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.

Molecular Characterization and Target Prediction of Candidate miRNAs Related to Abiotic Stress Responses and/or Storage Root Development in Sweet Potato

Sweet potato is a tuberous root crop with strong environmental stress resistance. It is beneficial to study its storage root formation and stress responses to identify sweet potato stress- and storage-root-thickening-related regulators. Here, six conserved miRNAs (miR156g, miR157d, miR158a-3p, miR161.1, miR167d and miR397a) and six novel miRNAs (novel 104, novel 120, novel 140, novel 214, novel 359 and novel 522) were isolated and characterized in sweet potato. Tissue-specific expression patterns suggested that miR156g, miR157d, miR158a-3p, miR167d, novel 359 and novel 522 exhibited high expression in fibrous roots or storage roots and were all upregulated in response to storage-root-related hormones (indole acetic acid, IAA; zeaxanthin, ZT; abscisic acid, ABA; and gibberellin, GAs). The expression of miR156g, miR158a-3p, miR167d, novel 120 and novel 214 was induced or reduced dramatically by salt, dehydration and cold or heat stresses. Moreover, these miRNAs were all upregulated by ABA, a crucial hormone modulator in regulating abiotic stresses. Additionally, the potential targets of the twelve miRNAs were predicted and analyzed. Above all, these results indicated that these miRNAs might play roles in storage root development and/or stress responses in sweet potato as well as provided valuable information for the further investigation of the roles of miRNA in storage root development and stress responses.