Other Herbal Medicines

For drugs examined in this exercise, the phenotypic measure of induction is CYP3A4 activity and since these responses are estimated by various techniques (midazolam pharmacokinetics, erythromycin breath test), it is difficult to relate the 

TABLE 8.5 PXR Induction Metric and CYP3A4 Induction In Vivo 

Drug Cmax In Vivoa ( XM) PXR EC50 (p.M) Cmax/ECso 

None Moderate Marked In vivo CYP3A4 induction 

FIGURE 8.1 In vivo induction follows classic pharmacological principles. C x/ECso predicts whether a PXR activator causes significant drug-drug interactions. 

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A wide diversity of herbal remedies have purported abilities to stimulate defense functions. Complexes of carbohydrate and lignin, which are present in some herbs, modulate enteric immune functions (Kiyohara et al, 2000), and the changes in cytokine secretion (Matsumoto and Yamada, 2000) can trigger systemic responses. The polysaccharides present in other herbal medicines augment production of immunoglobulin (Ig) A by the Peyer s patches in the small intestine (Sakushima et al, 1997 Yu et al, 1998). The responses of the enteric immune system to lectins are variable (Pusztai 1993), and can elicit systemic responses (Lavelle et al, 2000). Other phytochemicals provide protection by inducing detoxification pathways in mucosal cells (Williamson et al, 1998). 

As already discussed, the same cannot be said for natural products used as dietary supplements. In most cases, those drugs have not heen subjected to the programs of testing required for FDA approval. As a result, products may pose a hazard to human health. Those hazards usually fall into one of four categories (1) the product may prevent a person from receiving other forms of FDA-approved medication that may he more beneficial to them (2) it may interact with other herbal medicines, prescribed drugs, and over-the-counter medications, with harmful effects (3) it may have no effect at all on a person s health or well-being or (4) it may actually cause harm to a person s health. 

Thus, Kane s book can be perceived as being on the cautious side, although there are many mentions of medicinal uses, and an array of individual compoimds, and classes of compoimds, is presented for each herb listed. A general comment supplied that pertains to Essiac tea, Noni juice, and other herbal medicinals believed to possess extraordinary curative powers is that there may be a window of 5-10 years of trendy use, and then they fall by the wayside (Kane, 2006, p. 16). 

High-performance hquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC/DAD/ESI-MSN) has been used for the chromatographic fingerprint analysis and characterization of furocoumatins in the roots of A. dahurica [83] and other herbal medicines [59,84],... 

All other homeopathic and herbal medicines that do not qualify for simplified registration procedures will have to go through the standard authorisation procedure with supporting technical dossiers. The Committee for Herbal Medicinal Products has been charged with preparing monographs on herbal products so as to further facilitate the registration of traditional and well-established use herbal products. 

Phytochemicals influence other digestive secretions. Several traditional herbal medicines stimulate gastric mucous secretion, providing protection (Sairam et al., 2001). The secretion and recycling of bile are also responsive to phytochemicals. The way in which certain polysaccharides increase fecal concentrations of bile acids (DalT Angelo and Lino van Poser, 2000) and thereby influence recycling and synthesis is particularly noteworthy. 

Phyto chemicals can be used to either stimulate or inhibit motility of the GIT. For example, caffeine and other phytochemicals stimulate motility (Lis-Balchim etal, 2001 Boekema et al, 1999), whereas motility is slowed by peppermint oil (Beesley et al, 1996), protease inhibitors (Schwartz et al., 1994) and several other phytochemicals (Abdullahi et al, 2001 Odetola and Acojenu, 2000 Rojas et al, 1999 Amos et al, 1998). Many of the traditional herbal medicines used for treatment of diarrhea are based on aqueous extracts that slow small intestine transit and increase residence time for digesta (Lin et al, 2002). The opiates and derivatives are particularly noteworthy (Williams et al., 1997). 

GIT characteristics, either to improve or limit specific function, and thereby influence host health. However, the complex, multiple and varied nature of the combinations of phytochemicals present in plants and traditional herbal medicines has complicated efforts to better understand the specific interactions between phytochemicals and the GIT (Yuan and Lin, 2000). Phytochemicals have other applications, such as the use of guar gum as a vehicle to deliver therapeutics (Krishnaiah et al, 2001). 

Other patient care services provided by independent community pharmacies as a group are shown in Table 4. One of the strengths of the pharmacies in this group is the wide range of services provided. It should be noted that special knowledge is required to effectively deliver many of these services, and some areas such as herbal medicine have grown very dramatically. 

Borchers, A.T. et al., Shosaiko-to and other Kampo (Japanese herbal) medicines A review of their immunomodulatory activities, J Ethnopharmacol, 73, 1, 2000. 

Adulteration, which can be accidental or deliberate, is another problem. Many herbal products have been found to contain prescription or OTC drugs and dangerous heavy metals. In 1998, for example, the California Department of Health reported that 32% of Asian herbal medicines sold in that state contained undeclared pharmaceuticals or heavy metals. A subsequent study of more than 500 Chinese herbal medicines found that about 10% of them contained undeclared drugs or toxic levels of metals. The FDA and other investigators have also detected sildenafil, colchicine, adrenal steroids, alprazolam, and other prescription drug ingredients in products claimed to contain only natural ingredients. 

In free societies, individuals are able to choose between one approach or the other to the treatment of disease. The risk is that a person may choose one form of treatment (such as herbal medicine, for example) when a more efficacious medical treatment is available... 

The HMPC is expected to establish community herbal monographs for herbal medicinal products. These herbal remedies have their product particulars and literature. Apart from other controls, any advertisement for a medicinal product registered is required to contain the following statement Traditional herbal medicinal product for use in specified indication(s) exclusively based upon long-standing use. ... 

Detractors of herbal medicine use have legitimate concerns about dosage variability, possible toxicity and adulteration, herb-drug interactions, and above all, lack of FDA regulation. Far from being intrinsically harmless, many pharmacologically active plant alkaloids and other compounds are natural defensive poisons their very effectiveness may be an unanticipated consequence of their adaptive toxicity to grazing animals and... 

Z0342 Sugaya, A., T. Tsuda, T. Obuchi, and E. Sugaya. Effect of Chinese herbal medicine Hange-Koboku-To on la-ryngeal reflex of cats and in other phar-macological tests. Planta Med 1983 47(l) 59-62. 

Similar to the challenges outlined in Chapter 2, the fact that most Chinese herbal medicines are complex mixtures of multiple active constituents further complicates the interpretation of study data, as well as extrapolation to other botanical products. Japanese Kampo (traditional Chinese herbal mixtures) prescriptions have been used for many years to treat different chronic conditions and are presently manufactured in Japan as drugs with standardized quantities and qualities of constituents. Homma et al. (51) evaluated the effect of three commonly used Japanese Kampo prescriptions, Sho-saiko-to (Xiao Chai Hu Tang), Saiboku-to, and Sairei-to, on prednisolone pharmacokinetics in humans. All three botanical prescriptions contain glycyrrhizin, a strong inhibitor of 11-p-hydroxysteroid dehydrogenase. Chen et al. (52) had shown that glycyrrhizin decreased plasma clearance and increased AUC and concentration of prednisolone. 

When treating chronic diseases, herbal medicine can be taken twice a day, in the morning and in the evening. Once the patient s condition improves, the frequency may be reduced and the herbal medicine can be taken once a day, every other day, or even twice a week to maintain the condition of the patient. 

Other sources of knowledge of Chinese herbal medicine... 

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