Pine. Olive. Juniper. Seafoam. Sage. Mint. Fern. Lime. Apple. Kiwi. The shades of green and their apt names show their ever-presence in our lives, and their primordial history. A history that stretches to our present and crescendoes again, with the modern obsession with ‘green’ - energy, fashion, production, diets, urban planning, and, maybe most especially, biomedical science.

As antimicrobial resistance continues to challenge global health systems, interest has grown in evaluating plant-based compounds as potential alternatives or adjuncts to conventional antibiotics. In this context, Aiza Tanveer Hassan, Dounia Baroudi, and Hyeonjeong Oh conducted a project as part of their premedical Biology coursework to assess the antibacterial properties of lime (Citrus aurantiifolia), apple (Malus domestica), and kiwi (Actinidia deliciosa) -  as green as they get - extracts against Staphylococcus aureusand Escherichia coli.

The decision to use lime, apple, and kiwi - besides the fitting color scheme - was guided by a desire to examine substances with direct relevance to the general population. These fruits are widely consumed as fruit snacks, juices, and salads; and they’re widely studied, known to contain bioactive compounds such as flavonoids, phenolic acids, and saponins, molecules associated with antibacterial effects. The study aimed to evaluate the comparative efficacy of these fruits in inhibiting common Gram-positive and Gram-negative bacteria.

In an almost gastronomic display, extracts from the whole fruits were prepared and applied to agar plates inoculated with S. aureus and E. coli. After incubating for 24 hours, the green showed efficacy: where all fruit extracts demonstrated inhibitory effects on both bacterial species, with lime extract showing the greatest activity, followed by kiwi and then apple. Pairwise comparisons revealed statistically significant differences in inhibition between all fruit types. There were no significant differences in the response of the two bacterial species of the same extracts, suggesting that fruit efficacy was not dependent on bacterial type.

The results point to the role of bioactive compounds, particularly the aforementioned flavonoids and saponins, in mediating the antimicrobial effects of the green trinity they used. Therefore, the students proposed investigating potential synergistic effects with existing antibiotics; such findings could have implications for the development of dietary adjuncts or topical agents derived from natural sources.

Throughout this verdant project, the students developed skills as wide and as applicable as their idea. Setting up experimental trials that produce consistent interpretable results with a standardized approach allowed the students to strengthen their understanding of protocol optimization, data reproducibility, and experimental troubleshooting. The group also emphasized how understanding each member’s capabilities contributed to efficiency and improved outcomes. Whether through technical execution, data analysis, or poster design, each student took on responsibilities aligned with their competencies, resulting in a collaborative effort that taught them that-bit-more about teamwork. Moreover, the experience of designing and presenting a scientific poster allowed the students to translate experimental data into an accessible visual format, building their expertise in scientific communication, design, and problem-solving.