Oral bioavailability and gender-related pharmacokinetics of celastrol following administration of pure celastrol and its related tablets in rats

Ethnopharmacological relevance

Celastrol is a natural compound extracted from the traditional Chinese medicinal herb, Thunder God Vine (TGV). Owing to its potential anti-inflammatory and antitumor effects, celastrol has been considered as a promising candidate for drug development.

Aim of the study

To establish a sensitive LC–MS/MS method to investigate the pharmacokinetic properties of celastrol in rats. Key pharmacokinetic issues of celastrol including oral bioavailability, comparative pharmacokinetics between pure compound and tablet preparation, as well as gender-related pharmacokinetic difference are to be addressed for the first time.

Materials and methods

Sprague–Dawley rats were administrated an intravenous dose (100 μg kg⁻¹) of pure celastrol and an oral dose (1000 μg kg⁻¹) of pure celastrol and TGV tablets (corresponding to 534 μg kg⁻¹ of celastrol), respectively. At different time points, the concentration of celastrol in rat plasma was determined by a sensitive and well-validated LC–MS/MS method. Main pharmacokinetic parameters including area under the plasma concentration–time curve (AUC), maximal plasma concentration (Cmax), the time for maximal concentration (Tmax) and mean residence time (MRT) were estimated by Drug and Statistic1.0 pharmacokinetic software (Chinese Pharmacological Association, Anhui, PR China). Statistical analysis was performed using two one-side t test with p-values less than 0.05 as the level of significance.

Results

The standard curve of celastrol showed good linearity in the concentration range of 0.11∼54.3 ng mL⁻¹ in our current method, with acceptable selectivity, precision, recovery, and stability. The oral absolute bioavailability of celastrol significantly increased from 17.06% for pure celastrol to 94.19% for TGV tablets containing equivalent celastrol. After oral administration of TGV tablets, the Cmax and AUC values of celastrol in female rats were (32.03±8.41) μg L⁻¹ and (379.49±118.19) μg h L⁻¹, which were significantly higher (p<0.01) than that in males with the values of (14.31±7.33) μg L⁻¹ and (188.17±92.33) μg h L⁻¹.

Conclusion

Celastrol administered orally in the rat was poorly absorbed into the systemic circulation. However, the poor absorption of celastrol could be greatly improved when celastrol-containing TGV tablets orally administered, and thereby the oral bioavailability of celastrol was significantly increased. As for gender difference, female rats showed significantly better absorption of celastrol than males.     

Augmentation of expression of immunocytes’ functions by seed extract of Ziziphus mauritiana (Lamk.)

Aim of the study

The present study was carried out to evaluate the immunomodulatory potential of Ziziphus mauritiana (Lamk.) seed extract to ascertain the folkloric claim as immunomodulator.

Materials and methods

The aqueous-ethanolic seed extract (100–400 mg kg⁻¹) of Z. mauritiana was investigated for immunomodulatory potential in mice. The extract was standardized with HPLC using betulinic acid as a marker. Functions of various immunocytes in the form of humoral (development of anti-SRBC (sheep red blood cells) antibody titers) and cell-mediated immune response (delayed type hypersensitivity, nitroblue tetrazolium reduction, inducible nitric oxide synthase activity and bactericidal activity) was studied in SRBC immunized mice. The cytokine, IFN-γ (interferon-gamma) and IL-4 (interleukin-4) secretion was also measured quantitatively by ELISA as the expression of functions of Th-1 and Th-2 respectively. Levamisole (2.5 mg kg⁻¹) was used as standard drug.

Results

The seed extract demonstrated significant (P < 0.05–0.001) up-regulation of cell-mediated, humoral immune response and Th-1 mediated cytokine IFN-γ and decline in Th-2 mediated cytokine IL-4. At higher dose of extract the results were comparable to that of the levamisole.

Conclusion

The immunostimulatory potential of this seed extract is likely to be mediated through its effect on macrophage function and Th-1 mediated immunity confirming the folkloric use of this plant.     

Aqueous ethanol extract of the fruit of Xylopia aethiopica (Annonaceae) exhibits anti-anaphylactic and anti-inflammatory actions in mice

Ethnopharmacological relevance

Xylopia aethiopica has been traditionally used in the form of the dried fruit decoction to treat bronchitis, asthma, arthritis and rheumatism in Ghana, Nigeria and Cameroon. Aim of the study is to evaluate the anti-anaphylactic and anti-inflammatory effects of a 70% aqueous ethanol extract of the fruits of Xylopia aethiopica.

