Effect of Chinese herbs on CYP3A4 activity and expression in vitro

Ethnopharmacological relevance

Traditional Chinese Medicine (TCM) has become more popular among cancer patients in the Western world, who often use Chinese herbs as adjuvant therapy to reduce the adverse effects of conventional chemotherapy. However, pharmacokinetic (PK) interactions between Chinese herbs and anticancer drugs can occur and have dramatic consequences for these patients. Currently, only a few possible PK interactions between Chinese herbs and conventional Western drugs have been documented.

Aim of the study

Since the drug-metabolizing enzyme cytochrome P450 3A4 (CYP3A4) contributes to most of the PK interactions with (anticancer) drugs, the effect of four Chinese herbs (Oldenlandia diffusa, Codonopsis tangshen, Rehmannia glutinosa and Astragalus propinquus) on the activity and expression of CYP3A4 was investigated in vitro.

Materials and methods

Ethanol and water–ethanol extracts of the four Chinese herbs were prepared from raw material. CYP3A4 inhibition was assessed by the use of Supersomes^™ in a fluorescence assay. Furthermore, CYP3A4 induction was evaluated in a human pregnane X receptor (hPXR)-mediated CYP3A4 reporter gene assay and a quantitative real time PCR assay, both in human colon adenocarcinoma-derived LS180 cells (LS180).

Results

Extracts of Oldenlandia diffusa, Codonopsis tangshen, Rehmannia glutinosa and Astragalus propinquus inhibited CYP3A4 in human CYP3A4 Supersomes^™ (IC₅₀ values: 17–83 µg/mL). Oldenlandia diffusa and Rehmannia glutinosa significantly induced PXR-mediated CYP3A4 (p<0.001). Oldenlandia diffusa also significantly induced CYP3A4 mRNA levels (p<0.001 at 250 µg/mL).

Conclusions

Concomitant use of Oldenlandia diffusa and Rehmannia glutinosa could result in induction of CYP3A4, leading to a reduced efficacy of drugs that are CYP3A4 substrates and have a narrow therapeutic window. Because of the possible enhanced toxicity caused by CYP3A4 inhibition, clinical effects of CYP3A4 inhibition by Astragalus propinquus and Codonopsis tangshen must also be taken into account. In conclusion, herb–drug interactions between Chinese herbs and various CYP3A4 substrates can occur. Further research to investigate the clinical relevance of the interactions caused by Oldenlandia diffusa, Codonopsis tangshen, Rehmannia glutinosa and Astragalus propinquus is required.     

Fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats

Ethnopharmacological relevance

The aerial parts of Coccinia cordifolia L. are used to treat female infertility in West Bengal state of India.

Aim of the study

The present study was undertaken to evaluate the fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats.

Materials and methods

The effect of aqueous extract of Coccinia cordifolia L. on hyperprolactinemia induced infertility, endometriosis induced infertility and androgen-induced infertility was studied. The effect on serum estrogen level, serum progesterone level and reproductive tract was also evaluated in normal healthy female rats. The extract was administered orally at two different doses of 500 mg/kg and 1000 mg/kg.

Results

In hyperprolactinemia induced infertility model, the numbers of uterine implants were almost 10 times more in the extract treated groups as compared to control. The high dose of extract also produced a significant increase in serum estrogen levels (p < 0.01) and number of corpus luteum (p < 0.05) in healthy female rats. The extract at both doses was effective in reducing the weight of endometrial implants by 70–80%, but failed to induce fertility in rats with endometriosis. The extract was ineffective in inducing fertility in androgen-induced infertility model.

Conclusions

The aqueous extract of Coccinia cordifolia L. induces fertility in hyperprolactinemia induced infertility model in female rats.     

Inhibitory effects of Geijigajakyak-Tang on trinitrobenzene sulfonic acid-induced colitis

Aim of the study

Water extract of Geijigajakyak-Tang (GJT) consisting of five crude drugs [dried root of P. lactiflora Peony (Paeoniaceae), dried trunk bark of C. cassia Blume (Lauraceae), seed of Z. jujube var. inermis Mill (Rhamnaceae), fresh root of Z. officinale Rocoe (Zingiberaceae) and dried trunk bark of G. uralensis Fish (Leguminosae)] is a folk medicine used for the treatment of chronic colitis. This study was designed to further elucidate the effect of GJT on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.

