Effects of traditional Chinese medicines on pharmacokinetics of levofloxacin

Inhibiting Neutrophil Extracellular Traps Protects against Ultraviolet B-Induced Skin Damage: Effects of Hochu-ekki-to and DNase I

UV-B radiation induces sunburn, and neutrophils are pivotal in this inflammation. In this study, we examined the potential involvement of neutrophil extracellular traps (NETs) in ultraviolet B (UVB)-induced skin inflammation, correlating the skin inflammation-mitigating effects of Hochu-ekki-to on UV-B irradiation and NETs. To elucidate NET distribution in the dorsal skin, male ICR mice, exposed to UVB irradiation, were immunohistologically analyzed to detect citrullinated histone H3 (citH3) and peptidylarginine deiminase 4 (PAD4). Reactive oxygen species (ROS) production in the bloodstream was analyzed. To establish the involvement of NET-released DNA in this inflammatory response, mice were UV-B irradiated following the intraperitoneal administration of DNase I. In vitro experiments were performed to scrutinize the impact of Hochu-ekki-to on A23187-induced NETs in neutrophil-like HL-60 cells. UV-B irradiation induced dorsal skin inflammation, coinciding with a significant increase in citH3 and PAD4 expression. Administration of DNase I attenuated UV-B-induced skin inflammation, whereas Hochu-ekki-to administration considerably suppressed the inflammation, correlating with diminished levels of citH3 and PAD4 in the dorsal skin. UV-B irradiation conspicuously augmented ROS and hydrogen peroxide (H2O2) production in the blood. Hochu-ekki-to significantly inhibited ROS and H2O2 generation. In vitro experiments demonstrated that Hochu-ekki-to notably inhibited A23187-induced NETs in differentiated neutrophil-like cells. Hence, NETs have been implicated in UV-B-induced skin inflammation, and their inhibition reduces cutaneous inflammation. Additionally, Hochu-ekki-to mitigated skin inflammation by impeding neutrophil infiltration and NETs in the dorsal skin of mice.

Beneficial effects of rikkunshito, a Japanese kampo medicine, on gastrointestinal dysfunction and anorexia in combination with Western drug: a systematic review

Background. Kampo medicines are traditional herbal medicines which have been approved for medicinal use by the Japanese Ministry of Health and Welfare and are currently being used more and more, often in combination with Western drugs. Thus, the need for investigation of interactions between Kampo medicines and Western drugs is now widely recognized. Aim. To summarize the effects and drug interactions of rikkunshito, a Kampo medicine often prescribed for upper gastrointestinal disorders and anorexia. Methods. Animal and human studies were systematically reviewed to identify published data on rikkunshito. Results describing its effects were abstracted, with an emphasis on drug interactions. Results and Discussion. Rikkunshito ameliorates anorexia induced by anticancer drugs, improves quality of life scores, and can even prolong survival compared with monotherapy. Rikkunshito combined with proton pump inhibitor therapy is shown to be useful in the treatment of PPI-refractory gastroesophageal reflux disease patients and patients with gastrointestinal symptoms after endoscopic submucosal dissection. Rikkunshito reduces antidepressant-induced adverse events and improves quality of life without influencing antidepressant effects. Conclusions. Rikkunshito shows ameliorative effects on adverse reactions induced by various Western drugs and can achieve better results (e.g., anticancer drugs and proton pump inhibitor) without influencing the efficacy and bioavailability of Western drugs.

Repetitive administration of Shaoyao-Gancao-tang to rats restores the bioavailability of glycyrrhizin reduced by antibiotic treatment

Shaoyao-Gancao-tang (SGT), a traditional Chinese formulation, is often used together with antibiotics such as amoxicillin and metronidazole (AMPC-MET) for the treatment of peptic ulcers in Japan. However, the bioavailability of glycyrrhizin (GL) in SGT is severely reduced by a single administration of AMPC-MET, and the reducing effect continues for 12 days. GL is one of the major pharmacologically important glycosides in SGT and is transformed into the active metabolite 18β-glycyrrhetic acid (GA) by intestinal bacteria in the gut, followed by absorption of the latter into the blood. In order to reduce the negative effect of AMPC-MET on the bioavailability of GL, the optimum scheduling of the medications was examined. We found that the reduction in the plasma GA concentration and the GL-metabolizing activity in faeces caused by a single dose of AMPC-MET could be sharply attenuated by the repetitive administration of SGT for 4 days. The GA concentration and the GL-metabolizing activity were strongly enhanced by further continuous administration of SGT. These findings suggest that repetitive administration of SGT starting 1 or 2 days after the administration of AMPC-MET speeds the recovery of the bioavailability of GL in SGT. Similar strategies for administering medications may also be useful for combination therapy of antibiotics with other traditional Chinese formulations containing bioactive glycosides.

