The aim of the present study was to determine the content of phenolics, flavonoids and tannins, as well as the biological functions of propolis extracts from the stingless bee (Heterotrigona itama). The raw propolis was extracted via maceration with ultrasonic pretreatment in 100% water and 20% ethanol. The yield of ethanolic propolis extracts was about 1% higher than its aqueous counterpart. The colorimetric assays showed that the ethanolic propolis extract had about two times higher phenolics (17.043 mg GAE/g) and tannins (5.411 mg GAE/g), and four times higher flavonoids (0.83 mg QE/g). The higher phenolic content had enhanced the antiradical and antibacterial capacities of the ethanolic extract. The propolis extracts significantly exhibited higher antibacterial activity against gram-positive bacteria (Staphylococcus aureus) than gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). However, aqueous extract was found to have a higher anticancer property based on the viability of lung cancer cells. No cytotoxic effect was observed on normal lung cells as the cell viability was maintained >50%, even the concentration of propolis extracts were increased up to 800 µg/mL. Different chemical compositions of propolis extract would show different bioactivities depending upon the individual applications. The high content of phenolics suggests that the propolis extract could be a natural source of bioactive ingredients for the development of innovative and functional foods.
Extraction and fractionation were carried out to concentrate the rosmarinic acid from Orthosiphon aristatus in order to increase the value of herbal candy formulated using polyphenolic rich extract. The herb was extracted and fractionated in column chromatography, and then analyzed by LC-MS/MS. The collected plant fractions with similar chromatographic profiles were combined and determined for antioxidant capacities expressed in radical scavenging activity. The results showed that the antioxidant capacity was in good agreement with the concentration of rosmarinic acid in the combined fractions. The combined fraction II showed the highest rosmarinic acid content, 3.8%w/w and the highest antioxidant capacity (IC50=14.922 ppm). The incorporation of rosmarinic acid rich extract into candy formulation did not statistically affect the antioxidant capacity. Hence, the rosmarinic acid rich extract could be another choice of ingredient to enhance the beneficial property of candies. Candy is another form of carrier to deliver herbal ingredient for health promotion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.