Liuweidihuang-tang improves spatial memory function and increases neurogenesis in the dentate gyrus in rats

The aqueous extract of Liuweidihuang-tang given to rats at doses of 100 mg/kg/day for 10 days induced a reduction in the frequency of error and increased neurogenesis in the hippocampal dentate gyrus. Our data suggest that Liuweidihuang-tang improves spatial learning ability by increasing neurogenesis in the dentate gyrus.     

Hypoglycemic and antidiabetic activities on the stem bark aqueous and ethanol extracts of Musanga cecropioides in normal and alloxan-induced diabetic rats

Daily oral administration of the aqueous and ethanolic extracts of Musanga cecropioides stem bark in normal and diabetic rats at doses of 250, 500 and 1000 mg/kg/day, for 14 days significantly lowered the fasting plasma glucose levels in normal and alloxan-induced diabetic rats in dose-dependent fashion. The ethanol extract induced more significant antidiabetic effect than the aqueous extract.     

Evaluation of antidiabetic effect of Momordica cymbalaria fruit in alloxan-diabetic rats

The oral treatment with the aqueous extract of Momordica cymbalaria fruit (MC) (0.5 g/kg) for 6 weeks showed a significant antihyperglycemic as well as antihyperlipidemic effects in the alloxan-induced diabetic rats.     

Antihyperglycemic activity of Euphrasia officinale leaves.

The effects of the aqueous extract of the leaf of Euphrasia officinale on blood glucose levels in normal and alloxan-diabetic rats were investigated. The treatment of alloxan-induced diabetic rats brought down the raised glucose levels, while the extract was devoid of hypoglycemic effect in normal rats.     

Antidiabetic properties of aqueous barks extract of Parinari excelsa in alloxan-induced diabetic rats

The aqueous extract of the Parinari excelsa barks at doses of 100 and 300 mg/kg/day for 7 days has a significant antihyperglycemic effect on alloxan-induced diabetic rats. At the same dose the acute oral administration of aqueous extract of the P. excelsa barks (100 and 300 mg/kg) induced a significant decrease of blood glucose on glucose-loaded normoglycaemic rats. Our results seem to confirm the rational bases for its use in traditional medicine.     

Hypoglycemic effect of Mucuna pruriens seed extract on normal and streptozotocin-diabetic rats

The hypoglycemic effect of the aqueous extract of the seeds of Mucuna pruriens was investigated in normal, glucose load conditions and streptozotocin (STZ)-induced diabetic rats. In normal rats, the aqueous extract of the seeds of Mucuna pririens (100 and 200 mg/kg body weight) significantly (P<0.001) reduced the blood glucose levels after an oral glucose load from 127.5+/-3.2 to 75.6+/-4.8 mg% 2 h after oral administration of seed extract. It also significantly lowered the blood glucose in STZ diabetic rats from 240.5+/-7.2 to 90.6+/-5.6 mg% after 21 days of daily oral administration of the extract (P<0.001). Thus, this study shows that M. pruriens has an anti-hyperglycemic action and it could be a source of hypoglycemic compounds.     

Antidiabetic potential of Butea monosperma in rats

The antihyperglycemic activity of the ethanolic extract of Butea monosperma (BMEE) was studied in glucose-loaded and alloxan-induced diabetic rats. Single dose treatment of BMEE (200 mg/kg, p.o.) significantly improved glucose tolerance and caused reduction in blood glucose level in alloxan-induced diabetic rats. Repeated oral treatment with BMEE (200 mg/kg/day) for 2 weeks significantly reduced blood glucose, serum cholesterol and improved HDL-cholesterol and albumin as compared to diabetic control group.     

Compositional analysis and in vivo anti-diabetic activity of wild Algerian Marrubium vulgare L. infusion

Marrubium vulgare (Lamiaceae) is a plant traditionally used for the treatment of diabetes in Algeria. Compositional analysis of the aqueous infusion revealed the presence of fifteen metabolites, all belonging to the class of polyphenols. Particularly, seven flavonoids have been detected, together with 5-caffeoylquinic (chlorogenic) acid in small amounts; the extract is dominated by the presence of a series of complex molecules, characterized as verbascoside (acteoside) derivatives. Concerning the anti-diabetic effectiveness a series of in vivo experiments were carried out on albinos Wistar rats. Diabetes was induced in the animals by intra-peritoneal injection of alloxane; they were treated twice a day with aqueous extract from aerial part infusion (100, 200 and 300 mg/kg body weight) and glibenclamide (5mg/kg body weight) for 15 days. Oral administration of 200 and 300 mg/kg body weight of aqueous extract the Marrubium vulgare induced an significant effect antidiabetic and antihyperlipidemic (dose-dependent effect). A decrease in blood glucose by 50% for the dose 100 mg/kg and more than 60% for doses 200 and 300 mg/kg, as well as a significant lowering of total lipids, triglycerides, and total cholesterol levels in treated animals, compared with diabetic controls group (p<0.001), have been observed. Glibenclamide was used as reference and showed similar effects.     

