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.     

Cytochrome P450 inhibitory potential of Triphala--a Rasayana from Ayurveda

Ethnopharmacological relevance

‘Triphala’ is one of the age-old, most commonly used polyherbal preparation from Ayurveda as Rasayana drug.

Aim of the study

This study was aimed at evaluating the effect of ‘Triphala’ on drug modulating enzymes to assess its safety through its potential to interact with co-administered drugs.

Materials and methods

The cytochrome P450 inhibitory effect of ‘triphala’ formulation was investigated on rat liver microsomes using CYP450-CO complex assay and on individual isoform such as CYP3A4 and 2D6 using fluorescence screening. RP-HPLC method was developed to standardize ‘triphala’ and its individual components using gallic acid as analytical marker compound.

Results

RP-HPLC analysis demonstrated the presence of gallic acid (4.30 ± 2.09 mg/g) in the formulation. The formulation showed 23% inhibition of the rat liver microsomes through CYP450-CO complex assay which is comparatively less when compared with the individual components. Further, the effect of standardized formulation dissolved in ethanol showed CYP3A4 and CYP2D6 inhibitory activity at the IC₅₀ values of 119.65 ± 1.91 μg/ml and 105.03 ± 0.98 μg/ml respectively. Gallic acid was also found to inhibit both the isoforms at the IC₅₀ values of 87.24 ± 1.11 μg/ml and 92.03 ± 0.38 μg/ml respectively.

Conclusions

Various concentrations of the formulation and its individual components showed significantly less inhibitory activity (p < 0.001) on individual isoforms when compared with the positive control. Assessment on the in vitro effect of ‘triphala’ on drug modulating enzymes has important implications for predicting the likelihood of herb-drug interactions if these are administered concomitantly.     

A new TCM formula FTZ lowers serum cholesterol by regulating HMG-CoA reductase and CYP7A1 in hyperlipidemic rats

Ethnopharmacological relevance

Based on a theory of Chinese Medicine, Regulating Gan (liver) to lower lipids that is in brief to regulate the lipid metabolic related factors in the liver will improve serum lipid profile, we have developed Fufang Zhenzhu Tiao Zhi (FTZ) which includes eight herbs that are quality assured. FTZ has been developed with the potential to correct abnormal lipid metabolism. This Chinese herbal medicine has been prescribed for 20 years, which has been issued patent and clinically proven for use in the treatment of dyslipidemia.

Aim of the study

To investigate the cholesterol-lowering effect and the mode of action of FTZ extract on high lipid diet induced hyperlipidemic rats.

Materials and methods

The FTZ was prepared by alcohol and water extraction of eight herbs that have been quality-controlled according to the protocol. The cholesterol-lowering effect of FTZ was evaluated on SD rats fed with high-lipid diet. RT-PCR and western blot were used to analyze the gene expression of cholesterol metabolism-related enzymes including HMG-CoA reductase and cholesterol 7α-hydroxylase (CYP7A1) in the livers of the rats. The activity of HMG-CoA reductase and CYP7A1 were assessed by colorimetrical method and by quantification of the cholesterol metabolite of CYP7A1 using HPLC analysis respectively.

Results and conclusions

FTZ significantly decreased the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), whilst elevated the serum high-density lipoprotein cholesterol (HDL-C) and decreased serum atherogenic index (A.I.) values in high lipid diet induced hyperlipidemic rats. Furthermore, FTZ showed significant antihyperlipidemic effect by at least three pathways in the high lipid diet induced hyperlipidemic rats: (1) upregulating the gene expression and activity of CYP7A1 which promotes the conversion of cholesterol into bile acid; (2) downregulating the gene expression and activity of HMG-CoA reductase to reduce de novo synthesis of cholesterol; (3) increasing the cholesterol excretion from feces. In these three pathways, HMG-CoA reductase and CYP7A1 are two pivotal enzymes in lipid cholesterol metabolism and are expressed mainly in hepatic cells, which support our new TCM treatment strategy: Modulating Liver to Treat Hyperlipemia.     

