Prevention of type 2 diabetes induced by high fat diet in the C57BL/6J mouse by two medicinal plants used in traditional treatment of diabetes in the east of Algeria

Aim of the study

The preventive effect of the hydro-alcoholic extracts of Artemisia herba-alba Asso (AHA), and Centaurium erythraea Rafn (CE), two medicinal plants used in traditional treatment of diabetes in the north-eastern Algeria, were evaluated in animal models of type 2 diabetic induced with a standardised high fat diet (HFD).

Materials and methods

Plant extracts were administered orally by gavage at a dose of 2 g/kg bodyweight daily for 20 weeks to male C57BL/6J mice fed HFD. Animals were weighed and plasma glucose measured weekly and insulin at the end of study using standard ELISA methods.

Results

After 6 weeks, blood glucose levels increased in HFD control mice. At end of study (20 weeks) in groups treated with AHA or CE extracts vs. HFD control group there was a significant reduction in mean (±SD) fasting blood glucose (respectively 108.0 ± 42.0 and 120.4 ± 45.1 vs. 183.1 ± 19.1 mg/dl, p < 0.05), triglyceride concentrations (26.9 ± 6.7 and 27.9 ± 17.8 vs. 48.9 ± 12.1 mg/dl, p < 0.05) and serum insulin levels (1.1 ± 1.0 and 0.6 ± 0.7 vs. 3.1 ± 1.8 ng/ml, p < 0.05). Plant extracts also markedly reduced insulin resistance as measured by the homeostasis model assessment (HOMA) compared to HFD controls (AHA: 4.4 ± 5.3, CE: 3.0 ± 3.3 vs. HFD control 38.3 ± 26.6, p < 0.05). The plant extracts had no effect on calorie intake or body weight.

Conclusion

AHA had been shown to have a hypoglycaemic effect in diabetes but this is the first demonstration of a preventive effect of AHA and CE on HFD-induced diabetes.     

Treatment of high fat diet induced type 2 diabetes in C57BL/6J mice by two medicinal plants used in traditional treatment of diabetes in the east of Algeria

Aim of the study

Hydro-alcoholic extracts of Centaurium erythraea Rafn (CE), Gentianaceae and Artemisia herba-alba Asso (AHA), Asteraceae, medicinal plants used in traditional treatment of diabetes in north-eastern Algeria, were tested in established type 2 diabetes induced with a standardized high fat diet (HFD) in mice.

Materials and methods

After confirmation of diabetes (17th week), plant extracts were administered orally by gavage at a dose of 2 g/kg daily for 18 weeks to male C57BL/6J mice fed HFD. Animals were weighed, food intake and plasma glucose measured weekly, insulin and lipid profile at study end.

Results

At 35 weeks, groups treated with AHA or CE vs. HFD control had a significant reduction in mean (±SD) fasting blood glucose concentrations (143.8 ± 23.9 and 139.5 ± 14.2 vs. 229.0 ± 20.8 mg/dL, p < 0.05, respectively), triglyceride (18.9 ± 11.1 and 16.0 ± 6.5 vs. 62.8 ± 18.3 mg/dL, p < 0.05), total cholesterol (1.2 ± 0.1 and 1.2 ± 0.3 vs. 1.8 ± 1.1 g/L, p < 0.05) and serum insulin concentrations (1.7 ± 0.7 and 0.9 ± 0.7 vs. 3.3 ± 14.3 ng/mL, p < 0.05). Plant extracts also markedly reduced insulin resistance as compared to HFD controls (AHA: 15.6 ± 9.1, CE: 9.0 ± 7.7 vs. HFD control 38.5 ± 30.3, p < 0.05). The plant extracts decreased calorie intake and had little effect on body weight or HDL-cholesterol.

Conclusion

AHA has already been shown to have a antihyperglycaemic and antihyperlipidemic effect but this is the first demonstration of an effect of AHA and CE on established HFD-induced diabetes.     

Pharmacokinetics of aconitine as the targeted marker of Fuzi (Aconitum carmichaeli) following single and multiple oral administrations of Fuzi extracts in rat by UPLC/MS/MS

Ethnopharmacological relevance

Fuzi, which is the processed lateral roots of Aconitum Carmichaeli. Debx and is widely distributed over the southwest provinces of China, is recognised for its anti-inflammatory and analgesic effects.

Aim of the study

The pharmacokinetic properties of Fuzi are inadequately understood. Aconitine, the primary highly toxic ingredient of Fuzi, is well known as the target marker of Fuzi. The purpose of the present study is to investigate the pharmacokinetic behaviours of aconitine in vivo following single and multiple administrations of processed Fuzi extracts and to compare the pharmacokinetic characteristics of aconitine after administrations of pure aconitine or Fuzi extracts as well as compare the difference at single dose and multiple doses. The in vitro aconitine protein binding in plasma through equilibrium dialysis was also examined.