Effects of treatment with St. John's Wort on blood glucose levels and pain perceptions of streptozotocin-diabetic rats

This present study was undertaken to examine treating effects of St. John's Wort (SJW) extract on nociceptive perception of STZ-diabetic animals based on its potential antidiabetic and antinociceptive activities. One week administrations of SJW extract (125 and 250 mg/kg) induced significant decrease in high blood glucose levels of three weeks STZ-diabetic rats and improved their dysregulated metabolic parameters. In addition, SJW extract treatment caused restoration in the mechanical hyperalgesia of diabetic animals. These findings provide a rationale for the traditional use of SJW against diabetes and display the potential of this plant as a new drug candidate/source for the treatment of diabetic pain.     

Comparative pharmacokinetics of baicalin in normal and the type 2 diabetic rats after oral administration of the Radix scutellariae extract

Radix scutellariae was used alone or in combination with other medicinal herbs in the treatment of type 2 diabetes mellitus in China. At present, the pharmacokinetics of baicalin in type 2 diabetic rats following oral administration of Radix scutellariae extract was investigated. The results showed that the pharmacokinetics (especially AUC) of baicalin in type 2 diabetic rats after oral administration of Radix scutellariae extract was remarkably different from that in normal rats. Then the mechanism which resulted in the increased AUC of baicalin in diabetic rats was investigated from system clearance and presystemic metabolism. And it was found that the increased AUC of baicalin in diabetic rats at least partly resulted from higher production of baicalein in the intestinal tract of type 2 diabetic rats. Moreover, the activity of β-glucuronidase in intestinal mucosa of type 2 diabetic rats was demonstrated to be higher than that in normal rats, which confirmed the results above. In conclusion, the pharmacokinetic behavior of baicalin was significantly altered in type 2 diabetic rats after orally administrated Radix scutellariae extract, which may partly result from the increased activity of intestinal β-glucuronidase under the pathological state of type 2 diabetes mellitus.     

Antioxidant effects of Gongronema latifolium in hepatocytes of rat models of non-insulin dependent diabetes mellitus

Gongronema latifolium is a rainforest plant, which has been traditionally used in the South Eastern part of Nigeria for the management of diabetes. The effects of oral administration of aqueous and ethanolic G. latifolium leaf extracts for 2 weeks on streptozotocin-induced diabetic rats were investigated. Both extracts were shown to significantly increase the activity of superoxide dismutase and the level of reduced glutathione. The aqueous extract further increased the activity of glutathione reductase while the ethanolic extract caused a significant increase in the activity of glutathione peroxidase and glucose-6-phosphate dehydrogenase and a significant decrease in lipid peroxidation. These results suggest that the extracts from G. latifolium leaves could exert their antidiabetic activities through their antioxidant properties.     

Hypoglycaemic activity of Ocimum gratissimum in rats

The hypoglycaemic effect of the methanolic extract of Ocimum gratissimum leaves was evaluated in normal and alloxan-induced diabetic rats. Intraperitoneal injection of the extract (400 mg/kg) significantly reduced plasma levels both in normal and diabetic rats by 56 and 68%, respectively.     

Antihyperglycemic activity of the aqueous extract of Urtica dioica

When administered 30 min before glucose loading, the aqueous extract of Urtica dioica (nettle) (250 mg/kg) showed a strong glucose lowering effect. The decrease of glycemia has reached to 33+/-3.4% of the control value 1 h after glucose loading. This effect was persistent during 3 h. In contrast, nettle did not show hypoglycemic effect in alloxan-induced diabetic rats. The amount of glucose absorbed in a segment jejunum in situ was 8.05+/-0.68 mg in presence of nettle extract vs. 11.11+/-0.75 mg in control rats during 2 h (P<0.05). The results indicate that nettle has a significant antihyperglycemic effect in OGTT model. This effect may be caused in part by the reduction of intestinal glucose absorption. LD(50) is 3.5 g/kg (i.p.).     

