Plants drugs derived from

Examples of Classic Plant Drugs Derived from Higher Plants with and without a Correlation between Clinical Action and Traditional Use... 

Nursing alcohol lamps and charcoal fires in his tiny home laboratory during the Easter vacation of 1856, a teenager slowly teased out the constituents of a black and tarry goo. Working nights, weekends, and holidays on chemistry, he was searching for a test-tube substitute for quinine, the antimalaria drug derived from plants. The black precipitate he had made was obviously not quinine, but the youth was well trained in chemistry, so he did not throw it out. Instead, he treated it with alcohol, and a fabulously intense purple appeared. Then he tested the purple on a piece of silk. 

For centuries opium was used for both medicinal and recreational purposes. Derived from the poppy Papaver somniferum, it contains numerous opiates, the primary one of which is morphine. The term opiate has largely been replaced by opioid, which represents all compounds with morphinelike activity and includes morphine, morphine derivatives, and peptides. Opiate is used to refer to morphinelike drugs derived from the plant and structurally similar analogues. These drugs are frequently referred to as narcotics, a Greek term for stupor, which is scientifically obsolete. Even in its early history, opium presented a problem when it was smoked or taken orally. The introduction of the hypodermic needle and syringe, however, drastically enhanced the euphoric properties of opioids and thereby altered their abuse liability. In addition, the synthesis of heroin resulted in an opioid that was more potent than morphine and ideally suited for intravenous administration. 

Pharmacognosy deals with the study of the sources of drugs derived from plants and animal origin. 

The word Aloe in pharmacopoeias and formularies means a drug derived from the dried leaf juice. This has always created confusion because the leaves of the genus Aloe are the source of two products that are quite different in their chemical composition and therapeutic properties aloe latex and aloe gel. These two products are obtained from two different specialized cells, latex from pericyclic cells and gel from parenchymatous cells. Therefore, the term juice must be avoided, as it could mean either the latex from the pericyclic cells or the gel after extraction from the leaf. However, to add to the confusion, there is also a preparation obtained from the whole leaf (total extract) and another obtained from the aloe wood, the so-called lignaloe or aloe of the Bible, a fragrant wood obtained from an entirely different plant that was once used as an incense (Capasso et al 1998). 

Codeine is extracted from opium. Opium is a chemically complex drug derived from a flowering plant, the opium poppy. The scientific name for the opium poppy is Papaver somniferum, which translated from Greek means poppy that causes sleep. Opium is produced by drying the thick liquid harvested from the unripe seed capsule of the flower. It contains several different medically important chemicals known as alkaloids (non-acidic chemicals), the most important being morphine and codeine. 

In the late 1800s and early 1900s, advances in chemistry allowed scientists to further modify the drugs derived from plants to reduce their side effects. Chemists were also able to synthesize in the laboratory entirely new drugs with new beneficial properties. Eventually, it became cheaper and easier to synthesize the substances once derived from plants, rather than extract them from herbs themselves. 

The cannabinoids are a class of psychoactive substances contained both in Cannabis and Echinacea plants. The first reliable evidence of the effects of drugs derived from cannabis is a compendium of Chinese medicine (a herbarium), dated 2700 bc today it has become very common in many parts of the world. 

A drug derived from the foxglove plant. It contains digoxin which causes the heart to beat more strongly, dioxins... 

The most common route of exposure is ingestion of any part of the plant or of any material or drug derived from the plant. 

Camptothecin, a plant alkaloid derived from Camptotheca acuminata, is a potent inhibitor of DNA topoisomerase I. Clinical trials failed to show expected antitumor activity, and the drug produced severe, unpredictable toxicity. The camptothecin analogs irinotecan and topotecan were synthesized to reduce toxicity and improve therapeutic... 

The study of natural products, or Nature s Combinatorial Library , has had a long history as a source of drugs, and plants have historically been at the forefront of natural product drug discovery. In the anticancer area, for example, vinblastine and vincristine, etoposide, paclitaxel (Taxol), docetaxel, topotecan, and irinotecan, among others, are all plant-derived natural products or modified versions of plant compounds, while antimalarial therapy would be much poorer without quinine and artemisinin and the drugs derived from these plant products. This chapter provides an overview of the major medicinal agents that are themselves natural products isolated from plants or are chemical modifications of such lead compounds. It covers the therapeutic areas of cancer, HIV, malaria, cardiovascular, and central nervous system (CNS) diseases. Natural plant products have also made contributions in areas such as immunomodulatory and antibiotic activities," and the reader is referred to the cited reviews for information on these areas. 

Han R. Highlight on the studies of anticancer drugs derived from plants in China. Stem Cells 1994 12 53-63. 

Beck WT, Cass CE, Houghton PJ. Microtubule-targeting anticancer drugs derived from plants and microbes vinca alkaloids, taxanes, and epothiolones. In Bast RC Jr, Kufe DW, Pollock RE, Weichselbaum RR, Holland JF, Frei E III, eds. Holland-Frei Cancer Medicine. 5th Ed. Hamilton, Ontario BC Decker, 2000 680-698. 

Narcotics Narcotic drugs have analgesic effects and tend to depress the CNS and promote sleep. Opiate alkaloids (drugs derived from the opium plant) cue the best-known narcotics and include morphine, codeine, heroin, hydromor-phone, oxycodone, and hydrocodone. 

In this chapter, some successful drugs derived from plant secondary metabolites in their original or modified forms, and other substances, currently under clinical trial as drug candidates, as well as several additional compoimds used as biochemical probes afforded from plants, will be described. A general description of the importance and perspective of plants in drug discovery will also be given. 

Table 2 Examples of medicinal drugs derived from plants...

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