Methods

A high performance liquid chromatography (HPLC) method was developed for the determination of aconitine in Fuzi crude extracts and a fast ultra performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) was developed to investigate the pharmacokinetic behaviour of aconitine as the targeted marker of Fuzi.

Results

The absolute bioavailability (F %) after the administration of 0.5 mg/kg aconitine and Fuzi extract (0.118 mg/kg aconitine) in rat was 8.24 ± 2.52% and 4.72 ± 2.66%, respectively. Aconitine absorption was very fast at the t_max 30.08 ± 9.73 min for pure aconitine and 58.00 ± 21.68 min for Fuzi extract administration. Aconitine was also eliminated rapidly with a short half-life (i.v., 80.98 ± 6.40 min) and a low rate of protein bounding (23.9–31.9%). No significance was observed on all the pharmacokinetics parameters following the single and multiple doses of pure aconitine (ANOVA, p > 0.05). However, the absorption of aconitine after multiple administrations of Fuzi extract was much faster than that of a single dose (t_max: 58.00 ± 21.68 vs. 20.00 ± 8.66 min, p < 0.05), and the area under the plasma concentration–time curve (AUC) was higher than that of a single dose.

Conclusions

The pharmacokinetic behaviour of processed Fuzi was determined in this paper. The aconitine has low bioavailability. No variation in the pharmacokinetic behaviours of pure aconitine was observed after single and multiple administrations. In contrast, multiple administrations of processed Fuzi extract could result in variations in its pharmacokinetic behaviour in AUC and t_max indicating that multiple dose might increase the bioavailability of aconitine, which may result in its toxicity. In addition, aconitine has a low protein bounding (23.9–31.9%), resulting in its rapid elimination.     

Hancornia speciosa: indications of gastroprotective, healing and anti-Helicobacter pylori actions

Ethnopharmacological relevance

Mangaba (Hancornia speciosa Gomez) is a medicinal plant frequently cited in ethnopharmacological inventories of the central region of Brazil against gastrointestinal disorders such as diarrhoea, ulcer, gastritis and stomachache.

Aim of the study

The hydroalcoholic extract (HE) and infusion (BI) of Hancornia speciosa bark were investigated for their ability to prevent and heal rodent gastric ulcer.

Materials and methods

The preventive and healing action of both preparations of Hancornia speciosa were evaluated in experimental models in rodents that simulated this disease in human gastric mucosa.

Results

BI did not exert gastroprotective effect, in contrast to HE (500 mg/kg, p.o.) that decreased (p < 0.05) the severity of gastric damage induced by HCl/ethanol (52%), indomethacin/bethanechol (51%), stress (52%) or pylorus ligature experiments (54%). HE increased (p < 0.05) the pH and decreased acid output of gastric juice. This extract promoted increase of mucus amount (3.62 mg/wt. tissue vs. 5.81 mg/wt. tissue), healing action (67%) and displayed anti-Helicobacter pylori effect.

Conclusions

The antiulcer action of Hancornia speciosa resulted in increase of gastric mucus formation and antioxidant properties of polymeric proanthocyanidins present in the bark composition of this medicinal plant.     

Beneficial effects of Aesculus hippocastanum L. seed extract on the body's own antioxidant defense system on subacute administration

Aim of the study

Seeds of Aesculus hippocastanum L. have long been used in European phytotherapy to treat inflammatory and vascular problems. In Turkish folk medicine, tea prepared from the crushed seeds was used to pass kidney stone and against stomach ache, while a fraction of seed was swallowed to alleviate hemorroids symptoms.In order to evaluate the in vivo effects of escin mixture from Aesculus hippocastanum seed on the blood and tissue antioxidant defense systems in standard pellet diet (SPD) and in high-fat diet (HFD) consumed male mice.

Materials and methods

Escin mixture was obtained from the ethanol extract of seeds. Escin mixture was administered orally to male mice fed either standard pellet diet (SPD) or high-fat diet (HFD) at 100 mg/kg doses daily for 5 weeks and the tissue (liver, kidney and heart) and blood samples were collected at the end of experimental period. The effect of escin mixture on the plasma antioxidant activity; blood and tissue malondialdehyde (MDA) and reduced glutathione (GSH) levels; erythrocyte and tissue superoxide dismutase (SOD) and catalase activity (CAT) in SPD and HFD consumed animals were experimentally studied.

