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 discovered -sitosterol isolated in the plant have considerable cytotoxic activities ERRα Gene ID against HepG-2, MCF-7, and HL-60 cells [13]. Stigmast-4-en-3-one also displayed higher HIV Integrase Purity & Documentation antitumor-promoting activity [14]. Hence, to decide whether or not these compounds had been responsible for the activities of these extracts, we evaluated the cytotoxic activities of these compounds against PC3, Bcap-37, and MGC-803 cells. The outcomes are shown in Table two. It may be noticed in the IC50 values that -amyrin, -sitosterol, and stigmast-4-en-3-one suppressed proliferation from the above three cancer cell lines in distinctive extents (IC50 values of 43.8-79.3 M). These compounds showed equivalent inhibition activity against PC3 and MGC-803 cells, though the proliferation inhibition of MGC-803 cells was superior to other types of cancer cells. Even so, -amyrin displayed weak activities against the 3 cells. These finding indicated thatHOHO HO-Amyrin-Amyrin-SitosterolFigure 1 The structures in the key components of pitaya peel extracts.Luo et al. Chemistry Central Journal 2014, 8:1 journal.chemistrycentral/content/8/1/Page four ofTable 2 Effect of steroids and triterpenoids from supercritical carbon dioxide extracts of H. polyrhizus and H. undatus against cell viability of diverse cancer cell linesCompound -Amyrin -Amyrin -Sitosterol Stigmast-4-en-3-one ADMaIC50 (M)a PC3 bBcap-37 100 78.four ?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.two ?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 development by 50 at 72 h following treatment. b When 50 inhibition couldn’t reached at the highest concentration, then 100 M was provided. c Adriamycin, positive handle.-amyrin, -sitosterol, and stigmast-4-en-3-one may be accountable for the activities in the two extracts.Antioxidant activityThe principle of in vitro antioxidant activity is based on the availability of electrons to neutralize an free radicals [15,16]. Within 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. Along with the adverse handle group was treated with ethanol. The two extracts and Vc have been dissolved in ethanol. Each experiment was repeated at the very least 3 instances. 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 four. A decrease IC50 worth and higher DPPH radical scavenging percentages indicate larger antioxidant activity. Both on the two extracts exhibited some antioxidant activities. The IC50 values of H. polyrhizus and H. undatus extracts had been 0.83 and 0.91 mg/mL, respectively.It also is often observed from Figure 4 that the two extracts showed dose dependent antioxidant activity. Antioxidants terminate these chain reactions by removing absolutely free radical intermediates, and inhibit other oxidation reactions, and they do that by being oxidized themselves [17-19]. High phenolic content material were normally correlated with higher radical scavenging activity [20]. Choo et al. found that H. polyrhizus and H. undatus had fantastic antioxidant properties, due to higher content of polyphenols [2]. Additionally, polyphenols could be extracted by super.