Effect of oral administration of fennel (Foeniculum vulgare) on ciprofloxacin absorption and disposition in the rat

Herb-drug interactions and toxicity: Underscoring potential mechanisms and forecasting clinically relevant interactions induced by common phytoconstituents via data mining and computational approaches

Herbals in the form of medicine are employed extensively around the world. Herbal and conventional medicine combination is a potentially dangerous practice mainly in comorbid, hepato insufficient and frail patients leading to perilous herb-drug interactions (HDI) and toxicity. This study features potential HDI of 15 globally famous plant species through data mining and computational methods. Several plant species were found to mimic warfarin. Phytochemicals from M. charantia induced hypoglycemica. M. chamomila and G. biloba possessed anticoagulant activities. S. hispanica reduces postprandial glycemia. R. officinalis has been reported to inhibit the efflux of anticancer substrates while A. sativum can boost the clearance of anticancer agents. P. ginseng can alter blood coagulation. A cross link of the biological and in silico data revealed that a plethora of herbal metabolites such as ursolic and rosmarinic acid among others are possible/probable inhibitors of specific CYP450 enzymes. Consequently, plant species/metabolites with a given pharmacological property/metabolizing enzyme should not be mixed with drugs having the same pharmacological property/metabolizing enzyme. Even if combined with drugs, herbal medicines must be used at low doses for a short period of time and under the supervision of a healthcare professional to avoid potential adverse and toxic effects.

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.

Inhibitory Effects of Multiple-Dose Treatment with Baicalein on the Pharmacokinetics of Ciprofloxacin in Rats

Ciprofloxacin is used as a treatment for urinary and respiratory tract infections in clinical practice. Baicalein, a major flavonoid present in Scutellaria baicalensis, is a well-known and potent antibacterial compound used in complementary and alternative medicine practices. The present study aimed to clarify the effects of multiple-dose treatment with baicalein on the pharmacokinetics of ciprofloxacin in rats. Following the oral administration of baicalein (20, 40, or 80 mg/kg) for five consecutive days, the rats received an oral administration of ciprofloxacin (20 mg/kg). Blood samples were collected at specific time points, and the plasma concentrations of ciprofloxacin were determined by using high-performance liquid chromatography. To evaluate the mechanisms underlying the interaction between baicalein and ciprofloxacin, a rhodamine 123 accumulation assay was performed in LS-180 cells. A pharmacokinetic study revealed that multiple-dose treatment with baicalein significantly decreased the peak serum concentration (C_max ), area under the curve (AUC_{0 → 480 min} ), and relative bioavailability (F_rel ) of ciprofloxacin (p < 0.05). The rhodamine 123 accumulation assay revealed that treatment with baicalein for 48 h markedly reduced the intracellular accumulation of rhodamine 123. Taken together, these findings suggest that baicalein may result in the therapeutic failure of ciprofloxacin or other quinolone-based antibiotics used for chemotherapy in clinical practice. Copyright © 2016 John Wiley & Sons, Ltd.

Medicinal properties of Foeniculum vulgare Mill. in traditional Iranian medicine and modern phytotherapy

Foeniculum vulgare Mill. (F. vulgare), commonly known as Fennel, is a popular medicinal plant with various pharmacological activities mentioned in traditional Iranian medicine (TIM) and modern phytotherapy such as antioxidant, cytotoxic, anti-inflammatory, antimicrobial, bronchodilatory, estrogenic, diuretic, lithontripic, galactogogue, emmenagogue, antithrombotic, hypotensive, gastroprotective, hepatoprotective, memory enhancing, and antimutagenic activities. No serious adverse events were recorded after ingestion of F. vulgare except some cases of allergic reactions. The estrogenic activity of F. vulgare brings some side effects such as decrease in protein concentration and acid and alkaline phosphatase in male genital organs, increase in weight of mammary glands and reproductive organs in women and premature thelarche in girls. However, no evidence of teratogenicity was recorded, it is better not to use F. vulgare during pregnancy due to its estrogenic activity. Because of inhibition of cytochrome P450 3A4 (CYP3A4), the pharmacokinetic parameters of drugs mainly metabolized by this isozyme may be affected by F. vulgare. In addition, a significant interaction between cyprofloxacin and F. vulgare was demonstrated. The aim of current paper is to review pharmacological properties, toxicity and adverse events, and drug interactions of vulgare and brings conclusive results about the use of this plant in men, women and during pregnancy.

