Acute and sub-chronic toxicity profile of methanol leaf extract of Gouania longipetala in rats

Ethnopharmacological relevance

Gouania longipetala leaves are commonly used in folkloric medicine in Africa and other parts of the world for treatment of edema, febrifuges, veneral diseases, lumbago, heart diseases, diabetes mellitus malaria, etc. This study therefore evaluated safety profile of the methanol leaf extract of the plant using acute and sub-chronic studies in rat model.

Materials and methods

Acute toxicity test of the plant lasted for 48 h with oral administration of graded doses (100–4000 mg/kg) of Gouania longipetala extract (GLE) in rats. The rats were observed for signs of toxicity and death. The sub-chronic toxicity was evaluated by administration of different doses (2.5, 5 and 10 mg/kg) of GLE daily in feed for 90 days. On days, 30, 60 and 90, blood samples collected from the retro-orbital plexus of the eye of the rats were used for evaluation of serum biochemistry, hematology, lipid peroxidation and in vivo antioxidant activities. Histopathological evaluations of the kidney, liver, lungs and heart were also done.

Results

The acute toxicity test revealed no observable signs of toxicity or morbidity. Sub-chronic study showed that GLE significantly (p<0.05) increased relative liver weight on day 90 at 10 mg/kg. There were no significant variations in the hematological parameters of both GLE treated and untreated rats. The extract significantly (p<0.05) reduced total cholesterol, triglycerides, very low density lipoproteins and increased high density lipoproteins which was more prominent on day 90 at the dose of 10 mg/kg. The extract significantly (p<0.05) increased liver enzyme markers at the doses used. GLE also significantly (p<0.05) increased serum urea at the dose of 10 mg/kg on day 90. The extract caused dose-dependent and significant (p<0.05) increase in superoxide dismutase and decrease in malondiadehyde. Histopathological studies revealed degenerative changes in the kidney and liver.

Conclusion

The results of the study suggest that Gouania longipetala is well tolerated in short term therapies, but may have long term toxic effects on the kidney and liver.     

Effects of hydroxysafflor yellow A on the activity and mRNA expression of four CYP isozymes in rats

Ethnopharmacological relevance

In traditional therapy with Chinese medicine, hydroxysafflor yellow A (HSYA), a main active component isolated from the dried flower of Carthamus tinctorius L., is the principal efficiency ingredient of Safflor Yellow Injection. Now HSYA has been demonstrated to have good pharmacological activities of antioxidation, myocardial and cerebral protective and neuroprotective effects. The purpose of this study was to find out whether HSYA influences the effect on rat cytochrome P450 (CYP) enzymes (CYP1A2, CYP2C11, CYP2D4 and CYP3A1) by using cocktail probe drugs in vivo; the influence on the levels of CYP mRNA was also studied.

Materials and methods

A cocktail solution at a dose of 5 mL/kg, which contained phenacetin (20 mg/kg), tolbutamide (5 mg/kg), dextromethorphan (20 mg/kg) and midazolam (10 mg/kg), was given as oral administration to rats treated with short or long period of intravenous HSYA via the caudal vein. Blood samples were collected at a series of time-points and the concentrations of probe drugs in plasma were determined by HPLC–MS/MS. The corresponding pharmacokinetic parameters were calculated by the software of DAS 2.0. In addition, real-time RT-PCR was performed to determine the effect of HSYA on the mRNA expression of CYP1A2, CYP2C11, CYP2D4 and CYP3A1 in rat liver.

Results

HSYA had significant inhibition effects on CYP1A2 and CYP2C11 in rats as oriented from the pharmacokinetic profiles of the probe drugs. Furthermore, HSYA had no effects on rat CYP2D4. However, CYP3A1 enzyme activity was induced by HSYA. The mRNA expression results were in accordance with the pharmacokinetic results.

Conclusions

HSYA can either inhibit or induce activities of CYP1A2, CYP2C11 and CYP3A1. Therefore, co-administration of some CYP substrates with HSYA may need dose adjustment to avoid an undesirable herb–drug interaction.     

Effect of Bridelia ferruginea Benth (Euphorbiaceae) ethyl acetate and acetone fractions on insulin resistance in fructose drinking mice

Ethnopharmacological relevance

The root of Bridelia ferruginea is traditionally used as a treatment for type 2 diabetes. The present study was investigated to evaluate the effect of Bridelia ferruginea root bark fractions on some markers of type 2 diabetes on fructose drinking mice.