Materials and methods

Systemic anaphylaxis was induced by the injection of either compound 48/80 or lipopolysaccharide, LPS and survival rates of mice monitored for 1 h or 7 days respectively while IgE-mediated anaphylaxis in a local allergic reaction was studied in the pinnal inflammation model in mice. Clonidine-induced catalepsy in mice was used to evaluate the indirect antihistamine effect of Xylopia aethiopica, XAE. The effects of XAE assessed on the maximal and total oedema responses in the carrageenan-induced paw oedema in mice was used to evaluate the anti-inflammatory action of the extract.

Results

Administered at 30, 100, 300 and 1000 mg kg⁻¹ p.o., XAE dose dependently suppressed compound 48/80-induced mouse systemic anaphylactic shock and offered 63% protection to mice against LPS-induced endotoxic shock at a dose of 300 mg kg⁻¹. In addition, the extract (30–300 mg kg⁻¹) in a dose dependent manner significantly inhibited by 23–62% the mouse pinnal inflammation. Clonidine-induced catalepsy in mice was significantly suppressed in a dose and time dependent manner when administered both prophylactically and therapeutically. In the same doses, when administered before the induction of the mouse carrageenan-induced paw oedema, the mean maximal swelling attained during 6 h was reduced to 41.02±6.94%, 35.61±4.30%, and 29.09±4.90% of the inflamed control response respectively and total paw swellings induced over the 6 h were also dose-dependently and significantly suppressed to 74.84±14.84%, 63.95±9.37%, and 48.13±10.90% of the inflamed control response respectively. Administered after the induction of the carrageenan paw oedema the mean maximal swelling attained during 6 h was suppressed to 49.84±3.95%, 43.62±1.01%, and 35.97±1.34% of the inflamed control response respectively while the total paw swellings induced over the 6 h were also dose-dependently and significantly suppressed at 100 and 300 mg kg⁻¹ to 72.39±4.38% and 60.81±3.25% of the inflamed control response respectively.

Conclusion

These findings suggest that XAE inhibits mast cell-dependent immediate allergic reactions and exhibit anti-inflammatory actions through the inhibition of histamine release from mast cells via stabilizing the cell membrane. Our results contribute towards validation of the traditional use of Xylopia aethiopica in the treatment of bronchitis, asthma, arthritis and rheumatism.     

The hepatoprotective effect and chemical constituents of total iridoids and xanthones extracted from Swertia mussotii Franch

Ethnopharmacological relevance

Total iridoids and xanthones (TIXS) were extracted from Swertia mussotii Franch, one of the most important eight Tibetan medicines in China, which was recorded in the book of Jingzhu Bencao and used for clinical treatment of cholestatic hepatitis for many years. Our aim was to study the hepatoprotective effect and chemical constituents of the TIXS.

Materials and methods

Crude extracts were prepared using 90% ethanol, and individual fractions were collected following HPD-300 macroporous resin column chromatography. HPLC/MS was applied to qualitatively and quantitatively analyze the TIXS. Then, the alpha-naphthylisot hiocyanate-induced liver damage model was used to assess the hepatoprotective effect of the TIXS.

Results

A total of 12 compounds were identified by the fingerprint chromatography of the TIXS, and swertiamarin and swertianolin were shown to be its two main components. Oral administration of the TIXS at a dose of 35, 70 or 140 mg kg⁻¹, swertiamarin at a dose of 20 mg kg⁻¹ or swertianolin at a dose of 20 mg kg⁻¹, for 7 days in mice significantly reduced the alpha-naphthylisot hiocyanate-induced levels of alanine aminotransferase, aspartate aminotransferase and the total and direct bilirubins, and increased the bile flow (P<0.01).

Conclusion

These findings suggest that the TIXS exhibits significant hepatoprotective effect in the liver damage model induced by alpha-naphthylisot hiocyanate. Its active constituents include swertiamarin and swertianolin.     

Leucas cephalotes regulates carbohydrate and lipid metabolism and improves antioxidant status in IDDM and NIDDM rats

Ethnopharmacological relevance

Leucas cephalotes (Roth.) Spreng. (Laminaceae) is an ayurvedic traditional medicinal plant used in India, Nepal and Pakistan to treat several ailments including diabetes.

Aim of the study

The aim of the present study is to investigate the antidiabetic, antihyperlipaemic and antioxidant activities of Leucas cephalotes for its purported use in diabetes.