In vitro modulatory effects of Andrographis paniculata, Centella asiatica and Orthosiphon stamineus on cytochrome P450 2C19 (CYP2C19)

Ethno pharmacological relevance

Andrographis paniculata (AP), Centella asiatica (CA) and Orthosiphon stamineus (OS) are three popular herbs traditionally used worldwide. AP is known for the treatment of infections and diabetes and CA is good for wound healing and healthy skin while OS is usually consumed as tea to treat kidney and urinary disorders. Interaction of these herbs with human cytochrome P450 2C19 (CYP2C19), a major hepatic CYP isoform involved in metabolism of many clinical drugs has not been investigated to date.

Aim of the study

In this study, the modulatory effects of various extracts and major active constituents of AP, CA and OS on CYP2C19 activities were evaluated.

Materials and methods

S-Mephenytoin, the CYP2C19 substrate probe, was incubated in the presence or absence of AP, CA and OS components. The changes in the rate of metabolite (hydroxymephenytoin) formation were subsequently determined by a high-performance liquid chromatography (HPLC)-based enzyme assay to characterize the modulatory effects.

Results

Among the herbal extracts studied, AP ethanol extract and CA dichloromethane extract exhibited mixed type inhibition towards CYP2C19 with K_i values of 67.1 and 16.4 μg/ml respectively; CA ethanol extract and OS petroleum ether extract competitively inhibited CYP2C19 activity (K_i = 39.6 and 41.5 μg/ml respectively). Eupatorin (a major active constituent of OS) was found to significantly inhibit CYP2C19 by mixed type inhibition (K_i = 7.1 μg/ml or 20.6 μM).

Conclusions

It was observed that AP, CA and OS inhibited CYP2C19 activity with varying potency. While weak inhibitory effect was observed with AP, moderate to strong inhibition was observed with CA dichloromethane extract and eupatorin, the major OS constituent. Therefore care should be taken when these CA and OS components are co-administered with CYP2C19 substrates (such as omeprazole, proguanil, barbiturates, citalopram, and diazepam).     

Action mechanism of Zuo Gui Yin Decoction's promotion on estradiol production in rats during the peri-menopausal period

Aim of the study

Although Zuo Gui Yin Decoction has long been used in Traditional Chinese Medicine to treat menopausal symptoms, the underlying mechanism(s) by which these effects are induced remains to be defined. The aim of this study was to investigate the action mechanism of Zuo Gui Yin Decoction on estradiol production in the rat ovary during peri-menopause.

Materials and methods

The peri-menopausal animal model was established by natural aging. Peri-menopausal rats were treated by intragastric administration (ig) with low (13.78 g kg⁻¹), middle (20.67 g kg⁻¹) or high (31 g kg⁻¹) dose of Zuo Gui Yin Decoction per day for 8 weeks. At the 8th weekend, the rats were sacrificed for sampling. Estradiol (E₂) levels in rats’ serum were evaluated by radioimmunoassay (RIA). RT-PCR, in situ hybridization and immunohistochemistry were used to determine mRNA and protein expression of relevant genes.

Results

Medium- and high-dose of Zuo Gui Yin Decoction could significantly increase serum estradiol concentration, ovarian CYP19 mRNA levels, and P450_arom protein expression in rats during peri-menopause. Zuo Gui Yin Decoction at three different dosages all could promote FSHR expression and the effect of low-dose was the greatest. Zuo Gui Yin Decoction could elevate LRH-1 and ER_α expression in a dose dependent manner.

Conclusions

Taken collectively, these findings suggest that Zuo Gui Yin Decoction could promote estradiol production in rat serum during peri-menopausal period through ovarian ER_α → LRH-1 → CYP19 pathway as well as the ovarian classical FSHR → CYP19 mechanism.     