Materials and methods

GJT orally given to mice before and after TNBS intoxication, and their clinical and morphological changes, myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels in colon tissues, were evaluated on Day 8 post-TNBS. Furthermore, the effect of six major constituents of individual herbs on ileum smooth muscle contraction and neutrophil chemotaxis was studied.

Results

GJT had a significant anti-inflammatory effect based on clinical and morphologic changes, MPO activity and MDA levels in colon tissues as compared with sham control. GJT and 5 major active constituents of individual herbs, paeoniflorin, cinnamaldehyde, jujuboside A, jujubogenin, and diammonium glycyrhhizinate significantly inhibited neutrophil chemotaxis. GJT significantly inhibited muscle contraction (IC₅₀; 2.10 ± 0.11 mg/ml), and 1,8-cineol has the most spasmolytic activity (IC₅₀; 0.10 ± 0.03 mg/ml).

Conclusion

GJT has significant anti-inflammatory effects on TNBS-induced colitis via inhibitions of smooth muscle contraction and neutrophil chemotaxis.     

The roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) inhibit atherogenic events: A study of the combination effects of the 2-herb formula

Ethnopharmacological relevance

The roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) are principle herbs of Chinese herbal formulae which have long been used to treat cardiovascular diseases.

Aim of study

The present study validated the anti-atherogenic effects of three extracts, Danshen alone (DE), Gegen alone (GE) as well as DGE and interpreted their combination effects statistically.

Materials and methods

The anti-atherogenic effects of the three extracts were studied in three assays with regards to inflammation, foam cell formation and vascular smooth muscle cell (vSMC) proliferation using lipopolysaccharide (LPS)-induced nitric oxide production model, macrophage foam cell formation model and platelet-derived growth factor (PDGF)-induced vSMC proliferation model, respectively. The combination effects of DGE were statistically analyzed using combination index (CI) and fixed-ratio experimental design.

Results

The anti-atherogenic effects of the three extracts including anti-inflammation, anti-foam cell formation and anti-vSMC proliferation were demonstrated in this study. Their combination effects in anti-inflammation, anti-foam cell formation and anti-vSMC proliferation were found to be synergistic, additive and antagonistic, respectively.

Conclusions

This study provided scientific support for the combination use of DGE on atherosclerosis and presented one of the first applications of statistical interpretations of the combination effects of the 2-herb formula.     

Curculigo orchioides (Xian Mao) modifies the activity and protein expression of CYP3A in normal and Kidney-Yang Deficiency model rats

Aim of the study

In Chinese medicine clinics, traditional Chinese herbs are used to treat disorders of Yin and Yang balance, including Kidney-Yang Deficiency. The activity of the hepatic cytochrome P450 3 A (CYP3A) is closely associated with body status. The aim of the present study is to investigate CYP3A enzymatic activity and CYP3A4 protein expression using a Kidney-Yang Deficiency rat model and furthermore to investigate the intervention effects of the Pungent-hot herb Xian Mao. This work contributes rationale for personalized medicine and enhances our understanding of herb–drug interactions.

Materials and methods

Rats were randomly divided into three groups: the model group, the Xian Mao group and the intervention group (model rats treated with Xian Mao). The model rats were given an intramuscular injection of hydrocortisone for 14 days, and the control rats were given normal saline. The Xian Mao group consisted of normal rats treated with Xian Mao by oral gavage for 7 days. The intervention group was given Xian Mao for 7 days after treatment with hydrocortisone. The activity of CYP3A was detected by using the erythromycin-N-demethylase method. CYP3A4 protein expression level was detected by Western-blot.

Results

CYP3A enzymatic activity in the Kidney-Yang Deficiency rat was decreased by 44% compared to normal animals. The relative CYP3A4 protein expression level of the Kidney-Yang Deficiency rat (mean value 0.663±0.188) was 20% lower than that of normal rat (0.830±0.199). The in vitro data showed that CYP3A activity was significantly (P<0.001) inhibited (decreased by 59%) by Xian Mao concentrations of 1 mg/mL. The in vivo data also showed that CYP3A activity was significantly decreased in the rats treated with the three doses of Xian Mao. The CYP3A4 protein expression was significantly decreased by Xian Mao treatment at the high and intermediate doses (30 and 20 g/kg, respectively) compared with the normal group. However, the intervention group (the Kidney-Yang Deficiency rat treated with Xian Mao at 20 and 30 g/kg) showed an increased CYP3A activity and CYP3A4 protein expression compared with the herb-untreated model rats.