Materials and methods

Mice received a solution of fructose 15% during 42 days ad libitum; at the 15th day to the 42nd day, they received distilled water for fructose drinking control group, metformin 50 mg/kg per day or fractions 50 mg/kg per day for treatment groups. The normal control group received only distilled water during the experiment. After 6 weeks of experiment, OGTT, fasting blood glucose, plasma insulin, triglycerides (TG), total cholesterol, AST and ALT levels were measured.

Results

Fructose drinking control group (F) showed significant (p<0.001) increase of glucose tolerance, plasma levels of total cholesterol, triglycerides and insulin index for insulin resistance (Homeostasis Model Assessment ratio HOMA-IR) as compared to normal control mice. In treated groups, there was a significant reduction of glucose intolerance respectively 74% (p<0.001), 25% (p<0.5) and 92% (p<0.001) for ethyl acetate fraction, acetone fraction and metformin at the same dose of 50 mg/kg per day during 4 weeks administration. In ethyl acetate fraction and metformin treated groups, biochemical parameters and insulin index were significantly (p<0.001) lower than that of fructose drinking control group.

Conclusions

This indicates that Bridelia ferruginea root bark ethyl acetate fraction improved insulin resistance as metformin significantly in type 2 diabetes.     

Biochemical and hematological effects of acute and sub-acute administration to ethyl acetate fraction from the stem bark Scutia buxifolia Reissek in mice

Ethnopharmacological relevance

Scutia buxifolia is a native tree of Southern Brazil, Uruguay, and Argentina, which is popularly known as “coronilha” and it is used as a cardiotonic, antihypertensive and diuretic substance. The aim of this study was to assess the acute and sub-acute toxicity of the ethyl acetate fraction from the stem bark Scutia buxifolia in male and female mice.

Materials and methods

The toxicity studies were based on the guidelines of the Organization for Economic Cooperation and Development (OECD-guidelines 423 and 407). In an acute study, a single dose of 2000 mg/kg of Scutia buxifolia was administered orally to male and female mice. Mortality, behavioral changes, and biochemical and hematological parameters were evaluated. In the sub-acute study, Scutia buxifolia was administered orally to male and female mice at doses of 100, 200, and 400 mg/kg/day for 28 days. Behavioral changes and biochemical, hematological, and histological analysis were evaluated.

Results

The acute administration of Scutia buxifolia did not cause changes in behavior or mortality. Male and female mice presented decreased levels of platelets. Female mice presented decreased levels of leukocytes. On the other hand, in a sub-acute toxicity study, we observed no behavioral changes in male or female mice. Our results demonstrated a reduction in glucose levels in male mice treated to 200 and 400 mg/kg of Scutia buxifolia. Aspartate aminotransferase (ASAT) activity was increased by Scutia buxifolia at 400 mg/kg in male mice. In relation to the hematological parameters, male mice presented a reduction in hemoglobin (HGB) and hematocrit (HCT) when treated to 400 mg/kg of plant fraction. Female mice showed no change in these parameters. Histopathological examination of liver tissue showed slight abnormalities that were consistent with the biochemical variations observed.

Conclusion

Scutia buxifolia, after acute administration, may be classified as safe (category 5), according to the OECD guide. However, the alterations observed, after sub-acute administration with high doses of ethyl acetate fraction from the stem bark Scutia buxifolia, suggest that repeated administration of this fraction plant can cause adverse hepatic, renal, and hematological effects.     

Effect of sulfated polysaccharides from Laminaria japonica on vascular endothelial cells in psychological stress rats

Ethnopharmacological relevance

Laminaria japonica is a popular seafood and medicinal plant in China. Laminaria japonica is used in traditional Chinese medicine to treat and prevent hypertension and edema.

Materials and methods

The vascular protective activity and mechanism of sulfated polysaccharides were studied in adrenalin-induced vascular endothelial damage in rats after psychological stress (PS). Vehicle (sham and PS groups), sulfated polysaccharide from Laminaria japonica (LP; 1 mg/kg and 5 mg/kg) and enoxaparin sodium (1 IU/kg, reference drug) were all administered for 10 days. Behavioral changes were recorded. Plasma levels of adrenalin, cortisol, monoamine oxidase (MAO), semicarbazide-sensitive amine oxidase (SSAO), formaldehyde, H₂O₂, nitric oxide (NO), endothelin-1 (ET-1), 6-keto-prostaglandin F_1a (6-keto-PGF_1a), and thromboxane B₂ (TXB₂) were measured. Endothelium-dependent relaxation of the thoracic aorta was measured and transmission electron microscopy of aortic vessels was performed.

