Involvement of bradykinin and prostaglandins in the diuretic effects of Achillea millefolium L. (Asteraceae)

Ethnopharmacological relevance

Achillea millefolium L. (Asteraceae), popularly known as “mil-folhas”, is well recognized and widely used in Brazilian folk medicine to treat heart and kidney disorders. Among its popularly described effects are diuretic and hypotensive actions.

Aim of the study

The diuretic activity of Achillea millefolium L. extracts and its semi-purified fractions, as well as the mechanisms involved, were evaluated in male Wistar rats.

Material and methods

An aqueous extract (AEAM, 125–500 mg/kg), hydroethanolic extract (HEAM, 30–300 mg/kg), dichloromethane subfractions (DCM-2, 10 and 30 mg/kg), or hydrochlorothiazide (10 mg/kg), were orally administered and the animals were kept in metabolic cages for 8 h for urine collection. To evaluate the involvement of bradykinin and prostaglandins in the diuretic action of Achillea millefolium, selected groups of rats received HOE-140 (1.5 mg/kg, i.p.) or indomethacin (5 mg/kg, p.o.), before treatment with a DCM-2 subfraction (30 mg/kg). The urinary volume, conductivity, pH, density and electrolyte excretion were measured.

Results

Similar to hydrochlorothiazide, both HEAM and DCM-2, but not AEAM, increased urinary volume and the excretion of Na⁺ and K⁺ when compared with the control group (vehicle). The diuretic effect of DCM-2 was abolished by HOE-140 (a bradykinin B2 receptor antagonist), as well as by indomethacin (a cyclooxygenase inhibitor).

Conclusion

The present study reveals that extracts obtained from Achillea millefolium are able to effectively increase diuresis when orally administered in rats. This effect depends on both the activation of bradykinin B2 receptors and the activity of cyclooxygenases.     

Triptolide promotes generation of FoxP3+ T regulatory cells in rats

Ethnopharmacological relevance

Triptolide (TPT), a component of the Chinese herb Triptergium wilfordii, has potent immunosuppressive and anti-inflammatory activity and is used clinically in recipients of kidney transplantation.

Aim of the study

This work aimed to investigate the effect of TPT on the differentiation of regulatory T lymphocytes (Tregs) from CD4+ cells in rats.

Materials and methods

MACS-purified rat CD4+ cells were costimulated with anti-CD3 and anti-CD28 in the presence of TGF-β to induce the expression of FoxP3, which was detected by flow cytometry. TPT and cyclosporine A (CsA) were separately added into the cultures to observe the effect on the expression of FoxP3. Kidney transplantation was performed in rats that either received no treatment or were treated with TPT after transplantation.

Results

TPT treatment enhanced the expression of FoxP3 in CD4+ cells, whereas CsA inhibited the FoxP3 expression. In the rat kidney transplantation model, the recipient rats treated with TPT survived longer than the control rats (18–19.83 vs 6.83 days, P < 0.05). Meanwhile, the FoxP3+ T cells in the spleens of treated rats were higher than those from the untreated rats (12.4% vs 4.7%, P < 0.05).

Conclusions

These data suggest that TPT may promote the differentiation of CD4+ cells to FoxP3+ Tregs. This would be at least one of the pathways responsible for the immunosuppressive activity of TPT.     

Immunomodulatory activity of Asparagus racemosus on systemic Th1/Th2 immunity: Implications for immunoadjuvant potential

Ethnopharmacological relevance

Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations.

Aim of the study

To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals.

Materials and methods

We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside^®) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls.

Results

Treatment with ARE (100 mg/(kg b.w. p.o.)) resulted in significant increase of CD3⁺ and CD4/CD8⁺ percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes.

Conclusion

The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.     

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.     

