_____________________________________________________________________________________________________ *Corresponding author: E-mail: oilori@aul.edu.ng, olasupoilori@yahoo.com; Journal of Advances in Biology & Biotechnology 25(3): 22-27, 2022; Article no.JABB.86601 ISSN: 2394-1081 Effects of Helianthus annuus and Anthocleista djalonensis on Staphylococcus aureus and Escherichia coli Olasupo John Ilori a* , Esther Chidima Okeke a , Adesola Esther Adeneye a , Temiloluwa Folasayo Afolayan a , Abiola Hilder Emmanuel-Akerele a and Omolola Abiola Bassey a a Department of Biological Sciences, Faculty of Science and Science Education, Anchor University, Lagos, Nigeria. Authors’ contributions This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/JABB/2022/v25i330271 Open Peer Review History: This journal follows the Advanced Open Peer Review policy. Identity of the Reviewers, Editor(s) and additional Reviewers, peer review comments, different versions of the manuscript, comments of the editors, etc are available here: https://www.sdiarticle5.com/review-history/86601 Received 04 March 2022 Accepted 09 May 2022 Published 21 May 2022 ABSTRACT Plant based medicines have been a part of traditional healthcare in most parts of the world for thousands of years. The medicinal plants are of great interest to human health. It has been proven that antimicrobials of plant origin work more efficiently with fewer side effects. The study aimed to identify the phytochemicals in the extracts of Helianthus annus and Anthocleista djalonensis and examine the effects of extracts of these plants on the growth of clinical bacterial isolates. Leaves of Helianthus annus and Anthocleista djalonensis were extracted in methanol, distilled water and hot water. The extract solution (100%) was further diluted to various concentrations (75%, 50%, and 25%). The data obtained were analyzed by Analysis of Variance (ANOVA) to determine significant (P< 0.05) effects. Significant differences between means were determined using Duncan’s Multiple Range Test (DMRT). The phytochemical screening indicated the presence of alkaloids, phenols, glycosides, flavonoids, terpenoids, saponins and quinone. The extracts of the plants inhibited the growth of the bacteria tested with varied effectiveness. The maximum antibacterial activities were observed in the aqueous extracts. Thus the extracts of Helianthus annus and Anthocleista djalonensis can be used in the development of new pharmaceuticals that address unmet therapeutic use. Original Research Article