_____________________________________________________________________________________________________ *Corresponding author: E-mail: ola.ayepola@covenantuniversity.edu.ng; Journal of Complementary and Alternative Medical Research 5(4): 1-6, 2018; Article no.JOCAMR.41086 ISSN: 2456-6276 In vitro Antioxidant and Anti-staphylococcal Activity of Bixa orellana Linn. and Milicia excelsa Welw Olayemi Oluseun Ayepola 1* , Amarachi Faithfulness Samson 1 and Olabode Onile-Ere 1 1 Department of Biological Sciences, Covenant University, Ota, Ogun State, Nigeria. Authors’ contributions This work was carried out in collaboration between all authors. Author OOA designed the study and approved the final draft. Author OOE managed the analyses of the study and prepared the final draft of manuscript. Author AFS performed the assays. All authors read and approved the final manuscript. Article Information DOI: 10.9734/JOCAMR/2018/41086 Editor(s): (1) Dr. Manikant Tripathi, Department of Microbiology, Dr. Ram Manohar Lohia Avadh University, Faizabad, India. (2) George Perry, Dean and Professor of Biology, University of Texas at San Antonio, USA. (3) Francisco Cruz-Sosa, Metropolitan Autonomous University Iztapalapa Campus Av. San Rafael Atlixco, Mexico. Reviewers: (1) Esraa Ashraf Ahmed ElHawary, Ain Shams University, Egypt. (2) Samia Mezaache-Aichour, University Ferahat Abbas Sétif 1, Algeria. Complete Peer review History: http://www.sciencedomain.org/review-history/24588 Received 21 st February 2018 Accepted 1 st May 2018 Published 12 th May 2018 ABSTRACT An estimated 80% of persons in the world depend on medicinal plants for their healthcare needs. It is essential to study these plants in a bid to evaluate their therapeutic properties, adding credence to their applications in folklore. In this study, we report the antioxidant and antibiotic properties of Bixa Orellana (BO) and Milicia excelsa (ME) against Staphylococcus aureus isolates. Antioxidant profile, Total phenol content and total flavonoid content of both plants were performed using standard methods. Also, methanolic extracts of Bixa orellana and Milicia excelsa prepared in concentrations ranging from 3.125 mg/ml to 100 mg/ml were assessed for their antimicrobial activity using the agar well diffusion method. Total phenol content was 1.039 mg/g and 1.032 mg/g while total flavonoid content was 0.76mg/g and 0.5mg/g for Milicia excelsa and Bixa Orellana respectively. Both plant extracts also showed good free radical scavenging ability. The S. aureus isolates showed a dose- dependent sensitivity to the test extracts with sensitivity reducing at lower concentrations. Bixa Orellana showed better activity than Milicia excelsa. However, Milicia excelsa inhibited more organisms at lower concentrations (≤25 mg/ml). This study has shown the efficacy of both plants as alternative herbal treatments. Original Research Article