Are the plants used in Algerian traditional medicine effective? Assessment of the antibacterial, anti-inflammatory and anti-oxidative effects of three plants used in Algerian traditional medicine; Olea europaea, Glycyrrhiza glabra and Ocimum basilicum

Abstract

Background: Algeria has a very large vegetation biodiversity. Algerians use herbs in phytotherapy because of their easy, safe and inexpensive use. However, the consumption of these plants remains uncontrolled or regulated by the authorities, which lacks reassurances concerning their use. Objective: The purpose of this work is to confirm or refute the empirical use of the plants as well as to start adjusting the dosages for each therapeutic purpose.

Methods: The present experimentation was done during the year 2017 (April-June) at the laboratory for the valorization of natural biological substances at the University of Setif 1. The in vitro anti-inflammatory effect of Olive and basil leaves and Licorice root aqueous extracts were evaluated against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 by the disc diffusion assay. The in vitro anti-inflammatory activity was realized by the estimation of the protein denaturation of the BSA, and the anti-oxidative test was done by the DPPH method. All experiments were done in triplicate results and were reported as mean ± SD. Data were analyzed by GraphPad prism 5 software; the statistical analysis was done by the one way ANOVA.

Results: Olive leaf extract (OLE) and Licorice root extract (LRE) were active on both E. coli (13.5, 10mm) and S. aureus (14, 12mm) at 200 mg/ml. While the Basil leaf extract (BLE) was inactive against all strains. The percentage of BSA denaturation was concentration-dependent by both BLE and LRE and the maximum inhibition was recorded by the OLE at 250 μg/ml, it was slightly different from BLE at P≤0.05, but not significantly different from LRE. The three extracts showed good values of IC50 with 0.65, 4.98 and 0.91 mg/ml OLE, LRE and BLE respectively, but they were inferior to that of BHT.

Conclusion: These results confirm the use of these plants but under control.