Results

Adrenalin metabolites in plasma were significantly lower (P<0.01) in rats after LP administration compared with those in the PS groups. The normalized ratios of plasma NO/ET-1 and 6-keto-PGF_1a/TXB₂ were maintained and endothelium-dependent relaxation of the aorta was greatly enhanced after LP treatment (P<0.05). Morphological alterations were observed in vascular endothelial cells (VECs) in PS rats, with a higher number of lysosomes and vague mitochondrial cristae compared with those in the sham group. However, these histopathological changes were markedly alleviated after LP treatment.

Conclusions

This study shows a protective effect of LP on VECs in PS rats. LP can regulate plasma levels of NO, ET-1, and 6-keto-PGF_1a, enhance endothelium-dependent relaxation, and alleviate histopathological changes of lysosomes and mitochondria in VECs. The potential mechanism of LP on VECs in PS rats is related to its function of reducing metabolites of adrenalin.     

Lepidium meyenii (Maca) enhances the serum levels of luteinising hormone in female rats

Ethnopharmacological relevance

Lepidium meyenii (Maca) is traditionally employed in the Andean region for its supposed fertility benefits. This study investigated the effect of Maca on the serum pituitary hormone levels during the pro-oestrus phase.

Materials and methods

Maca powder was made from the tubers of Lepidium meyenii Walp collected, dried, and reduced to powder at the plantation in Junín Plateau and was purchased from Yamano del Perú SAC. The Maca powder was identified by chemical profiling and taxonomic methods. Two groups of female Sprague-Dawley rats were provided feed with normal feed containing 5%, 25%, or 50% Maca powder ad libitum for 7 weeks. At 1800 h of the proestrus stage, the rats were euthanised, and blood samples were collected for serum isolation. The serum pituitary hormone levels were measured using enzyme-linked immunosorbent assays (ELISAs).

Results

No significant differences in feed intake or growth rate were observed among the rats. During the pro-oestrus stage, a 4.5-fold increase (P<0.01) in luteinising hormone (LH) and a 19-fold increase (P<0.01) in follicle-stimulating hormone (FSH) were observed in the sera of rats fed with 50% Maca powder compared with the control rats. No significant differences were observed in the levels of the other pituitary hormones, including growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and thyroid-stimulating hormone (TSH). A dose-dependent increase of LH serum levels was observed within the range of 3–30 g Maca/kg. Furthermore, the enhancement of the LH serum levels was specific to the pro-oestrus LH surge.

Conclusions

The present study demonstrates that Maca uniquely enhances the LH serum levels of pituitary hormones in female rats during the pro-oestrus LH surge and acts in a pharmacological, dose-dependent manner. These findings support the traditional use of Maca to enhance fertility and suggest a potential molecular mechanism responsible for its effects.     

Essential oil of Perilla frutescens-induced change in hippocampal expression of brain-derived neurotrophic factor in chronic unpredictable mild stress in mice

Ethnopharmacological relevance

Perilla frutescens (Perilla leaf), a traditional Chinese medicinal herb, has been used for centuries to treat various conditions including depression. A previous study of the authors demonstrated that essential oil of Perilla frutescens (EOPF) attenuated the depressive-like behavior in mice.

Aim of the study

This study was undertaken to explore the dynamic change of behaviors and brain-derived neurotrophic factor (BDNF) expression induced by chronic unpredictable mild stress (CUMS), and improved by EOPF.

Materials and methods

Four separate CUMS experimental groups (1-week, 2-week, 3-week and 4-week treatment) were treated with EOPF (3 mg/kg and 6 mg/kg, p.o.) or fluoxetine (20 mg/kg, p.o.), followed by sucrose preference, locomotor activity, immobility and hippocampal BDNF measurement.

Results

EOPF, as well as fluoxetine, restored the CUMS-induced decreased sucrose preference and increased immobility time, without affecting body weight gain and locomotor activity. Furthermore, CUMS (3 or 4-week) produced a reduction in both BDNF mRNA and protein expression in the hippocampus, which were ameliorated by EOPF (4-week) and fluoxetine (3 or 4-week) treatment.