Pharmacokinetic changes of unbound theophylline are due to plasma protein binding displacement and CYP1A2 activity inhibition by baicalin in rats

Ethnopharmacological relevance

Baicalin is one of the major bioactive constituents of Scutellariae Radix, the root of Scutellariae baicalensis Georgi and possesses a wide variety of pharmacological properties.

Aim of the study

To elucidate the effect of baicalin on the pharmacokinetics of theophylline in rats, focusing on plasma protein binding displacement and inhibition effect on CYP1A2 in vivo and in vitro.

Materials and methods

The study was a randomized, three-period crossover design. Nine rats were given saline (control) or 450 mg/kg baicalin (dosage regimen A or B). Dosage regimen A was administered once at 0 h. Dosage regimen B was divided into three dosages (225,112.5, 112.5 mg/kg) and was given at 0, 2 and 4 h, respectively. Then theophylline (5 mg/kg, i.v.) was administered immediately. The effect of baicalin on CYP1A2 activity was determined by metabolism of phenacetin in vitro and plasma protein binding of theophylline was determined by ultrafiltration.

Results

C_max decreased from (12.4±1.6) to (8.7±0.9) and (8.6±2.0) mg/L, T_1/2 increased by 116 and 96%, V_d increased by 51 and 49% for total theophylline in rats treated with dosage regimen A and B of baicalin, respectively. C_max was significantly increased, V_d decreased by 43 and 29% for unbound theophylline in rats treated with dosage regimen A and B of baicalin, respectively (P<0.01). T_1/2 of unbound theophylline increased by 104% only in rats treated with dosage regimen B. No significant effects on the CL and AUC of both total and unbound theophylline were observed in the rats treated with dosage regimen A, but the CL decreased and AUC increased for total theophylline and CL decreased for unbound theophylline in the group treated with dosage regimen B (P<0.05). Correlation analysis showed that the mean unbound theophylline (%) and mean baicalin concentration was in good correlation (P<0.01). Baicalin decreased metabolism of phenacetin and exhibited a mixed-type inhibition in rat liver microsomes, with a K_i value of 88.1 μM in vitro. Moreover baicalin was a competitive displacer of theophylline from plasma protein in vitro.

Conclusions

The changes in C_max, T_1/2, CL and AUC of theophylline due to baicalin may be attributed to two mechanisms, plasma protein binding displacement and CYP1A2 activity inhibition.     

Inhibitory effects of cytochrome P450 enzymes CYP2C8, CYP2C9, CYP2C19 and CYP3A4 by Labisia pumila extracts

Ethnopharmacological relevance

Labisa pumila (LP), popularly known with its local name, Kacip Fatimah, is a well known herb grown in Indochina and Southeast Asia and is traditionally used to regain energy after giving birth in women. The propensity of LP to cause drug–herb interaction via cytochrome P450 (CYP) enzyme system has not been investigated.

Aim of the study

To evaluate the in vitro inhibitory effects of various LP extracts (aqueous, ethanol, dichloromethane (DCM) and hexane) on cytochrome P450 2C8 (CYP2C8), CYP2C9, CYP2C19 and CYP3A4 activities.

Materials and methods

Probe substrate-based high performance liquid chromatography (HPLC) methods were established for CYP2C9, CYP2C19 and CYP3A4 whereas a fluorescence-based enzyme assay was established for CYP2C8. The metabolite formations were examined after incubation of probe substrate with respective CYP isoform in the present or absent of LP extracts. The inhibitory effect of LP was characterized with kinetic parameters IC₅₀ and K_i values.

Results

LP extracts showed differential effect of CYP activities with the order of inhibitory potency as follows: dichloromethane>hexane>ethanol>aqueous. This differential effect was only observed in CYP2C isoforms but not CYP3A4. Both the hexane and DCM extracts exhibited moderate to potent inhibition towards CYP2C activities in different modes including non-competitive, competive and mixed-type. The DCM effect was notably strong for CYP2C8 and CYP2C9 showing K_i values of below 1 μg/ml. The selectivity of LP for CYP2C isoforms rather than CYP3A4 may be attributed to the presence of relatively small, lipophilic yet slightly polar compounds within the LP extracts.

