With the growing global threat of the 2019 Novel Coronavirus (COVID-19), it's important to maintain an effective arsenal of antiviral protection to keep our hands clean and mitigate transmission, especially when in public environments where hand-washing facilities are not available or sanitary. A number of terpenes have shown promise in the literature in destroying viruses, and make ideal candidates for use in hand sanitisers to form a barrier of protection. Many also show antibacterial benefits to bolster their broad spectrum activities.
d-Limonene has been shown to destroy coronaviruses and herpesviruses at the right concentration, and thus is effective as an antiviral ingredient in hand sanitiser (1,2,6). Alpha and beta pinene have also demonstrated antiviral effects against herpesviruses and infectious bronchitis virus as well as antibacterial effects against endocarditis causing bacteria (1,3,7). Linalool has also demonstrated antibacterial effects and potentially anticoronaviral effects (5,6). Hemp seed oil has also demonstrated some antibacterial effect (4).
1 - Astani, A., & Schnitzler, P. (2014). Antiviral activity of monoterpenes beta-pinene and limonene against herpes simplex virus in vitro. Iranian journal of microbiology, 6(3), 149.
2 - Bevilacqua, A., Corbo, M. R., & Sinigaglia, M. (2010). In vitro evaluation of the antimicrobial activity of eugenol, limonene, and citrus extract against bacteria and yeasts, representative of the spoiling microflora of fruit juices. Journal of Food Protection, 73(5), 888-894.
3 - Leite, A. M., Lima, E. D. O., Souza, E. L. D., Diniz, M. D. F. F. M., Trajano, V. N., & Medeiros, I. A. D. (2007). Inhibitory effect of beta-pinene, alpha-pinene and eugenol on the growth of potential infectious endocarditis causing Gram-positive bacteria. Revista Brasileira de Ciências Farmacêuticas, 43(1), 121-126.
4 - Khan, B. A., Warner, P., & Wang, H. (2014). Antibacterial properties of hemp and other natural fibre plants: a review. BioResources, 9(2), 3642-3659.
5 - Park, S. N., Lim, Y. K., Freire, M. O., Cho, E., Jin, D., & Kook, J. K. (2012). Antimicrobial effect of linalool and α-terpineol against periodontopathic and cariogenic bacteria. Anaerobe, 18(3), 369-372.
6 - Ulasli, M., Gurses, S. A., Bayraktar, R., Yumrutas, O., Oztuzcu, S., Igci, M., & Arslan, A. (2014). The effects of Nigella sativa (Ns), Anthemis hyalina (Ah) and Citrus sinensis (Cs) extracts on the replication of coronavirus and the expression of TRP genes family. Molecular biology reports, 41(3), 1703-1711.
7 - Yang, Z., Wu, N., Zu, Y., & Fu, Y. (2011). Comparative anti-infectious bronchitis virus (IBV) activity of (-)-pinene: effect on nucleocapsid (N) protein. Molecules, 16(2), 1044-1054.