Why we should use Plant Based Medicines?

Plants have been used as the source of drugs for long ages, and as of today, approximately 70,000 species have been screened for their potential utility as medicines. In recent decades, several antitumor drugs have been derived from plants, including paclitaxel (from Taxus brevifolia) and camptothecin, using fractionation techniques based on bioactivity.

At present, about 8 out of 10 drugs used to treat infection, cardiovascular disease, or cancers, or as immunosuppressives, come from plants, directly or as derivatives. Between 1981 and 2006, approval was granted to 155 antitumor drugs, of which almost half were derived from natural products.

Only about one in 10,000 screened compounds are eventually proved to be safe and effective by regulatory authorities. Even at late stages of clinical trials, approximately one in two drug leads fail to make the mark. There have been many examples of drugs that are released commercially, only to be pulled within weeks, months or years due to unacceptable side effects.

This high degree of uncertainty has led to a focus on plant-based chemicals for drug discovery, especially since these are seen as safe and more effective than synthetic chemicals.

Examples of modern drug discovery from plants

An outstanding example of such a drug discovery process is artemisinin derivatives from Artemisia annua. Also known as Qing-hao in Chinese, this plant yields a highly oxygenated sesquiterpene called Qinghaosu, or artemisinin. This is poorly bioavailable on oral administration despite its potent antimalarial activity.

It was therefore reduced, yielding far more potent and bioavailable derivates such as dihydroartemisinin, artemether, and artesunate, all of which are in use today as the most rapidly acting and powerful antimalarials, including against the multidrug-resistant Plasmodium falciparum variants.

The discovery of bicyclol for the treatment of hepatitis, an often fatal condition, is another example. The hepatitis B virus alone causes millions of cases and over a million deaths every year. Bicyclol is a synthetic second-generation derivative of a compound obtained from the fruit of the Chinese magnolia vine or orange magnolia vine (Schisandra chinensis), following the direction of traditional Chinese medicine (TCM).

This fruit yields multiple active compounds, such as schisandrin C. Its synthetic intermediate, bifendate, was further developed into bicyclol. Other compounds in this fruit have anti-steatotic effects in liver cells, opening up new opportunities for the treatment of hypercholesterolemia.

The typical development process of a drug derived from herbal medicines includes:

• Isolation/chemical synthesis of bioactive ingredients
• Safety/efficacy studies by different methods including systems pharmacology and conventional pharmacology
• Regulatory approval