Conclusion

These results presented here show that BDNF is expressed depending on length of CUMS procedure and EOPF administration. And this study might contribute to the underlying reason for the slow onset of antidepressant activity in clinic.     

Simulated gastrointestinal tract metabolism and pharmacological activities of water extract of Scutellaria baicalensis roots

Ethnopharmacological relevance

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Scutellaria baicalensis

Georgi (Labiatae) is a well-known traditional Chinese medicine to treat inflammation, cardiovascular diseases, respiratory and gastrointestinal infections, etc. The present study was to understand the metabolism of the root of Scutellaria baicalensis (a.k.a. Huangqin in Chinese) in the gastrointestinal tract and the correlation between the metabolites and their respective pharmacological activities.

Materials and methods

The water extract of the root of Scutellaria baicalensis (WESB) was incubated with simulated gastric and intestinal juices, and human fecal microflora for 24 h at 37 °C. The HPLC–DAD analysis was used to monitor the in vitro metabolic process and identify its metabolites by comparing their absorption spectrum and retention time with those of chemical references. The in vitro anticomplementary and antimicrobial activity was evaluated with hemolysis assay, agar disc-diffusion method and MIC value, respectively.

Results

Main constituents of WESB remain unchanged during the incubation with simulated gastric juice (pH=1.5) and intestinal juice (pH=6.8), whereas four flavones, baicalin, wogonoside, oroxyloside and norwogonoside were metabolized into their respective aglycons by human intestinal bacteria. All four metabolites were demonstrated to have higher anticomplementary and antimicrobial activity than those of WESB. The anticomplementary active metabolites were identified to be baicalein, oroxylin A and norwogonin, among them, norwogonin is the most active compound.

Conclusion

The presence of intestinal bacteria is demonstrated to play an important role in the gastrointestinal metabolism of WESB, and the pharmacological effects of Scutellaria baicalensis may be dependent on the intestinal bacteria metabolism.     

Huangqi−Honghua combination and its main components ameliorate cerebral infarction with Qi deficiency and blood stasis syndrome by antioxidant action in rats

Ethnopharmacological relevance

Combination of Radix Astragali (Huangqi) and Carthamus tinctorius L. (Honghua) has been extensively used as traditional herb medicine in China for the treatment of stroke and myocardial ischemia diseases with Qi deficiency and blood stasis (QDBS) syndrome.

Aim

To investigate the effect of Huangqi−Honghua combination (HH) and its main components astragaloside IV (AS-IV) and Hydroxysafflor yellow A (HSYA) on cerebral ischemia-reperfusion (IR) with QDBS in rat model.

Materials and methods

Male rats were randomly divided into the following six groups: sham group, QDBS+I/R model group and treatment group including AS-IV, HSYA, AS-IV+HSYA and HH. The whole blood viscosity (WBV), plasma viscosity (PV), neurological examination, infarct volume, histopathology changes and some oxidative stress markers were assessed after 24 h of reperfusion.

Results

HH and its main components AS-IV+HSYA could significantly decrease WBV, PV, and also significantly ameliorate neurological examination and infarct volume after 24 h of reperfusion. They also significantly increased expression of Nuclear factor erythroid 2-related factor 2 (Nrf2), activities of antioxidants, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px), led to decrease levels of malondialdehyde (MDA) and reactive oxygen species (ROS).

Conclusion

AS-IV and HSYA are responsible for the main curative effects of HH. The study may provide scientific information to further understanding the mechanism(s) of HH and its main components in removing blood stasis and ameliorating cerebral infarction. Additionally, AS-IV and HSYA appear to have synergistic effects on neuroprotection.     

