4.6.1 Alkaloids from Plants that Are Used to Treat Malaria: Quinine (Chinchona spp.)
The bark of Chinchona trees is the source of the drug, quinine, which has been used to treat patients afflicted with malaria. Malaria is a disease in humans caused by the parasite, Plasmodium falciparum. The parasite is transmitted by the mosquito, Anopheles spp. Quinine, or more generally, the drug, chloroquine, since l986 in Brasil and Africa, has been shown to be no longer effective in treating malaria due to resistance by P. falciparum to the drug.24 The consequences of this are dire. In Africa, 80% of the world's malaria cases were recorded in 1990 with over 95% of the deaths occurring on this continent, mainly due to the ineffectiveness of chloroquine in treating patients having malaria.24
Are there any solutions? One possible solution is the use of the drug arte-misinin or quinghaosu (Chinese name for the drug) (a sesquiterpene lactone compound) from the common "weed", Artemisia annua (Sweet Annie) (Figure 4.19). This compound is very effective in treating patients with malaria at the present time because it kills chloroquine-resistant P. falciparum cells25 (see also Chapter 6, Section 6.2.5 on antimalarial compounds and Table 6.2). It also has fewer adverse side effects. Artemisinin has now been synthesized and derivatives of artemisinin have been synthesized which have an improved action in curtailing malaria. Artemisinin is an unusual drug with a 6-member lactone ring which is termed a-methyl-y-lactone. The compound is also a peroxide, which is required for its activity.25 One of the primary questions raised here is whether or not P. falciparum will soon develop resistance to artemisinin or its derivatives as it did with chloroquine.
4.6.2 The Indole Alkaloids, Psilocybin and Psilocin
(Psilocybe Mushrooms), that Act as Hallucinogens
Psilocybe mushrooms (Figure 4.20) are the source of two metabolites, psilcybin (4-phosphoryloxy-N,N-dimethyltryptamine) and psilocin (4-hydroxy-N,N-dim-
ethyltryptamine).14 These are both psychoactive compounds that produce hallucinations in humans. Psilocybe mushrooms are called Teonanacatl by Mexican Amerinds, a term which means "flesh of the gods".
FIGURE 4.20 The Liberty Cap mushroom, Psilocybe semilaceata, common in Northern Europe and the western coast of the U.S. north to British Columbia, Canada. The Mexican species are the hallucinogenic species collected by Mexican Amerinds. (Photo by David Bay.)
In Mexican Indian religious ceremonies, the Psilocybe mushrooms, are collected and dried by women, then served to tribal members in pairs in all night ceremonies. The ingested mushrooms have a vision-inducing action that is typified by the following symptoms: muscular relaxation, flaccidity, and pupil dilation in the early stages followed by emotional disturbances and visual and auditory hallucinations, and eventually causing lassitude and mental and physical depression. The subject feels isolated from the world around him/herself without loss of consciousness and becomes indifferent to the environment.14 Richard Evans Schultes, the famous ethnobotanist (now retired) from Harvard University, described these hallucinogenic effects of Psilocybe mushrooms and the religious ceremonies surrounding their use by Mexican Amerinds when he presented a seminar on this subject at the University of Michigan in the l960s.25a
4.6.3 The Protoalkaloid, Mescaline (Lophophora williams//), that Acts as a Hallucinogen
Mescal button or peyote (Lophophora williamsii) (Figure 4.21) is native from South Texas to central Mexico. In the Aztec Empire of Mexico, it was referred to as "Peyote". The hallucinogenic compound of interest in the "buttons" (top parts) of this plant is the protoalkaloid, mescaline. It is used in Amerind religious ceremonies and eaten as mescal buttons or the dried, brown pieces of the above-ground parts of the cactus (which has no spines), or occasionally, as fresh green pieces. Sometimes, it is brewed and drunk as a tea. Lewis and Elvin-Lewis14 describe how humans respond to this plant when it is ingested as dry or fresh tissue or as a tea. It produces nausea, chills, and vomiting often accompanied by terror, anxiety, and a dislocation of visual perspection. These symptoms then subside and are followed by mental stimulation expressed in terms of clarity and intensity of thought, brilliant colored visions, and exaggerated sensitivity to sounds. Dr. Elzada U. Clover, former Botanist at the University of Michigan, while collecting cacti along the Colorado River in the Grand Canyon of Arizona in Havasupi Indian territory, ingested some of the peyote cactus and described her visions as a technicolor display of sheep jumping fences.
4.6.4 The Steroid (Aconitum spp.), Used for Aconite Poison Whaling in Asia and Alaska*
Aconitine is a toxic alkaloid derived from all parts of Aconitum spp. plants. The roots are the most dangerous part, but the leaves are greatest in toxicity just before flowering commences.14 Symptoms of poisoning include numbness followed by paralysis of upper and lower extremities. A weak pulse develops
* The primary source material for this section was provided by Maureen McKenzie, CEO, Naniquah Corp., Girdwood, AK.
accompanied by respiratory paralysis. Convulsions typically occur and death follows after about 2 h.14
Kodiak and Aleutian Indians as well as natives to the Pacific littoral zone of northeast Asia (Kurile Islands and the Kamchatkan coast) use aconite poison obtained from the roots of monkshood plants on their whaling spears to kill whales. The procedure used is relatively simple. The Indians throw a lance into the whale, the stone point or dart (typically made of ground slate) becomes detached when it enters the whale. The tips of the stone points are smeared with aconite poison.26 The spear heads were also greased with human fat, grease obtained from corpses found in burial caves. The purpose of this ritual is to deceive others not familiar with the whaling techniques by leading them to believe that the human fat is the source of the poison! In effect, they do this so as not to divulge the real source of the poison.26
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