Ethnobotanical survey and antibiofilm evaluation of medicinal plants used for the control of tomato bacterial wilt caused by Ralstonia solanacearum

Introduction Tomato is an important economic activity for rural populations in Burkina Faso. However, tomato wilt, caused by Ralstonia solanacearum is a serious threat to tomato yields. However, market gardeners use toxic pesticides to combat pests and plant diseases. The aim of this study was to identify medicinal plants traditionally used to treat crop diseases, so as to assess the plant’s potential to inhibit biofilm formation in R. solanacearum . Methods An ethnobotanical survey was conducted in the Northen region of Burkina Faso. We collected information on the chemical and biological treatment methods used by market gardeners. Five most frequently cited plants were selected for a biological study. The minimum inhibitory concentration (MIC), antibiofilm activity against R. solanacearum were assessed. The total polyphenol and flavonoid contents of the extracts were quantified. Results A random sample of 103 volunteer market gardeners were interviewed. Seven plants and twenty-one pesticides were identified for treating crop diseases, grouped into seven (7) major chemical families. The avermectins were the most frequently cited and with the carbamates are classed as very hazardous. The plants most cited were A. indica (32.03%), N. tabacum (9.7%), K. senegalensis (9.7%), O. americanum (9.7%) and C. chinense (9.7%). O. americanum exhibited the most significant antibacterial activity, against strains 1743(12.5 mg/mL), OH19 (12.5 mg/mL) and B28 (25 mg/mL). Other extracts showed MIC values ≥50 mg/mL against all strains except OH19 for N. tabacum (25 mg/mL) and K. senegalensis (12.5 mg/mL). In addition, A. indica (63.33%), O. americanum (56.53%), C. chinense (54.8%), and N. tabacum (51.73%) presented the significative antibiofilm activities. K. senegalensis extract, which lack flavonoids, have shown no significant antibiofilm effect. O. americanum extract, rich in flavonoids (1. 93 ± 0.61 μg QE/100 mg) exhibited a significant antibiofilm inhibition. Conclusion The significant antibiofilm effect of C. chinense , O. americanum , A. indica , and N. tabacum suggests that these plants are a promising alternative in the fight against R. solanacearum .