Materials and methods

The ethanol extract of leaves of Leucas cephalotes was administered (150, 300 and 450 mg kg⁻¹ bw) to diabetes induced (IDDM and NIDDM) rats and carbohydrate, lipid, antioxidant, urea and creatinine profiles were assessed.

Results

All the three doses of extract decreased plasma glucose and lipid profiles and, improved the antioxidant status of both types of diabetic rats. The extract administration improved hepatic glycogen content and hexokinase activity, decreased glucose-6-phosphatase activity, blood urea, creatinine contents and decreased lipid peroxidation in diabetic rats. Of the three doses used, 450 mg kg⁻¹ bw dose was found to be more potent in its effects comparable to those of glibenclamide and metformin.

Conclusion

Leucas cephalotes regulates both carbohydrate and lipid metabolism and, improves body antioxidant defense systems in both types of diabetes.     

Appraisal of scopolamine-induced antiamnesic effect in mice and in vitro antiacetylcholinesterase and antioxidant activities of some traditionally used Lamiaceae plants

Ethnopharmacological relevance

Salvia species and Melissa officinalis are used for their memory-enhancing effects in European folk medicine. Teucrium polium was reported to be used in Anatolia for memory-enhancement in a very old book written by an Ottoman herbalist–physician.

Aim of the study

Alzheimer's disease (AD) is a progressive neurological disorder mostly affecting the elder population. Currently, there is no cure for the treatment of severe type of AD. Therefore, in this study, the hydroalcoholic extracts of three traditionally used Lamiaceae species for memory-enhancement; Salvia triloba L., Melissa officinalis L., and Teucrium polium L., were assessed for their in vivo antiamnesic activity along with in vitro anticholinesterase and antioxidant activities.

Materials and methods

Scopolamine-induced antiamnesic activity was determined in mice by passive avoidance test, while anticholinesterase effect was measured by spectrophotometric Ellman method at 0.25, 0.50, 1.0, and 2.0 mg ml⁻¹ and antioxidant activity was assessed by scavenging effect against 2,2-diphenylpicrylhydrazyl (DPPH). Total phenol contents of the extracts were determined by Folin-Ciocalteau method.

Results

Salvia triloba was the most effective in antiamnesic experiment at 100, 200, and 400 mg kg⁻¹ doses having 22.7, 57.1, and 71.4% of relative effects, respectively. Teucrium polium was also active dose-dependently, whereas Melissa officinalis was completely inactive. In the anticholinesterase assay, the extracts showed similar inhibitions against acetylcholinesterase and Teucrium polium had the highest inhibition (65.8% at 1.0 mg ml⁻¹). Concerning the antioxidant effect, all the extracts exerted the highest activity among all having IC₅₀ values between 0.227 and 0.428 mg/ml.

Conclusion

Our data suggest that Teucrium polium among the screened plants deserves to be examined further as a herbal alternative for AD treatment.     

Pharmacokinetics of artemisinin delivered by oral consumption of Artemisia annua dried leaves in healthy vs. Plasmodium chabaudi-infected mice

Ethnopharmacological relevance

The Chinese have used Artemisia annua as a tea infusion to treat fever for >2000 years. The active component is artemisinin. Previously we showed that when compared to mice fed an equal amount of pure artemisinin, a single oral dose of dried leaves of Artemisia annua (pACT) delivered to Plasmodium chabaudi-infected mice reduced parasitemia at least fivefold. Dried leaves also delivered >40 times more artemisinin in the blood with no toxicity. The pharmacokinetics (PK) of artemisinin delivered from dried plant material has not been adequately studied.

Materials and methods

Healthy and Plasmodium chabaudi-infected mice were oral gavaged with pACT to deliver a 100 mg kg⁻¹ body weight dose of artemisinin. Concentrations of serum artemisinin and one of its liver metabolites, deoxyartemisinin, were measured over two hours by GCMS.