Conclusions

The results of our study revealed that phytoconstituents contained in LP, particularly in hexane and dichloromethane extracts, were able to selectively inhibit CYP2C isoforms. The inactivation was characterized by low K_i values, in particular, in CYP2C8 and CYP2C9. These in vitro data indicate that LB preparations contain constituents that can potently inhibit CYP2C activities and suggest that this herb should be examined for potential pharmacokinetic drug interactions in vivo.     

Identification of novel pregnane X receptor activators from traditional Chinese medicines

Aim of the study

To investigate the ability of traditional Chinese medicines (TCMs) and their bioactive compounds to activate pregnane X receptor (PXR) signalling pathway.

Materials and methods

We screened ethanol extracts of 28 commonly used TCMs for their capability to induce cytochrome P450 3A4 (CYP3A4) via PXR signalling pathway using a cell-based reporter gene assay combined with RT-PCR analysis. In addition, 34 bioactive components from these TCMs were examined for their potential to activate PXR.

Results

Our observations showed that 22 ethanol extracts and 8 compounds could activate human PXR and induce CYP3A4 reporter construct in HepG2 cells. Among them, Ginkgo biloba, Ligusticum chuanxiong, Chinese angelica, prepared Rehmannia root, Epimedium brevicornum, Atractylodes macrocephala, Schisandra chinensis, Paeonia lactiflora, Ophiopogon japonicus, Polygonum multiflorum, Coptis chinensis, Artemisia scoparia, Trichosanthes kirilowii, Silybum marianum, Gardenia fruit and Lycium chinense could strongly trans-activate PXR. Moreover, ligustilide, schisantherin A, berberine hydrochloride and trans-resveratrol were identified for the first time as efficacious PXR agonists.

Conclusions

Twenty-two TCM ethanol extracts and eight bioactive compounds could activate PXR signalling pathway and induce CYP3A4 reporter gene. Therefore, caution should be taken when these PXR activators are used in combination with prescribed drugs metabolized by CYP3A4.     

Effects of Panax notoginseng saponins on the activities of CYP1A2, CYP2C9, CYP2D6 and CYP3A4 in rats in vivo

The aim of this study was to assess the influence of the Panax notoginseng saponins (PNS) on the activities of the drug‐metabolizing enzymes cytochrome P450 (CYP450) 1A2, 2 C9, 2D6 and 3A4 in rats. The activities of CYP1A2, 2 C9, 2D6 and 3A4 were measured using specific probe drugs. After pretreatment for 1 week with PNS or physiological saline (control group), probe drugs caffeine (10 mg/kg; CYP1A2 activity), tolbutamide (15 mg/kg; CYP2C9 activity), metoprolol (20 mg/kg; CYP2D6 activity) and dapsone (10 mg/kg; CYP3A4 activity) were administered to rats by intraperitoneal injection. The blood was then collected at different times for ultra performance liquid chromatography/tandem mass spectrometry (UPLC‐MS/MS) analysis. The data showed that PNS exhibited an induction effect on CYP1A2 by decreasing caffeine C_max (36.3%, p < 0.01) and AUC_0‐∞ (22.77%, p < 0.05) and increasing CL/F (27.03%, p < 0.05) compared with those of the control group. Western blot analysis was used to detect the effect of PNS on the protein level of CYP1A2, and the results showed that PNS could upregulate the protein expression of CYP1A2. However, no significant changes in CYP2C9, 2D6 or 3A4 activities were observed. In conclusion, the results indicate that PNS could induce CYP1A2, which may affect the disposition of medicines primarily dependent on the CYP1A2 pathway. Our work may be the basis of related herb–drug interactions in the clinic. Copyright © 2011 John Wiley & Sons, Ltd.     

