Phytochemical Screening and Antibacterial Evaluation of Anarcardium occidentale Root Collected in Agbani, Eastern Nigeria

Background: Different parts of Anacardium occidentale (Cashew) are used in folk medicine to treat dysentery, diarrhea piles, toothache and sore gums. Evaluation of phytoconstituents or novel compounds from the plant is highly needed to authenticate these claims. Aim: The aim of the research was to conduct phytochemical analysis and antibacterial evaluations of extract and fractions of root of Anarcadium occidentale got from Agbani. Methods: The pulverized material was extracted with methanol using cold maceration method. Solvent fractions were obtained using separating funnel based on liquid-liquid extraction technique starting with non-polar to high polar solvent. The cup-plate agar diffusion was used to conduct preliminary antibacterial evaluation of the extract and fractions. Agar dilution and streaking on the solid agar techniques were used to evaluate the test extract and fractions against some selected bacteria for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) respectively. Results: The phytochemical screening of the extract and fractions showed that terpenoids, saponins, glycosides, fat and oil, alkaloids, flavonoids and tannins were present. The preliminary evaluations of the agent showed promising activity by producing inhibition zone diameter (IZD) ranging from 10 + 0.66 to 20 + 0.98 mm. The MIC and MBC of the test extract and fractions against the test bacteria - Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, Streptococcus spp, Escherichia coli, Klebsiella spp, Salm typhi, Bacillus subtilis.  Salmonella. spp and Proteus. mirabils – ranged from 0.0025-0.040 mg/mL and  0.020 – 0.080 mg/mL respectively. Conclusion: Our study showed that the extract and fractions of the cashew root possess promising antimicrobial activity. This suggests that the agents may provide novel compounds for antibacterial drug development research.