Results

The first order elimination rate constant for artemisinin in pACT-treated healthy mice was estimated to be 0.80 h⁻¹ with an elimination half-life (T_½) of 51.6 min. The first order absorption rate constant was estimated at 1.39 h⁻¹. C_max and T_max were 4.33 mg L⁻¹ and 60 min, respectively. The area under the curve (AUC) was 299.5 mg min L⁻¹. In contrast, the AUC for pACT-treated infected mice was significantly greater at 435.6 mg min L⁻¹. Metabolism of artemisinin to deoxyartemisinin was suppressed in infected mice over the period of observation. Serum levels of artemisinin in the infected mice continued to rise over the 120 min of the study period, and as a result, the T_½ was not determined; the C_max and T_max were estimated at ≥6.64 mg L⁻¹ and ≥120 min, respectively. Groups of healthy mice were also fed either artemisinin or artemisinin mixed in mouse chow. When compared at 60 min, artemisinin was undetectable in the serum of mice fed 100 mg AN kg⁻¹ body weight. When plant material was present either as mouse chow or Artemisia annua pACT, artemisinin levels in the serum rose to 2.44 and 4.32 mg L⁻¹, respectively, indicating that the presence of the plant matrix, even that of mouse chow, had a positive impact on the appearance of artemisinin in the blood.

Conclusions

These results showed that artemisinin and one of its drug metabolites were processed differently in healthy and infected mice. The results have implications for possible therapeutic use of pACT in treating malaria and other artemisinin-susceptible diseases.     

Effect of Moringa oleifera Lam. leaves aqueous extract therapy on hyperglycemic rats

Ethnopharmacological relevance

In Indian traditional system of medicine, Moringa oleifera Lam. Syn. Moringa pterygosperma Gaerth (Moringaceae) is commonly used as healing herb to treat diabetes.

Aim of the study

The purpose of the present study was to assess the effect of M. oleifera leaves aqueous extract therapy on glycemic control, haemoglobin, total protein, urine sugar, urine protein and body weight.

Materials and methods

Variable doses of 100, 200 and 300 mg kg⁻¹ of aqueous extract were administered orally by gavage for evaluating their hypoglycemic and antidiabetic effects on fasting blood glucose (FBG), oral glucose tolerance test (OGTT) and post prandial glucose (PPG) of normal and streptozotocin (STZ) induced sub, mild and severely diabetic rats.

Results

The dose of 200 mg kg⁻¹ decreases blood glucose level (BGL) of normal animals by 26.7 and 29.9% during FBG and OGTT studies respectively. In sub and mild diabetic animals the same dose produced a maximum fall of 31.1 and 32.8% respectively, during OGTT. In case of severely diabetic animals FBG and PPG levels were reduced by 69.2 and 51.2% whereas, total protein, body weight and haemoglobin were increased by 11.3, 10.5 and 10.9% respectively after 21 days of treatment. Significant reduction was found in urine sugar and urine protein levels from +4 and +2 to nil and trace, respectively.

Conclusion

The study validates scientifically the widely claimed use of M. oleifera as an ethnomedicine to treat diabetes mellitus.     

Short-term administration of an aqueous extract of kalanchoe integra var. crenata (Andr.) Cuf leaves produces no major organ damage in Sprague-Dawley rats

Ethnopharmacological relevance

Kalanchoe intergra (Ki) leaf extract is an orally administered multipurpose plant medicine in Ghana and other parts of the world for the treatment of ulcers, pain and adenoma of the prostate gland. There is paucity of information concerning its short-term usage. The present study is aimed at conducting histopathological and biochemical studies in a 14-day sub-acute toxicity studies using female Sprague-Dawley rats.

Materials and methods

Crude extract of Ki leaves was prepared and freeze-dried. A 14-day sub-acute toxicity studies was conducted using 2 week old nulliparous and non-pregnant female Sprague-Dawley rats (120–150 g). Reconstituted Ki was administered at a dosage of 900 mg kg⁻¹ (high dose), 300 mg kg⁻¹ with a control group receiving an equivalent volume of distilled water (as vehicle) by gastric lavage. Histopathological studies of major organs and blood chemistry analysis were performed on blood obtained via cardiac puncture into EDTA tubes after euthanisation.

Results

There was a significant decrease in urea (p<0.016) and creatinine levels (p<0.001) in both the high and low dose groups. There was an increase in ALP levels (P=0.01) in both the high and low dose groups. ALT and AST rather decreased significantly in both the high and low dose groups (p<0.0001). Histopathological results did not show any abnormalities in all the H&E stained paraffin sections. Thus the photomicrographs of the liver, kidney and heart were within histopathological limits.

Conclusion

Ki leaf extract is non-toxic when administered by the oral route over a time period of 14 days at the above doses.     

In vitro antimicrobial activity of Caesalpinia ferrea Martius fruits against oral pathogens

Aim

In the Amazon region of Brazil, the fruits of Caesalpinia ferrea Martius (Brazilian ironwood) are widely used as an antimicrobial and healing medicine in many situations including oral infections. This study aimed to evaluate the antimicrobial activity of Caesalpinia ferrea Martius fruit extract against oral pathogens.