Biochemical mechanism of Wu-Zi-Yan-Zong-Wan,a traditional Chinese herbal formula,against alcohol-induced oxidative damage in CYP2E1 cDNA-transfected HepG2 (E47) cells

Aim of the study

Wu-Zi-Yan-Zong-Wan (WZ) is a traditional Chinese herbal formula which is commonly used for treating patients with “Yang deficiency”. In the present study, the effect of WZ on ethanol-induced toxicity in CYP2E1 cDNA-transfected HepG2 (E47) cells was investigated.

Materials and Methods

WZ extract was obtained by extracting the herbal powder with 50% ethanol (v/v, in water) and the effect of the extract on ethanol-induced toxicity was investigated in cultured cells.

Results

The treatment with WZ extract (12.5–200 μg/mL) for 24 h dose-dependently protected against ethanol-induced toxicity in E47 cells, as evidenced by the enhanced cell viability and decreased extent of lactate dehydrogeanse leakage. The cytoprotection against ethanol-induced toxicity was associated with decreases in the extents of reactive oxygen species production and lipid peroxidation, as well as increases in mitochondrial reduced glutathione and membrane potential. In addition, WZ extract treatment also suppressed the formation of DNA fragments in ethanol-intoxicated E47 cells.

Conclusions

WZ extract was found to protect against the ethanol-induced toxicity in E47 cells, possibly by virtues of its antioxidant activity.     

Pharmacological properties of Anagallis arvensis L. ("scarlet pimpernel") and Anagallis foemina Mill. ("blue pimpernel") traditionally used as wound healing remedies in Navarra (Spain)

Ethnopharmacological relevance

: Anagallis arvensis and Anagallis foemina are traditionally used in Navarra (Spain) for dermatological purposes regarding wound healing properties. In some cases they are also used to threat internal infections although they are known to be toxic at high doses.

Aim of study

: Due to lack of studies, we decided to evaluate the potential of the plants as wound healing remedies measuring antimicrobial and anti-inflammatory properties using in vitro procedures.

Materials and methods

Antimicrobial effects were studied against four bacteria and one fungus. Anti-inflammatory properties were measured in terms of COX-1 and -2 inhibition as well as superoxide radical scavenging capacity.

Results

Both species exerted antimicrobial and anti-inflammatory effects. The methanolic extract obtained from Anagallis arvensis seemed to produce the highest inhibition in Candida albicans (MIC = 0.31 mg/ml). Inhibition of COX-1 and -2 was also stronger for methanolic extracts whereas aqueous were revealed as better free radical scavengers.

Conclusions

The study reveals that both species posses antimicrobial and anti-inflammatory activities related to their ethnomedicinal uses.     

清开灵注射液对大鼠CYP1A2和2D6的影响

目的：通过清开灵注射液的大鼠体内、外实验,观察清开灵注射液对大鼠CYP1A2亚型,CYP2D6亚型的影响。方法：通过HPLC法测定全血中咖啡因的代谢率,观测清开灵注射液对大鼠CYP1A2活性的影响；通过HPLC法测定大鼠肝微粒体重组系统非那西丁的代谢比率,确定清开灵注射液对大鼠肝微粒体CYP1A2亚型的作用；测定大鼠肝微粒体重组系统右美沙芬的代谢比率,确定清开灵注射液对大鼠肝微粒体CYP2D6亚型的作用。结果：实验组中给予大鼠不同浓度的清开灵注射液(0.15,0.3,0.6 mL·kg^-1),其咖啡因代谢率为(15.9±3.8)%,(14.5±1.8)%,(12.3±1.2)%,对照组为(16.8±5.9)%,各剂量组及对照组间均无显著性差异；肝微粒体体外重组系统中,实验组各浓度清开灵注射液对CYP2D6没有影响；高剂量组清开灵注射液对CYP1A2有抑制作用。结论：清开灵注射液对CYP1A2和 CYP2D6的活性没有影响。     

Realgar and realgar-containing Liu-Shen-Wan are less acutely toxic than arsenite and arsenate

Ethnopharmacological relevance

Liu-Shen-Wan (LSW) is a widely-used traditional Chinese medicine containing realgar (As₄S₄).