The effect of Chaihu-Shugan-San and its components on the expression of ERK5 in the hippocampus of depressed rats

Ethnopharmacological relevance

Chaihu-Shugan-San (CSS) is a well-known, Chinese traditional medicine used to treat depression. Little is known about the antidepressant mechanism of CSS. The main aims of the this study were to evaluate the antidepressant-like effects of CSS and its components and further explore the CSS?s effect upon signal transduction of extracellular signal-regulated kinase 5 (ERK5) expressions in the hippocampus of rats with depression induced by chronic unpredicted mild stress.

Materials and methods

SD rats were randomly divided into six groups: Normal; Model; CSS; Component I; Component II; and Fluoxetine. Antidepressant-like effects of CSS and two of its constituents, Components I and II in aqueous extract, were assessed using rats exposed to chronic unpredictable mild stress (CUMS) by measuring weight change, observing the open-field test and measuring sucrose water consumption. Antidepressant mechanism were examined by measuring the effect of CSS, and two of its constituents, on extracellular signal-regulated kinase 5 (ERK5) expression, phosphorylation-ERK5 (p-ERK5), and ERK5 mRNA in the hippocampus by using western blotting and Real-time Polymerase Chain Reaction (PCR). Three preparations were prepared: (1) an aqueous extract of CSS (5.9 g/kg·d); (2) Component I (3.3 g/kg·d); and (3) Component II (2.6 g/kg·d). During the 28-day CUMS, the three preparations were intragastrically administered all three preparations. Simultaneously a parallel positive fluoxetine control group was given fluoxetine hydrochloride (1.8 mg/kg·d). Normal and Model groups were intragastrically administered with a isovolumic distilled water (4.5 ml/kg·d).

Results

Depressed rats had decreased weight gain; decreased locomotor activity as measured by the open field test; and reduced sucrose consumption. The rats? hippocampus ERK5 activation was significantly suppressed. CSS reduced the incidence of depressive-like behaviors and increased ERK5 activation in depressed rats at the same rate as fluoxetine. Component I, and II, each had only a partial effect on the depression indicators measured.

Conclusions

CSS aqueous extract has antidepressant-like effects on CUMS-induced depression model rats. The antidepressant effect of CSS is greater than that of either the two separate components measured. CSS?s antidepressant mechanism may be mediated by reversing the stress-induced disruption of ERK5 activity.     

Total saponins of Panax Notoginseng modulate the expression of caspases and attenuate apoptosis in rats following focal cerebral ischemia-reperfusion

Ethnopharmacological relevance

Total saponins of Panax notoginseng (TSPN), main constituents extracted from Panax Notoginseng, a highly valued traditional Chinese medicine, have been shown to be an effective agent on cerebral infarction.

Aim of the study

The effects of TSPN on apoptosis and expressions of caspase-1, caspase-3 and caspase-8 were studied after cerebral ischemia for 2 h followed by reperfusion for 46 h in rats.

Materials and methods

Rats were subjected to transient middle cerebral artery occlusion (MCAO) model using the intraluminal thread. TSPN was administered intraperitoneally at 5 min before and 12 h, 24 h and 36 h after MCAO, respectively.

Results

TSPN (at the dose of 25 mg/kg) significantly attenuated TUNEL-positive cells and reduced the expression of caspase-1 and caspase-3 compared to the model group, while it had no obvious effect on the expression of caspase-8.

Conclusions

The neuroprotective effect of TSPN on focal ischemia may be related to inhibition of apoptosis and caspases activation.     

Nigella sativa inhibits intestinal glucose absorption and improves glucose tolerance in rats

Aim of the study

Nigella sativa L. (Ranunculaceae) seeds have been used traditionally for centuries, notably for treating diabetes.

Materials and methods

We studied the effects of the crude aqueous extract of Nigella sativa seeds on intestinal glucose absorption in vitro using a short-circuit current technique and in vivo using an oral glucose tolerance test.

