Butylparaben sodium (BP), sodium diacetate (SDA) and potassium sorbate (PS) are safe and internationally recognized preservatives. The aim of this study is to further evaluate their toxicities using microalgae cells, and a comparison is made with their mammalian cell cytotoxicities. Unicellular Dunaliella tertiolecta, was employed to test the possible toxicities of BP, SDA and PS. The results show that the three preservatives have a negative effect on D. tertiolecta, as manifested by a strong decrease in chlorophyll and carotenoid content, viable algal cells, and superoxide dismutase (SOD) and catalase (CAT) activities. SDA and PS had small effects on the normal hepatocytes HL7702, but similar to that for MCF-10A cells, BP is toxic. The effective concentration (EC50) value for HL7702 is 215.97 mg L−1. It is concluded that BP, SDA and PS have low toxicities to D. tertiolecta under slightly alkaline conditions, while under acidic conditions, SDA has moderate toxicity and PS has high toxicity. The sensitivity of algal cells is higher than that of HL7702 cells under slightly alkaline conditions, and is even more sensitive under acidic conditions. D. tertiolecta can be used as a pre-screen for toxicity testing.

In order to evaluate the health effects of Ilex latifolia Thunb., a Chinese bitter tea widely consumed as a health beverage, flavonoids, saponins, polysaccharides and alkaloids were extracted from its leaves and their in vitro antioxidant activity, anticomplement system activity, antiproliferative effects against human cervical carcinoma Hela cells, and anti-inflammatory effects against mouse macrophage RAW 264.7 cells were analyzed. Results showed that the polysaccharides exhibited a considerable inhibition of the complement system, the hemolysis inhibition rate reached 98% at a concentration of 0.8 mg mL−1, which was clearly higher than that of the positive control (heparin sodium). The total flavonoids displayed significant DPPH scavenging activity and an inhibition effect on the generation of NO in LPS-induced RAW 264.7 macrophages. In addition, the total saponins showed a better antiproliferative effect against Hela cells, and the total alkaloids exhibited a high reducing power. It is obvious that I. latifolia has a variety of nutritional and health functions which are attributed to its different components. The analysis method presented in this research can suggest lessons for analysis of other plant foods.

As olive oil is the main source of calories in the Mediterranean diet, a large number of studies have been carried out to characterize its role in various diseases and exploitation for the prevention and treatment of hypertension, carcinogenesis, diabetes, atherosclerosis, and other diseases. As one of the major polyphenols present in virgin olive oil, hydroxytyrosol shows a variety of pharmacological activities such as antioxidant properties, anticancer, anti-inflammatory, and neuroprotective activities, and beneficial effects on the cardiovascular system, which show its potentiality for the development of dietary supplements. In the future, more attention should be paid to its action mechanism in vivo and synergistic effect. Further research will be performed to provide the theoretical basis for hydroxytyrosol and its derivatives use as health supplements.