Turning a New Leaf: Extracting the Invasive Water Hyacinth for Medicinal Treatments
Featured Image Caption: The Water hyacinth is a floating plant that has clusters of leaves, lavender spiked flowers, and feathery roots. This plant is native to Brazil, but has become invasive to many warm parts of the world. It has an aggressive growth rate and is illegal to possess in Florida without a special permit. Water Hyacinth by Wouter Hargens Public domain via Wikimedia Commons
Primary Source Article:
Rabiepour, A., Babakhani, A., & Rahimabadi, E. Z. (2025). Effect of extraction methods on the antioxidant properties of water hyacinth, Eichhornia crassipes. Caspian Journal of Environmental Sciences, 23(1), 97–115. https://doi.org/10.22124/CJES.2024.8015
Secondary Source Articles:
Desautels, D. J., Hartman, R. B., Weber, M. E., Jacob, N., Sun, A., & Civitello, D. J. (2023). Experimental water hyacinth invasion and destructive management increase human schistosome transmission potential. Ecological Applications, 33(2), e2767-n/a. https://doi.org/10.1002/eap.2767
Khoshkam, M., Marzuki, A., & Al-Mulali, U. (2016). Socio-demographic effects on Anzali wetland tourism development. Tourism Management (1982), 54, 96–106. https://doi.org/10.1016/j.tourman.2015.10.012
Harun, I., Pushiri, H., Amirul-Aiman, A. J., & Zulkeflee, Z. (2021). Invasive Water Hyacinth: Ecology, Impacts and Prospects for the Rural Economy. Plants (Basel), 10(8), 1613. https://doi.org/10.3390/plants10081613
How to control water hyacinth – aquaplant: Management of Pond Plants & Algae. AquaPlant. (2025, August 1). https://aquaplant.tamu.edu/management-options/water-hyacinth/
The Water Hyacinth (Eichhornia crassipes) is a free-floating aquatic plant that grows in freshwater bodies such as lakes, rivers, streams, ponds, and wetlands. It is native to the Amazon Basin in South America. The plant has wide waxy leaves and lavender clustered flowers. Although the plant is considered a floating beauty, it is an invasive species with a global distribution in North America, South America, Europe, Africa, Asia, Australia, and New Zealand. The water hyacinth (WH) is considered harmful because of its ability to block waterways, cause secondary pollution by destroying the water quality after death, and act as a breeding place for disease vectors. Two such examples are human schistosome transmission and malaria. Controlling this plant is no easy task. Plant management can take the form of physical removal by raking them off the water’s surface, applying natural insect enemies like water hyacinth weevil (Neochetina burchi), or using herbicides. Herbicides are a dangerous method of control that can harm other wildlife, and once the WH plant decomposes, it can cause oxygen depletion, further harming other aquatic waterlife.
In the Anzali Wetland in Iran, the WH problem is no different. The Anzali Wetland is a large freshwater lagoon in northern Iran, near the Caspian Sea. It is home to diverse species of birds, fish, mammals, amphibians, and reptiles. The location is ideal for local fishing, drives agricultural economies, and is a popular place for tourists. It is estimated that the wetland is visited by 180,000 domestic and 31,000 international tourists each year. The WH depletes dissolved oxygen, blocks waterways, and physically impedes fishing in the Anzali Wetland. However pesky this plant appears, there may be some benefits to this floating flower of havoc. In order to turn an environmental problem into a solution, researchers from Iran sought to determine the pharmaceutical benefits of WH.
Repurposing a Pesky Plant: The Extraction Method
The extraction method is an important step in discovering whether a plant has bioactive compounds- chemical substances with positive benefits to health. In this study, researchers were particularly interested in antioxidants, since plants tend to have a wide variety of antioxidants. Antioxidants are molecules that protect cells from damage caused by free radicals—unstable atoms that seek to bind with other atoms to gain stability. These free radicals can form naturally in the body or come from environmental sources. Three different parts of the plant were tested: the leaf, stem, and root.
Fresh samples of the flower were collected from the Anzali Wetland. After they were washed, plant extraction was performed using the solvent extraction method (SE) and the ultrasound-assisted extraction method (UAE). The goal of an extraction method is to separate the plant material from its liquid extract. The SE method involves mixing the dried plant powder with a liquid mixture. In the case of this study, various water and ethanol combinations were used. After the plant is mixed with the liquid mixture, it undergoes a series of filtering and separating steps until researchers obtain the plant extract that they want to study. The UAE method has the same goal. However, instead of just using a solvent to get the desired extract, the technique involves high-intensity ultrasound waves applied to the mixture so that the plant material can break down more easily without a heavy reliance on a solvent.
Although both methods achieved the same goal, researchers wanted to use these two techniques to determine which method was most efficient in extracting natural antioxidant compounds from the WH plant.
In order to determine the antioxidant properties of the WH, researchers studied the total phenol content (TPC), free radical scavenging activity (DPPH), total antioxidant capacity (TAC), and ferric-reducing antioxidant power (FRAP). Essentially, all of these tests are laboratory methods used to test for the presence of different antioxidants in the plant.
Do Water Hyacinths Have Antioxidants and Can We Use Them?
Researchers discovered that WH is a good candidate for extracting antioxidants and that the leaf of the plant was the best area to perform an extraction. Obtaining antioxidants from WH is possible and easy, but depending on what researchers were testing for, they obtained different results from the different extraction methods and the solvents that they used. For example, they determined that using the SE method with just water was best for testing free radical scavenging activity. However, if they wanted to obtain more total phenol content (TPC), the UAE method was the more efficient method.
There was no clear “winner” on which extraction method or solvent is more efficient.These results make sense because WH, like most plants, contains a mixture of antioxidants with different properties. Depending on the extraction method, the results will favor extracting some antioxidants over others depending on the antioxidant’s preference to water, ethanol, pH, temperature, or even how delicate it is to the UAE. Overall, finding a suitable extraction process for natural antioxidants is a tricky process. In addition to determining what method will give the highest yield, there are economic costs to consider such as the instrument, raw materials, labor costs, and whether the method is eco-friendly. The UAE is considered an eco-friendly method, but adapting this method to a larger scale to deal with WH covering a span of 20,000 hectares remains to be seen.
Still, this promising study demonstrates that extracting antioxidants from WH could potentially offset the rehabilitation costs of removing the plant from Iran’s Anzali Wetland in the future. If engineers and researchers can one day figure out how to apply an efficient extraction method on a large scale, it would change the landscape of Anzali Wetland for the better.
Want to learn more about the water hyacinth and Iran’s Anzali Wetlands? Click on the articles and videos below!
- Sadeghi Pasvisheh, R., Eurie Forio, M. A., Ho, L. T., & Goethals, P. L. M. (2021). Evidence-Based Management of the Anzali Wetland System (Northern Iran) Based on Innovative Monitoring and Modeling Methods. Sustainability, 13(10), 5503. https://doi.org/10.3390/su13105503
- https://www.eavartravel.com/blog/2024/11/9/161060/anzali-lagoon/
- The Anzali Wetland from the Sky
- Harun, I., Pushiri, H., Amirul-Aiman, A. J., & Zulkeflee, Z. (2021). Invasive Water Hyacinth: Ecology, Impacts and Prospects for the Rural Economy. Plants (Basel, Switzerland), 10(8), 1613. https://doi.org/10.3390/plants10081613
- A Dangerous Beauty, the Water Hyacinth
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