Results

Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in SPD and HFD consumed male mice. Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in SPD and HFD consumed male mice. Combined administration of high-fat diet with escin mixture decreased blood (p < 0.01), liver (p < 0.01), kidney (p < 0.05), and heart (p < 0.05) of MDA, liver SOD (p < 0.01) and CAT (p < 0.05) levels and increased blood (p < 0.01) and liver GSH (p < 0.001) levels in mice.

Conclusion

The present results indicate that Aesculus hippocastanum increase the antioxidative defense system of the body and prevent HFD-induced lipid peroxidation in male mice.     

Involvement of the L-arginine-nitric oxide pathway in the antinociception caused by fruits of Prosopis strombulifera (Lam.) Benth

Ethnopharmacological relevance

Prosopis strombulifera (Lam.) Benth. is a rhizomatous shrub that grows in the north and central zone of Argentina. In folk medicine, the fruits of this plant have been used as an astringent, anti-inflammatory and odontalgic agent and anti-diarrheic.

Aim of the study

To investigate the antinociceptive effect of ethanol (EE), chloroform (CE) and ethyl acetate (EtOAcE) extracts of Prosopis strombulifera fruits and the involvement of the l-arginine-nitric oxide pathway in this effect.

Materials and methods

The antinociceptive effects of the EE, CE and EtOAcE of Prosopis strombulifera fruits were evaluated in vivo using the formalin-induced pain test in mice with aspirin and morphine as reference antinociceptive compounds. The participation of the l-arginine-nitric oxide pathway in the antinociceptive effect was investigated in the same animal model using l-arginine as a nitric oxide (NO) precursor. The in vitro inhibitory effect of the extracts on LPS-induced nitric oxide production and iNOS expression was investigated in a J774A.1 macrophage-derived cell line.

Results

CE (300 mg/kg), in contrast to EE and EtOAcE, caused significant inhibition (p < 0.05) of the in vivo nociceptive response. Moreover, CE (100–1000 mg/kg, p.o.) produced a dose-dependent inhibition of the neurogenic and the inflammatory phases of the formalin test with inhibition values (at 600 mg/kg) of 42 ± 7% and 62 ± 7%, respectively. CE inhibition was more potent in the inflammatory phase, with an ID₅₀ of 400.1 (252.2–634.8) mg/kg. The antinociception caused by CE (600 mg/kg, p.o.) was significantly attenuated (p < 0.05) by i.p. treatment of mice with l-arginine (600 mg/kg). In addition, CE (100 μg/mL) produced significant in vitro inhibition (p < 0.001) of LPS-induced NO production, which was not observed with EE and EtOAcE at the same concentration. The inhibition of NO production by CE (10–100 μg/mL) was dose-dependent, with an IC₅₀ of 39.8 (34.4–46.1) μg/mL, and CE significantly inhibited LPS-induced iNOS expression in J774A.1 cells.

Conclusions

This study supports, in part, the ethnomedical use of Prosopis strombulifera fruits by showing that its CE produces moderate antinociception in vivo. The findings also provide scientific information for understanding the molecular mechanism involved in the analgesic effect of this plant.     

LC-MS/MS determination and pharmacokinetic study of four lignan components in rat plasma after oral administration of Acanthopanax sessiliflorus extract

Ethnopharmacological relevance

Acanthopanax sessiliflorus (Rupr. et Maxim.) Seem. is a shrub mainly present in China, Japan and Korea, the root bark of which is considered as one of the sources of Wujiapi and widely used for its various pharmacological effects.

Aim of the study

A selective and sensitive UPLC–MS/MS method was developed and validated for the determination and pharmacokinetic study of asarinin, sesamin, helioxanthin and savinin in rat plasma.

Materials and methods

Sample preparation involved a liquid–liquid extraction of the analytes with methyl tert-butyl ether (MTBE). LC separation was achieved on a UPLC C₁₈ column at 30 °C with a mobile phase consisting of methanol–2 mM ammonium acetate (68:32, v/v). The detection was accomplished by multiple-reaction monitoring (MRM) scanning with electrospray ionization (ESI) source operating in the positive ionization mode. The optimized mass transition ion-pairs (m/z) monitored for asarinin, sesamin, helioxanthin, savinin and IS were 372.2/233.0, 372.2/233.0, 349.1/319.0, 352.9/334.9 and 180.0/109.7, respectively.

Results

The current LC–MS/MS assay was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery and stability and was suitable for pharmacokinetic studies of the four lignans after oral administration of Acanthopanax sessiliflorus extract. The time to reach the maximum plasma concentration (T_max) was 2.50 ± 0.15 h for asarinin, 1.94 ± 0.28 for sesamin, 2.22 ± 0.48 h for helioxanthin and 2.83 ± 0.29 h for savinin. The elimination half-time (t_1/2) of asarinin, sesamin, helioxanthin and savinin was 6.08 ± 1.10, 11.69 ± 0.50, 7.16 ± 0.52 and 6.26 ± 0.57 h, respectively.

