Phytochemical profiling, in-vitro Antibacterial and Synergistic Assessment of Harrisonia abyssinica (Radlk.) Exell and Dichrostachys cinerea (L) Wight&Arn. Root Extracts

Introduction: The increasing emergence of antimicrobial resistance necessitates the exploration of medicinal plants as alternative sources of novel antibacterial agents. This study investigated the phytochemical composition and in vitro antibacterial activity of Harrisonia abyssinica (Radlk.) Exell and Dichrostachys cinerea (L) Wight&Arn., two medicinal plants traditionally used in the management of infectious diseases. Materials and Methods: Crude extracts were subjected to Gas Chromatography–Mass Spectrometry (GC–MS) analysis to identify bioactive constituents, while antibacterial activity was evaluated using the minimum inhibitory concentration (MIC) method against selected pathogenic bacteria. GC–MS analysis revealed the presence of diverse bioactive compounds, including alcohols, fatty acid derivatives, terpenoids, and phenolic compounds, with notable constituents such as 2,3,4-trimethyl-2-pentanol and other oxygenated hydrocarbons detected in Dichrostachys cinerea. Results: Both plant extracts demonstrated measurable antibacterial activity, with MIC values indicating moderate to strong inhibition against tested Gram-positive and Gram-negative bacterial strains. Comparative analysis showed that Harrisonia abyssinica exhibited relatively stronger antibacterial effects, which may be attributed to the higher abundance and diversity of antimicrobial phytochemicals. Conclusion: The observed antibacterial activity and their phytochemical constituents reveal the ethnomedicinal use of Harrisonia abyssinica and Dichrostachys cinerea as promising sources of antibacterial agents for further isolation, characterization, and pre-clinical evaluation of their active compounds.