β-Asarone Exhibits Antifungal Activity by Inhibiting Ergosterol Biosynthesis in Aspergillus niger ATCC 16888
Fungi play an important role in the degradation of leather goods. Economics often influence the choice of fungicide, thus, search for highly effective and low cost fungicides is immensely important. The authors have screened antifungal activity of ten Indian traditional medicinal plants viz Acalypha fruticosa, Acalypha indica, Aegle marmelos, Adathoda vasika, Calotropis gigantea, Erythrina indica, Morinda citrifolia, Nerium oleander, Pithecellobium dulce, and Acorus calamus based upon their traditional knowledge and usage. Various solvent extracts and essential oils were screened for antifungal activity against Aspergillus niger. The antifungal potency was compared to untreated control and standard antifungal drugs itraconazole and voriconazole. The bioactive principle from highly active fragment was isolated and chemically characterized. The mode of action was determined by a range of studies that include the lesion of plasma membrane, ergosterol content in the plasma membrane, acidification of external medium, and mitochondrial dehydrogenase activity in A. niger ATCC 16888. Among the ten plants studied, A. calamus exhibited greater antifungal potency in comparison to untreated control and standard drugs itraconazole and voriconazole. The minimum inhibitory concentration of both methanolic extract and essential oil of A. calamus against A. niger ATCC 16888 is around 5 µg/ml. The authors identified β-Asarone as the bioactive principle of A. calamus using spectral studies viz ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy and gas chromatography coupled mass spectroscopy. The results indicate that β-Asarone interfere and reduces the ergosterol content in the plasma membrane of A. niger ATCC 16888 thus exert their antifungal activity.
KeywordsAntifungal activity Acorus calamus Essential oil Methanolic extract Aspergillus niger
American Type Culture Collection
Czapek Dox Agar
Yeast Extract Sucrose
Minimum inhibitory concentration
Fourier transform infrared spectroscopy
Gas chromatography coupled mass spectroscopy
Differential scanning colorimetry
Thermo gravimetric analysis
Thin layer chromatography
The authors thank all the members of Dr. Gnanamani Laboratory for helpful discussions. One of the authors RV expresses her sincere thanks to Dr. Tirupathi Kumara Raja and her fellow students Ms. S. Swaathy, Ms. S. Iswarya and Ms. Nisha Bharathi. RV acknowledges Centralized Sophisticated Instrumentation Laboratory, for instrumental analysis. The authors are grateful to Dr. Subha, Bharthi Womens College, Chennai and Dr. Sahaya Pravin, CLRI, Adyar, Chennai for authenticating plant materials.
Compliance with Ethical Standards
Conflict of interest
The authors declare no potential conflict of interest in terms of funding.
- 3.World Health Organization (2000) The world health report 2000: health systems: improving performance. World Health Organization, GenevaGoogle Scholar
- 5.Kamboj V (2000) Herbal medicine. Curr Sci Bangalore 78(1):35–38Google Scholar
- 6.Joshi BC, Joshi RK (2014) The role of medicinal plants in livelihood improvement in Uttarakhand. Int J Herb Med 1(6):55–58Google Scholar
- 15.Subha TS, Gnanamani A (2009) In vitro assessment of anti-dermatophytic effect of active fraction of methanolic extracts of Acorus calamus. J Anim Plant Sci 5(1):450–455Google Scholar
- 17.Thankamma A, Radhika LG, Soudamini C (1995) Detection of Acorus calamus in ayurvedic preparations. Anc Sci Life 14(4):276–280Google Scholar
- 20.Nawrocki ST, Drake KD, Watson CF, Foster GD, Maier KJ (2005) Comparative aquatic toxicity evaluation of 2-(thiocyanomethylthio)benzothiazole and selected degradation products using Ceriodaphnia dubia. Arch Environ Contam Toxicol 48(3):344–350. https://doi.org/10.1007/s00244-004-0105-1 CrossRefGoogle Scholar