UPLC/HR-ESI-MS/MS and GC/MS profiling of Eriobotrya japonica L. fruit in correlation to its antioxidant, anti-inflammatory, and anti-arthritic effects

Eriobotrya japonica Lindl. (Loquat) fruit is a subtropical edible fruit originally from China. It grows well in Egypt, but it is not widely known. In the current study, the fruit was extracted with 80% ethanol to get the total ethanol extract (TEE). A part of which was fractionated by dichloromethane to yield polar and nonpolar fractions (PF and NPF). The antioxidant and anti-inflammatory activities of the TEE were in vitro evaluated. The complete Freund's adjuvant (CFA) arthritis model was used to explore the in vivo biological assessment of the anti-arthritic properties in vivo of the TEE, PF, and NPF of the fruit. Additionally, the inspected limbs detached from all animals were subjected to histological inspection. Moreover, GC/MS analysis of the unsaponifiable (USF) and saponifiable (SF) fractions of the NPF was performed. Furthermore, 64 metabolites from various chemical classes were identified using UHPLC/HR-MS/MS analysis of the TEE of the fruit in both positive and negative ionization modes. The positive ionization mode of loquat fruit allowed for the first time the detection of two kinds of lyso-glycerophospholipids (Lyso-GPLs): lyso-glycerophosphoethanolamines (Lyso-PtdEtn) and lyso-glycerophosphocholines (Lyso-PtdCho). The fruit extracts exhibited a notable in vivo anti-arthritic activity by decreasing paw thickness in the treated rats and adjusting the inflammatory mediators. The TEE showed the highest anti-arthritic activity, followed by the PF that showed an observed activity, while the NPF exhibited the lowest activity. Histopathological findings showed a marked improvement in the arthritic condition of the excised limbs. Thus, E. japonica fruit may be considered as a promising natural antioxidant and anti-arthritic agent.