Conclusion

CYP3A enzymatic activity and CYP3A4 protein expression could be inhibited by Xian Mao. The CYP3A activity and CYP3A4 expression in the Kidney-Yang Deficiency model rat were lower than that of normal rat but this deficiency could be rescued by treatment with Xian Mao.     

Meta-analysis of Traditional Chinese Medicine in treating functional dyspepsia of liver-stomach disharmony syndrome

Objective

To systematically assess the clinical effectiveness of traditional Chinese medicine (TCM) in the treatment of functional dyspepsia (FD) of liver-stomach disharmony syndrome by meta-analysis.

Methods

Random controlled trials (RCTs) were retrieved from databases, including Pubmed, China national knowledge infrastructure, Wanfang Data, VIP Information, and the Cochrane Library. Trials were selected according to inclusion criteria. The effects of traditional Chinese medicine (TCM) versus prokinetic agents in the treatment of functional dyspepsia (FD) of liver-stomach disharmony syndrome were compared by meta-analysis. RevMan 5.0.24 was used for data analysis. The effective rate was assessed by odds ratios (ORs), and 95% confidence intervals (Cls) were calculated. The cure rate was analyzed by the Peto OR. Simple statistical analysis was chosen to assess the frequency of prescribed Chinese herbs in treating this syndrome.

Results

Thirteen trials were included, involving 1153 patients, and these were of poor methodological quality. Twelve studies mentioned the effective rate and cure rate. TCM therapy showed a better clinical effect rate compared with that with prokinetic agents [OR: 3.2, 95% CI (2.27, 4.51)]. The TCM group also had a better cure rate than that in the group of prokinetic agents [Peto OR: 2.26, 95% CI (1.61, 3.18)]. With regard to the frequency of Chinese herbs used in these 13 trials, Baishao (Radix Paeoniae), Chaihu (Radix Bupleuri), and Gancao (Radix Glycyrrhizae) were mostly prescribed, followed by Xiangfu (Rhizoma Cyperi), Zhishi (Fructus Aurantii Immaturus), Zhiqiao (Fructus Aurantii), Foshou (Citrus medica var.sarcodactylis), and Chenpi (Pericarpium Citri Reticulatae). No serious adverse effects were reported.

Conclusion

TCM therapy shows a superior effective rate and cure rate compared with those in prokinetic agents in the treatment of FD of liver-stomach disharmony syndrome. However, further strictly designed RCTs are required because of the poor quality of included trials.     

Evidence-based toxicity evaluation and scheduling of Chinese herbal medicines

Ethnopharmacological relevance

While there is an increasing number of toxicity report cases and toxicological studies on Chinese herbal medicines, the guidelines for toxicity evaluation and scheduling of Chinese herbal medicines are lacking.

Aim

The aim of this study was to review the current literature on potentially toxic Chinese herbal medicines, and to develop a scheduling platform which will inform an evidence-based regulatory framework for these medicines in the community.

Materials and methods

The Australian and Chinese regulations were used as a starting point to compile a list of potentially toxic herbs. Systematic literature searches of botanical and pharmaceutical Latin name, English and Chinese names and suspected toxic chemicals were conducted on Medline, PubMed and Chinese CNKI databases.

Results

Seventy-four Chinese herbal medicines were identified and five of them were selected for detailed study. Preclinical and clinical data were summarised at six levels. Based on the evaluation criteria, which included risk–benefit analysis, severity of toxic effects and clinical and preclinical data, four regulatory classes were proposed: Prohibited for medicinal usage, which are those with high toxicity and can lead to injury or death, e.g., aristolochia; Restricted for medicinal usage, e.g., aconite, asarum, and ephedra; Required warning label, e.g., coltsfoot; and Over-the-counter herbs for those herbs with a safe toxicity profile.

Conclusion

Chinese herbal medicines should be scheduled based on a set of evaluation criteria, to ensure their safe use and to satisfy the need for access to the herbs. The current Chinese and Australian regulation of Chinese herbal medicines should be updated to restrict the access of some potentially toxic herbs to Chinese medicine practitioners who are qualified through registration.     

Chinese herbal medicine for subacute thyroiditis: a systematic review of randomized controlled trials

Objective

To evaluate the effectiveness and safety of Chinese herbal medicine (CHM) in the treatment of subacute thyroiditis.