Results

The aqueous extract of Nigella sativa (0.1 pg/ml to 100 ng/ml) exerted dose-dependent inhibition of sodium-dependent glucose transport across isolated rat jejunum. Maximal inhibition exceeded 80% and IC₅₀ was close to 10 pg/ml. An oral glucose tolerance test was carried out in rats after the initial dose and after a 6-week treatment of Nigella sativa (2 g/(kg day)), and compared to metformin (300 mg/(kg day)). Chronic Nigella sativa treatment improved glucose tolerance as efficiently as metformin. Nigella sativa and metformin also reduced body weight without any toxic effect.

Conclusions

To our knowledge, this is the first demonstration that Nigella sativa directly inhibits the electrogenic intestinal absorption of glucose in vitro. Together with the observed improvement of glucose tolerance and body weight in rats after chronic oral administration in vivo, these effects further validate the traditional use of Nigella sativa seeds against diabetes.     

Momordica charantia extract on insulin resistance and the skeletal muscle GLUT4 protein in fructose-fed rats

Aim of the study

We investigated the preventive effect of Momordica charantia Linn. (Cucurbitaceae) fruit, commonly known as bitter melon, on hyperglycemia and insulin resistance in rats fed with a fructose-enriched diet.

Materials and methods

First, rats were divided randomly into two groups: the control group was fed with control diet, whereas the experimental group was fed with a 60% high-fructose diet for 8 weeks. After the first 6 weeks, the fructose-treated rats were further subdivided into six groups and were orally fed with or without Momordica charantia L. or rosiglitazone (ROS) for 2 weeks while rats were still on fructose diet.

Results

We demonstrated that bitter melon was effective in ameliorating the fructose diet-induced hyperglycemia, hyperleptinemia, hyperinsulinemia, and hypertriglyceridemia as well as in decreasing the levels of free fatty acid (FFA) (P < 0.001, P < 0.05, P < 0.05, P < 0.05, P < 0.05, respectively). Bitter melon reversed fructose diet-induced hypoadiponectinemia (P < 0.05), which provides a therapeutic advantage to insulin resistance in improving insulin sensitivity. Additionally, bitter melon decreased the weights of epididymal (P < 0.05) and retroperitoneal white adipose tissue (WAT) (P < 0.05). Bitter melon increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) in white adipose tissue (WAT). Conversely, bitter melon decreased the expression of leptin in WAT. Furthermore, we demonstrate that bitter melon significantly increases the mRNA expression and protein of glucose transporter 4 (GLUT4) in skeletal muscle.

Conclusions

This study demonstrates, for the first time, the beneficial effects of two different extracts of bitter melon on insulin resistance in rats fed a high-fructose diet thereby producing evidence of the role of changes in expression of PPARγ and GLUT4.     

Antihyperglycemic,hypolipidemic and antioxidant activities of total saponins extracted from Aralia taibaiensis in experimental type 2 diabetic rats

Ethnopharmacological relevance

As a well-known traditional Chinese medicine the root bark of Aralia taibaiensis has multiple pharmacological activities, including relieving rheumatism, promoting blood circulation to arrest pain, inducing diuresis to reduce edema, and antidiabetic action. It has long been used as a folk medicine for the treatment of traumatic injury, rheumatic arthralgia, nephritis, edema, hepatitis and diabetes mellitus in China.

Aim of study

To evaluate the antihyperglycemic, hypolipidemic and antioxidant activities of total saponins extracted from Aralia taibaiensis (SAT) in experimental type 2 diabetic mellitus (T2DM) rats.

Materials and methods

Acute toxicity was studied in rats to determine the safe oral dose of SAT. Then, SAT was given orally to normal and streptozotocin–nicotinamide induced T2DM rats at 80, 160 and 320 mg/kg doses for a series of 28 days to determine the antihyperglycemic activity. Glibenclamide (600 μg/kg), a standard antidiabetic drug, was used as a positive control drug. At the end of treatment, biochemical parameters and antioxidant levels were measured to evaluate the hypolipidemic and antioxidant activities of SAT.