Aim of the Study

Realgar has been included in many traditional medicines, and is often taken as arsenite for risk assessment in realgar-containing traditional remedies. Is realgar toxicologically similar to arsenite?

Materials and Method

Mice were orally given LSW (60 and 200 mg/kg; 200 mg LSW contains 27 mg realgar), realgar (30 mg/kg, equivalent to 21 mg As/kg), and the equivalent As dose as sodium arsenite (NaAsO₂), or as arsenate (Na₂HAsO₄). Acute toxicity and tissue As accumulation were determined 8 h later.

Results

Arsenite and arsenate increased serum alanine aminotransferase (ALT) levels, indicative of liver injury; blood urea nitrogen (BUN) was also increased by arsenite and arsenate, indicative of nephrotoxicity. No elevations of ALT and BUN were observed in LSW and realgar groups. Histopathology showed more damage in arsenite- and arsenate-treated liver and kidneys, while in realgar- and LSW- treated animals, only mild alterations were seen. Hepatic and renal As contents were dramatically increased to 6200 and 3350 ng/g, respectively, after arsenite, but only increased to 260 and 180 ng/g after LSW. The expressions of arsenic-sensitive stress genes, namely metallothionein-1 and heme oxygenase-1, were increased after arsenite or arsenate by 3-10-folds, but were unaltered after LWS and realgar.

Conclusions

Realgar and LSW are much less toxic than arsenite and arenate. The use of total As content to evaluate the safety of realgar-containing traditional medicines is not scientifically sound.     

Apocynum venetum leaf aqueous extract inhibits voltage-gated sodium channels of mouse neuroblastoma N2A cells

Ethnopharmacological relevance

Apocynum venetum Linn. (Apocynaceae family), also called Luobuma, is a shrub which grows widely in the Xinjiang Autonomous Region of China. Its leaves are used in herbal tea for the treatment of hypertension, anxiety and depression. Animal studies have also shown that Apocynum venetum leaf extract (AVLE) also exerts anti-depressant and anti-anxiety activities. The effects of AVLE on neuronal tissues in vitro are not fully understood.

Materials and methods

Using the whole-cell voltage-clamp method, we studied the effects of AVLE on ion channels in cultured mouse neuroblastoma N2A cells.

Results

AVLE inhibited voltage-gated inward Na⁺ current in a reversible and concentration-dependent manner (half-inhibitory concentration was 18 μg/ml and maximum inhibition at 100 μg/ml). AVLE specifically promoted steady-state inactivation of Na⁺ channels but did not affect voltage-dependence of activation. The inhibitory effect was not use-dependent and was not affected by 300 μM L-NAME, suggesting that NO was not involved in the action of AVLE in neuronal cells. AVLE also had a mild inhibitory effect on voltage-gated K⁺ channels, but did not affect ATP-sensitive K⁺ channels.

Conclusions

Since voltage-gated Na⁺ and K⁺ channels are associated with neuronal excitability and therefore affect neurotransmission, the modulation of neuronal ion channels by AVLE may exert neuropharmacological effects. In particular, the inhibition of voltage-gated Na⁺ currents by AVLE may in part account for the psychopharmacological effects of this herbal remedy.     

The in vivo and in vitro diabetic wound healing effects of a 2-herb formula and its mechanisms of action

Ethnopharmacological relevance

The herbs Radix Astragali (RA) and Radix Rehmanniae (RR) have long been used in traditional Chinese Medicine and serve as the principal herbs in treating diabetic foot ulcer.