Hypoglicemic effect of Leandra lacunosa in normal and alloxan-induced diabetic rats

Leandra lacunosa, popularly known as "erva-do-jabuti", is used in Brazilian folkloric medicine for the treatment of diabetes mellitus. Based on this traditional indication, the aim of this work was to evaluate the hypoglycemic activity of the hydroalcoholic extract of L. lacunosa aerial parts (LLH) in normal and alloxan-induced diabetic rats. Chromatographic fractionation of LLH was also carried out by several techniques, affording isolation of the following major compounds: ursolic acid (1), kaempferol (2), luteolin (3), and quercetin (4). The oral administration of LLH (500 mg/kg) in normal rats caused a significant reduction of 24.7% (P<0.05) in the blood glucose levels after 2 h of treatment, while the administration of chlorpropamide (20 mg/kg, p.o.) led to a reduction of 40.2% (P<0.01). After oral administration of glucose (10 g/kg, p.o.), LLH (500 mg/kg, p.o.) significantly inhibited the increase in blood glucose levels compared with the negative control group. The oral treatment with LLH (500 mg/kg) in alloxan-induced diabetic rats significantly reduced the blood glucose levels in 47.8% after 4 h of treatment, while chlorpropamide resulted in a significant reduction of 71.7% in the 4th hour. Our results showed that LLH, displays hypoglycemic activity, which may be related to the effect of the major compounds identified in the crude extract. This study seems to provide biological evidence for the folkloric use of L. lacunosa in the treatment of diabetes mellitus.     

Hypoglycemic activity of Nymphaea stellata leaves ethanolic extract in alloxan induced diabetic rats

The ethanolic extract of leaves of Nymphaea stellata given by oral route to diabetic rats at dose of 100 and 200 mg/kg/day for seven days reduced significantly by 31.6 and 42.6 % the plasma glucose level increased by intraperitoneal injection of 120 mg/day of alloxan. Moreover, the treatment significantly affected the plasma level of cholesterol and triglyceride.     

Immunomodulatory effects of the methanolic extract of Epimedium alpinum in vitro

The effect of the methanolic extract of root and rhizome of Epimedium alpinum (MEEA) on phenotype and functions of rat lymphocytes in vitro was studied. It has been found that MEEA at lower concentrations (0.1 microg/ml and 1 microg/ml) significantly enhanced proliferation of splenocytes and thymocytes triggered by concanavalin A (Con A), whereas higher concentrations of the extract (50 microg/ml-500 microg/ml) were inhibitory. The stimulatory effect of MEEA on Con A-induced proliferation of splenocytes correlated with the up-regulation of interleukin-2 receptor alpha (IL-2Ralpha) expression. In addition, increased production of IL-2 was observed when a blocking IL-2Ralpha monoclonal antibody (mAb) was added to cell cultures. MEEA-suppressed proliferation of splenocytes was due to the inhibition of IL-2 production, the down-regulation of IL-2Ralpha expression and the induction of apoptosis. Cellular proliferation in the presence of inhibitory concentrations of MEEA higher than 50 microg/ml could not be restored by the addition of exogenous IL-2.     

Effects of Yerba Mate tea (Ilex paraguariensis) on vascular endothelial function and liver lipoprotein receptor gene expression in hyperlipidemic rats

Yerba Mate tea (Mate), an infusion made from the leaves of the tree Ilex paraguariensis, is a widely consumed beverage in South America. This study was performed to investigate the effect of Mate tea on vascular endothelial dysfunction and liver lipoprotein receptor gene expression in hyperlipidemic rats, with the aim of gaining insight into its known lipid-lowering protective mechanisms. Sixty male Sprague–Dawley rats were randomly divided into five groups: a normal control group (NC), a high-fat diet group (HC), and three Mate tea-treated groups. In the NC group, rats were fed with standard diet while in the other groups the rats were fed a high-fat diet for 8 weeks. In the Mate tea-treated groups, the rats were fed a high-fat diet supplemented with low, moderate or high concentrations of aqueous Mate tea extract for the final 4 weeks. Compared to the HC group, aqueous Mate tea extract significantly reduced endothelin (ET) and thromboxane B₂ (TXB₂) levels and increased nitric oxide (NO) and 6-keto prostaglandin F_1α (6-keto-PGF_1α) levels in the blood, reduced the pathological damage of vascular endothelial cells, decreased intercellular adhesion molecule-1 (ICAM-1) protein expression in the thoracic aorta, and upregulated mRNA expression of hepatic low density lipoprotein receptor (LDLR) and scavenger receptor B1 (SR-B1). These findings indicate that Mate tea administration might have a regulatory effect on blood fat and endothelial function in hyperlipidemia rats. The mechanism may involve protecting vascular endothelial cell function and upregulating the expression of LDLR and SR-B1 genes, thereby inhibiting the occurrence of atherosclerosis.     

