Plant Alkaloids in Cancer Treatment

The word alkaloid goes back to the 1800s and refers to chemical compounds derived from plants that contain at least one nitrogen atom in their molecules and that produce an observable physiological effect on humans.  The word seems archaic in modern chemistry, but it for historical purposes it finds some use. Some alkaloids are effective as medicines. Others (e.g. nicotine) are used by humans but for other purposes.

Alkaloids used for cancer treatment are a major part of the chemotherapy arsenal.  In addition to compounds taken directly from plants, hemisynthesized congeners inspired by natural materials have also found use.

Mechanism

Alkaloids tend to be cell-cycle specific, although their mechanism at the biochemical level differs from medicine to medicine.

Classifications

See our page on vinca alkaloids for more on these medicines derived from the Madagascar periwinkle.  The taxanes are drugs with origins in the yew genus of trees.

Podophyllotoxins

These drugs are derived from Podophyllum peltatum, also called the Mayapple and are also called Epipodophyllotoxins.  Podophyllotoxin is a plant product incorporated into a cream medication called podofilox and used for viral skin infections.   It is used in topical applications for illnesses such as warts.  The cancer drugs Etoposide and Tenisopide are derived from podophyllotoxin.  These are called antimitotic or antimocrotubule agents, or just mitotic inhibitors.

Podophyllotoxin itself (sometimes called podofilox) is not approved for cancer treatment but there has been research interest in it.

Taxanes

Paclitaxel and Docetaxel.

Camptothecan analogs

Camptotheca is a genus of tree found in China.  It is sometimes called the Happy Tree.   Camptothecin was first found in this tree.  Follow-on research has produced similar compounds also used in cancer treatment.

Irinotecan

Topotecan

 

Others

Other alkaloids of some interest but not approved are

Rohitukine

Harringtonine 

Cephalotaxine

Acronycin

Thalicarpine

Ellipticine

Isoreserpiline

Usambarensine

Matrine

So-called nutraceuticals have less science behind them but are of some tangential interest to serious investigators.  These include

Berberine

Evodiamine

Piperine

Sanguinarine

Tetrandrine

 

 

 

Ixabepilone

Brand/Trade Names: Ixempra

Formula: C27H42N2O5S

Mechanism: Microtubule Inhibitor

Class: plant alkaloid

Administration: Intravenous

Notes:

Teniposide

Brand/Trade Names: Vumon

Formula: C32H32O13S

Mechanism: topoisomerase II inhibitor

Class: plant alkaloid

Administration: Intravenous

Notes:

Omacetaxine

Brand/Trade Names: Synribo

Formula: C29H39NO9

Mechanism: protein translation inhibitor

Class: plant alkaloid

Administration: Intravenous

Notes: Approved for cancers that have not responded to tyrosine kinase inhibitors