A comparative study on antioxidant, anti-inflammatory, antimicrobial activities and chemical composition of Pyrus ussuriensis cultivars from northeastern China

Pyrus ussuriensis is the most important cultivated pear in the northeastern, cold areas of China. However, studies on the biological activity of Pyrus ussuriensis fruit are rare in the public domain. The present study compared antioxidant, anti-inflammatory, and antimicrobial activities and chemical composition in tissues from the peel and flesh of nine Pyrus ussuriensis cultivars. The chemical composition differed among cultivars and tissue sources. Phenolics were predominant in peel samples, whereas sugars were predominant in flesh samples. Twenty-one phenolic compounds were identified and quantified, including hydroxycinnamic acids, hydroquinones, flavanols, flavonols, flavones, and anthocyanins (only in peel samples). The total phenolic content ranged between 363.0 and 1734.0 mg kg(- 1) FW in the peel and from 28.5 to 182.3 mg kg(- 1) FW in the flesh. In addition, cultivars with high total phenolic and flavonoid contents had significantly higher antioxidant activities. The in vitro anti-inflammatory study, performed using an egg albumin denaturation assay, demonstrated that both peel and flesh samples had strong activity, which was comparable with that of the standard anti-inflammatory drug diclofenac sodium. The antimicrobial results showed that 'Jianba' and 'Balixiang' cultivars exhibited strong activity against bacteria strains in the peel and flesh, respectively. The present study provided information for selecting promising Pyrus ussuriensis cultivars with improved health benefits.