Toxicity and anthelmintic efficacy of crude aqueous of extract of the bark of Sacoglottis gabonensis

The water extract of the stem bark of Sacoglottis gabonensis was evaluated for its preliminary acute toxicity and anthelmintic efficacy against gastro-intestinal nematodes of small ruminants and mice in both in vitro and in vivo studies. Intra-peritoneal administration of doses ranging from 400 to 3200 mg/kg of the aqueous stem bark extract produced varying degrees of toxicity manifested as depression, drowsiness and unsteady gait, paralysis of the hind limbs, dyspnoea, coma and death. The pathological lesions noted at necropsy were mainly congestion and edema of the lungs, bronchi and bronchioles and hepatomegally with focal necrosis of liver cells. The severity of the clinical symptoms and pathological lesions were dose-related. In the in vitro study, the extract significantly (P<0.05) reduced the hatching of strongyline nematode eggs from naturally infected small ruminants. The 100 mg/ml concentration of the extract produced the highest (94.4%) inhibition on nematode egg hatch and the result was comparable to similar effect produced by either levamisole (100% at 15 mg/ml) or albendazole (99.7% at 6.25 mg/ml). In rats experimentally infected with Heligmosomoides polygyrus, treatment with the S. gabonensis stem bark aqueous extract significantly (P<0.05) reduced adult worm burden and completely inhibited faecal egg output 5 days post treatment.     

Sedative properties of the decoction of the rhizome of Cyperus articulatus

The decoction of the rhizome of Cyperus articulatus is empirically used in several African countries in the treatment of a wide variety of human diseases. Studies were conducted in mice in order to determine scientifically the pharmacological properties of this medicinal herb. At the same time, the qualitative chemical characterisation of the total extract showed that C. articulatus contains flavonoids, saponins, tannins, terpenes and sugars. The total extract of the rhizome of C. articulatus does not appear to possess either anaesthetic or paralysing effects. In contrast, spontaneous motor activity is significantly reduced by the extract. However, when compared to diazepam, C. articulatus does not seem to have muscle relaxant effects. When associated with sodium thiopental or diazepam, the total extract facilitates sleep induction, and increases the total sleep time without any concomitant analgesic effect. These observations suggest that the rhizome of C. articulatus has pharmacological properties similar to those of sedatives. The sedative actions probably explain at least part of the therapeutic efficiency claimed for this plant in traditional medicine.     

Comparative pharmacokinetics of paclitaxel after oral administration of Taxus yunnanensis extract and pure paclitaxel to rats

Taxus yunnanensis (T. yunnanensis) is endemic to China and has been used in traditional medicine for the treatment of cancer, diabetic ailments and others. Paclitaxel is a representative antitumor compound in the Taxus species. The pharmacokinetic behavior of paclitaxel after oral administration of the crude extract of T. yunnanensis has not been investigated. This study attempts to compare the pharmacokinetics of paclitaxel after an oral administration of the crude extract of the twigs and leaves of T. yunnanensis and pure paclitaxel. A UPLC and a UPLC/MS/MS analysis method were developed for the determination of paclitaxel in T. yunnanensis extract and in the comparative pharmacokinetic study. Caco-2 cells were used to investigate the transport profile of paclitaxel in vitro. In the pharmacokinetic study, rats were randomly grouped and administered with T. yunnanensis extract or pure paclitaxel. The results showed that the AUC and C_max of paclitaxel in rats receiving the T. yunnanensis extract were significantly increased than those receiving the pure paclitaxel, and the in vitro Caco-2 cell monolayer transport study found that the coexisting constituents in the extract of T. yunnanensis could inhibit the efflux of paclitaxel. These findings suggested that the oral absorption and bioavailability of paclitaxel in T. yunnanensis extract were remarkably higher when compared with the pure paclitaxel, and the coexisting constituents in the T. yunnanensis extract might play an important role for the enhancement of the oral absorption and bioavailability of paclitaxel.