Anthocyanin composition of fruit extracts from Lycium ruthenicum and their protective effect for gouty arthritis

Lycium ruthenicum Murray (LR) represents an agricultural cash crop found in Northwest China and has been used in traditional folk medicine for a long time. However, detailed qualitative and quantitative analyses of LR anthocyanins, as well as their pharmacological research, remain scarce. In this work, we established a rapid method for the simultaneous identification and quantification of six anthocyanidins and six anthocyanins from LR via UPLC-quadrupole-Orbitrap mass spectrometry (UPLC-Q-Orbitrap MS) analysis. Finally, five anthocyanidins and five anthocyanins were qualitatively and quantitatively analyzed. Among these, 10 constituents (delphinidin-3-glu, cyanidin-3-glu, petunidin-3-glu, peonidin-3-glu, malvidin-3-glu, delphinidin, cyanidin, petunidin, pelargonidin and malvidin) were detected and petunidin-3-glu proved to be the predominant species in LR. Furthermore, the anti-inflammatory effects of anthocyanin extracts and petunidin-3-glu were investigated using a rat model involving gouty arthritis induced by monosodium urate. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-18 (IL-18), prostaglandin E2 (PE2), cyclooxygenase-1 (COX-1) enzymes in serum, the paw COX-1 mRNA expression and paw volume could be determined to be significantly increased in rats suffering from gouty arthritis induced by monosodium urate. However, these indicators were found to be significantly reduced after treatment with anthocyanin extracts (200 mg/kg b.wt, p.o.) and petunidin-3-glu (40 mg/kg b.wt, p.o.). Taken in concert, our study shows that anthocyanin extracts and petunidin-3-glu may significantly reduce monosodium urate crystal-induced inflammation. Use and administration of these compounds may be potentially valuable for the further development and clinical applicability of the active compounds in this plant.