Effect of a Kampo preparation, byakkokaninjinto, on pharmacokinetics of ciprofloxacin and tetracycline

The effect on the bioavailability of the antimicrobial agents (ciprofloxacin and tetracycline), which are well known to form chelates with cationic metals such as calcium, was evaluated in 20 healthy male volunteers according to an open, random crossover fashion using a Kampo preparation, byakkokaninjinto (TJ-34) which contains various cationic metals including calcium. Each subject received a single oral dose of tetracycline (250 mg) alone or ciprofloxacin (200 mg) alone along with a single coadministration of one pack (3 g) of the Kampo preparation, at one-week intervals. Concentrations of the drugs in plasma and urine were analyzed by HPLC. Concomitant administration of the Kampo preparation significantly decreased the peak plasma concentration (C(max)) and area under the plasma concentration-time curves (AUC), but not time to reach C(max) (T(max)), of ciprofloxacin and tetracycline. However, the decrease in bioavailability of ciprofloxacin was slight (15%) compared with that of tetracycline (30%). The Kampo preparation significantly decreased the urinary recovery of tetracycline, but not ciprofloxacin, and it had no effect on the renal clearance of either ciprofloxacin or tetracycline. These results indicate that the Kampo preparation tested in this study reduces the extent of bioavailability of ciprofloxacin and tetracycline, but not renal excretion, by decreasing the gastrointestinal absorption due to the formation of insoluble chelates with calcium. We recommend that the dose timing of the Kampo preparation should be carefully controlled to avoid therapeutic failure especially for patients receiving the treatment with tetracycline.

Pharmacology and toxicology of Bupleurum root-containing Kampo medicines in clinical use

Kampo (Japanese traditional herbal) medicines have been produced by combining multiple crude drugs, almost all of plant origin but with some of animal or mineral origin, and contain a great many substances. Their effect is a combination of the various interactions of the constituent substances, whether they are enhancing, synergistic or suppressive. Kampo medicine has an overall effect that is different from the combined effects of individual crude drugs, and several side effects such as anorexia, slight fever and nausea have been reported in the treatment of certain disorders and disease states with Kampo medicines. Among 210 medical formulations used in Japan, some relevant information on the clinical uses, pharmacology and toxicology of six manufactured Kampo medical formulations, Shosaikoto, Daisaikoto, Saikokeishito, Hochuekkito, Saibokuto and Saireito, containing Bupleurum root are reviewed. Studies of some potential interactions between Kampo medicine and western drugs are also considered.

Natural health product-drug interactions: a systematic review of clinical trials

Interactions between natural health products (NHP) and prescription medications are of increasing concern. This paper aims to identify all clinical trials of NHP-drug interactions. To determine the prevalence and outcomes of clinical investigations of NHP-drug pharmacokinetic interactions, electronic databases were searched from inception through March 2004, as well as reference lists from published reports and experts in the field for unpublished studies. Eligible studies were clinical investigations of the interaction between a NHP and the metabolism of a regulated medication in humans. Studies were excluded that only investigated the metabolism of an NHP or examined food-drug or NHP-NHP interactions. Two reviewers selected studies for inclusion and independently extracted data. Forty-seven trials were identified, studying an average of 14 participants/study (95% confidence interval [CI] 11-18), examined drug interactions with 19 different herbal preparations. All trials were pharmacokinetic studies, 41 of healthy volunteers and 6 of patients. Ten different herbal medicines as well as 5 different traditional herbal concoctions were studied. Potentially clinically significant drug interactions were observed with St. John wort (16/24 studies), garlic (2/5 studies), and American ginseng (1 study). Research on NHP-drug interactions is limited in number and scope. With the exception of St. John wort, clinicians and the public do not have information that permits strong inferences about interactions between NHPs and conventional medications.

Toxicological considerations of Kampo medicines in clinical use

Kampo (Japanese herbal) medicines, produced by combining multiple crude drugs, almost all of plant origin but with some of animal or mineral origin, contain great many substances. Since Kampo medicine results from the combination of many substances, their effect is a combination of the various interactions of the constituent substances. It has been demonstrated that several potential side effects such as allergic reactions, diarrhea and vomiting may be experienced when administering Kampo medicine. In addition, it has been reported that Kampo medicine may have antagonistic or synergistic interactions with western drugs or with some foods such as grapefruit juice. Among the 210 medicinal prescriptions used in present-day Japan, the clinical uses and the acute, chronic and mutagenic toxicity of some Kampo medicines are described. Studies of some potential interaction between Kampo medicines and western drugs are also considered.

Toxicological aspects of Kampo medicines in clinical use

Among 210 medicinal prescriptions used in present-day Japan, the clinical uses and the acute, chronic and mutagenic toxicity study of 16 Kampo (Japanese herbal) medicines are summarized. These Kampo medicines are classified into two categories; eight prescriptions containing Bupleurum root (Bupleurum falcatum L.) such as Sho-saiko-to and Saiko-keishi-to, and eight prescriptions not containing Bupleurum root such as Juzen-taiho-to and Ninjin-yoei-to. Studies of some potential interaction between herbal medicine and western drugs are also described.

