Herbal medicines activities

GMPs have spread from being applicable strictly to drug dosage form manufacture, to a world where every dosage form or business sector involved with medicinals or their constituents has a detailed GMP code. These sectors include herbal medicines, active pharmaceutical excipients (inactives), clinical trial manufacture, biotechnology-sourced materials, sunscreen products, and so on. 

An herb or herbal prescription is chosen as the source of a potential new drug based on folk or clinical experiences. The initial research (new lead discovery) focuses on isolation of a bioactive natural lead compound(s), as illustrated graphically below. After extraction of the herbal medicine, activity is verified by pharmacological testing. Bioactivity-directed fractionation and isolation (BDFl)... 

Chinese Herbal Medicines. Many traditional Chinese medicines have been screened for radioprotective activity in experimental animals. In one study of more than a thousand Chinese herbs, a number of agents increased the survival rate of dogs exposed to a lethal dose of y-rays by 30—40%, and some symptoms of radiation injury were ameHorated. These effects are potentially related to stimulation of the hemopoietic and immune systems (130). Extracts of five Chinese dmg plants, as weU as aspirin, effectively protected mice exposed to 7.5—8.0 Gy (750—800 rad) of y-radiation, and increased survival rates by 8—50% (131). Several Chinese traditional medicines, adininistered ip before or after irradiation, protected against Hpid peroxidation in a variety of mouse tissues, including BM, Hver, and spleen, as weU as in mouse Hver microsomal suspensions irradiated in vitro (132). 

It is one of the peculiarities of herbal drugs that their indications have for the most part been determijied empirically. The reason is easily understood most herbal drugs have been used for a very long time to alleviate or cure illnesses and more especially disorders. Their introduction in therapeutics happened at a time when pharmacodynamics and pharmacokinetics were unknown concepts, when there was no Medicines Act to require proof of the quality, efficacy, and innocuity of herbal medicines. Today, when introducing a new medicine, extensive investigations are required in the interest of safety. To many the requirement of the proof of activity of such a drug as chamomile appears to be superfluous, but nevertheless, as a representative of a scientifically oriented pharma-... 

The results have not been entirely satisfactory. On the one hand, it would be expected that for many preparations a relicensing would be simplified and, on the other hand, it should not be overlooked that the opinions of the risks in the partly very schematic and uniform details regarding the indications take up a considerable amount of space. For combined drugs, including herbal mixtures, the second bill modifying the AMG, which came into force on 1.2.1987, led to further problems now it has to be shown that each medicinally active component contributes to the positive evaluation of the remedy. 

This study has found that dmg regulation does not meet these requirements in all the countries studied. In some countries, legislation omits or exempts certain areas of pharmaceutical activity from the scope of control. In Australia, Malaysia and the Netherlands, legislation requires traditional/herbal medicines to be assessed and registered. But this is not the case in Cypms, Uganda or Zimbabwe. As a result of such gaps, dmg regulation provides only partial protection for consumers. 

The purported prophylactic use of Japanese herbal medicines to combat neuronal ageing has been related to their free-radical scavenging activity (Hiramatsu a al., 1992). Inhibition of the pro-inflammatory effects of cytokine interleukin-1 by recombinant endogenous interleukin-1 receptor antagonist in experimental rats is associated with alleviation of excitotoxic neuronal damage, an action which has also been related to the antiinflammatory effect of lipocortin 1 (Relton and Roth well, 1992). 

Relatively few reports have examined the benefits or perils of herb combinations. Because the activity of a particular herb in a mixture might differ from its activity as a single component, it would be prudent to test the effects of prescribed formulas. The potential for herbal formulae to affect the immune system are increasingly being found in the use of Kampo (Japanese herbal) medicinals as described in an excellent review by Borchers and colleagues. [94], For example, Shosaiko-to is a seven-herb mixture that has been shown to protect patients from viral hepatitis via modulation of several cytokines such as IFN-a/p, G-CSF, and TNF-a. Animal studies have been conducted to evaluate the immunomodulatory effects of the various herbs in Shosaiko-to. Interestingly, four of its individual constituents induced several-fold higher levels of TNF-a when... 

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

Conversely, active constituents may have cooperative effects and together act in an additive or synergistic (supra-additive) manner. In such cases, it would be better to consume the whole plant or extract, because the combination of constituents would give a greater effect than one alone. Thus, to blindly advocate either the use of whole herb or refined single constituents is naive. To fully know what is best for the desired effect, herbs must be considered on a case-by-case basis and the nature of the interactions between the chemical constituents must be carefully considered. Not only must we understand what the plant s chemical constituents do, we must also investigate how they interact. The Use of Herbal Medicine The Current Prevalence of Alternative Medicine... 

Herbal medicines contain active drugs, in every sense of the word. As such, the principles of pharmacology pertain to them and allow us to understand their effects. The purpose of this chapter is to outline some of these principles. For a more complete treatment of the topic, the reader is directed to the sources listed in the references. Although these principles apply to all drugs, this chapter will draw upon examples from plant drugs to illustrate them. 

The anti-HP activities of Gosyuyu, a crude extract from the fruit of Evodia rutaecarpa, a Chinese herbal medicine, have also been tested for activity... 

Hamasaki N, Ishii E, Tominaga K, Tezuka Y, Nagaoka T, Kadota S, Kuroki T, Yano 1. (2000) Highly selective antibacterial activity of novel alkyl quinolone alkaloids from a Chinese herbal medicine, Gosyuyu (Wu-Chu-Yu), against Helicobacter pylori in vitro. Microbiol Immunol 44 9-15. 

It was recently observed that a iplant, Adhatoda vasica, long used in Indian herbal medicine (the source of many therapeutic leads) for the relief of cough and respiratory tract congestion, did appear to reduce the quantity and viscosity of sputum. The plant was studied and its active alkaloid named vasicine. The tricyclic quinazoline structure (XXVIII) was then reduced to fragments and a series of derivatives prepared [350]. From these bromhexine (XXIX, Na 274, Bisolvon)... 

A herbal medicinal product is defined as any medicinal product, exclusively containing as active ingredients one or more herbal substances or... 

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... 

Luo, ]., ]. H. Yin, and Q. Wei. The effect of calcineurin activator, extracted from Chinese herbal medicine, on memory and immunity in mice. Pharmacol Biochem Behav... 

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. 

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