Studies On Bioactivity Of Coconut Testa Oil Extract

Coconut is a typical representative of plants in Hainan, coconut flower juice, coconut oil have been researched, but the studies about coconut testa oil activity have less reported. In this study, coconut testa oil polyphenol were extracted by using the extraction method, and studied the biological activity of extracts, including inhibition of LDL oxidation, the protective effect of protein oxidative damage, and the protective effect of DNA damage; and high performance liquid chromatography for the determination of several polyphenolic compounds content. Specific research contents and results are as follows:1. Preparation of coconut testa oil and its extracts:preparation of coconut testa oil by using isopropanol as the extraction solvent, solid-liquid ratio:1:4, extraction temperature:60℃, extraction time:3h, the extraction ratio was30%; the coconut testa oil extract was obtained by using methanol/water as the solution, ultrasonic-assisted, the extraction ratio was1.09%, the total phenol content in the extract was67.93±0.306mg/g.2. Take human low-density lipoprotein (LDL) as test materials, contrast to Trolox, studied including the inhibition of coconut testa oil extracts on low density lipoprotein oxidation, the content of TBARS, copper chelation assay, lipoxygenase and the total antioxidant ability of the extracts. The experimental results show that: although the effect is slightly lower than Trolox, but extract significantly prolong the LDL oxidation delay time, reduce the generation of lipid peroxidation product malondialdehyde (MDA), strong chelation ability with copper ion, and inhibition activity of lipoxygenase and with the increase of concentration effect improved trend. That protection of coconut testa oil extracts on low density lipoprotein oxidation is related to concentration.3. Human serum albumin as the research object, protective effect of different coconut testa oil extracts on human serum albumin (HSA) damage induced by hydrogen peroxide was investigated with Trolox as standard. The protein damage were studied by measuring protein carbonyl groups and protein hydroperoxides, the impact of protein structural changes, as well as the scavenging activity of extracts on DPPH(2,2-diphenyl-1-picrylhydrazyl) radical, hydrogen peroxide. The results showed that:coconut testa oil extracts extract can significantly reduce the generation of hydrogen peroxide-induced protein carbonyl and hydro peroxides; and could protect the structure of protein,; have the strong scavenging activity on DPPH radical and hydrogen peroxide, indicating that coconut testa oil extract has a strong protective effect on protein oxidation.4. Using hydroxyl radical which was generated by the fenton reaction induced pBR322DNA damage, study the protective effect of the coconut testa oil extracts on DNA damage, and scavenging activities of extracts on ABTS free radical, inhibition activity of linoleic acid oxidation of β-carotene. The results showed that:the protective effect of Trolox on the DNA damage is not a linear relationship between concentrations. Coconut testa oil extracts have a significant protective effect on DNA damage, and this effect is enhanced as the concentration increases. Strong scavenging effect on ABTS free radical, and the inhibition ability of coconut testa oil extracts have no significant difference with Trolox.5. High performance liquid chromatographic photodiode array detection (HPLC-PAD) method for the determination of six polyphenols in coconut testa oil extracts was developed. The results showed that the content of epicatechin, catechin is relatively high; the content of ferulic acid, caffeic acid, gallic acid, p-hydroxybenzoic acid is relatively small.