Handbook of Plant and Crop Physiology

(Steven Felgate) #1

Although extracts of Eleuthrococcusroots have been reported to have effects similar to those of the
ginsenosides in animal systems, the active constituents may be quite different [19]. In Eleuthrococcus,
the active constituents are thought to be lignanglycosides (eleutheroside E) or phenylpropane glycosides
(eleutheroside B) [12,19]. However, the pharmacological action of these compounds remains unclear and
little information is available on their biosynthetic pathway (Ref. 19 and references therein).


D. Garlic


Garlic is truly an ancient medicine, being used by more cultures and over a longer time period than any
other medicinal plant. Garlic has been used by many cultures as an herbal medicine for infections, diges-
tive problems, expelling parasites, and promoting health. Many of these effects of garlic are the basis for
its use today. The earliest recorded use of garlic was in about 3000 BCby the Sumerians of Mesopotamia
and by people of ancient India [35,36]. Garlic was an important herbal medicine of the Egyptians, and its
use was recorded in a medicinal text known as the Ebers Papyrus in about 1550 BC[36]. The use of gar-
lic was also described in ancient texts of Indian Ayurvedic medicine and traditional Chinese medicine
[36]. The Greek physician Hippocrates was a strong proponent of the use of garlic for treatment of infec-
tions, parasites, pneumonia, and cancer [36]. Interestingly, Dioscorides, a Roman often considered the
founder of the science of pharmacy, noted in about AD1 that in addition to its antiseptic action, garlic was
useful for “clearing the arteries.” At present, a major interest in the use of garlic stems from its effects on
lowering cholesterol levels and decreasing blood pressure [15,35,36]. Prior to the development of mod-
ern antibiotics, garlic was extensively used for its antiseptic properties in reducing infection [35,36].
These beneficial effects of garlic appear to be due to sulfur-containing compounds present in the bulb that
are also responsible for the culinary flavoring uses of this plant.
Garlic (Allium sativum) is a member of the lily family and originated in central Asia [15,36]. How-
ever, today most garlic is grown commercially in many parts of the world for culinary and medicinal pur-
poses, with the world production being about 2 million tons per year [35]. On a worldwide basis, 60% of
garlic is grown in Asia, 20% is grown in Europe, 10% is grown in Africa, and 10% is grown in North
America [35].
The portion of the garlic plant utilized for culinary and medicinal purposes is the multisegmented
bulb, and different modes of postharvest processing are utilized. Following harvest, most garlic is dried


490 BRISKIN

Figure 3 The ginsenosides from ginseng (Panaxsp.) as panaxadiol and panaxatriol derivatives. (Adapted
from Ref. 21.)

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