Conclusion

This paper described a simple, sensitive and validated UPLC–MS/MS method for simultaneous determination of four lignans in rat plasma after oral administration of Acanthopanax sessiliflorus extract, and investigated on their pharmacokinetic studies as well.     

Populus balsamifera L. (Salicaceae) mitigates the development of obesity and improves insulin sensitivity in a diet-induced obese mouse model

Ethnobotanical relevance

: In previous in vitro bioassay studies, Populus balsamifera L. (Salicaceae), a medicinal plant ethnobotanically identified from the traditional pharmacopoeia of the Cree of Eeyou Istchee (Eastern James Bay area of Canada), exhibited a strong anti-obesity potential by potently inhibiting adipogenesis in 3T3-L1 adipocytes. The aim of the study is to evaluate the effectiveness of this plant extract in mitigating the development of obesity and the metabolic syndrome in diet-induced obese (DIO) C57BL/6 mice.

Materials and methods

Mice were subjected for eight weeks to a standard diet (CHOW), a high fat diet (HFD; DIO group), or HFD to which Populus balsamifera was incorporated at 125 and 250 mg/kg.

Results

The results showed that Populus balsamifera decreased in a dose-dependent manner the weight gain of whole body, retroperitoneal fat pad and liver as compared to DIO controls and reduced the severity of hepatic macrovesicular steatosis and triglyceride accumulation. This plant extract also decreased glycemia in the second half of the feeding period and improved insulin sensitivity by diminishing insulin levels and the leptin/adiponectin ratio, as well as augmenting adiponectin levels. These effects were associated with slightly but significantly reduced food intake with 250 mg/kg Populus balsamifera as well as with an increase in energy expenditure (increase in skin temperature and increased expression of uncoupling protein-1; UCP-1). Data also suggest other mechanisms, such as inhibition of adipocyte differentiation, decrease of hepatic inflammatory state and potential increase in hepatic fatty acid oxidation.

Conclusion

Taken together, these results confirm the potential of Populus balsamifera as a culturally adapted therapeutic approach for the care and treatment of obesity and diabetes among the Cree.     

Cerebral protection of purified Herba Leonuri extract on middle cerebral artery occluded rats

Aim of study

Oxidative stress is involved in stroke. In particular, Chinese Herbal Medicine with antioxidant properties is believed to have potential therapeutic effect. In this study, neuroprotective effects of purified Herba Leonuri (pHL) were evaluated in Wistar rats undergone middle cerebral artery occlusion (MCAO).

Materials and methods

The rats were treated with their respective treatments for 2 weeks prior to the MCAO, continually treated for another 7 days after MCAO. During the post-surgery treatment period, neurological deficit score was measured. At the end of treatment, animals were sacrificed and samples were collected for analysis of infarct volume, apoptosis and antioxidant analysis.

Results

Under the treatment of pHL, the infarct volume was reduced significantly from 20.75 ± 0.03% to 15.19 ± 0.02% (p < 0.05). The neurological impairment was alleviated to 1.82 as compared to vehicle (2.43). Plasma antioxidant concentration was increased from 0.31 ± 0.03 mM to 0.42 ± 0.05 mM (p < 0.05). DNA oxidative damage was reduced to 1.19 ± 0.03 in stroke pHL treated group (p < 0.05 as compared to vehicle group, 1.78 ± 0.03). pHL could reduce the level of apoptosis and also the pro-apoptotic proteins, but increase the level of anti-apoptotic proteins.

Conclusion

pHL is believed to have promising therapeutic effect for stroke treatment through antioxidant mechanisms.     

A report on anti-oedemogenic activity of Byttneria herbacea roots--possible involvement of histamine receptor (type I)

Ethnopharmacological relevance

The traditional healers of the Kol tribes of West Bengal, Bihar and Jharkhand (India), widely use the woody rootstock of Byttneria herbacea to reduce the swelling of limbs, due to filariasis. Besides filariasis different part of this plant is used for the treatment of cholera, diarrhoea and asthma.

Aim of this study

This study is a preliminary attempt to evaluate the anti-oedemogenic activity of the roots of Byttneria herbacea.

Materials and methods

The anti-oedemogenic activity of the hydroalcoholic extract of the roots of Byttneria herbacea (HBH) was evaluated against carrageenan and histamine induced rat paw oedema, acetic acid induced writhing and histamine induced vascular permeability in mice. Further, the effect of HBH on the expression of human histamine receptor type I (H1R) was studied in HeLa cells.

