HPTLC-Bioautography-MS-Guided Strategy for the Detection of Phthalides With Antimicrobial and Antioxidant Activities From Ligusticum chuanxiong Essential Oil.

Abstract

Introduction: Antimicrobial resistance and free radical-mediated oxidative stress and inflammation involved in many pathological processes have become treatment challenges. One strategy is to search for antimicrobial and antioxidant ingredients from natural aromatic plants. This study established a rapid and high-throughput effect-component analysis method to screen active ingredients from Ligusticum chuanxiong essential oil (CXEO).

Objective: The study aims to screen phthalides with antimicrobial and antioxidant activities from CXEO by high-performance thin-layer chromatography (HPTLC)-bioautography combined with HPLC-TOF/MS method.

Methods: Antimicrobial activity was evaluated by disc diffusion and micro broth dilution methods. Antioxidant capacity was performed by DPPH scavenging test. Phthalides in CXEO were identified using HPLC-TOF/MS method. HPTLC-bioautography technique was established to screen phthalides of antifungal and antioxidant activities.

Results: CXEO had significant inhibitory activity against Candida albicans, weak or undetected inhibitory activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. For tested strains of C. albicans, inhibition zone diameters ranged from 13 to 17 mm, and MICs were from 0.5 to 2 mg mL^-1. CXEO also had strong antioxidant activity, IC₅₀ value for scavenging DPPH free radicals was 1.014 ± 0.014 mg mL^-1. Nine phthalides in CXEO were tentatively identified. Ligustilide and senkyunolide A were screened to have both antimicrobial activity against C. albicans and strong DPPH scavenging property.

Conclusion: HPTLC-bioautography-MS-guided strategy is very practical for high-throughput screening of antifungal and antioxidant phthalides from CXEO. In vitro experiments have shown that phthalides and CXEO have good biological activities, which may be used to the treatment of C. albicans infection or oxidative stress damage caused by various diseases. The therapeutic potential should be validated in vivo in the future.