Powerful Antioxidants and Cytotoxic Activities of the Methanol Extracts from Eight Soybean Cultivars

Abstract

In the present study, the chemical composition and total phenolic (TPC) and total flavonoid contents (TFC) of eight soybean cultivars (Giza 21, Giza 22, Giza 35, Giza 111, Giza 82, Giza 83, Crawford, and Holliday) were estimated. Moreover, antioxidant activity and in vitro cytotoxic activities against HepG-2 and MCF-7 were evaluated. Giza 21, Giza 111, and Crawford cultivars recorded higher than 40% crude protein. The analysis revealed that TPC values in seed extracts ranged from 10.5 mg GAE/g extract in Giza 35 to 6.4 mg GAE/g extract in Giza 22. TFC varied from 1.20 mg QE/g extract in Giza 111 to 0.55 mg QE/g extract in Crawford. Giza 35 exhibited the highest content of genistein and daidzein and the highest free radical scavenging activity (61.833%). The results of the MTT assay demonstrated that the soybean methanolic extracts inhibited the proliferation of HepG-2 and MCF-7 cells in a dose-dependent manner. Giza 35 exhibited the highest cytotoxic activity. In conclusion, Giza 35 cultivar recorded the highest TPC and TFC values and antioxidant and cytotoxic activities. Therefore, this cultivar can be used as a source for the production of pharmaceutical and medicinal products rather than as a nutritional source of protein.

Keywords: DPPH assay; MTT assay; cytotoxicity; flavonoids; isoflavones; soybean.

Figure 1

HPLC of major phenolic, flavonoid, and isoflavone compounds (1: syringic, 2: quercetin, 3: gallic acid, 4: benzoic acid, 5: genistein, 6: daidzein, 7: p-coumaric, 8: glycitein, and 9: ferulic acid) in eight soybean cultivar extracts.

Figure 2

Cytotoxic activity of methanolic extracted from soybean Giza 35 at different concentrations (12.5, 25, 50, 100, and 200 µg/mL) against HepG-2 (A) and MCF-7 (B) compared to that of Doxorubicin as a control. All data are expressed as the mean (n = 3) with ±SD.