Materials and methods

Polyphenols estimation and spectral analysis (¹H NMR) of the methanol extract were carried out. The microorganisms Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were tested using the microdilution method for planktonic cells (MIC) and a multispecies biofilm model. Chlorhexidine was used as positive control.

Results

Polyphenols in the extract were estimated at 7.3% and ¹H NMR analysis revealed hydroxy phenols and methoxilated compounds. MIC values for Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were 25.0, 40.0, 66.0, 100.0, 66.0 μg/mL, respectively. For the biofilm assay, chlorhexidine and plant extract showed no growth at 10⁻⁴ and 10⁻⁵ microbial dilution, respectively. At 10⁻⁴ and 10⁻⁵ the growth values (mean ± SD) of the negative controls (DMSO and saline solution) for Streptococcus mutans, Streptococcus sp. and Candida albicans were 8.1 ± 0.7, 7.0 ± 0.6 and 5.9 ± 0.9 × 10⁶ CFU, respectively.

Conclusion

Caesalpinia ferrea fruit extract can inhibit in vitro growth of oral pathogens in planktonic and biofilm models supporting its use for oral infections.     

Astragaloside IV attenuates inflammatory cytokines by inhibiting TLR4/NF-кB signaling pathway in isoproterenol-induced myocardial hypertrophy

Ethnopharmacological relevance

Astragaloside IV (As IV) is one of the main effective components isolated from the traditional Chinese medical herb Astragalus membranaceus. The protective effect of Astragalus membranaceus on myocardial hypertrophy has been extensively proved. To test the hypothesis that Astragaloside IV can ameliorate the myocardial hypertrophy and inflammatory effect induced by β-adrenergic hyperactivity, we carried out in vivo and in vitro experiments.

Material and methods

In in vivo study, the isoproterenol (Iso) (5 mg kg⁻¹ d⁻¹) was used as a model of myocardial hypertrophy by intraperitoneal injection. SD rats were randomly assigned to following six groups: A: the control; B: Iso group; C: Iso plus As IV 20 mg kg⁻¹ d⁻¹; D: Iso plus As IV 40 mg kg⁻¹ d⁻¹; E: Iso plus As IV 80 mg kg⁻¹ d⁻¹; F: Iso plus Propranolol 40 mg kg⁻¹ d⁻¹. In in vitro study, cultured neonatal rat cardiomyocytes were pretreated with As IV (3, 10, 30 μ mol L⁻¹), Propranolol (2 μ mol L⁻¹) and BAY11-7082 (5 μ mol L⁻¹) for 30 min, and then incubated with Iso (10 μ mol L⁻¹) for 48 h. For the rats in each group, the heart mass index (HMI) and the left ventricular mass index (LVMI) were measured. To measure the transverse diameter of left ventricular myocardial cells (TDM), the hematoxylin-eosin (HE) staining method was applied. In addition, the volume and the total protein content of cardiomyocytes were measured, the mRNA expression of ANP and TLR4 were quantified by RT-PCR, the protein expression of TLR4, IκBα and p65 were quantified by Western blot, and the level of TNF-α and IL-6 were measured by ELISA.

Results

In vivo: Comparing the Iso group to the control, the HMI, LVMI, TDM were significantly increased; the protein expression of TLR4 and p65 were increased, while the IκBα were decreased; the expression of ANP, TLR4 mRNA, and TNF-α, IL-6 in serum were significantly increased. These changes could be partly prevented by As IV and Pro. In vitro: the over-expression of the cell size, total protein content could remarkably down-regulated by As IV and Pro, and the results of RT-PCR, Western blot and ELISA were similar to those of in vivo.

Conclusions

The results of these studies indicate that Astragaloside IV has good protective effect on myocardial hypertrophy induced by isoproterenol. More specifically, the cardioprotection is related to inhibiting the TLR4/NF-кB signaling pathway and the attenuating inflammatory effect.     

Macrophage immunomodulatory activity of the polysaccharides from the roots of Bupleurum smithii var. parvifolium

Aim of the study

Radix Bupleuri, one of the most frequently prescribed crude herbs in traditional Chinese medicine, has been used for centuries to treat inflammatory diseases. However, little is known about the therapeutic mechanisms of crude polysaccharides (BPs) isolated from the roots of Bupleurum smithii var. parvifolium. Macrophages play important roles in inflammatory diseases such as systemic lupus erythematosus (SLE). The purpose of the present work was to investigate immunomodulative effects of Bupleurum polysaccharides on murine peritoneal macrophages.