Influence of co-administered antibiotics on the pharmacokinetic fate in rats of paeoniflorin and its active metabolite paeonimetabolin-I from Shaoyao-Gancao-tang

The effects of orally co-administered antibiotics on the pharmacokinetics of paeoniflorin (PF) and paeonimetabolin-I (PM-I), a bioactive metabolite derived from PF by intestinal bacteria, from the traditional Chinese formulation, Shaoyao-Gancao-tang (SGT), were investigated in rats to clarify the effect of administering SGT together with some synthetic drugs. Co-administration of the antibiotics amoxicillin and metronidazole (AMPC-MET) significantly increased the area under the plasma concentration versus time curve (AUC) of PF, whereas it markedly decreased that of PM-I, to 2.6% of the normal AUC by administration of a single dose, and less than 1% by a 3-day pretreatment. Similar effects were observed using the combination of ofloxacin with SGT. The PF-metabolizing activity of intestinal bacteria was reduced to 16% and 33% of normal levels by treatment with AMPC-MET and ofloxacin, respectively, which caused alterations of that degree in the extent of absorption of PF and PM-I, but did not affect their rate of absorption or elimination. The present study suggests that it may not be appropriate to use SGT simultaneously with antibiotics such as AMPC-MET or ofloxacin, and also reveals the important role of intestinal bacteria in the pharmacokinetics of the active components of this traditional Chinese formulation.

Interactions of herbs with cytochrome P450

A resurgence in the use of medical herbs in the Western world, and the co-use of modern and traditional therapies is becoming more common. Thus there is the potential for both pharmacokinetic and pharmacodynamic herb-drug interactions. For example, systems such as the cytochrome P450 (CYP) may be particularly vulnerable to modulation by the multiple active constituents of herbs, as it is well known that the CYPs are subject to induction and inhibition by exposure to a wide variety of xenobiotics. Using in vitro, in silico, and in vivo approaches, many herbs and natural compounds isolated from herbs have been identified as substrates, inhibitors, and/or inducers of various CYP enzymes. For example, St. John's wort is a potent inducer of CYP3A4, which is mediated by activating the orphan pregnane X receptor. It also contains ingredients that inhibit CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. Many other common medicinal herbs also exhibited inducing or inhibiting effects on the CYP system, with the latter being competitive, noncompetitive, or mechanism-based. It appears that the regulation of CYPs by herbal products complex, depending on the herb type, their administration dose and route, the target organ and species. Due to the difficulties in identifying the active constituents responsible for the modulation of CYP enzymes, prediction of herb-drug metabolic interactions is difficult. However, herb-CYP interactions may have important clinical and toxicological consequences. For example, induction of CYP3A4 by St. John's wort may partly provide an explanation for the enhanced plasma clearance of a number of drugs, such as cyclosporine and innadivir, which are known substrates of CYP3A4, although other mechanisms including modulation of gastric absorption and drug transporters cannot be ruled out. In contrast, many organosulfur compounds, such as diallyl sulfide from garlic, are potent inhibitors of CYP2E1; this may provide an explanation for garlic's chemoproventive effects, as many mutagens require activation by CYP2E1. Therefore, known or potential herb-CYP interactions exist, and further studies on their clinical and toxicological roles are warranted. Given that increasing numbers of people are exposed to a number of herbal preparations that contain many constituents with potential of CYP modulation, high-throughput screening assays should be developed to explore herb-CYP interactions.

Studies on interactions between traditional herbal and Western medicines. IV: lack of pharmacokinetic interactions between Saiko-ka-ryukotsu-borei-to and carbamazepine in rats

The possibility of pharmacokinetic interactions between Saiko-ka-ryukotsu-borei-to extract powder (TJ-12), a widely used traditional Chinese herbal (Kampo) medicine, and carbamazepine (CBZ), an important anti-epileptic drug, was examined in rats. There were no significant differences in the serum protein binding of CBZ and carbamazepine- 10,11-epoxide (CBZ-E), its active metabolite, at two concentrations (1 and 10 Bg/ml) between twogroups pretreated orally with the vehicle andTJ-12 suspension (1 g/kg/d, p.o.) for 1 week. One-week repeated pretreatment with TJ- 12 (1 g/kg/d) did not influence liver weight, contents of cytochromes P450 and b5 in hepatic microsomes or the formation rate of CBZ-E from CBZ by its microsomes, while pretreatment with phenobarbital (80 mg/kg/d, i.p.) significantly increased these parameters. Neither a single nor 1-week repeated oral pretreatment with TJ-12 (1 g/kg/d) affected the plasma concentration-time profile and any pharmacokinetic parameter of CBZ or CBZ-E after oral administration of CBZ (50 mg/kg). These results indicated that oral co-administration of TJ-12 with CBZ has no effect ofthe pharmacokinetics of CBZ or CBZ-E in rats. Concomitant treatment with TJ- 12 and CBZ appears to be pharmacokinetically safe in humans.