More than six months have passed since the COVID-19 outbreak, and humanity has already acquired a better understanding of this disease, compared to the beginning of the pandemic. Even though scientists from several countries have reported to be closer to develop a vaccine, the search for a COVID-19 treatment continues.

Nevertheless, an increasing trend of promoting unproven treatments for COVID-19 is seen, particularly on the internet. One example is the case of oleander, which in August 2020, gained the media’s and scientists’ attention, because it is a toxic plant. Although there is one study (not peer reviewed) reporting the efficacy of oleander extract in inhibiting coronavirus in a lab test [1], other studies have proved its significant toxicity [2] [3]. According to Bethany Halford [4], the US Food and Drug Administration (FDA) has not approved the use of oleander for the treatment of any disease.

Organizations such as the American Herbal Products Association (AHPA), the American Botanical Council (ABC), as well as many other media published warning letters to the general public alerting about the potential risk of ingesting any part of the oleander plant, and its constituent oleandrin.

Oleander (Nerium oleander), a poisonous plant.

Nerium oleander L. is commonly used as an ornamental and landscaping plant and is known as nerium or oleander. It contains cardiac glycosides (for example, oleandrin), which account for the toxicity of this herbal drug. Consumption of even small amounts of oleander can cause nausea, vomiting, irregular heartbeat, and in some cases death. Cardiac glycosides are present in all parts of the plant [4]. 

Identification of oleander and oleandrin

Screening for toxic plants in herbal products can help to prevent accidental poisoning and is an important element of the quality control process. It can be done visually (with a microscope, for example) or chemically (using a technology that detects chemical substances).

With the aim of helping the consumers, regulators and herbal industry to identifying oleander with certainty and avoiding contamination of herbal products with this plant, the CAMAG team together with the HPTLC Association have released a new HPTLC method for oleander, available for download and free of charge. Based on the chemical pattern obtained in several detection modes, this method rapidly identifies different parts of oleander, and detects oleandrin plus other cardiac glycosides. In this application note, the largest amount of oleandrin was observed in the young leaf.

For more information on the HPTLC method for oleander, check these links:

https://www.hptlc-association.org/methods/methods.cfm

https://www.camag.com/applications/application-Notes