Methods

Randomized controlled trials found in PubMed, Cochrane Library, and three Chinese databases were selected. RevMan 5.2 software was used to analyze the data with relative risk or mean difference, expressed with 95% of confidence interval. The quality of trials was assessed and graded the quality of evidence with GRADE profiler software.

Results

Twenty one studies were included. CHM was superior to Western Medicine (include prednisone and NSAIDs) in abating fever, relieving thyroid pain, recovering blood sedimentation, improving thyroid function, and preventing hypothyroidism (P<0.05), while no statistical differences were found in eliminating goiter and reducing relapse rate. CHM plus Western Medicine were superior to Western Medicine in abating fever, relieving thyroid pain, eliminating goiter, and reducing relapse rate, while no statistical differences (P>0.05) were found in recovering blood sedimentation and improving thyroid function. The incidence of adverse reactions in treatment group was lower than that in control group (relative risk was 0.12 and 95% confidence interval was 0.03-0.51). The methodological quality of trials is generally poor with a high risk of bias.

Conclusion

CHM (particularly CHM combined with Western Medicine) used to treat subacute thyroiditis may improve clinical symptoms and signs, reduce relapse rate, and alleviate the side effects of hormones. Due to poor methodological quality of included trials, further more high-quality studies are warranted to confirm the effectiveness and safety of CHM.     

Partial agonistic effect of yokukansan on human recombinant serotonin 1A receptors expressed in the membranes of Chinese hamster ovary cells

Ethnopharmacological relevance

Yokukansan (YKS) is a traditional Japanese medicine consisted of seven medicinal herbs and has been used for treatment of neurosis, insomnia, and behavioral and psychological symptoms of dementia (BPSD) in Japan.

Aim of the study

The aim of the present study is to clarify the intrinsic activity of YKS on serotonin (5-HT)1A and 5-HT2A receptors and also to determine the constituent herbs which are responsible for the effect of YKS.

Materials and methods

The dry powdered extracts of YKS, seven constituent herbs, and YKS-analogues which were produced by eliminating one of the constituent herbs from YKS in the manufacturing process, were used for the evaluation. Competitive binding assays for 5-HT receptors and [³⁵S]GTPγS binding assays for the evaluation of agonistic/antagonistic activity were performed using Chinese hamster ovary cell membranes stably expressing human recombinant 5-HT1A or 5-HT2A receptors.

Results

YKS (6.25–400 μg/ml) concentration-dependently inhibited the binding of [³H]8-OH-DPAT to 5-HT1A receptors. The IC₅₀ value was estimated to be 61.2 μg/ml. In contrast, YKS failed to inhibit the binding of [³H]ketanserin to 5-HT2A receptors. Only Uncaria hook (3.13–50 μg/ml), of the seven constituent herbal extracts, inhibited the [³H]8-OH-DPAT binding to 5-HT1A receptors in a concentration-dependent manner, and the IC₅₀ value was estimated to be 7.42 μg/ml. The extracts of YKS or Uncaria hook increased [³⁵S]GTPγS binding to 5-HT1A receptors to approximately 50% of that of a full agonist, 5-HT. Both the competitive binding and [³⁵S]GTPγS binding of YKS to 5-HT1A receptors were remarkably attenuated by eliminating Uncaria hook from YKS, but it was almost unchanged when one of the other constituent herbs was eliminated from YKS.

Conclusion

These results suggest that YKS has a partial agonistic effect on 5-HT1A receptors, which is mainly attributed to Uncaria hook.     

Ameliorative and neuroprotective effect in MPTP model of Parkinson's disease by Zhen-Wu-Tang (ZWT), a traditional Chinese medicine

Aim of the study

Traditional Chinese medicine Zhen-Wu-Tang (ZWT) is a well-known PentaHerbs formula from “Treatise on Febrile Disease”. This study is to elucidate its neuroprotective effect and mechanism of ameliorative effect of the syndrome of Parkinson's disease (PD).

Materials and methods

The ameliorative effect of ZWT on symptom of PD through behavior tests including: swimming test, the tail suspension test and open-field test was investigated. The neuroprotective effect of dopaminergic neurons from the striatum and frontal cortex of brain was detected by high performance liquid chromatography with electrochemical detection (HPLC-ECD).

Results

This study proved that ZWT could ameliorate the typical symptom of PD and protect dopaminergic system.

