Toxicity Profile of Plectranthus glandulosus Hook. F. (Lamiaceae) Aqueous Extract, Hydro-Ethanolic Extract, and Ethyl Acetate Fraction.

Plectranthus glandulosus is valued for its culinary and medicinal properties. This study evaluated the cytotoxicity, acute oral toxicity, and subacute oral toxicity of its aqueous extract, hydro-ethanolic extract, and ethyl acetate fraction. Cytotoxicity was tested on African green monkey kidney (Vero) and murine macrophage (RAW 264.7) cell lines exposed to concentrations ≤ 200 μg/mL. Acute toxicity was assessed via a single oral dose of 5000 mg/kg, and subacute toxicity through daily oral doses of 250-1000 mg/kg over 28 days. All extracts maintained > 95% cell viability in Vero and RAW 264.7 cells, indicating no cytotoxicity. No mortality, behavioral changes, or clinical signs of toxicity were observed. Food and water intake, body weight, and organ weights were unaffected (p > 0.05). Macroscopic and histopathological examinations of the liver, kidneys, heart, and spleen showed no abnormalities. At the highest subacute dose (1000 mg/kg), hematological parameters remained within normal ranges, showing no significant differences compared to the control (p > 0.05): white blood cells (7.23-7.95 vs. 7.94 ± 1.29 × 103/mm3), red blood cells (3.00-3.38 vs. 3.57 ± 0.79 × 106/mm3), hemoglobin (12.10-12.40 vs. 12.20 ± 1.10 g/dL), hematocrit (29.60-44.53 vs. 41.70 ± 3.70%), and platelets (491.30-528.13 vs. 490.70 ± 0.40 × 103/mm3). Differential leukocyte counts (lymphocytes, monocytes, eosinophils, and basophils) also remained stable. Biochemical markers, including alanine transaminase (62.76-69.20 vs. 64.60 ± 10.25 U/L), aspartate transaminase (112.15-123.85 vs. 120.69 ± 9.56 U/L), total protein (64.45-65.80 vs. 65.2 ± 3.20 g/L), urea (20.35-21.22 vs. 21.62 ± 0.73 mg/dL), creatinine (0.56-0.58 vs. 0.56 ± 0.33 mg/dL), and C-reactive protein (≤ 350 µg/mL), were comparable to controls. In conclusion, P. glandulosus extracts and fraction exhibited no cytotoxic, acute, or subacute toxic effects at the tested doses, supporting their safety and potential in alternative medicine.