Results

Oral administration of SAT did not exhibit toxicity and death at a dose not more than 2000 mg/kg. SAT dose-dependently improved the symptoms of polydipsia, polyuria, polyphagia and weight loss in diabetic rats. Compared with diabetic control group, administration of 320 mg/kg SAT resulted in significant (P<0.05) fall in the levels of fasting blood glucose, glycosylated hemoglobin, creatinine, urea, alanine transarninase, aspartate aminotransferase, total cholesterol, triglycerides, low density lipoprotein cholesterol and malondialdehyde, but significant (P<0.05) increase in the levels of serum insulin, superoxide dismutase and reduced glutathione. However, SAT did not have any effect on the normal rats.

Conclusions

SAT had excellent antihyperglycemic, hypolipidemic and antioxidant activities in T2DM rats and might be a promising drug in the therapy of diabetes mellitus and its complications.     

Huangkui capsule,an extract from Abelmoschus manihot (L.) medic,ameliorates adriamycin-induced renal inflammation and glomerular injury via inhibiting p38MAPK signaling pathway activity in rats

Ethnopharmacological relevance

Abelmoschus manihot (L.) medic (AM) is a natural medicinal plant used for the treatment of inflammatory diseases in China. Huangkui capsule (HKC), an extract from AM, has been proved clinically effective in improving renal inflammation and glomerular injury in chronic kidney disease (CKD). However, the dose-effects and the mechanisms involved in vivo are still unclear.

Aim of the study

This study was performed to examine the dose-effects of HKC on renal inflammation and glomerular lesion in adriamycin-induced nephropathy (ADRN), then to clarify the mechanisms in vivo of HKC by investigating its actions on modulating the activation of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway.

Materials and methods

The rats with chronic ADRN, created by the unilateral nephrectomy and twice adriamycin injections (ADR, 4 mg/kg and 2 mg/kg) within 4 weeks, were divided into four groups, a Sham group, a Vehicle group, a high-dose HKC group, and a low-dose HKC group, and that, sacrificed at the end of the 4th week after the administration. The rat's general status, renal morphological appearance, proteinuria, blood biochemical parameters, glomerular morphological changes, podocyte shape, and macrophage (ED1⁺ and ED3⁺ cells) infiltration in glomeruli were examined, respectively. The protein expressions of inflammatory cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-2, as well as p38MAPK signaling molecules such as transforming growth factor (TGF)-β1, p38MAPK, and phosphorylated-p38MAPK (p-p38MAPK), were also evaluated individually.

Results

HKC at high dose of 2 g/kg/d not only significantly ameliorated the rat's general status, renal morphological appearance, proteinuria, albumin, and glomerulosclerosis, but also obviously reduced the infiltrated ED1⁺ and ED3⁺ macrophages in glomeruli and TNF-α protein expression in the kidney, in addition to these, evidently down-regulated TGF-β1 and p-p38MAPK protein expressions in ADRN rats, but had no influence on podocyte shape and renal function.

Conclusion

HKC could dose-dependently ameliorate renal inflammation and glomerular injury in ADRN rats, by way of reducing the infiltration and the activation of macrophages in glomeruli, and TNF-α protein expression in the kidney, as well as inhibiting p38MAPK signaling pathway activity via the down-regulation of p-p38MAPK and TGF-β1 protein expressions in vivo.     

Antihyperglycemic and hypolipidemic activity of aqueous extract of Cassia auriculata L. leaves in experimental diabetes

Ethnopharmacological relevance

Cassia auriculata L. (Caesalpiniaceae) is widely used from ancient period to treat diabetes mellitus. The leaves of Cassia auriculata are having potential in the development of drug for diabetes due to its antihyperglycemic and lipid-lowering activity.

Aim of the study

The present study was to evaluate antihyperglycemic and hypolipidemic activity of aqueous extract of Cassia auriculata leaves (CLEt) in streptozotocin (STZ)-induced mild diabetic (MD) and severe diabetic (SD) rats.