Aim of study

Diabetic complications, such as foot ulcer, impose major public health burdens worldwide. In our previous clinical studies, two Chinese medicine formulae F1 and F2 have achieved over 80% limb salvage. A simplified 2-herb formula (NF3) comprising of RA and RR in the ratio of 2:1 was used for further study. NF3 was examined for the ulcer healing effect in diabetic rats, and its potential mechanisms of action in fibroblast proliferation, angiogenesis and anti-inflammation in vitro.

Materials and methods

A chemically induced diabetic foot ulcer rat model was used for studying the wound healing effect. In the in vitro mechanistic studies, human fibroblast cells (Hs27), human umbilical vein endothelial cells (HUVEC) and mouse macrophage cells (RAW264.7) were assessed for tissue regeneration, angiogenesis and anti-inflammatory activities, respectively.

Results

Our in vivo results demonstrated a significant reduction of wound area at day 8 in NF3 (0.98 g/kg) group as compared to control (p < 0.01). NF3 could significantly stimulate Hs27 proliferation in a dose dependent manner (p < 0.05). Besides, NF3 could significantly increase the cell migration and tube formation (p < 0.05-0.001) of HUVEC in the angiogenesis study. Furthermore, significant inhibition of nitric oxide production (p < 0.01) was found in NF3-treated macrophage cells, suggesting its anti-inflammatory activity.

Conclusions

Our study presents for the first time scientific evidence towards the efficacy of the two-herb formula NF3 in enhancing diabetic wound healing through the actions of tissue regeneration, angiogenesis and anti-inflammation.     

齐墩果酸对健康人体CYP1A2,CYP2E1及CYP3A4抑制作用的研究

 目的在人体内研究齐墩果酸对CYP1A2,CYP2E1及CYP3A4酶活性的影响,以预测齐墩果酸与常用临床药物的相互作用。方法分别以咖啡因、氯唑沙宗和咪哒唑仑作为CYP1A2,CYP2E1及CYP3A4的探药,采用随机、开放、双周期交叉设计,12名健康男性受试者在服用7d齐墩果酸前后均服用100mg咖啡因、400mg氯唑沙宗和7.5mg咪哒唑仑,服探药后采血测定探药及相应代谢产物的浓度,并计算相关参数。探药和代谢物的浓度分别用RP-HPLC和HPLC-MS测定。结果服用齐墩果酸7d后,咖啡因的代谢受到显著的抑制,其达峰时间、消除半衰期及药-时曲线下面积显著增加;氯唑沙宗的代谢受到轻微抑制,达峰浓度、达峰时间、消除半衰期及药-时曲线下面积均有升高趋势,但无显著性差异;咪哒唑仑的代谢未受影响。结论服用7d齐墩果酸对CYP1A2体内活性有显著抑制作用,对CYP2E1体内活性有轻微抑制作用,而对CYP3A4酶活性无影响。     

Inonotus obliquus extracts suppress antigen-specific IgE production through the modulation of Th1/Th2 cytokines in ovalbumin-sensitized mice

Ethnopharmacological relevance

Chaga mushroom (Inonotus obliquus, IO) has been used as a folk remedy for cancer, digestive system diseases, and other illnesses in Russia and Eastern Europe.

Aim of the study

In the present study, we investigated the immunomodulating effects of IO through in vivo and ex vivo studies.

Materials and methods

Serum immunoglobulins (IgE, IgG₁, and IgG_2a) and cytokines (interleukin (IL)-4, interferon (IFN)-γ, and IL-2) were measured in concanavalin A (ConA)-stimulated splenocytes and CD4⁺ T cells. The nitric oxide (NO) secretion of lipopolysaccharide (LPS)-stimulated peritoneal macrophages was also measured after oral administration of 50, 100, or 200 mg kg⁻¹ d⁻¹ IO hot water extract (IOE) to ovalbumin (OVA)-sensitized BALB/c mice.

