Plant galls are widely distributed, and their extracts are used in traditional medicine worldwide. Traditional remedies containing extracts of plant galls in China, India and some African countries have effective in the treatment of various pathologies. To open a new promising procedure for screening bioactive compounds from plant galls, standardized plant materials were generated in vitro and used for phytochemical and biological investigations. Methanol aqueous chloroform and hexane extracts of Nicotiana tabacum leafy galls induced by Rhodococcus fascians were used to evaluate phenolic and flavonoid contents, and to investigate antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical scavenging and ferric reducing antioxidant/power assays and anti-inflammatory activity by the lipoxygenase inhibition assay. Infection by R. fascians modifies significantly the phytochemical profile of N. tabacum as well as its biological properties. The total polyphenolic content was increased (120–307%), and that of flavonoids was reduced (20–42.5%). Consequently, antioxidant and antiinflammatory activities of non-infected tobacco extracts are significantly modified compared to plants treated with leafy gall extracts. This shows that infection by R. fascians favoured the production of anti-inflammatory and antioxidant compounds in N. tabacum. The study indicates the benefit of plant galls used in traditional medicines against various pathologies.

Nicotiana tabacum, Rhodococcus fascians, leafy galls, anti-inflammatory activity