Herbs-are they safe enough? an overview

Drugs based on herbs have become a common form of therapy as well as for prophylaxis because they are often perceived as being natural and therefore harmless. Today they are one of the hottest trends and most sought after in the field of nutrition or herbal therapeutics. As the use of complementary medicine grows, so does the knowledge that many compounds in common use not only have a significant effect on the body but may also interact with pharmaceuticals and also with other alternative products. Concurrent use of herbs with drugs may mimic, magnify, or oppose the effect of drugs leading to herb-drug interactions. Currently, there is very little information published on herb-herb or herb-drug interactions as compared to the use of herbs which is progressively growing across the world. Many reports of herb-drug interactions are sketchy and lack laboratory analysis of suspect preparations. Health-care practitioners should caution patients against mixing herbs and pharmaceutical drugs. The article reviews the recent literature on the adverse effects of herbal remedies including the most widely sold herbal medicinal products, like liquorice, garlic, ginger, green tea, and turmeric, etc., and reinforce the safety aspect of herbal products, which are considered to be relatively safe by common people.

Assessment of herbal weight loss supplement counseling provided to patients by pharmacists and nonpharmacists in community settings

OBJECTIVE

To assess the extent of appropriate counseling provided to patients by pharmacists and nonpharmacists in retail settings regarding herbal dietary supplements for weight loss.

DESIGN

Descriptive, exploratory, nonexperimental study.

SETTING

Phoenix, AZ, metropolitan area, from June 2008 to January 2009.

PARTICIPANTS

Pharmacists and nonpharmacists (e.g., cashiers, sales clerks, pharmacy technicians) working in retail locations selling herbal dietary supplements (e.g., grocery stores, health food stores, pharmacies).

INTERVENTION

Investigators posing as patients sought herbal weight loss supplement product recommendations and counseling on potential safety, drug interaction, and adverse effect issues from pharmacists or nonpharmacists.

MAIN OUTCOME MEASURES

Level of knowledge regarding safety and efficacy of herbal dietary supplements for weight loss.

RESULTS

52 sites were visited, and 27 unique product recommendations were given. In general, counseling provided to investigators/patients by pharmacists versus nonpharmacists varied significantly (P < 0.05) except when participants were asked about expected weight loss (P = 0.39) or use of herbal supplements during pregnancy (P = 0.07) and breast-feeding (P = 0.48). Pharmacists were more reluctant to recommend herbal products for weight loss than nonpharmacists and tended to question the safety and/or efficacy of these products or refer the patient to an alternate health care provider.

CONCLUSION

The counseling that investigators/patients received regarding herbal products for weight loss in various retail settings from both pharmacists and non-pharmacists varied greatly. Efforts are needed from the medical and herbal communities to ensure that patients are adequately informed about herbal products at the point of purchase.

Drug Interactions Between Herbal and Prescription Medicines

Until reports of interactions between St John's wort and drugs such as digoxin, warfarin, protease inhibitors and oral contraceptives began to appear, very few herb-drug interactions were documented. These are now becoming more common, although still rare compared with drug-drug interactions. In the absence of hard data, potential interactions are being highlighted, and this review attempts to distinguish between the speculative and the proven. The subject is approached from a therapeutic point of view since in most cases the patient is already taking one or more prescription drugs, and the question is whether or not it is safe for a particular herb to be added to the regimen. Although many of the examples of herb-drug interactions are minor or theoretical at present, the fact remains that some are serious and life threatening, and these almost exclusively concern cyclosporin, anticoagulants, digoxin, antidepressants and protease inhibitors, taken with the herb St John's wort. Ginkgo and ginseng are implicated in a number of reports, but many of these are unsubstantiated. To date, the cardiovascular, central nervous and immune systems are the most common therapeutic categories cited in the literature and other than those, examples are very limited. Although many herbal drugs have good safety profiles, it must be borne in mind that herbal supplements are intended to be taken over an extended period of time, which provides the opportunity for enzyme induction and other mechanisms of interaction to take effect.