Results

HBH exhibited significant dose-dependent inhibition (*p < 0.05) against carrageenan and histamine induced rat paw oedema. Similar significant dose-dependent inhibition was observed against acetic acid induced writhing and histamine-induced vascular permeability in mice. Moreover, H1R specific mRNA expression was also significantly (*p < 0.05) suppressed by HBH.

Conclusion

HBH was observed to possess anti-oedemogenic activity which is probably mediated through suppression of H1R.     

Rhodiola crenulata root ameliorates derangements of glucose and lipid metabolism in a rat model of the metabolic syndrome and type 2 diabetes

Ethnopharmacological relevance

Rhodiola species are traditionally used as tonics and stimulants to treat asthenia, suggesting their possible regulatory effect on energy metabolism. Clinical trials have demonstrated their glucose-lowering effect in type 2 diabetes.

Aim of the study

To examine the effects of Rhodiola on glucose and lipid metabolism in the metabolic syndrome and type 2 diabetes.

Materials and methods

Zucker diabetic fatty (ZDF) rats were treated with Rhodiola crenulata root (RCR) powder (100 and 500 mg/kg, by gavage, once daily for 4 weeks). In addition, the effects of RCR on sucrose-induced acute hyperglycemia in mice and olive oil-induced hypertriglyceridemia in rats were also examined. Biochemical variables were determined enzymatically or by ELISA.

Results

In ZDF rats, RCR treatment decreased the increased plasma insulin and triglyceride concentrations at baseline, the index of the homeostasis model assessment of insulin resistance (HOMA-IR) and excessive hepatic triglyceride accumulation. This treatment also inhibited abnormal increases in plasma glucose and insulin concentrations during oral glucose tolerance test. Furthermore, RCR reversed the increased adipose insulin resistance index, and accelerated the decline of plasma concentrations of non-esterified fatty acids after exogenous glucose stimulation. However, RCR minimally affected sucrose-induced acute hyperglycemia in mice and olive oil-induced acute hypertriglyceridemia in rats.

Conclusions

The present results demonstrate that RCR treatment improves metabolic derangements in animal model of the metabolic syndrome and type 2 diabetes. Our findings may provide new pharmacological basis of therapeutics for the adaptogenic plants to treat metabolic derangements-associated disorders, such as asthenia.     

Vitexin and isovitexin from the Leaves of Ficus deltoidea with in-vivo α-glucosidase inhibition

Ethnopharmacological relevance

The leaves of Ficus deltoidea are used as a traditional medicine by diabetes patients in Malaysia.

Aim of the study

The objective of the study is to identify and evaluate bioactive constituents with in vivo α-glucosidase inhibition.

Materials and Methods

The partitioned extracts, subfractions and pure bioactive constituents were subjected to α-glucosidase inhibition assay. The identified bioactive constituents were administered orally to sucrose loaded normoglycemic mice and induced diabetic rats. The postprandial blood glucose levels were monitored at 30 min interval. Acute toxicity was evaluated in both normoglycemic mice and induced diabetic rats.

Results

Bioactivity guided fractionation led to the isolation of both vitexin (1) and isovitexin (2). Oral administration of 1 mg/kg of either vitexin (1) or isovitexin (2) significantly (p<0.05) reduced the postprandial blood glucose level in sucrose loaded normoglycemic mice at 30 min. The percentage of postprandial blood glucose reduction was highest in sucrose loaded induced diabetic rats administered orally with 200 mg/kg of vitexin (1) or 100 mg/kg of isovitexin (2). Both vitexin (1) and isovitexin (2) did not exert any signs of toxicity at the highest dose of 2 g/kg administered orally to normoglycemic mice and induced diabetic rats.

Conclusion

Both the C-glycosyl bioflavonoids, namely, vitexin (1) and isovitexin (2) exhibited in vivo α-glucosidase inhibition.     

Antidiabetic, anti-oxidant and antimicrobial activities of Fadogia ancylantha extracts from Malawi

Ethnopharmacological relevance

Communities in Chilumba, Malawi use herbal tea prepared from Fadogia ancylantha Schweinf (Rubiaceae) leaves for the management of diabetes, hypertension and alleviation of symptoms of gastrointestinal disorders and pneumonia. The objective of the study was to evaluate the in vitro antidiabetic, anti-oxidant and antimicrobial activities of the crude extracts of the leaves prepared by using three different extraction methods.

Materials and methods

Each of the organic, cold and hot aqueous extracts of the herbal tea was evaluated for its effect on glucose uptake in C2C12 muscle and Chang cell lines. Metformin and insulin were used as positive controls. The anti-oxidant activity, based on neutralisation of DPPH free radicals, was determined spectrophotometrically. The Agar serial dilution method was utilised to determine the minimum inhibitory concentration (MIC) of the extracts for the selected fungal and bacterial strains.

