PHYTO SCREENING, ANTIBACTERIAL AND ANTI-INFLAMMATORY ACTIVITIES, AND ACUTE ORAL TOXICITY OF ERYTHRINA ABYSSINICA LAM. EX DC. (FABACEAE) HYDROETHANOLIC LEAF AND BARK EXTRACTS

Objective: To evaluate the phytochemical profile, antibacterial and anti-inflammatory activities, and acute oral toxicity of Erythrina abyssinica hydroethanolic leaf and bark extracts. Methods: Leaves (177 g) and bark (216 g) were collected from Lake Chivero, Zimbabwe, air-dried, powdered, combined (1:1 w/w), and extracted with 70% ethanol by maceration (72 h). The extract was concentrated under vacuum, lyophilized (yield 9.8% w/w), and subjected to qualitative phytochemical screening. Antibacterial activity against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) was assessed by agar well diffusion (60–180 mg/mL) and macro broth dilution for minimum inhibitory concentration (MIC). Anti-inflammatory activity was evaluated by egg albumin denaturation inhibition (100–500 µg/mL). Acute oral toxicity was tested in Sprague-Dawley rats following OECD Guideline 425 (up-and-down procedure, 250, 2000 mg/kg). Results: Phytochemical screening revealed strong presence (+++) of alkaloids, flavonoids, phenolics, tannins, saponins, steroids, coumarins, glycosides, and terpenoids. The extract inhibited protein denaturation dose-dependently, reaching 77.82 ± 0.54% at 500 µg/mL (IC₅₀ = 147.6 µg/mL), comparable to diclofenac (81.13 ± 0.37%). Against S. aureus, the corrected zone of inhibition at 180 mg/mL was 16 mm (MIC = 15.6 µg/mL); against E. coli, MIC was 7.8 µg/mL. No mortality or clinical signs occurred up to 2000 mg/kg; the estimated oral LD₅₀ exceeded 2000 mg/kg. Conclusion: E. abyssinica hydroethanolic leaf and bark extracts are rich in bioactive phytochemicals, exhibit significant antibacterial and anti-inflammatory activity, and show low acute oral toxicity in rats, supporting their potential as a safe, plant-based therapeutic for inflammatory and infectious conditions.