In vitro bioactivities and subacute toxicity study of O. basilicum, T. vulgaris and R. officinalis

Abstract Background Ocimum basilicum, Thymus vulgaris, and Rosmarinus officinalis have been used for the treatment of different ailments for a historically long time but there have been no safety studies of these plants. Phytoconstituents of these plants were found to be good potential therapeutic agents which could be used in treatment regimens as a replacement of synthetic drugs if they are safe. Experimental Standard Folin ciocalteu reagent assay, aluminum chloride colorimetric assay and DPPH assay were employed to determine total phenolic, flavonoids and antioxidant activity, respectively. Broth microdilution method was used for investigation of synergistic effects of plant extracts with antibiotics. For toxicity assay, rats were treated with extracts of three plants at 1000 and 1500 mg/kg body weight. Results Ocimum basilicum extract showed highest total phenols, flavonoids, antioxidant and antibacterial activities. Thymus vulgaris extract caused hypertrophy of liver while Rosmarinus officinalis caused atrophy of spleen at both doses showing no significant histomorphological changes. Thymus vulgaris and O. basilicum extract significantly increased red blood cells, packed cell volume, hemoglobin and mean corpuscular volume at 1500 mg/kg body weight. Conclusion Ocimum basilicum, Thymus vulgaris and Rosmarinus officinalis have good phenolics and flavonoid content that shows antioxidant and antibacterial potential whilst having no evident toxic side effects on mammalian tissue and hematological parameters.