Results and discussion

The organic extract (12.5 μg/ml) exhibited the highest in vitro glucose uptake increases in Chang cells (181.24±0.29%) and C2C12 muscle cells (172.29±0.32%) while the hot and cold aqueous extracts gave lower uptakes, 145.94±0.37% and 138.70±0.52% in Chang cells respectively. At 100 μg/ml, aqueous extracts gave significantly higher (p<0.01) anti-oxidant activity (range 85.78–86.29%) than their organic counterpart (68.16%). The minimum inhibitory concentration (156 μg/ml) was obtained in the organic extract against the fungus Aspergillus fumigatus and moderate growth inhibition was observed with other test micro-organisms. The hot aqueous extract inhibited the growth of all test organisms except Pseudomonas aeruginosa. The cold aqueous extract was inactive against Pseudomonas aeruginosa and Candida albicans. The differences in the MIC values between the aqueous extracts seem to suggest that raised temperatures, as traditionally practised, facilitate the extraction of secondary bioactive metabolites.

Conclusion

These results show that Fadogia ancylantha extracts have high antidiabetic and anti-oxidant properties.     

In vitro and in vivo immunomodulatory activities of iridoids fraction from Barleria prionitis Linn

Ethnopharmacological relevance

Barleria prionitis Linn. (Family: Acanthaceae), one of the important Ayurvedic medicinal plant in India, has long been used to treat variety of ailments including swellings, gout, arthritic and rheumatic disorders, nervine and skin diseases, and also acts as immunorestorative.

Aim of the study

The present study was aimed to explore in vitro and in vivo immunomodulatory activities of the iridoids fraction i.e. n-butanol fraction of methanol extract from Barleria prionitis aerial parts (IFBp).

Materials and methods

IFBp was studied for in vitro [nitroblue tetrazolium (NBT) test and neutrophils candidacidal assay] and in vivo immunomodulatory activity on cellular and humoral immune responses to the antigenic challenge by sheep red blood cells (SRBCs) and by neutrophil adhesion test, phagocytic activity and cyclophosphamide-induced myelosuppression. The study comprised the preliminary phytochemical screening, HPTLC standardization and maximum tolerable dose determination of IFBp.

Results

IFBp (50, 100 and 200 μg/ml) significantly (P ≤ 0.01) increased the intracellular killing activity of stimulated neutrophils assayed by in vitro NBT reduction test and neutrophils candidacidal assay. Pretreatment of IFBp (100 and 200 mg/kg; p.o.) evoked a significant increase in percent neutrophils and neutrophils adhesion to nylon fibres. Oral administration of IFBp augmented the humoral immune response to SRBCs, evidenced by increase in antibody titres and dose dependently potentiated the delayed-type hypersensitivity reaction induced by SRBCs in mice. IFBp potentiated significantly (P ≤ 0.01) the macrophage phagocytic activity and ameliorated the red blood cells, total white blood cells and platelets count and haemoglobin concentration, and also restored the myelosuppressive effects induced by cyclophosphamide. The content (% w/w; mean ± SD, n = 3) of main iridoids i.e. shanzhiside methyl ester and barlerin was found to be 21.55 ± 2.40 and 10.03 ± 1.69 in IFBp of BP, respectively.

Conclusion

The present investigation reveals that IFBp is a potent immunostimulant, stimulating both the specific and non-specific immune mechanisms.     

Effect on blood pressure of a dietary supplement containing traditional medicinal plants of Côte d'Ivoire

Ethnopharmacological relevance

A medicinal composition containing salt (sodium chloride) is given as a traditional dietary supplement to hypertensive patients (TDSHP) in Côte d’Ivoire. It consists of whole plant of Bidens pilosa (Asteraceae) and fresh leaves of Moringa oleifera (Moringaceae).

Aim of the study

The aim of this study was to establish the scientific basis for the use of this traditional recipe rich in sodium chloride in hypertension settings.

Materials and methods

We used a total aqueous extract of this traditional dietary supplement containing medicinal plants (Bidens pilosa, Moringa oleifera) and salt (sodium chloride). Experiment was carried out to evaluate its effect on arterial blood pressure of rabbits. The experimental device used for recording blood pressure in rabbits is based on the principle of Ludwig mercury manometer.