Materials and methods

Male Albino rats were rendered diabetic by STZ (45 mg/kg, intraperitoneally). CLEt was orally administered to MD and SD rats at 100, 200 and 400 mg/kg doses for 1 day to determine antihyperglycemic activity. The 400 mg/kg dose was administered daily for 3 weeks to assess glycemic control and hypolipidemic effect.

Results

CLEt showed dose dependant fall in fasting blood glucose (FBG). After 5 h of extract administration at 400 mg/kg dose, FBG was reduced by 13.9% and 17.4% in MD and SD rats respectively. After 3 weeks treatment, CLEt produced significant reduction in FBG and glycosylated haemoglobin (GHb) in both MD and SD rats. Serum lipid levels were reversed towards normal in extract fed MD and SD rats.

Conclusions

The results demonstrate that CLEt possesses potent antihyperglycemic and hypolipidemic activity in both MD and SD rats.     

Hepatoprotective and in vivo antioxidant effects of Byrsocarpus coccineus Schum. and Thonn. (Connaraceae)

Ethnopharmacological relevance

The leaf decoction of Byrsocarpus coccineus (Connaraceae) is drunk for the treatment of jaundice in West African traditional medicine.

Aim of the study

To investigate the hepatoprotective and in vivo antioxidant effects of Byrsocarpus coccineus in carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats.

Materials and methods

Group allotment in this study included vehicle, CCl₄, Byrsocarpus coccineus 1000 mg/kg alone, Byrsocarpus coccineus 200, 400, and 1000 mg/kg + CCl₄ and Livolin^® 20 mg/kg + CCl₄, and treatment was carried out accordingly. On the 7th day, rats were sacrificed and blood was withdrawn by cardiac puncture. The levels and activities of serum biochemical parameters and antioxidant enzymes were then assayed using standard procedures.

Results

CCl₄ significantly (P < 0.05) increased the levels of ALT and AST and reduced total protein. In CCl₄ treated animals, Byrsocarpus coccineus (200, 400, and 1000 mg/kg) dose-dependently and significantly decreased ALT, AST and ALP levels with peak effect produced at the highest dose. Conversely, Byrsocarpus coccineus produced significant increases in albumin and total protein levels. The standard drug produced significant effects in respect of ALT (↓), albumin (↑), and total protein (↑). CCl₄ also produced significant (P < 0.05) reductions in the activity of catalase, SOD, peroxidase and GSH, and conversely increased MDA level. Byrsocarpus coccineus produced significant and dose-dependent reversal of CCl₄-diminished activity of the antioxidant enzymes and reduced CCl₄-elevated level of MDA. The standard drug also significantly increased CCl₄-diminished antioxidant enzymes activity and reduced CCl₄-elevated MDA level. In general, the effects of the standard drug were comparable and not significantly different from those of Byrsocarpus coccineus.

Conclusion

The results obtained in this study suggest that the aqueous leaf extract of Byrsocarpus coccineus possesses hepatoprotective and in vivo antioxidant effects. This finding justifies the use of this preparation in West African traditional medicine for the treatment of liver disease.     

Subchronic toxicity study of Coptidis Rhizoma in rats

Ethnopharmacological relevance

Coptidis Rhizoma (CR) is a medical herb from the family Ranunculacease that has been used to treat gastroenteritis, dysentery, diabetes mellitus, and severe skin diseases.

Aim of the study

To evaluate the no-observed-adverse-effect level (NOAEL) and the toxicity of CR, following repeat oral administration to rats for 13 weeks.

Materials and methods

CR was administered by oral gavage to groups of rats (n=10/group, each sex) at dose levels of 0 (control), 25, 74, 222, 667 or 2000 mg/kg/day 5 times per week for 13 weeks. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, urinalysis, vaginal cytology and sperm morphology, organ weights, gross and histopathological findings were compared between control and CR groups.