Materials and methods

BALB/c mice were administered intragastrically with Bupleurum polysaccharides 20, 40, and 80 mg kg⁻¹ day⁻¹, or prednisone 3 mg kg⁻¹ day⁻¹ or levamisole 25 mg kg⁻¹ day⁻¹ from day 0 to day 6. Peritoneal macrophages were isolated 5 days after intraperitoneal injection of 1 mL 5% sodium thioglycollate. Phagocytic functions of macrophages were studied; cytokines concentrations in the culture supernatants were determined by enzyme-linked immunosorbent assay and the secretion of nitric oxide (NO) was quantified by Griess reaction.

Results

Treatment with BPs enhanced phagocytic functions of macrophages (phagocytosis of apoptotic thymocytes, IgG-opsonized sheep red blood cells and chicken red blood cells) and inhibited LPS-induced productions of NO and proinflammatory cytokines (interleukin-1β, interleukin-6 and tumor necrosis factor-α).

Conclusions

Bupleurum polysaccharides up-regulated phagocytic activities but inhibited LPS-induced productions of proinflammatory mediators. These data suggested that at least part of the traditional beneficial effects of Bupleurum on inflammatory diseases could be ascribed to the immunomodulatory effects of Bupleurum polysaccharides on macrophages.     

Antiedematogenic effects of the polar fractions of Persea cordata Mez. (Lauraceae) on microvascular extravasation in rat skin

Ethnopharmacological relevance

Persea cordata Mez. (Lauraceae) is a medicinal plant used in veterinary ethnopharmacology, which is a popular medicine used as an anti-inflammatory and healing agent, mainly on animal skin diseases, characterized by cutaneous open wounds, in South Brazil.

Aim of this study

The purpose of this study was to investigate a possible antiedematogenic effect of ethyl acetate (EtAc) and butanol (BuOH) polar fractions of Persea cordata on Evans blue dye leakage induced by pro-inflammatory agents in rat skin.

Materials and methods

Male Wistar rats (180–200 g, n=5–6) were pretreated with a single intraperitoneal administration of EtAc or BuOH (1 to 600 mg kg⁻¹) fractions followed by intravenous Evans blue dye injection (1%, 30 mg kg⁻¹, i.v.), 60 min before the injection of phlogistic agents. Animals received intradermal injections (0.05 ml) of carrageenan (CAR, 300 µg/site), 48/80 compound (C4880, 10 µg/site), histamine (HIS, 0.3 µg/site), serotonin (5-HT, 0.01 µg/site), dextran (DEX, 200 µg/site), bradykinin (BK, 0.003 µg/site), capsaicin (CPS, 400 µg/site), substance P (SP, 0.003 µg/site) or prostaglandin E₂ (PGE₂ 10 nmol/site) and they were submitted to euthanasia after 60 min. Skin samples were obtained in the extravasation sites of Evans blue dye. Skin fragments were soaked in formamide at 37 °C (during 24 h) for Evans blue extraction. The amount of dye leakage in the tissue fragment was determined by a spectrophotometer (620 nm).

Results

In a very similar manner in terms of potency and efficacy, systemic administration of EtAc and BuOH fractions caused dose-dependent inhibition of vascular Evans blue dye leakage induced by phlogistic agents in the rat skin. The results obtained (ID₅₀ values in mg kg⁻¹ and maximal inhibition in %) with EtAc fraction, as follows were: CAR (34.42 and 63.0), 4880 (8.52 and 59.1), HIS (21.22 and 66.8), 5-HT (32.99 and 73.4), DEX (41.74 and 67.0), BK (34.03 and 68.0), CPS (100.7 and 77), SP (2.1 and 78.9) and PGE₂ (133 and 71.0). BuOH fraction significantly inhibited CAR (25.9 and 70)-, 4880 (36.8 and 66)-, HIS (17.6 and 77)-, 5-HT (32.8 and 56)-, DEX (89.6 and 75)-, BK (28.0 and 66)-, CPS (136.37 and 71)-, SP (5.6 and 78)- and PGE₂ (109.64 and 56)-induced VE, respectively.

Conclusion

Systemic administration of Persea cordata polar fractions exerts a non-specific inhibitory effect on microvascular leakage induced by pro-inflammatory agents in rat skin, probably to interfering with different biological systems involved in the development of the inflammatory process, reinforcing the popular use of Persea cordata as an anti-inflammatory and healing agent for skin.     

