Objective: This research aimed to determine the phytochemical composition and the antioxidant properties in vitro of three types propolis collected from the region of South Sulawesi Province of Indonesia. Methods: Samples from three types of propolis: smooth, rough and mix were extracted with 96% ethanol. The propolis ethanolic extracts (PEE) was dried and studied their antioxidant properties by using FRAP (Ferric Reducing Antioxidant Power) and DPPH radical scavenging assays. Total phenolic compounds were quantified by Folin-Ciocalteu, and total flavonoid contents were also quantitatively determined by the AlCl 3 colorimetric method with a microplate reader. The chemical compounds were identified by an ultraperformance liquid chromatography TOF mass spectrometer (UPLC-TOF-MS) using the MS E mode. Results: The sequence of potential antioxidant activity of PEE is smooth propolis > mix propolis > rough propolis. Which showed by EC 50 value with DPPH assays are 25.54; 31.66; and 69.96 µg/mL, respectively and also showed by EC 50 value with FRAP assays consecutively were 26.41; 32.10; and 34.62 μg/mL.Smooth propolis has the lowest EC 50 value of all the types of propolis examined, contains total flavonoid content 791.06+13.06 mg QE/g extract and total phenolics content 426.91+61.08 mg GAE.g-1 extract. Chemical component identified by UPLC-TOF-MS using the MS E mode were (-)-Sesamin C 20 H 18 O 6 ; Curcumin C 21 H 20 O 6 ; 8-epi-Helenalin C 15 H 18 O 4 ; and Kushenol F C 25 H 28 O 6. Conclusion: Smooth propolis which taken from inside the nest was the most potent antioxidant among of all the types of examined propolis. The antioxidant activity was influenced by the phenolic content of Propolis.

The use of doxorubicin and epirubicin as chemotherapy agent causes side effects such as liver damage due to oxidative stress by reactive oxygen species (ROS) that cause increased of ALT and AST level as liver parameter. One source of natural antioxidants as ROS neutralizer comes from flavonoid that contain in propolis. Most researchers claim that flavonoid can be used to protect the liver. The aim of this study was to test the hepatoprotective effect of flavonoid in propolis from South Sulawesi against doxorubicin and epirubicin. The experiment included male Sprague dawley rats divided into nine groups. The rats received the microcapsule propolis or the quercetin orally for 15 days. The hepatotoxicity was promoted by injection epirubicin and doxorubicin (i.v.) with a cumulative dose of 9 mg/kg. In this study, total polyphenol and flavonoid tests of propolis have been carried out, there were 1.1% polyphenols and 2.7% flavonoids, the antioxidant activity tests showed IC50 value of 9849 ppm and LCMS/MS tests supported the presence of phenolic compounds in propolis from South Sulawesi. Liver parameter was measured and the results showed that the propolis 200 mg/kg group produced the lowest ALT and had potential protective effect against doxorubicin and epirubicin-induced hepatotoxicity.

ATP drives the conformational change of the group II chaperonin from the open lid substrate-binding conformation to the closed lid conformation to encapsulate an unfolded protein in the central cavity. The detailed mechanism of this conformational change remains unknown. To elucidate the intra-ring cooperative action of subunits for the conformational change, we constructed Thermococcus chaperonin complexes containing mutant subunits in an ordered manner and examined their folding and conformational change abilities. Chaperonin complexes containing wild-type subunits and mutant subunits with impaired ATP-dependent conformational change ability or ATP hydrolysis activity, one by one, exhibited high protein refolding ability. The effects of the mutant subunits correlate with the number and order in the ring. In contrast, the use of a mutant lacking helical protrusion severely affected the function. Interestingly, these mutant chaperonin complexes also exhibited ATP-dependent conformational changes as demonstrated by small angle x-ray scattering, protease digestion, and changes in fluorescence of the fluorophore attached to the tip of the helical protrusion. However, their conformational change is likely to be transient. They captured denatured proteins even in the presence of ATP, whereas addition of ATP impaired the ability of the wild-type chaperonin to protect citrate synthase from thermal aggregation. These results suggest that ATP binding/hydrolysis causes the independent conformational change of the subunit, and further conformational change for the complete closure of the lid is induced and stabilized by the interaction between helical protrusions.