Results

TDSHP between 5 × 10⁻⁸ and 5 × 10⁻² mg/kg caused a dose-dependent hypotension. TDSHP elicited drops in blood pressure ranging between 7.14 ± 4 and 100 ± 7.5%, compared to normal blood pressure of rabbits. Fifty percent effective dose of TDSHP was 3.95 × 10⁻⁴ mg/kg. Similarly as the hypotension induced by acetylcholine, the one caused by TDSHP at dose of 3.95 × 10⁻⁴ mg/kg in rabbit was progressively inhibited by atropine, dosed between 5 × 10⁻⁴ to 5 × 10⁻² mg/kg. The percentage drop of recorded blood pressure ranged from 50.3 ± 1.87 to 3.71 ± 1.09% compared to the normal value of blood pressure. In the presence of atropine, TDSHP effect was partially inhibited. The same increasing doses of TDSHP reduced significantly the increase of blood pressure induced by adrenaline dosed at 4.76 × 10⁻⁴ mg/kg from 89.3 ± 2.19 to 1.19 ± 0.59%.

Conclusion

The consumption of this traditional dietary supplement is justified in hypertensive patients according to its composition and its ability to reduce blood pressure has been demonstrated experimentally. TDSHP should not be considered as an antihypertensive drug, it remains to us a salt substitute to be taken with moderation with strict adherence to the traditional dose.     

Diuretic activity of some Smilax canariensis fractions

Ethnopharmacological relevance

Smilax canariensis is an endemic species of the Canary Islands, popularly known as “Zarzaparrilla sin espinas”. The rhizome, leaves and stem of this species has wide use in folk medicine practice on the islands, where they are habitually employed as diuretic.

Aim of the study

In this paper we report on the diuretic activity in experimental animals of several fractions of the methanol extract of this species.

Materials and methods

Four fractions of the methanol extract of the rhizomes, leaves and stem of Smilax canariensis (50 and 100 mg/kg), Furosemide and Hydrochlorotiazide (10 mg/kg), were orally administered to laboratory animals to evaluate their diuretic activity. Water excretion rate, pH, conductivity, and content of Na⁺, K⁺ and Cl⁻ were measured in the urine of saline-loaded mice.

Results

All the studied extracts showed an interesting increase of the diuresis, although the n-buthanol (27%; p < 0.05) and ethyl acetate extract (35%; p < 0.01), at 100 mg/kg p.o., showed the most interesting diuretic activity, which suggested that this diuretic effect is associated with the compounds contained in the fractions of intermediate polarity (ethyl acetate and n-butanol), decreasing in the most extreme apolar and polar sub-extracts (dichloromethane and methanol: water respectively). The increase in diuresis produced by these two extracts was very close to the values of Hydrochlorothiazide (32%) or Furosemide (39%), used as reference diuretics.

Conclusions

These data, together with previous results on the aqueous and methanol extracts, reaffirm assertions made regarding the effectiveness of the extracts of this plant against urinary pathologies in the Canary Islands folk medicine.     

Synergistic antidiabetic activity of Vernonia amygdalina and Azadirachta indica: biochemical effects and possible mechanism

Ethnopharmacological relevance

A decoction from a combination of herbs is commonly used in Traditional African Medicine for the management of chronic ailments. In Nigeria, the leaves of Vernonia amygdalina Del. (VA) and Azadirachta indica A. Juss (AI) are used traditionally as a remedy against diabetes mellitus for which empirical evidence attests to its efficacy.

Aim of the study

To evaluate the synergistic antidiabetic action of VA and AI, the biochemical effects and possible mechanism in streptozotocin-induced diabetic rat (SDR) models.

Materials and methods

Ethanolic extracts of VA and AI were co-administered (200 mg/kg, 50:50) to non-diabetic rats (NDRs) and SDRs for 28 days. Blood glucose and body weight were monitored during this period, and at end of treatment, serum glucose, insulin, triiodothyronine (T3), tetraiodothyronine (T4) and α-amylase activity were studied. Glucose and activities of antioxidant enzymes, e.g., catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), were estimated in hepatocytes, along with the impact on the histology of the liver and pancreas. Medium acting insulin, HU (5 IU/kg, s.c.) was used as a positive control.

Results

The study reveals that compared with single extracts, the combined extract (VA/AI) promptly lowered blood glucose and maintained a relatively steady level over the study period, in tandem with HU. During this period, body weight gain successively increased. In SDRs, fasting blood glucose at days 0 and 28 was raised by 4.33 and 3.16 fold, respectively, and the serum glucose was raised by 7.70 fold vs. normal control (P < 0.05). The discrepancies in the individual effects of VA and AI on hepatic glucose and α-amylase activity were also restored. In NDRs, VA/AI lowered blood and serum glucose (1.14 and 1.94 fold, respectively), although to a lesser extent when compared with HU. Furthermore, VA/AI was found to lower serum insulin, T3 and T4 by 1.66, 1.57 and 2.16 fold, respectively, in SDR (P < 0.05). This was similar to HU, which demonstrated 1.79 and 1.68 fold reduction of insulin and T3, respectively (P < 0.05), but had no effect on T4. Conversely, in NDRs, VA/AI caused 1.32, 4.93 and 1.04 fold increase in insulin, T3 and T4, respectively, reciprocal to its effect on blood and serum glucose. Oxidative stress in SDR, characterised by decreased GPx and CAT activities, was ameliorated, as the activities of the enzymes and SOD increased following a 28-day treatment with VA/AI (P < 0.05). The features of diabetic pathology, indicated in the histology of the liver and pancreas, were reversed. However, the extent of recovery was partial with VA, better with AI, and distinct and total with VA/AI, compared with a null effect by HU.