Plasma pharmacokinetics and lung distribution of tetrahydropalmatine after topical application of cold asthma recipe extract: Feishu (BL 13) versus Non-Feishu acupoint

Ethnopharmacological relevance

Acupoint application of cold asthma recipe (CAR) was a traditional Chinese medicine (TCM) method, widely used as an alternative medicine for clinical prevention of the common winter diseases of asthma and bronchitis. Tetrahydropalmatine (THP) was a main active ingredient of CAR extract. The aim of this study is to compare plasma pharmacokinetics and lung distribution of THP between Feishu (FS) acupoint (BL 13) and Non-Feishu (NFS) acupoint application of CAR extract by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Materials and methods

The extract of CAR was topically administrated in FS and NFS acupoint of rats for plasma pharmacokinetics, and topically administrated in FS and NFS acupoint of mice for lung distribution. The plasma and lung homogenates were pretreated by protein precipitation with acetonitrile. Chromatographic separation was performed on an ACQUITY UPLC BEH C18 column with a mobile phase consisted of 0.1% formic acid in acetonitrile and 0.1% formic acid in water. The detection was accomplished by multiple-reaction monitoring (MRM) scanning in the positive electrospray ionization (ESI⁺) mode. All pharmacokinetic parameters were estimated by non-compartmental analysis.

Results

A sensitive, accurate and precise UPLC-MS/MS method was successfully established for determination of THP in 100 μL plasma and lung homogenate. The lower limit of quantification (LLOQ) of THP was 0.05 ng/mL and 0.072 ng/mL, respectively. The pharmacokinetic results manifested that THP was absorbed and eliminated slowly in plasma. Additionally, it was found that there was significantly higher amount of THP absorbed into blood and lung after FS acupoint application compared to NFS acupoint application.

Conclusions

Both of the rat plasma pharmacokinetics and mice lung distribution of THP could support that FS acupoint application of CAR extract has greater advantages of absorption into the blood circulation and distribution in target tissue over NFS acupoint application. The results might be helpful in providing a rational explanation for why the TCM chose the acupoint application and elucidating the underlying mechanism of this treatment.     

The pharmacology of medieval sedatives: The “Great Rest” of the Antidotarium Nicolai

Ethnopharmacological relevance

Past practices of compound drugs from different plant ingredients enjoyed remarkable longevity over centuries yet are largely dismissed by modern science as subtherapeutic, lethal or fanciful.

Aim of the study

To examine the phytochemical content of a popular medieval opiate drug called the “Great Rest” and gauge the bioavailability and combined effects of its alkaloid compounds (morphine, codeine, hyoscyamine, scopolamine) on the human body according to modern pharmacokinetic and pharmacodynamic parameters established for these compounds.

Calculations and theory

We reviewed the most recent studies on the pharmacodynamics of morphine, codeine, hyoscyamine and scopolamine to ascertain plasma concentrations required for different physiological effects and applied these findings to dosage of the Great Rest.

Results

Given the proportional quantities of the alkaloid rich plants, we calculate the optimal dose of Great Rest to be 3.1±0.1–5.3±0.76 g and reveal that the lethal dose of Great Rest is double the therapeutic concentration where all three alkaloid compounds are biologically active.

Conclusion

This study helps establish the effective dose (ED₅₀), toxic dose (TD₅₀) and lethal dose (LD₅₀) rates for the ingestion of raw opium, henbane and mandrake, and describes their probable combined effects, which may be applied to similar types of pre-modern pharmaceuticals to reveal the empirical logic behind past practices.     

Ethanol extracts from Hemerocallis citrina attenuate the decreases of brain-derived neurotrophic factor,TrkB levels in rat induced by corticosterone administration

Ethnopharmacological relevance

Hemerocallis citrina, a traditional herbal medicine, has been used for the improvement of behavioral and emotional status in Eastern-Asia countries.

Aim of the study

Our previous studies have demonstrated that the ethanol extracts of H. citrina flowers (HCE) reversed the behavioral alterations and monoamine neurotransmitter dysfunctions in stressed mice. However, the relation of its antidepressant-like action with neurotrophic molecular expressions remains unknown.

Materials and methods

To clarify this, we explored the effect of HCE (32.5, 65, 130 mg/kg, p.o.) on the behavior, brain-derived neurotrophic factor (BDNF) and its receptor (TrkB) in depression-like rats induced by exogenous administration of the stress hormone corticosterone (40 mg/kg, s.c.).

Results

It was observed that repeated administration of corticosterone induced an elevation on the serum corticosterone levels, which caused the abnormalities observed in the sucrose preference test and forced swimming test (FST). Administration of HCE (65 and 130 mg/kg) reversed the changes above and up-regulated the BDNF and TrkB receptor protein expressions in the brain region of frontal cortex and hippocampus.

Conclusion

These findings confirm that HCE produce an antidepressant-like effect in corticosterone-induced depression-like model of rats and this effect is at least partly mediated by BDNF-TrkB signaling in the frontal cortex and hippocampus.     

