VCOM Research Day Program Book 2023

Undergraduate Student Research Biomedical

06 Anti-Bacterial Activity of the Naturally-Occurring Resin, Dragon’s Blood

James C. Wilkes; Thomas Coffey; James E. Mahaney; Teresa R. Johnson Corresponding author: jamesw01@vt.edu

Edward Via College of Osteopathic Medicine- Virginia Campus Virginia Tech

Dragon’s Blood is a sap derived from four different genera of trees found in South America, Africa, and Asia, specifically Croton , Dracaena , Daemonorops , and Pterocarpus . The sap has been used by indigenous peoples for centuries to treat a wide variety of diseases. Dragon’s Blood is currently marketed in many countries as a liquid, capsules, incense, and candles. These products are sold as treatments for diarrhea, neurologic disease (e.g., neuralgia, neuropathy), cancer, diabetes, inflamed or receding gums, dry skin, and wounds as well as for digestive support, cardiovascular antioxidant, anti inflammatory, relaxation, anti-wrinkle cream, and spiritual rituals. Previous work in the laboratory has demonstrated that the sap has antiviral activity against respiratory syncytial virus, vaccinia virus, herpes simplex virus 1, and influenza A virus. Additionally, external collaborators have shared their use of Dragon’s blood to effectively treat infection with the molluscum

contagiosum virus. We now investigate the ability of the resin to inhibit the growth of various bacteria. In pilot studies, the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacteria Acinetobacter baumannii , Escherichia coli , Klebsiella pneumoniae , and Pseudomonas aeruginosa were incubated with dilutions of the resin in broth culture with some inhibition of growth observed. In addition, bacterial lawns of the panel of bacteria were created on tryptic soy agar plates. Blank disks saturated with varying dilutions of resin were distributed on each plate along with a positive control antibiotic disk saturated with penicillin-streptomycin. After overnight incubation, clear zones of inhibition were observed in the patterns of bacterial growth. These studies suggest antibacterial activity of the resin against Gram-positive Staphylococcus aureus as well as varying degrees of activity against the Gram negative bacteria. These findings demonstrate that

Dragon’s blood sap has activity against multiple and phylogenetically distinct bacteria. Furthermore, the varying degrees of effectiveness in limiting bacterial growth, especially among the Gram-negative bacteria, suggest the bacteria may utilize distinct defense mechanisms for evasion of the antibacterial activities of the Dragon’s blood resin.

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