Submit your papersSubmit Now
For Enquiries: [email protected]
IIARD LogoIIARD

Assessment of the Antifungal Activity and Phytochemical Composition of Hyptis Suaveolens L. (Bush Mint) Against Fungi Causing Watermelon Fruit Rot

Abdullahi A.1

Abstract

Watermelon (Citrullus lanatus) is an economically important fruit crop susceptible to post- harvest fungal diseases. Hyptis suaveolens L. (Bush Mint) is a medicinal aromatic shrub renowned for its diverse bioactive secondary metabolites, and the present study investigated the phytochemical composition and antifungal potential of its aqueous and ethanolic leaf extracts against Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, and Rhizopus oligosporus — major causative agents of watermelon fruit rot. Extraction was performed by the cold maceration method of Harborne (1998) with slight modifications; qualitative and quantitative phytochemical analyses were conducted using standard procedures; Gas Chromatography–Mass Spectrometry (GC-MS) was employed to characterize bioactive components; antifungal activity was evaluated by the agar well diffusion method (50–400 mg/mL); and the Minimum Inhibitory Concentration was determined by broth microdilution in Sabouraud Dextrose Broth across serial two-fold dilutions of 6.25–400 mg/mL. Phytochemical screening confirmed alkaloids, flavonoids, saponins, tannins, terpenoids, and phenols, with the ethanolic extract showing significantly higher concentrations; GC-MS identified 45 compounds, with resorcinol (15.05%), squalene (13.72%), d,α-tocopherol (12.13%), 2,4-di-tert-butylphenol (5.49%), and phytol isomer (4.17%) as the most abundant; the ethanolic extract exhibited superior antifungal efficacy with larger inhibition zones, particularly against A. flavus, followed by A. niger, F. oxysporum, and R. oligosporus, with the lowest MIC (12.5 mg/mL) recorded against A. flavus, while the aqueous extract required up to 50 mg/mL. These findings underscore the significant antifungal potential of H. suaveolens and support its application as a natural botanical fungicide for managing post-harvest fungal diseases in watermelon fruits.

Keywords

Hyptis suaveolens; Phytochemicals; GC-MS; Watermelon; Antifungal activity; post-harvest fungi

References

Agarwal, K., & Varma, R. (2013). Antioxidant activity and phytochemical analysis of Hyptis suaveolens (L.) Poit. Journal of Advanced Pharmacy Education & Research, 3(4), 541– 549. Bashir, A., Mukhtar, M. D., Adamu, S., & Aliyu, B. S. (2019). Antibacterial activity of Hyptis suaveolens leaves extract on some selected clinical isolates. Nigerian Journal of Microbiology, 33(2), 4652–4659. Bhattacharya, S., Virani, S., Zavro, M., & Haas, G. J. (2020). Inhibition of Streptococcus mutans and other oral streptococci by hop (Humulus lupulus) constituents. Economic Botany, 57(1), 118–125. Brent, K. J., & Hollomon, D. W. (2007). Fungicide Resistance in Crop Pathogens: How Can It Be Managed? (2nd ed.). Fungicide Resistance Action Committee , Brussels. Clinical and Laboratory Standards Institute . (2012). Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi (M38-A2, 2nd ed.). Wayne, PA: CLSI. Cowan, M. M. (1999). Plant products as antimicrobial agents. Clinical Microbiology Reviews, 12(4), 564–582. El-Hefny, M., Ashmawy, N. A., Salem, M. Z. M., & Salem, A. Z. M. (2019). Antibacterial activity of three essential oils and some monoterpenes against Ralstonia solanacearum and their application for control. Microbial Pathogenesis, 132, 10–17. Elaissi, A., Rouis, Z., Salem, N. A. B., Mabrouk, S., ben Salem, Y., Salah, K. B. H., . & Farhat, F. (2011). Chemical composition of 8 eucalyptus species essential oils and the evaluation of their antibacterial, antifungal, and antiviral activities. BMC Complementary and Alternative Medicine, 11, 81. FAOSTAT. (2022). Crops and Livestock Products. Food and Agriculture Organization of the United Nations. Retrieved from http://www.fao.org/faostat/en/#data/QCL Harborne, J. B. (1998). Phytochemical Methods: A Guide to Modern Techniques of Plant Analysis (3rd ed.). Chapman and Hall, London. Hayes, M., Carney, B., Slater, J., & Brück, W. (2018). Mining marine shellfish wastes for bioactive molecules: chitin and chitosan. Biotechnology Journal, 3(7), 871–877. Jain, R., Bhargava, M., & Sharma, N. (2015). Antifungal activity of natural compounds. Current Applied Science and Technology, 15(1), 1–12. Kumari, S., & Kaur, R. (2020). Antimicrobial activity and phytochemical screening of Hyptis suaveolens. International Journal of Pharmaceutical Sciences and Research, 11(2), 1000–1005. Mukherjee, P. K., Mehta, S., & Bhattacharya, S. (2019). Post-harvest losses in fruits and vegetables. Journal of Postharvest Technology, 7(1), 1–12. Nwachukwu, E. O., & Umechuruba, C. I. (2001). Antifungal activities of some leaf extracts on seed-borne fungi of African yam bean seeds, seed germination, and seedling emergence. Journal of Applied Sciences and Environmental Management, 5(1), 29–32. Okigbo, R. N., Eme, U. E., & Ogbogu, S. (2009). Biodiversity and conservation of medicinal and aromatic plants in Africa. Biotechnology and Molecular Biology Reviews, 3(6), 127–134. Owolade, O. F., Osikanlu, Y. O. K., Kolawole, G. B., & Afolabi, C. G. (2004). Effectiveness of plant extracts in controlling fungal diseases of cowpea under field conditions. African Journal of Plant Science and Biotechnology, 3(1), 41–47. Pachkore, G. L., Dhale, D. A., & Dharasurkar, A. N. (2011). Antimicrobial and phytochemical screening of Hyptis suaveolens (L. Poit) Lamiaceae. International Multidisciplinary Research Journal, 1(4), 1–3. Trease, G. E., & Evans, W. C. (2002). Pharmacognosy (15th ed.). Saunders Publishers, London.