Evaluation of anti-inflammatory activity of hydroethanolic extract of Dilodendron bipinnatum Radlk

Ethnopharmacological relevance

Dilodendron bipinnatum Radlk. (Sapindaceae), popularly known as “mulher-pobre”, is a native tree of the Pantanal of Mato Grosso, Brazil. The stem bark of Dilodendron bipinnatum is used by the population, in the forms of decoction and maceration in the treatment of inflammatory conditions. There is no information in the literature demonstrating the anti-inflammatory activity of Dilodendron bipinnatum and its respective mechanism of action. This study aimed to evaluate the anti-inflammatory activity and mechanism of action of the hydroethanolic extract of the stem bark of Dilodendron bipinnatum (HEDb) using in vivo and in vitro experimental models.

Materials and methods

The stem bark of Dilodendron bipinnatum was macerated in 70% hydroethanolic solution (1:3, w/v) for 7 days, filtered, concentrated on a rotary evaporator and the residual solvent removed in oven at 40 °C, thus obtaining HEDb. Cytotoxicity of HEDb in RAW 264.7 was assessed by the Alamar blue assay. in vivo anti-inflammatory activity of HEDb was evaluated with carrageenan and dextran-induced paw edemas and lipopolysaccharide (LPS)-induced peritonitis in mice. Effects of HEDb on the inflammatory cytokines (TNF-α, IL-1β and IL-10) concentrations in the peritoneal fluid were evaluated using commercial ELISA kits. The in vitro anti-inflammatory activity was evaluated using RAW 264.7 cells stimulated with LPS and/or INF-γ, while a Griess method was employed to determine nitric oxide (NO) concentrations in the peritoneal lavage and in the supernatants of RAW 264.7 cells. Preliminary phytochemical analysis was carried out using classical methods and secondary metabolites detected on HEDb were analyzed and confirmed by high performance liquid chromatography (HPLC).

Results

HEDb showed very low cytotoxicity with IC₅₀>200±0.38 μg/mL. HEDb effectively inhibited paw edema by carrageenan in the 2nd hour at 20 mg/kg (36%, p<0.001), and by dextran in the 1st hour at 100 mg/kg (46%, p<0.01), after induction with the phlogistic agents. Furthermore, HEDb reduced total leukocytes and neutrophils migration at all doses tested producing maximum effect at 20 mg/kg (45% and 64%, p<0.001 respectively). HEDb also attenuated increases in the concentrations of the pro-inflammatory cytokines (IL-1β and TNF-α) and increased the level of the anti-inflammatory cytokine IL-10 in the peritonitis model. However, it had no effect on NO production in activated RAW 264.7 cells. Preliminary phytochemical analysis revealed the presence of phenolic compounds, chalcones, flavones, flavonones, flavonoids, saponins and coumarins. HPLC analyses identified some tannins, with epigallocatechin gallate being the major compound.

Conclusions

Our findings provide evidence for the popular use of the stem bark of Dilodendrum bipinnatum in inflammation. Its anti-inflammatory action was due, at least in part, to the inhibition of cell migration, of the inflammatory mediators and Th1 cytokines and an increase in Th2 cytokines, without affecting NO pathway. It can be suggested that tannins account at least in part for the anti-inflammatory activity of HEDb.     

Pharmacokinetic comparisons of five ephedrine alkaloids following oral administration of four different Mahuang–Guizhi herb-pair aqueous extracts ratios in rats

Ethnopharmacological relevance

Herba Ephedra (Mahuang in Chinese), is derived from dried Ephedra sinica Stapf stems and has been widely used to treat the common cold, coughs, asthma, and edema for thousands of years. The Mahuang–Guizhi herb-pair is a famous formula composed of Mahuang and Ramulus Cinnamomi (Guizhi in Chinese, the dried twig of Cinnamomum cassia Presl.), used to improve pharmacological effects and reduce toxicity. In order to investigate the influence of Mahuang–Guizhi herb-pair ratios on bioavailability, the plasma pharmacokinetics profiles of five ephedrine alkaloids were compared following oral administration of four different ratios to rats.

