Glucosinolates profile, volatile constituents, antimicrobial, and cytotoxic activities of Lobularia libyca

Abstract

Context: Brassicaceae plants are associated with protection against cancers due to their glucosinolate contents.

Objectives: We investigate fresh leaves, roots and ripe seeds of Lobularia libyca (Viv.) C.F.W. Meissn. (Brassicaceae) to identify their glucosinolate constituents, antimicrobial and cytotoxic activities

Materials and methods: The glucosinolates were identified using GC-MS analysis of their hydrolysis products and LC-MS analysis in the case of seeds. Disc diffusion (1 mg/disc) and minimum inhibitory concentration (0–160 μg/mL) methods were used to evaluate the antimicrobial activity of seed hydrolysate. In vitro cytotoxicity against colorectal HCT-116, hepatic HUH-7, breast MCF-7 and lung A-549 cells was evaluated for seed hydrolysate (0.01–100 μg/mL) using the sulforhodamine B assay and doxorubicin as a standard

Results: Three glucosinolates were identified for the first time in this plant and genus Lobularia. Glucoiberverin was the major compound accumulated in the seeds and leaves, while glucoiberin and glucoerucin were detected only in the seeds. No glucosinolates were detected in roots under the same experimental conditions. Other volatile constituents, e.g., terpenes and fatty acids were only identified in the seeds. The seed hydrolysate showed significant antimicrobial activities against Candida albicans and Pseudomonas aeruoginosa (MIC = 64 and 82 μg/mL, respectively). The seed hydrolysate exhibited a marked selective cytotoxicity in vitro against colorectal, hepatic and breast cancer cell lines. The IC50 values were 0.31, 2.25 and 37 μg/mL, respectively.

Discussion and conclusion: The results indicated the antimicrobial activity of L. libyca and the selective effect of the seed hydrolysate as a cytotoxic drug that is potentially more active than doxorubicin against HCT-116.