If you watch much TV news, you’ve probably heard about the use of DNA “fingerprinting” to identify victims or perpetrators of crimes. A Hong Kong research group has recently used this method to determine the identity of ginseng species and adulterants in Hong Kong herb markets. Pang-Chui Shaw and Paul Pui-Hay But of the Chinese Medicinal Material Research Centre at the Chinese University of Hong Kong found that “fingerprints” of American ginseng (Panax quinquefolius) and Asian ginseng (P. ginseng) could clearly and consistently be distinguished, regardless of how old the roots were or where they came from.
In the Hong Kong market, American ginseng is five to ten times as expensive as Asian ginseng; consequently, it is often adulterated not only with Asian ginseng, but with the roots of other plants, such as balloon flower (Platycodon grandiflorus), four-o’clock (Mirabilis jalapa), and Asian pokeweed (Phytolacca acinosa). Those of four-o’clocks and Asian poke can be toxic. Before the advent of DNA fingerprinting, assays of ginsenoside compounds used to distinguish the two species of ginseng could be unreliable, as amounts of these compounds vary with the age and source of the roots. DNA fingerprinting of ginseng (and presumably other herbs) is expected to ensure that consumers receive exactly what the label claims.(1)
Grapes are among the best known of human foods. Vitis vinifera is native to Asia Minor but was introduced into Europe and other continents centuries ago. The common cultivated grape is now represented by more than 8000 varieties. Familiar as they are as a fruit and the stuff of fermented beverages, however, grapes are less well known for their medicinal uses.
In recent years, plant-derived antioxidants have received increasing attention for their role in preventing chronic degenerative diseases and aging skin. Procyanidins extracted from grape seeds are among the more interesting of this class of compounds. Numerous pharmacological and clinical studies have confirmed their usefulness in treating chronic circulatory insufficiency related to disorders of the capillaries, showing that they increase the tone of veins. Procyanidins are now available in standardized products for circulatory disorders. Several clinical studies have shown that procyanidins also produce improvement in visual acuity and contrast sensitivity.(2)
No other plant is used as a folk medicine in the United States as much as aloe (Aloe vera). Everyone knows of its reputation for treating minor burns and cuts. A number of properties have been attributed to aloe gel, including the ability to penetrate and anesthetize tissue, kill micro-organisms, reduce inflammation, dilate capillaries, and enhance blood flow. The fact is, however, few studies have examined aloe’s role in wound healing. Recently, researchers from the surgery department at the University of Texas Medical Branch and Shriners Burn Institute in Galveston and at the University of Texas (San Antonio) reported that aloe and other topical antibacterials all increased overall healing rates significantly compared with control groups. Furthermore, topical aloe gel, when combined with silver sulfadiazine (an ingredient of some prescription antibacterial ointments), reversed the tendency of that compound to retard healing. The researchers also confirmed the presence in aloe gel of an unidentified substance that encourages cellular growth. The results of this study are likely to stimulate further work to maximize aloe’s efficacy in wound healing, whether used alone or in combination with other substances.(3)
A number of animal and human studies have reported that eating the seeds of fenugreek (Trigonella foenum-graecum) can lower blood sugar. However, there are differing opinions on the nature of the active compound or compounds and their mechanism of action. Recently researchers at the Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders studied fenugreek seed powder, a methanol extract, and the residue of methanol extract. They found that a soluble dietary fiber fraction and other, as-yet-unknown compounds are responsible for lowering blood sugar. This study supports the development of fenugreek seed products in the management of diabetes, especially in developing countries.(4)
(1) Shaw, P. C., and P. P.-H. But. Planta Med. 1995, 61:466–469.
(2) Bombardelli, E., and P. Morazzoni. Fitoterapia 1995, 66(4):291–317.
(3) Heggers, J. P., et al. Phytotherapy Res. 1995, 9(6):455–457.
(4) Ali, L., et al. Planta Med. 1995, 61:358–360.