Materials and methods

Sprague-Dawley rats were randomly assigned to four groups and orally administered Mahuang–Guizhi (ratios 3:0; 3:1; 3:2; 3:4, w/w). Assays for five ephedrine alkaloids (ephedrine, pseudoephedrine, methylephedrine, norephedrine, and norpseudoephedrine) were developed and validated using ultra-high-performance liquid chromatography tandem mass spectrometry coupled with liquid-liquid extraction.

Results

Key pharmacokinetic parameters of the five ephedrine alkaloids (maximal plasma concentration, mean residence time, and half-life) were significantly different (p<0.05) after oral administration of Mahuang–Guizhi herb-pair ratios, as compared to those of Mahuang.

Conclusion

Ephedrine alkaloid pharmacokinetic differences in rat plasma could help explain previous findings of pharmacological and toxicity differences between Mahuang and Mahuang–Guizhi herb-pair preparations. These results could facilitate future studies to increase the efficacy and decrease the toxicity of Mahuang and Guizhi.     

Arnebin-1 promotes the angiogenesis of human umbilical vein endothelial cells and accelerates the wound healing process in diabetic rats

Ethnopharmacological relevance

Zicao is a traditional wound healing herbal medicine that has been used for several hundred years in China. A survey of the published literatures revealed that arnebin-1, one of the naphthoquinone derivatives, played the most important role in wound healing property of this plant. However, whether arnebin-1 affects angiogenesis in vitro and has an effect on wound healing process in diabetic rats remains enigmatic. To investigate the effect of arnebin-1 with or without VEGF on proliferation, migration and tube formation of HUVECs in vitro and the effect of its topical application in the form of ointment on wound healing in a cutaneous punch wound model of alloxan-induced diabetic rats in vivo.

Materials and methods

The pro-angiogenic functions of arnebin-1 on HUVECs including proliferation, migration and angiogenesis were evaluated through MTT assay, wound healing assay, transwell assay and tube formation assay in vitro. Male Sprague-Dawley rats were injected intraperitoneally with alloxan to induce type ? diabetic rats. Three wounds were created in each rat on the dorsal surface, and then divided to be basement treated, arnebin-1 ointment treated and untreated group correspondingly. The indicators including wound closure rate and histological evaluation were investigated on day 4 and 7 post-wounding.

Results

Without VEGF, arnebin-1 did not affect the proliferation of HUVECs significantly, but had a positive effect on cell migration and tube formation. However, in the presence of minimal VEGF, Arnebin-1 could increase the proliferation, enhance the migration and promote the tube formation of HUVECs significantly. The wound closure rate was increased significantly in arnebin-1 treated group compared to that of untreated and basement treated groups in diabetic rats, and the histological evaluation also showed well organized dermal layer, reduced number of macrophages, increased number of fibroblasts, remarkable degree of neovascularization and epithelization in arnebin-1 treated group.

Conclusion

These findings suggest that arnebin-1 has a pro-angiogenic effect, and a synergetic effect with VEGF promotes the wound healing process in diabetic rats.     

Bioactive compounds from Cornus officinalis fruits and their effects on diabetic nephropathy

Ethnoparmacological relevance

The fruit of Cornus officinalis, called “Shanzhuyu”, a traditional medicine in China, is used for the treatment of kidney diseases, including diabetic nephropathy. The aim of this study is to investigate the anti-diabetic nephropathy activity of Shanzhuyu and the active compounds in the fruit.

Materials and methods

The air dried fruit of Cornus officinalis was extracted in 80% EtOH, the obtained residue was fractioned on D101 resin column eluted with H₂O/EtOH solution to get five crude fractions (fr. A–E). The anti-diabetic nephropathy activity of fractions (fr. A–E) was evaluated in vitro by inhibiting the expression of collagen IV (Col V), fibronectin (FN) and IL-6 in high-glucose-induced mesangial cells. By preliminary bio-assay screenings, repeated column chromatography on fraction B–D led the isolation of 22 compounds, whose structures were determined by extensive spectroscopic analysis, and the anti-diabetic nephropathy activity of the isolated compounds was also evaluated.

Results

Two new iridoid glucosides, logmalicids A and B (1 and 2), together with 20 known compounds (3–22) were isolated from the extract of Shanzhuyu under the bioassay-guided screenings. The anti-diabetic nephropathy activity assay displayed that fractions A, D and E could significantly inhibit the production of Col IV; fractions A and C could significantly inhibit the expression of FN and IL-6 in the high-glucose-stimulated mesangial cells at concentration of 50 μg/mL; and loganin (3) and its derivatives (1 and 2) could significantly inhibit the expression of FN and IL-6 at concentration of 10 μM, respectively.

