Antibacterial, cytotoxic activities and chemical composition of fruits of two Cameroonian Zanthoxylum species.

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum leprieurii (Syn. Fagara leprieurii) is a plant extensively used by traditional healers in Cameroon for the treatment of stomach disorders, gonorrhea, intestinal parasites and sterility. The infusion from the fruit is taken in Cameroon for the treatment of sickle cell anemia, as well. Similarly, the roots of Zanthoxylum zanthoxyloides (Syn. Fagara zanthoxyloides) are also used for wound dressing, sickle cell anemia and as pain reliever, in addition to the uses mentioned for Zanthoxylum leprieurii.

AIM OF THE STUDY

To scientifically validate their traditional use, the in vitro antimicrobial and anticancer assays were performed. In addition, chemical compositions of their fruit extracts and essential oils were also studied.

MATERIAL AND METHODS

The chemical compositions of their essential oils and methanol extracts were studied. GC and GC-MS were used for analyzing the essential oils while various chromatographic methods were used to isolate the pure compounds from methanol extracts. MTT assay was used for the cytotoxic studies of methanol extracts, their fractions and some pure compounds. Antimicrobial activity of methanol extracts, some isolated compounds as well as essential oils was tested against a panel of human pathogenic bacteria by diffusion and dilution methods.

RESULTS

The principal constituents of the essential oil of Zanthoxylum zanthoxyloides were identified as citronellol and geraniol whereas Zanthoxylum leprieurii was rich in E-β-ocimene. Furthermore, we report for the first time, the presence of 7,8-dimethoxycoumarin and sinapic acid in the methanol extract of Zanthoxylum leprieurii. In vitro bioassays reveal that the methanol extracts, essential oil and some of the isolated compounds from fruits of both the plants exhibit moderate anticancer and antimicrobial activities.

CONCLUSION

Altogether, the present findings justify the traditional use of Zanthoxylum zanthoxyloides and Zanthoxylum leprieurii in the treatment of stomach disorders and cancer disease. The antimicrobial properties in the essential oil of Zanthoxylum zanthoxyloides are of additional significance.