Chemopreventive and remediation effect of Hydrocotyl bonariensis Comm. Ex Lam (Apiaceae) leave extract in galactose-induced cataract

Ethnopharmacological relevance

Hydrocotyl bonariensis Comm. Ex Lam (Apiaceae) is being widely used in Western Nigeria in treating various symptoms of ophthalmic diseases; however scientific data in support of this medicinal use have not been reported.

Aim of the study

This study, investigated the efficacy of Hydrocotyl bonariensis leave extract in offering protection against experimental cataract and also examined its remediation effect when administered after cataract onset.

Materials and methods

Weanling albino rats fed with 30% galactose diet were used in the study. Mechanisms of action of the extract were investigated by measuring the degree of lens peroxidation, lens antioxidant status and lens protein concentration. Severity of cataract was determined by measuring the cataract index.

Results

The extract at 500 mg kg⁻¹ reduced cataract index significantly and also reduced cataract progression when administered after cataract onset. Administration of this dosage also significantly reduced the degree of lens peroxidation, increased the level of reduced glutathione (GSH) and the lens catalase and superoxide dismutase activity. The extract also prevents protein insolubilization. Administration of the extract at 1000 mg kg⁻¹ reduced cataract index and lens peroxidation but did not increase the antioxidant status significantly. Administration of the extract after cataract onset reduced cataract index, moderately increased percentage soluble protein above the value prior to the arrest of hypergalactosemia but did not increase the antioxidant status.

Conclusion

Our study suggests that Hydrocotyl bonariensis protects against galactose-induced cataract, and that administration of the extract after cataract onset reduced cataract progression but did not reverse cataractogenesis.     

Pharmacokinetic study of salvianolic acid A in beagle dog after oral administration by a liquid chromatography–mass spectrometry method: A study on bioavailability and dose proportionality

Ethnopharmacological relevance

Salvianolic acid A (SAA) is one of the main water-soluble components isolated from Salvia miltiorrhiza Bunge. Pharmacological researches revealed that it had various curative activities after oral and intravenous administration, including beneficial effects on diabetes and its complications, cardioprotective effect, anti-platelet aggregation, and so on. However, there is no report regarding the pharmacokinetics of SAA in beagle dogs after oral administration up to now.

Aim of the study

To study the pharmacokinetics of different doses of SAA in beagle dogs and figure out the absolute bioavailability and dose proportionality of SAA after oral administration.

Materials and methods

Male and female beagle dogs were orally administered SAA 5, 10 and 20 mg/kg randomly. The plasma drug concentration was detected by a rapid, sensitive and reproducible liquid chromatography–mass spectrometry (LC–MS) method. The pharmacokinetic parameters were calculated from plasma concentration–time data using the DAS pharmacokinetic software Data Analysis System Version 3.0 program.

Results

After single-dose oral administration of SAA, the mean peak plasma concentration (C_max) values for groups treated with 5, 10 and 20 mg/kg doses ranged from 14.38 to 38.18 µg/L, and the mean area under the concentration–time curve (AUC_(0–t)) values ranged from 38.77 to 130.33 (µg/L⋅ h). SAA showed lack of dose proportionality over the dose range 5–20 mg/kg, based on the power model. However, the increase in systemic exposure with dose appeared linear. The absolute bioavailability was calculated to range from 1.47% to 1.84%.

Conclusion

The pharmacokinetic properties of SAA in beagle dogs after oral administration were characterized as rapid oral absorption, quick clearance, and poor absolute bioavailability. Systemic exposure exhibited lack of dose proportionality over the dose range 5–20 mg/kg. Furthermore, a readily preparative LC–MS method was demonstrated in this study for the research of traditional Chinese medicine.     

Protective effects of astragaloside IV on porcine-serum-induced hepatic fibrosis in rats and in vitro effects on hepatic stellate cells

Ethnopharmacological relevance

Astragaloside IV is the primary pure saponin isolated from Astragalus membranaceus, one of the valuable traditional medical herbs. Antifibrotic activities of Astragalus membranaceus have been extensively proved.

Aim of the study

To investigate the effects of astragaloside IV on hepatic stellate cells (HSCs) and hepatic fibrosis in rats induced by porcine-serum (PS).

