Effect of berberine on in vitro metabolism of sulfonylureas: A herb-drug interactions study.

Patients with type 2 diabetes may co-ingest herbal and prescription medicines to control their blood sugar levels. Competitive binding of drug and herb may mutually affect their metabolism. This can alter the level of drug and its kinetics in the body, potentially causing toxicities or loss of efficacy. Understanding how the metabolism of sulfonylureas like glyburide and gliclazide can be affected by the presence of berberine and vice versa can provide valuable information on the possible risk of toxicities caused by co-ingestion of drugs. METHODS: Berberine and sulfonylureas (glyburide and gliclazide) were co-incubated with rat liver microsomes in the presence of a NADPH-regenerating system. The metabolites of berberine and sulfonylureas were analysed using liquid chromatography with high-resolution mass spectrometry in the positive ion mode. The role of individual isozymes in the metabolism of berberine, glyburide and gliclazide was investigated by using specific inhibitors. RESULTS: In vitro metabolism of berberine led to the formation of demethyleneberberine (B1a) and its isomer B1b through demethylenation. Berberrubine (B2a) and its isomer B2b were formed through demethylation. The isozymes CYP3A and CYP2D were found to be involved in the metabolism of berberine. In vitro metabolism of glyburide and gliclazide led to the formation of hydroxylated metabolites. The isozymes CYP3A and CYP2C were found to be involved in the metabolism of glyburide. Gliclazide was metabolised by CYP2C. In vitro co-incubation of glyburide or gliclazide with berberine showed that each drug's metabolism was compromised as they share a common isozyme. A strong negative linear correlation of glyburide or gliclazide metabolite levels and the concentration of berberine confirmed the effect of berberine on the metabolism of sulfonylureas. CONCLUSIONS: The metabolism of sulfonylureas and berberine was affected when these compounds were co-incubated with each other. This may be attributable to competitive binding of the herb and drug to the catalytic sites of the same isozymes.

Herb-Drug Interactions of Commonly Used Chinese Medicinal Herbs.

With more and more popular use of traditional herbal medicines, in particular Chinese herbal medicines, herb-drug interactions have become a more and more important safety issue in the clinical applications of the conventional drugs. Researches in this area are increasing very rapidly. Herb-drug interactions are complicated due to the fact that multiple chemical components are involved, and these compounds may possess diverse pharmacological activities. Interactions can be in both pharmacokinetics and pharmacodynamics. Abundant studies focused on pharmacokinetic interactions of herbs and drugs. Herbs may affect the behavior of the concomitantly used drugs by changing their absorption, distribution, metabolism, and excretion. Studies on pharmacodynamics interactions of herbs and drugs are still very limited. Herb-drug interactions are potentially causing changes in drug levels and drug activities and leading to either therapeutic failure or toxicities. Sometime it can be fatal. The exposures to drugs, lacking of knowledge in the potential adverse herb-drug interactions, will put big risk to patients' safety in medical services. On the contrary, some interactions may be therapeutically beneficial. It may be used to help develop new therapeutic strategies in the future. This chapter is trying to review the development in the area of herb-drug interactions based on the recently published research findings. Information on the potential interactions among the commonly used Chinese medicinal herbs and conventional drugs is summarized in this chapter.

Treatment of Insomnia With Traditional Chinese Herbal Medicine.

Insomnia is a condition with sleep problems and many people suffered from it. Chronic insomnia can last for long time and it will severely affect people's health and the quality of life. In conventional medicine, the most commonly used the medicine is benzodiazepine. It is effective but also has significant side effects. Patients try to use some kinds of alternative medicines. Chinese medicinal herbs and formulas have been used in the treatment of insomnia for more than 2000 years in China. In recent decades, Chinese herbal medicine has been widely used in the Western countries. Many clinical studies including randomized controlled clinical trials and research on pharmacological action mechanisms of the herbs for treatment of insomnia have been conducted. It is very important and very helpful to review the published research papers to gather the available information for a critical analysis. This chapter evaluated the data from both of clinical studies and pharmacological researches on the therapeutic formulas and on some key herbs used in the treatment of insomnia. Clinical studies showed a very wide spectrum of herbs that were used in clinical treatment of insomnia. This was due to different syndrome patterns happened with insomnia. This brought complexity and difficulties to identify which are the essential key herbs or formulas. It was found Suanzaoren decoction (Ziziphus spinose decoction ) is the most frequently used formula for the treatment of insomnia. Based on the clinical data, several herbs were identified as most frequently used sedative and hypnotic herbs in Chinese herbal medicine including Suanzaoren (Ziziphus spinose ), Fuling (Poria cocos ), and Gancao (Glycyrrhiza uralensis ). The underlying pharmacological action mechanisms discovered in the studies on some key herbs used in the treatment of insomnia were evaluated. The major pharmacological action mechanisms shared by most of the sedative herbs are to act through the neurotransmitter gamma-aminobutyric acid (GABA) or via stimulation of GABAAA receptor. Some herbs exert sedative activities via inhibition of 5-hydroxytryptamine 1A receptor. Another mechanism shown by some herbs is to upregulate the expression of orexin-A, leptin, orexin receptor-1, and leptin receptor in the brain, reducing insomnia-induced negative consequences, and thus indirectly help improvement of insomnia.