Conclusions

The results suggested that loganin and its derivatives were the active compounds in Cornus officinalis fruit (Shanzhuyu) on diabetic nephropathy. This study further supported the traditional use of Shanzhuyu to treat diabetic nephropathy and related kidney diseases.     

Protective effects of bajijiasu in a rat model of Aβ25-35-induced neurotoxicity

Ethnopharmacological relevence

Neurodegenerative diseases (NDs) caused by neurons and/or myelin loss lead to devastating effects on patients? lives. Although the causes of such complex diseases have not yet been fully elucidated, oxidative stress, mitochondrial and energy metabolism dysfunction, excitotoxicity, inflammation, and apoptosis have been recognized as influential factors. Current therapies that were designed to address only a single target are unable to mitigate or prevent disease progression, and disease-modifying drugs are desperately needed, and Chinese herbs will be a good choice for screening the potential drugs. Previous studies have shown that bajijiasu, a dimeric fructose isolated from Morinda officinalis radix which was used frequently as a tonifying and replenishing natural herb medicine in traditional Chinese medicine clinic practice, can prevent ischemia-induced neuronal damage or death.

Materials and methods

In order to investigate whether bajijiasu protects against beta-amyloid (Aβ_25-35)-induced neurotoxicity in rats and explore the underlying mechanisms of bajijiasu in vivo, we prepared an Alzheimer?s disease (AD) model by injecting Aβ_25-35 into the bilateral CA1 region of rat hippocampus and treated a subset with oral bajijiasu. We observed the effects on learning and memory, antioxidant levels, energy metabolism, neurotransmitter levels, and neuronal apoptosis.

Results

Bajijiasu ameliorated Aβ-induced learning and memory dysfunction, enhanced antioxidative activity and energy metabolism, and attenuated cholinergic system damage. Our findings suggest that bajijiasu can enhance antioxidant capacity and prevent free radical damage. It can also enhance energy metabolism and monoamine neurotransmitter levels and inhibit neuronal apoptosis.

Conclusion

The results provide a scientific foundation for the use of Morinda officinalis and its constituents in the treatment of various AD. Future studies will assess the multi-target activity of the drug for the treatment of AD.     

Antinociceptive and anti-inflammatory activities of extract and two isolated flavonoids of Carthamus tinctorius L

Ethnopharmacological relevance

Safflower (Carthamus tinctorius L.) has been long used both in the traditional system and folk medicine as an analgesic anti-inflammatory agent in China. The aim of the study was to evaluate the antinociceptive and anti-inflammatory activities of hydroalcoholic extract (HE) and two isolated kaempferol glycosides of Carthamus tinctorius L. to provide experimental evidence for its traditional use.

Materials and methods

Antinociceptive effects of HE, kaempferol 3-O-rutinoside (K-3-R) and kaempferol 3-O-glucoside (K-3-G) were assessed in mice using the acetic acid-induced writhing test, formalin test and cinnamaldehyde test. The anti-inflammatory effects of HE, K-3-R and K-3-G were determined in two animal models: carrageenan-induced paw edema and xylene-induced ear edema.

Results

The HPLC analysis showed the presence of K-3-R and K-3-G in Carthamus tinctorius L. HE (500 and 1000 mg/kg) as well as K-3-R and K-3-G (150, 300 and 600 mg/kg) produced significant inhibition on nociception induced by acetic acid and formalin. Oral treatment of HE, K-3-R and K-3-G at all doses significantly reduced both the nociceptive response and cinnamaldehyde-induced paw edema, effect that was superior to aspirin. In anti-inflammatory tests, HE and K-3-G significantly inhibited the paw edema during the both phases of carrageenan-induced inflammation while K-3-G suppressed the late phase inflammation only. HE (400 and 800 mg/kg) and K-3-G (200, 400, 800 mg/kg) produced significant dose-dependent inhibition of xylene-induced ear edema development. K-3-R only suppressed ear edema formation at a high dose (800 mg/kg).

Conclusions

These results demonstrate that Carthamus tinctorius L. extract possess remarkable antinociceptive and anti-inflammatory activities which may be due to K-3-R and K-3-G at least in part, supporting the folkloric usage of the plant to treat various inflammatory and pain diseases.