Conclusion

Taken together, our results contribute towards validation of enhanced antidiabetic efficacy of VA and AI when combined. This synergy may be exerted by oxidative stress attenuation, insulin mimetic action and β-cell regeneration.     

Anti-nociceptive and anti-inflammatory effects of Croton crassifolius ethanol extract

Ethnopharmacological relevance

Croton crassifolius has been used to treat snake bites, stomach ache, sternalgia, joint pain, as well as pharyngitis, jaundice, and rheumatoid arthritis in traditional Chinese medicine. However, there is no scientific evidence which supports the use in the literature.

Aim of the study

To investigate the anti-nociceptive and anti-inflammatory effects of ethanol extract of C. crassifolius.

Materials and methods

Anti-nociceptive actions of C. crassifolius were assessed in mice using the hot-plate test, acetic acid-induced writhing test, and formalin test. Anti-inflammatory effects of C. crassifolius were determined in three animal models: acetic acid-induced capillary permeability accentuation in mice, carrageenan-induced edema of the hind paw in rats, and cotton pellet-induced granuloma formation in rats.

Results

Ethanol extract of C. crassifolius showed no significant anti-nociceptive activity in the hot-plate test. However, extract at dosages of 45, 90 and 180 mg/kg significantly reduced acetic acid-induced writhing by 28.89% (P<0.05), 38.37% (P<0.05), and 56.53% (P<0.001), respectively. The extract also caused marked dose-related inhibition of formalin-induced pain in the second phase (P<0.05 for 45 mg/kg, P<0.001 for 90 and 180 mg/kg extract). C. crassifolius extract at dosages of 45, 90 and 180 mg/kg significantly reduced acetic acid-induced capillary permeability accentuation in mice by 26.18% (P<0.05), 65.70% (P<0.001), and 79.19% (P<0.001), and suppressed carrageenan-induced paw edema by 21.28% (P<0.05), 30.69% (P<0.01), and 49.17% (P<0.001) at 6 h after carrageenan injection, respectively. 180 mg/kg of the extract also showed significant activity against carrageenan-induced paw edema at 4 h. At 90 and 180 mg/kg, the extract inhibited cotton pellet-induced granuloma formation in rats.

Conclusions

These results collectively demonstrate that the ethanol extract of C. crassifolius possesses peripheral anti-nociceptive and anti-inflammatory effects, providing evidence to rationalize the traditional use of C. crassifolius for the treatment of pain and inflammation.     

Hyperpigmentant activity of leaves and flowers extracts of Pyrostegia venusta on murine B16F10 melanoma

Ethnopharmacological relevance

Pyrostegia venusta is a native Brazilian plant which has a variety of uses in traditional folk medicine including the treatment of vitiligo. However, its effectiveness on melanogenesis is not yet elucidated.

Aim of the study

This study aimed to investigate the melanogenic activity of hydroalcoholic extracts from the leaves and flowers of P. venusta on murine B16F10 melanoma cells.

Materials and methods

Different concentrations of the hydroalcoholic extracts of flowers and leaves of P. venusta were evaluated in trials of spontaneous melanin content (4 days), and cell viability by the MTT assay in murine B16F10 cells, and in the mushroom tyrosinase activity in vitro.

Results

Both extracts, leaves (0.1; 0.3; 1 and 3 μg/mL) and flowers (0.03 and 0.1 μg/mL) increased the melanin content in a concentration dependent manner after 4 days of incubation on melanoma cells. Leaves extract promoted enhancement of melanogenesis with maximum effect of 33.3 ± 3% (3 μg/mL), and the flower extract increased in 23.4 ± 3% (0.1 μg/mL). The cell viability test using MTT showed that in the same tested concentrations of both extracts no cell death was detected. Actually, either extract was not able to cause any change in the tyrosinase activity. HPLC analysis of P. venusta extracts found 0.09% and 1.08% of allantoin on leaves and flowers extracts, respectively.

Conclusions

The leaves and flowers extracts of P. venusta stimulates B16F10 melanogenesis at very low concentrations. These findings support the folk medicinal use of P. venusta on the treatment of hypopigmentation diseases, such as vitiligo.