Effect of Acupuncture on the Motor and Nonmotor Symptoms in Parkinson's Disease--A Review of Clinical Studies.

Parkinson's disease is a neurodegenerative disorder. Parkinson's clinical feature is characterized by its motor manifestations, although its many nonmotor symptoms occur earlier and have more profound impact on the quality of patient's life. Acupuncture has been increasingly popular and has been used to treat patients with Parkinson's. In this article, we have studied the clinical reports of acupuncture treatment for Parkinson's, which were listed in Medline, PubMed, EMBASE, CNKI, and CINAHL databases in the past 15 years. It was found that acupuncture either manual or electroacupuncture stimulation at specific acupoints relieved some motor symptoms in patients with Parkinson's and markedly improved many nonmotor symptoms such as psychiatric disorders, sleep problems, and gastrointestinal symptoms. When it was used as an adjunct for levodopa, acupuncture improved therapeutic efficacy and reduced dosage and the occurrence of side effects of levodopa. However, the results were constrained by small sample sizes, methodological flaws, and blinding methods of studies. Although the evidence for the effectiveness of acupuncture for treating Parkinson's is inconclusive, therapeutic potential of acupuncture seems quite promising. More studies, either comparative effectiveness research or high-quality placebo-controlled clinical studies are warranted.

[Identification of ancient Chinese medicinal specimens preserved at Natural History Museum in London].

On-site field investigation was conducted to authenticate a batch of ancient Chinese medicinal decoction pieces that have been preserved in a rare collection at the Natural History Museum in London. These treasured artifacts comprise a portion of the Sloane Collection, and the nearly one hundred Chinese medicinal specimens examined within provide an objective record of the real situation regarding the Chinese medicinal materials in commercial circulation three hundred years ago. The precious data from this collection pro-vides an extremely valuable reference for the research into the history of medicinal exchange between China and the West during the Age of Exploration, shedding light on the evolution and historical changes in the species used in Chinese medicine, as well as the history of medicinal processing and decoction pieces.

Acupuncture for the treatment of insomnia.

Insomnia appears to be a fast-spreading problem in the modern days, which not only affects people's living quality but also impairs people's working efficiency even causing disability. Pharmacological treatment is effective but frequently with significant side effects. Acupuncture is traditionally used for the treatment of insomnia in China and now is widely accepted in the Western countries. Many research works on clinical applications of acupuncture in the treatment of insomnia and the potential mechanisms underlying the acupuncture treatment have been reported. This chapter will try to provide a systematic review on the research findings. A number of clinical studies, mainly randomized controlled clinical trials, have shown positive effects in acupuncture treatment of insomnia. Some of the studies demonstrated that acupuncture treatment appeared to be better than conventional pharmacological drugs in the improvement of insomnia. These encouraging findings are limited by the qualities problems of the methodology used in these clinical studies. The clinical efficacy of acupuncture appeared to be supported by evidence obtained from basic neuroendocrinological studies. A number of studies have demonstrated that acupuncture may modulate a wide range of neuroendocrinological factors following stimulation of acupoints. Evidence has suggested that the clinical efficacy of acupuncture in treatment of insomnia is potentially mediated by a variety of neurotransmitters including norepinephrine, melatonin, gamma-aminobutyric acid, and ß-endorphin. However, due to the complexity, these findings are far from conclusive. More research is necessary. More rigors methodology and integrated approach to evaluate both clinical and basic research evidence are required for future studies.