Results

We found that the OVA-induced increase in serum IgE and IgG_2a was significantly suppressed when IOE was orally administered after the second immunization with OVA. ConA stimulation in spleen cells isolated from OVA-sensitized mice treated with 100 mg kg⁻¹ IOE resulted in a 25.2% decrease in IL-4 production and a 102.4% increase in IFN-γ, compared to the controls. Moreover, IL-4, IFN-γ, and IL-2 were significantly reduced after ConA stimulation in isolated CD4⁺T cells. We also determined that IOE inhibits the secretion of NO from LPS-stimulated peritoneal macrophages ex vivo.

Conclusions

We suggest that IO modulates immune responses through secretion of Th1/Th2 cytokines in immune cells and regulates antigen-specific antibody production.     

2-methoxycinnamaldehyde from Cinnamomum cassia reduces rat myocardial ischemia and reperfusion injury in vivo due to HO-1 induction

Ethnopharmacological relevance

Cinnamomum cassia Blume has been used as a traditional Chinese herbal medicine for alleviation of fever, inflammation, chronic bronchitis, and to improve blood circulation.

Aim of the study

We addressed whether 2-methoxycinnamaldehyde (2-MCA), one of active ingredients of Cinnamomum cassia, reduces vascular cell adhesion molecule-1 (VCAM-1) expression in tumor necrosis factor-alpha (TNF-α)-activated endothelial cells and protects ischemia/reperfusion (I/R)-injury due to heme oxygenase (HO)-1 induction.

Materials and methods

Adult male rats were subjected to 30 min of ischemia by occlusion of the left anterior descending coronary artery followed by 24 h of reperfusion. Rats were randomized to receive vehicle or 2-MCA (i.v.) 10 min before reperfusion.

Results

Administration of 2-MCA significantly improved I/R-induced myocardial dysfunction by increasing the values of the first derivative (±dp/dt) of left ventricular pressure and decreased infarct size. In addition, 2-MCA reduced the expression of high mobility group box 1 (HMGB1), an activator of the inflammatory cascade when released into the extracellular space, and VCAM-1 in I/R myocardium along with increase of HO-1 induction. The reduced injury was accompanied by significantly reduction of neutrophils infiltration and increased SOD activity in ischemic tissues and reduced serum level of cardiac troponin I (cTnI). Furthermore, 2-MCA significantly increased HO-1 induction by translocation of Nrf-2 from cytosol to nucleus in endothelial cells. Inhibition of VCAM-1 expression by 2-MCA was reversed both by SnPPIX, a HO-1 inhibitor and siHO-1 RNA trasfection in TNF-α-activated cells. In addition, 2-MCA significantly inhibited NF-κB luciferase activity in TNF-α-activated endothelial cells. As expected, 2-MCA significantly inhibited monocyte (U937) adhesion to endothelial cells.

Conclusion

We concluded that 2-MCA protects of myocardial I/R-injury due to antioxidant and anti-inflammatory action possibly by HO-1 induction which can be explained why Cinnamomum cassia has been used in inflammatory disorders.     

Dragon's Blood extract has antithrombotic properties, affecting platelet aggregation functions and anticoagulation activities

Ethnopharmacological relevance

Dragon's Blood from Dracaena cochinchinensis (Lour.) S.C. Chen (Yunnan, China), as a traditional Chinese medicinal herb, was shown to have certain antithrombotic effects. A new preparation process was used to extract effective components from Dragon's Blood. A 95% ethanol extract A (EA) and a precipitate B (PB) fraction were obtained and compared. Reliability of the preparation process was validated by pharmacodynamic experiments.

Materials and methods

A rat/mouse thrombosis and blood stasis model was developed for this study, and EA and PB effects on thrombosis, platelet functions and blood coagulation activities were analyzed.

Results

It was observed that the EA fraction had significantly better inhibitory effects than the PB fraction on thrombosis (p < 0.05), platelet aggregation function (p < 0.01) and anticoagulation activity (p < 0.05-0.01).

Conclusions

The results obtained here showed that EA fraction from Dragon's Blood contained pharmacologically effective compounds with antithrombotic effects, partially improving platelet function and anticoagulation activity.