Results

Urinalysis showed a significant increase in N-acety1-β-glucosaminidase in males in the 2000 mg/kg/day group (P<0.01). However, no mortality or remarkable clinical signs were observed during this 13-week study. No adverse effects on body weight, food consumption, hematology, serum chemistry, organ weights, gross lesion, histopathology, vaginal cytology, sperm motility, or deformity were observed in the males or female rats treated with CR.

Conclusions

On the basis of these results, the NOAEL of CR is determined to be 667 mg/kg/day for males and 2000 mg/kg/day for females.     

Potent relaxant effect of a Celastrus paniculatus extract in the rat and human ileum

Ethnopharmacological importance

Celastrus paniculatus Willd. (Celastraceae) is an Ayurvedic remedy used for the treatment of a number of diseases, including bowel spasms.

Aim of the study

To investigate the mode of the relaxing action of a methanolic extract prepared from the seeds of Celastrus paniculatus (CPE, 0.0001–10 μg/mL) in the rat ileum and to try to confirm on human tissues the intestinal pharmacological activity of the extract.

Materials and methods

The relaxant effect of CPE was studied in vitro by evaluating its effect on the spontaneous contractions of the isolated ileum.

Results

CPE exerted a tetrodotoxin- and ω-conotoxin-resistant inhibitory effect on rat ileum motility (IC₅₀: 0.24 ± 0.02 μg/mL; E_max: 99.0 ± 0.60%). The inhibitory effect was reduced by nifedipine but not by cyclopiazonic acid. Experiments with specific antagonists enabled us to exclude the involvement of the main endogenous spasmogenic (i.e. acetylcholine and tachykinins) and relaxing (noradrenaline, nitric oxide, ATP) compounds. CPE also relaxed the isolated human ileum (IC₅₀: 0.26 ± 0.02 μg/mL; E_max: 99.1 ± 0.46%).

Conclusion

It is concluded that (i) CPE exerted a powerful myogenic and L-type Ca²⁺-dependent relaxing effect in the isolated rat ileum and that (ii) the human ileum is sensitive to the inhibitory effect of CPE. If confirmed in vivo, our data could explain the traditional use of this herb in the treatment of intestinal spasms.     

Antifibrotic effects of CGX,a traditional herbal formula,and its mechanisms in rats

Aim

CGX is a modification of a traditional herbal medicine for “liver cleaning,” which is used to treat various chronic liver disorders in oriental clinics. This study investigated the antifibrotic effects and associated mechanisms of CGX.

Materials and methods

Liver fibrosis was induced in rats by dimethylnitrosamine (DMN; 10 mg kg⁻¹, ip) injection on 3 consecutive days per week for 4 weeks. CGX (100 or 200 mg kg⁻¹, po) was administrated once a day for 4 weeks. Three cell lines (HepG2, RAW 264.7, and HSC-T6) were used to examine its mechanisms.

Results

CGX treatment dramatically ameliorated the change in liver and spleen weight and serum albumin (p < 0.01), aspartate transaminase (p < 0.01), alanine transaminase (p < 0.01), alkaline phosphatase (p < 0.01), and total bilirubin (p < 0.01) levels. Histopathologically, CGX administration decreased necrosis, inflammatory cell infiltration, and collagen accumulation. The antifibrotic effects of CGX were confirmed from hydroxyproline determination and the reduction in the numbers of activated hepatic stellate cells. In addition, antioxidant proteins, glutathione content, and glutathione peroxidase, catalase, and superoxide dismutase activities were maintained in the CGX-treated groups compared with the DMN group. CGX downregulated fibrosis-related genes (inducible nitric oxide synthase, tumor necrosis factor-alpha, transforming growth factor-beta, connective tissue growth factor, and platelet-derived growth factor-beta) and decreased the protein levels of profibrotic cytokines (transforming growth factor-beta and platelet-derived growth factor-beta) in liver tissues. In the cell line-based studies, CGX showed supportive effects, such as the protection of hepatocytes from CCl₄-toxicity, inhibition of NO production in RAW 264.7 cells, and inactivation of hepatic stellate cells.