Materials and methods

Liver fibrosis was induced by PS injection (0.5 ml, twice a week) for 12 weeks. Astragaloside IV (2.0, 4.0 mg kg⁻¹) was administered intragastrically. Liver samples were subjected to histological and immunohistochemical studies. In vitro effects of astragaloside IV on primary cultured HSCs were detected by incorporation assays.

Results

Astragaloside IV delayed the formation of liver fibrosis and decrease the serum levels of hyaluronic acid (HA), procollagen type III (PCIII) and hydroxyproline (Hyp) content in liver. The levels of transforming growth factor-β₁ (TGF-β₁) in serum and expression in liver were significantly decreased by astragaloside IV. Collagen synthesis and proliferation were significantly inhibited by astragaloside IV (1.5, 3.0, 6.0, 12.0 and 24.0 mg L⁻¹) in HSCs.

Conclusion

The results showed that astragaloside IV displays antifibrotic effects in rats induced by PS, the mechanism by which might be associated with its inhibitory effects on collagen synthesis and proliferation in HSCs.     

Antihyperglycemic effect of a natural chicoric acid extract of chicory (Cichorium intybus L.): A comparative in vitro study with the effects of caffeic and ferulic acids

Ethnopharmacological relevance

In Eurasia folk medicine, roots of chicory (Cichorium intybus L.) have been reported to exert antidiabetic benefits. In vitro, a natural chicoric acid extract (NCRAE) from Cichorium intybus root has been shown to increase insulin secretion by pancreatic β-cells and glucose uptake by muscle cells.

Materials and methods

In vitro experiments were designed to compare the effects of two hydroxycinnamic acids, caffeic and ferulic acids, to those obtained with NCRAE (50 and 100 µg.mL⁻¹) on the three major tissues implicated in glycemic regulation (pancreas, muscle and liver). In vivo experiments were performed in Wistar rats submitted to a daily intraperitoneal injection of NCRAE (3, 15 or 30 mg kg⁻¹) for 4 days. On the fourth day, an intraperitoneal glucose tolerance test (IPGTT; 1 g kg⁻¹) was carried out.

Results

Our results show that the three compounds we used are able each to induce an original response. Caffeic acid mainly promotes a decrease in hepatic glycogenolysis. Ferulic acid elicits a clear increase of insulin release and a reduction of hepatic glycogenolysis. However, this compound induces an inhibition of muscle glucose uptake. NCRAE provokes an increase of insulin release and glucose uptake without any effect on hepatic glycogenolysis. We could also show that none of these compounds implicates hepatic glucose 6-phosphatase in contrast to chlorogenic acid, known as an inhibitor of glucose 6-phosphatase and which is able to decrease glucose output from hepatocytes. Our results point out that NCRAE is able to decrease blood glucose without any effect hepatic effect. Our in vivo experiments bring evidence that 4 daily IP administrations of NCRAE improve IP glucose tolerance in a dose-dependent manner and mainly via an insulin sensitizing effect.

Conclusions

We conclude that NCRAE presents an antihyperglycemic effect essentially due to a peripheral effect on muscle glucose uptake.     

Antiemetic effect of Xiao-Ban-Xia-Tang,a Chinese medicinal herb recipe,on cisplatin-induced acute and delayed emesis in minks

Ethnopharmacological relevance

Xiao-Ban-Xia-Tang (XBXT), a traditional Chinese herbal medicine, has been used in China for more than 2000 years, and proved to be effective on various cases of vomiting in the clinic.

Objective

To investigate the antiemetic effect of XBXT on cisplatin-induced acute and delayed emesis and its effective mechanism on Neurokinin-1 receptor (NK₁-R) in the new vomiting model of minks.

Materials and methods

Minks were randomly divided into the normal group, cisplatin group, cisplatin + ondansetron group, cisplatin + low-dose XBXT group and cisplatin + high-dose XBXT group. The antiemetic effect of drugs was investigated in the vomiting model of minks induced by cisplatin (6 mg kg⁻¹, i.p.) in 72 h observation, and the expression of NK₁-R in the area postrema and ileum was measured by Western blot.

Results

The frequency cisplatin induces retching and vomiting was significantly reduced by pretreatment with XBXT in a dose-dependent manner during the 0–24-h and 24–72-h periods (P < 0.05), and XBXT exhibited effective dose-dependent (P < 0.05) inhibition on the increase of expression levels of NK1 receptor in both the ileum and area postrema.

Conclusions

XBXT has good activity against cisplatin-induced acute and delayed emesis in minks possibly by inhibiting central or peripheral increase of NK₁-R.