Ellagic Acid from Hull Blackberries: Extraction, Purification, and Potential Anticancer Activity.

Ellagic acid (EA) is present at relatively high concentrations in many berries and has many beneficial health effects, including anticancer properties. To improve the development and utilization of blackberry fruit nutrients, we divided Hull blackberry fruits into five growth periods according to color and determined the EA content in the fruits in each period. The EA content in the green fruit stage was the highest at 5.67 mg/g FW. Single-factor tests and response surface methodology were used to optimize the extraction process, while macroporous resin adsorption and alkali dissolution, acid precipitation, and solvent recrystallization were used for purification. The highest purity of the final EA powder was 90%. The anticancer assessment results determined by MTT assay showed that EA inhibited HeLa cells with an IC50 of 35 µg/mL, and the apoptosis rate of the cells increased in a dose-dependent manner, with the highest rate of about 67%. We evaluated the changes in the mRNA levels of genes related to the EA-mediated inhibition of cancer cell growth and initially verified the PI3K/PTEN/AKT/mTOR pathway as the pathway by which EA inhibits HeLa cell growth. We hope to provide a theoretical basis for the deep exploration and utilization of this functional food.

Fruit Quality and Metabolomic Analyses of Fresh Food Accessions Provide Insights into the Key Carbohydrate Metabolism in Blueberry.

Blueberry is a nutrient-rich berry, and its taste and flavor directly determine the consumer preference. Until now, few studies have focused on the comparison of fresh food quality and the key metabolites in superior fresh-eating blueberry cultivars. Herein, fruit quality indicators of 10 highbush blueberry cultivars were evaluated using 'Bluerain' as the control. Appearance quality analysis of fruits showed that 'Brigitta' had a larger fruit size and 'Anna' was the smallest. 'Anna' fruits, followed by 'O'Neal', had the highest ratio of soluble solids to acidity because of their lowest titratable acidity content. Despite the high soluble sugar content, the antioxidants in 'Anna' fruits such as total flavonoids, anthocyanins and vitamin C were lowest among all cultivars, while 'Duke' seemed to have opposite patterns. Furthermore, a total of 553 and 557 metabolites were identified by non-targeted metabolomics liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive and negative ion mode, respectively. Particularly, the numbers of differentially accumulated metabolites (DAMs) were the most between the 'O'Neal' vs. 'Bluerain' group. The DAMs involved in the metabolic pathways, sesquiterpenoid and triterpenoid biosynthesis, monoterpenoid biosynthesis, galactose metabolism, starch and sucrose metabolism, may be mainly related to the synthesis of flavor and carbohydrate substances. Moreover, the expression patterns of genes involved in sugar metabolism were verified by quantitative real-time PCR (qRT-PCR) analysis in different cultivars. Therefore, the systematical comparison of the quality characteristics, metabolites and expression profiles of related genes in highbush blueberries with good flavor could provide some basis for further research on fresh fruit breeding of blueberries.

Polyphenols from Prunus mume: extraction, purification, and anticancer activity.

Prunus mume is an ancient medicinal herb and food that are commonly used in Asian countries with high nutritional ingredients and biological activities. Polyphenols are important functional components in Prunus mume. To obtain a more efficient extraction process of Prunus mume polyphenols, a single-factor test and response surface method were used. After extraction and purification, the final polyphenol content of Prunus mume (L1) was up to 90%. Biological experiments showed that L1 had high anticancer activity against HeLa (125.28 µg mL-1), HepG2 (117.24 µg mL-1), MCF-7 (170.19 µg mL-1), and A549 (121.78 µg mL-1) in vitro by MTT assay. The combination of DDP and DOX significantly enhanced the anticancer activity of the four cell lines, especially L1-DOX had the smallest IC50 value of 0.04 µg mL-1 against HepG2 cells, indicating the combination of drugs had synergistic effects. It is further demonstrated that L1 could inhibit cell proliferation by inducing apoptosis with ROS detection and confocal fluorescence images. The relative tumor proliferation rate (T/C) was 40.6%, and the tumor inhibition rate was 57.9%, indicating L1 to have no significant toxicity but high anti-HepG2 activity in vivo. Although the study is very limited, it is anticipated to provide a reference for further exploration of the functionality of the plant.

The Extraction and High Antiproliferative Effect of Anthocyanin from Gardenblue Blueberry.

Blueberries are rich in flavonoids, anthocyanins, phenolic acids, and other bioactive substances. Anthocyanins are important functional components in blueberries. We collected 65 varieties of blueberries to investigate their nutritional and functional values. Among them, Gardenblue had the highest anthocyanin content, with 2.59 mg/g in fresh fruit. After ultrasound-assisted solvent extraction and macroporous resin absorption, the content was increased to 459.81 mg/g in the dried powder. Biological experiments showed that Gardenblue anthocyanins (L1) had antiproliferative effect on cervical cancer cells (Hela, 51.98 µg/mL), liver cancer cells (HepG2, 23.57 µg/mL), breast cancer cells (MCF-7, 113.39 µg/mL), and lung cancer cells (A549, 76.10 µg/mL), and no apparent toxic effects were indicated by methyl thiazolyl tetrazolium (MTT) assay, especially against HepG2 cells both in vitro and in vivo. After combining it with DDP (cisplatin) and DOX (doxorubicin), the antiproliferative effects were enhanced, especially when combined with DOX against HepG2 cells; the IC50 value was 0.02 µg/mL. This was further evidence that L1 could inhibit cell proliferation by inducing apoptosis. The detailed mechanism might be L1 interacting with DNA in an intercalation mode that changes or destroys DNA, causing apoptosis and inhibiting cell proliferation. The findings of this study suggest that L1 extract can be used as a functional agent against hepatoma carcinoma cells.