The search for anti-cancer active substances remains the number one goal of scientists in the world. For the same purpose, over the past decades, Vietnamese and international scientists have spent a lot of effort investigating herbs that have the ability to cure cancer.

Accordingly, recently, researchers at the Department of Biotechnology, International University, Ho Chi Minh City National University have successfully extracted anti-cancer compounds in milkweed.

Milkweed grows wild in the nature widely distributed in the southern plains, often used by people to treat wounds, eye pain, cough, asthma. Aside from its long-known antibacterial properties, no new properties or pharmaceuticals have been developed from this popular plant so far.

Realizing that there is a lot of potential, from 2018, MSc Tran Kim Ngan (33 years old, Faculty of Biotechnology, International University, Vietnam National University, Ho Chi Minh City) and her colleagues learned about new properties of milkweed. After two years, the team discovered the antioxidant and cancer-inhibiting compounds of this species, the potential to make natural antibacterial drugs and functional foods to support the treatment of liver and lung cancer.

To find potential compounds in milkweed, the team performed organic solvent extraction and liquid-liquid extraction techniques. Ms. Ngan said that these two methods are commonly used to extract compounds, with the advantages of high content of recovered compounds and especially easy to replicate the model at pilot scale in pharmaceutical production.

After picking, milkweed is treated (washed, dried, pureed), then the powder is soaked in methanol for 24 hours and the solution is filtered. From there, organic solvents were used by the team to separate the natural compounds in milkweed, including methanol, petroleum ether, chloroform, ethyl acetate and butanol. These solvents are highly polar, allowing easy recovery of low concentrations of compounds.

According to MSc Ngan, for effective extraction concentration and efficiency, the choice of solvent ratio is the most important factor, because the higher the solvent ratio, the lower the concentration of recovered compounds, which is costly and difficult to refine later. After many experimental mixing formulas, the research team selected the optimal ratio, ensuring a stable compound structure, not being destroyed by temperature and pH when separating.

After synthesizing the extracts, MSc Ngan and colleagues found two valuable compounds including phenolic and flavoinoids, containing high concentrations up to 100 μg/mL. Through analysis, phenolic has the ability to reduce a type of free radical DPPH, causing oxidation, inhibiting the reaction that damages cells.

In particular, at a concentration of 100 μg/mL, flavonoid compounds in milkweed can completely inhibit the growth of two cell lines of lung cancer NCI-H460 and liver cancer Hep G2. In addition, resistant to some types of gram-negative and gram-positive bacteria, such as Bacilluss subtilis (intestinal bacteria), S. aureus (bacteria that cause skin infections), P. aeruginos (bacteria that cause pneumonia).

MSc Ngan said that there are still many compounds with potential biomedical applications in milkweed. Therefore, from this result, the team continued to isolate new extracts with high biological activity. Especially in anti-cancer compounds, the team will do controlled trials, comparing with compounds with the same function in other medicinal species.

From a practical need, permitted by the US Food and Drug Administration (FDA), Bristol Myer Squibb has signed a contract with the US National Cancer Institute to manufacture cancer drugs from Taxol for $120,000,000.

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