Conclusion

These results demonstrated the antifibrotic effects of CGX and the corresponding mechanisms associated with sustaining the antioxidative system and inhibiting hepatic stellate cell activation via the downregulation of fibrogenic cytokines.     

Prophylactic effects of Orthosiphon stamineus Benth. extracts on experimental induction of calcium oxalate nephrolithiasis in rats

Ethnopharmacological relevance

Orthosiphon stamineus (OS) popularly known as “diuretic agent” are traditionally used in folk medicine in the treatment of hyperuricemia, rheumatism, gout, nephritis, nephrolithiasis, urethritis and cystitis.

Aim of the study

To evaluate prophylactic potentials of total flavonoids, total phenolics and polysaccharides from OS on experimental induction of calcium oxalate (CaOx) nephrolithiasis in rats.

Materials and methods

Nephrolithic rats were induced by treating with 1.0% ethylene glycol and 1.0% ammonium chloride for 7 days. Rats in the treated groups were also given OS extracts at the doses of 80 mg/kg and 160 mg/kg. Urine samples (4 h) and serum samples were collected at 7th day for biochemical analysis. Kidney tissues were stained with H.E. and analyzed by light microscopy. Expressions of OPN protein were detected by immunohistochemistry. Rates of nucleation and aggregation of calcium oxalate crystals were derived from 20-min time-course measurements of optic density at 620 nm after mixing solutions containing calcium chloride, sodium oxalate and OS extracts at 37 °C, pH 5.7.

Results

Polysaccharides exhibited the most significant prophylactic effects by reversing BUN and S_cr levels, ameliorating histopathological changes, increasing urine C₂O₄²⁻ and Ca²⁺ excretion and down-regulating OPN protein expression of kidney in the model rats in comparison with those effects of total flavonoids and total phenolics. Polysaccharides could also significantly inhibit both nucleation and aggregation of CaOx crystals.

Conclusions

Polysaccharides were the main therapeutic materials in OS. It had impressive prophylactic effects on CaOx stones in nephrolithic rats, playing a role as a regulator of OPN protein expression to increase urine C₂O₄²⁻ and Ca²⁺ excretion and also as an inhibitor of CaOx crystallization.     

Chebulagic acid,a COX–LOX dual inhibitor isolated from the fruits of Terminalia chebula Retz., induces apoptosis in COLO-205 cell line

Ethnopharmacological relevance

Terminalia chebula has an esteemed origin in Indian mythology; its fruits are used to treat many diseases such as digestive, diabetes, colic pain, chronic cough, sore throat, asthma, etc.

Aim of the study

The water or ethanolic extracts of the fruits were reported to have anti-oxidant, anti-inflammatory, anti-cancer and radio-protector properties. The present study is to isolate and identify the compounds that inhibit COX and 5-LOX, the key enzymes involved in inflammation and carcinogenesis.

Materials and methods

The ethanolic extract of the fruits was fractionated by RP-HPLC and fractions were tested for enzyme inhibition activity against COX and 5-LOX. One of the fractionated compounds showed potent dual inhibition against COX and 5-LOX. It was identified as chebulagic acid by LC–MS, NMR and IR analyses. The chebulagic acid was also tested for anti-proliferative activity.

Results

Chebulagic acid showed potent COX–LOX dual inhibition activity with IC₅₀ values of 15 ± 0.288, 0.92 ± 0.011 and 2.1 ± 0.057 μM for COX-1, COX-2 and 5-LOX respectively. It also showed anti-proliferative activity against HCT-15, COLO-205, MDA-MB-231, DU-145 and K562 cell lines. Further mechanistic studies on COLO-205 cells revealed induction of apoptosis by chebulagic acid.

Conclusions

Chebulagic acid, a COX-2 and 5-LOX dual inhibitor isolated from the fruits of Terminalia chebula, induces apoptosis in COLO-205 cells.     

Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta

Aim of the study

The present study was aimed to investigate the pharmacological basis for the use of Loranthus ferrugineus in hypertension.

Materials and methods

Loranthus ferrugineus methanol extract (LFME) was obtained using Soxhelt extractor and then successively fractionated using chloroform, ethyl acetate and n-butanol. The n-butanol fraction of LFME (NBF-LFME) was studied using isolated rat thoracic aorta.

Results

NBF-LFME (1.0 × 10⁻⁵ to 3.0 mg/ml) was found to be the most potent to concentration-dependently relax the endothelium-intact phenyephrine (PE, 1 μM)- and high K⁺ (80 mM)-precontracted rat aortic rings. Removal of the endothelium completely abolished the vascular relaxing properties of NBF-LFME. Pretreatment with atropine (1 μM), l-NAME (10 μM), indomethacin (10 μM) and methylene blue (10 μM) significantly blocked NBF-LFME-mediated relaxation. Endothelium-dependent and -independent relaxations induced by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, were significantly enhanced in aortic rings pretreated with NBF-LFME when compared to those observed in control aortic rings. On the contrary, glibenclamide (10 μM), propranolol (1 μM) and prazosin (0.01 μM) did not alter NBF-LFME-induced relaxation.

Conclusions

The results suggest that NBF-LFME induced vascular relaxation by stimulating muscarinic receptors, activating the endothelium-derived nitric oxide-cGMP-relaxant pathway, promoting prostacyclin release and/or possibly through its ability to lengthen the released nitric oxide half-life. The present data further supports previous in vivo findings and explain the traditional use of Loranthus ferrugineus as an anti-hypertensive agent.     

Further evaluation of antihyperglycaemic activity of Hunteria umbellata (K. Schum) Hallier f. seed extract in experimental diabetes

Ethnopharmacological relevance

In African traditional medicine, water decoction made from the dry seeds of Hunteria umbellata (K. Schum) Hallier f. is highly valued in the management of diabetes mellitus.

Aim

In the present study, the antihyperglycaemic activity of the seed aqueous extract of Hunteria umbellate (K. Schum) Hallier f. (HU) was investigated in alloxan-induced, high fructose- and dexamethasone-induced hyperglycaemic rats.

Materials and methods

Alloxan-induced, dexamethasone-induced and high fructose-induced hyperglycaemic rats were treated with single, daily oral administration of 1 mg/kg of glibenclamide, 50 mg/kg, 100 mg/kg and 200 mg/kg of HU in Groups III, IV, V and VI, for 14 days, 21 days and 8 weeks, respectively. The effects of these drugs on FBG, free plasma insulin levels, HbA_1c, serum TG and TC, and insulin resistance indices were investigated.

Results

Data generated in the current study showed that glibenclamide and graded oral doses of HU caused significant dose related (p < 0.05, <0.01 and <0.001) reductions in FBG when compared to the values obtained for the model control (Group II) rats. Similarly, daily oral administration of 66.7 g/kg fructose to rats for 8 weeks was associated with significant (p < 0.001) hyperglycaemia, elevations in plasma HbA_1c, free insulin, fasting insulin resistance indices, serum TG, and cholesterol. However, concomitant oral treatments with 1 mg/kg of glibenclamide, 50 mg/kg, 100 mg/kg, and 200 mg/kg of HU extract significantly and dose dependently (p < 0.05, <0.01 and <0.001) attenuated development of hyperglycaemia, decreased levels of plasma HbA_1c, free insulin, and serum triglyceride and cholesterol, in the Groups III, IV, V and VI rats, respectively, when compared to fructose-induced hyperglycaemic (Group II) rats. Similar effect was also recorded in the dexamethasone-induced hyperglycaemic rats.

Conclusion

Results of this study suggest that the hypoglycaemic and antihyperlipidaemic effects of HU are mediated via enhanced peripheral glucose uptake and improvements in hyperinsulinaemia.