWRKY70 up-regulated the genes involved in ABA biosynthesis, stress-response, ROS-scavenging system, and stomatal aperture in transgenic plants under drought stress. Taken together, these results demonstrated that ItfWRKY70 plays a positive role in drought tolerance by accumulating the content of ABA, regulating stomatal aperture and activating the ROS scavenging system in sweet potato.

High-Density Single Nucleotide Polymorphisms Genetic Map Construction and Quantitative Trait Locus Mapping of Color-Related Traits of Purple Sweet Potato [Ipomoea batatas (L.) Lam.]

Flesh color (FC), skin color (SC), and anthocyanin content (AC) are three important traits being used for commodity evaluation in purple-fleshed sweet potato. However, to date, only a few reports are available on the inheritance of these traits. In this study, we used a biparental mapping population of 274 F1 progeny generated from a cross between a dark purple-fleshed (Xuzishu8) and white-fleshed (Meiguohong) sweet potato variety for genetic analyses. Correlation analysis showed a significant positive correlation among AC, SC, and FC. Medium-to-high heritability was observed for these traits. We detected single nucleotide polymorphisms (SNPs) by specific length amplified fragment sequencing (SLAF-seq) with the average sequencing depth of 51.72 and 25.76 for parents and progeny, respectively. Then we constructed an integrated genetic map consisting of 15 linkage groups (LGS) of sweet potato spanning on 2,233.66 cm with an average map distance of 0.71 cm between adjacent markers. Based on the linkage map, ten major quantitative trait loci (QTLs) associated to FC, SC, and AC were identified on LG12 between 0 and 64.97 cm distance, such as one QTL for SC and FC, respectively, which explained 36.3 and 45.9% of phenotypic variation; eight QTLs for AC, which explained 10.5–28.5% of the variation. These major QTLs were highly consistent and co-localized on LG12. Positive correlation, high heritability, and co-localization of QTLs on the same LG group confirm the significance of this study to establish a marker-assisted breeding program for sweet potato improvement.