Ll lines with IC50 values of 46.2 and 38.six M, respectively [12]. In 2012, Lin et al. studied the chemical constituents of Rabdosia serra (MAXIM.) HARA, and located -sitosterol isolated in the plant have considerable cytotoxic activities against HepG-2, MCF-7, and HL-60 cells [13]. Stigmast-4-en-3-one also displayed higher antitumor-promoting activity [14]. As a result, to determine whether or not these compounds were responsible for the activities of those extracts, we evaluated the cytotoxic activities of those compounds against PC3, Bcap-37, and MGC-803 cells. The outcomes are shown in Table 2. It can be seen from the IC50 values that -amyrin, -sitosterol, and stigmast-4-en-3-one suppressed proliferation of the above three cancer cell lines in distinct extents (IC50 values of 43.8-79.3 M). These compounds showed related inhibition activity against PC3 and MGC-803 cells, whilst the proliferation inhibition of MGC-803 cells was superior to other sorts of cancer cells. On the other hand, -amyrin displayed weak activities against the three cells. These locating indicated thatHOHO HO-Amyrin-Amyrin-SitosterolFigure 1 The structures with the primary elements of pitaya peel extracts.Luo et al. Chemistry Central Journal 2014, 8:1 journal.chemistrycentral/content/8/1/Page four ofTable 2 Impact of steroids and triterpenoids from supercritical carbon dioxide APC Synonyms extracts of H. polyrhizus and H. undatus against cell viability of different cancer cell linesCompound -Amyrin -Amyrin -Sitosterol Stigmast-4-en-3-one ADMaIC50 (M)a PC3 bBcap-37 100 78.4 ?0.93 58.2 ?0.44 79.3 ?0.49 1.34 ?0.MGC-803 one hundred 51.9 ?0.87 43.8 ?0.63 56.9 ?0.81 0.83 ?0.73.2 ?1.02 74.four ?0.65 65.four ?1.13 1.09 ?0.cFigure two Effect of H. polyrhizus extract on proliferation of cancer cells.Agent concentration (M) that inhibited cell growth by 50 at 72 h right after therapy. b When 50 inhibition couldn’t reached at the highest concentration, then 100 M was offered. c Adriamycin, optimistic control.-amyrin, -sitosterol, and stigmast-4-en-3-one could be accountable for the activities of your two extracts.Antioxidant activityThe principle of in vitro antioxidant activity is depending on the MyD88 Species availability of electrons to neutralize an free of charge radicals [15,16]. In this study, the antioxidant activities of supercritical carbon dioxide extracts of H. polyrhizus and H. undatus were evaluated by DPPH radical scavenging assay, with vitamin C (Vc) as the good control. And the unfavorable manage group was treated with ethanol. The two extracts and Vc were dissolved in ethanol. Each experiment was repeated at the very least three times. The scavenging rate of Vc at 0.1 mg/mL was 98.9 . DPPH freeradical scavenging properties on the two extracts are present in Figure 4. A decrease IC50 worth and greater DPPH radical scavenging percentages indicate higher antioxidant activity. Each in the two extracts exhibited some antioxidant activities. The IC50 values of H. polyrhizus and H. undatus extracts were 0.83 and 0.91 mg/mL, respectively.Additionally, it might be seen from Figure 4 that the two extracts showed dose dependent antioxidant activity. Antioxidants terminate these chain reactions by removing free radical intermediates, and inhibit other oxidation reactions, and they do this by becoming oxidized themselves [17-19]. Higher phenolic content material had been ordinarily correlated with higher radical scavenging activity [20]. Choo et al. located that H. polyrhizus and H. undatus had fantastic antioxidant properties, due to high content of polyphenols [2]. Moreover, polyphenols might be extracted by super.