Screening of Antioxidant Alkaloid Components in Tinosporae Radix by Response Surface Method, Characteristic Chromatogram, Antioxidant Analysis, and Molecular Docking.

Abstract

Background: Tinosporae Radix is a valuable plant with applications in medicinal and edible fields. Alkaloids are one of the main active components of Tinosporae Radix, showing prominent antioxidant activity and great potential in healthcare fields.

Objective: Response surface method was applied to determine the optimal enrichment process of total alkaloids of Tinosporae Radix (TRTA). Antioxidant alkaloid components were screened by characteristic chromatogram, antioxidant analysis and molecular docking, so as to provide the basis for Tinosporae Radix to develop as a medicinal and edible homologous plant and antioxidant products.

Methods: In this study, a single-factor investigation experiment and a response surface optimization experiment were used to determine the optimal enrichment process of D101 macroporous resin. High-performance liquid chromatography (HPLC) was employed to establish the characteristic chromatogram of TRTA, after which chemometrics was applied to evaluate the data. The antioxidant activity of TRTA was assessed using DPPH and ABTS assays. Gray relational analysis was applied to explore the spectrum-effect relationship, and molecular docking techniques were combined to predict targets of antioxidant activity.

Results: The best enrichment process of total alkaloids is presented as follows: water removal 3 BV, 10% ethanol removal 3 BV, and 30% ethanol elution 3 BV. All four identified alkaloid components contributed to the antioxidant activity of TRTA, potentially processing binding interactions with multiple antioxidant protein targets, including TNF, NO-1, and XOD.

Conclusions: Alkaloids significantly contributed to the antioxidant activity of TRTA, with columbamine and palmatine playing particularly prominent roles, and the antioxidant activity of TRTA is likely exerted through a complex multicomponent, multitarget mechanism, involving the coordinated action of various alkaloid components and multiple biological targets.

Highlights: The optimized enrichment process demonstrated remarkable efficiency in concentrating total alkaloids from Tinosporae Radix. This study contributes significantly to the formulation of its quality control methods.