Conclusion

These results suggested that ZWT possessed protective and ameliorative properties of dopaminergic neurons.     

The anti-arthritic effects of Aconitum vilmorinianum, a folk herbal medicine in Southwestern China

Ethnopharmacological relevance

Aconiti Radix (AC) and Aconiti Kusnezoffii Radix (AK) are two traditional Chinese medicines commonly used to treat joint pain and arthritis. In Southwestern China, Huangcaowu (AV), the root of Aconitum vilmorinianum Kom., has long been used as a local substitute for these herbs for analgesia and anti-inflammation. However, its anti-arthritic effects have not been investigated.

Aim of study

To investigate the anti-arthritic effects of Huangcaowu (AV).

Materials and methods

Mono-arthritis in SD rats was induced by unilateral intra-articular injection of Freund's complete adjuvant. Physiological saline was injected in the contralateral knee. Seventy five percent ethanol extracts of AV (10 mg/kg/day and 100 mg/kg/day), AC (100 mg/kg/day) and AK (100 mg/kg/day) were administered to rats by oral gavage for 14 consecutive days (Day -6 to Day 7) while arthritis was induced at the seventh day (Day 0). The anti-arthritic effects of the herbs were assessed by measuring allodynia, swelling, hyperaemia and the vascular permeability of the knee joints.

Results

AV (10 mg/kg/day and 100 mg/kg/day), AC (100 mg/kg/day) and AK (100 mg/kg/day) suppressed joint allodynia. AV (10 mg/kg/day and 100 mg/kg/day) and AK (100 mg/kg/day) significantly reduced join swelling and hyperaemia while AC (100 mg/kg/day) did not. AV (100 mg/kg/day) attenuated vascular permeability while AC (100 mg/kg/day) and AK (100 mg/kg/day) showed no improvement.

Conclusions

Huangcaowu (AV) significantly improved allodynia, swelling, hyperaemia and vascular permeability in arthritic knee joints. It showed the highest anti-arthritic effects among the three tested Aconitum herbs.     

Topical application of serine proteases from Wrightia tinctoria R. Br. (Apocyanaceae) latex augments healing of experimentally induced excision wound in mice

Ethnopharmacological relevance

Wrightia tinctoria R. Br. (Apocyanaceae) is a folk medicinal plant known to have immunomodulatory, anti-inflammatory and antihemorrhagic potential. Wrightia tinctoria latex is used for treatment of various clinical conditions including psoriasis, blisters, mouth ulcers, and extensively for topical application on fresh wounds to promote accelerated healing.

Aims of the study

To investigate the wound healing potential of Wrightia tinctoria latex proteases using a mouse model.

Materials and methods

Proteolytic activity of Wrightia tinctoria latex proteases (WTLP) was determined on various substrates (casein, gelatin and collagen (type-I and IV)). The thermal stability and the class of proteases present in WTLP were determined using heat treatment and specific protease inhibitors, respectively. Excision wound model in mice was used to evaluate the healing potential of WTLP application (twice daily, 10 mg/kg). Neosporin, a standard drug, was used for comparison. The progression of healing was monitored using physical (wound contraction), biochemical (collagen content, catalase and MMP activity) and histological examinations.

Results

WTLP contains thermostable serine proteases, which are completely inhibited by PMSF. WTLP showed strong caseinolytic, gelatinolytic and collagenolytic activity. The excision wound healing rate upon WTLP treatment was significantly higher than (>2-fold) the control group (49% vs. 18%, ^??p<0.01) on day 3 and throughout the study. PMSF pre-treated and heat denatured WTLP failed to promote wound healing. In addition, serial biochemical analysis of the granulation tissue demonstrated 1.5-fold more (2444±100 vs. 1579±121 µg/100 mg tissue) hydroxyproline content and 5.6-fold higher catalase activity (16.7±1.3 vs. 3±0.3 units/mg) compared to controls. Further, the enhanced collagen content and matrix metalloproteinase activity correlated with wound contraction rate following WTLP and Neosporin treatment. Histological analysis on day 9 confirmed complete epithelialization, re-establishment of skin structure and accelerated wound healing following WTLP treatment.

Conclusions

The thermostable serine proteases of Wrightia tinctoria latex are directly involved in the wound healing process. Our findings provide a biochemical basis for the role of WTLP in the enhancement of wound healing. The study supports traditional topical application of Wrightia tinctoria latex on fresh wounds to promote accelerated healing.