Pharmacological evaluation of Alstonia scholaris: Anti-inflammatory and analgesic effects

Ethnopharmacological relevance

Alstonia scholaris (Apocynaceae) has been historically used in “dai” ethnopharmacy to treat chronic respiratory diseases. The leaf extract, developed as a commercially available traditional Chinese medicine, used to release tracheitis and cold symptom, has also been prescribed in hospitals and sold over the counter in drug stores.

Aim of the study

The investigation evaluated the anti-inflammatory and analgesic activities of the ethanolic extract, fractions and main alkaloids of Alstonia scholaris leaf to provide experimental evidence for its traditional and modern clinical use. Besides, to discover the active fraction and components for further better use in Chinese medicine is hopeful.

Materials and methods

The leaf of Alstonia scholaris was extracted with ethanol and then separated into different fractions. Furthermore, alkaloids were isolated by phytochemical method. The analgesic activities were investigated using acetic acid-induced writhing, hot-plate and formalin tests in mice. The anti-inflammatory activities were carried out in vivo and in vitro, including xylene-induced ear edema and carrageenan-induced air pouch formation in mice, and COX-1, -2 and 5-LOX inhibition.

Results

It has been exhibited that the EtOAc and alkaloid fractions reduced acetic acid-induced writhing response in mice, significantly. The ethanolic extract, EtOAc and alkaloid fractions remarkably inhibited xylene-induced ear edema. Further investigation was focused on the alkaloids fraction and three main alkaloids isolated from the alkaloids fraction, in different animal models. Alkaloids reduced acetic acid-induced writhing response, and xylene-induced ear edema in mice. In the hot-plate test, alkaloids did not increase the latency period of mice obviously. In the formalin test, alkaloids did not inhibit the licking time in first phase, but significantly inhibited the licking time in second phase of mice. Alkaloids increased significantly SOD activity and decreased levels of NO, PGE2 and MDA significantly, in air pouch mice model. Moreover, some alkaloids isolated from the leaf of Alstonia scholaris exhibited inhibition of COX-1, COX-2 and 5-LOX in vitro anti-inflammatory assay, which supported alkaloids as the bioactive fraction.

Conclusions

The alkaloids fraction of Alstonia scholaris leaf, three main alkaloids, picrinine, vallesamine and scholaricine, may produce the anti-inflammatory and analgesic effect peripherally based on several in vivo assays. In in vitro tests, alkaloids exhibited inhibition of inflammatory mediators (COX-1, COX-2 and 5-LOX), which is accordant with results on animal models. Besides, COX-2/5-LOX dual inhibitors found in the experiment, such as 16-formyl-5α-methoxystrictamine, picralinal, and tubotaiwine might be valuable for further attention.     

Effects of leaf extracts from Croton zambesicus Müell. Arg. on hemostasis

Ethnopharmacological relevance

The leaf decoction of Croton zambesicus Müell. Arg. (Euphorbiaceae; syn. Croton amabilis Müell. Arg., Croton gratissimus Burch) is traditionally used in Benin to treat hypertension.

Aim of the study

As hypertension and thromboembolism are often associated in several cardiovascular diseases, we studied the potential effects of leaf extracts from Croton zambesicus on hemostasis.

Materials and methods

We prepared the dichloromethane and aqueous extracts from the air-dried leaves of Croton zambesicus and separated the aqueous extract in its aqueous and dichloromethane fractions. The potential effects of these four extracts/fractions were investigated on red blood cells integrity using spectrophotometric lysis assays, on primary hemostasis using platelet aggregation studies and on secondary hemostasis using calibrated automated thrombin generation assays and coagulation factors inhibition tests.

Results

In the in vitro testing, we found that none of the tested extracts/fractions exhibit hemolytic or antiplatelet activity. However, they display a moderate but significant anticoagulant activity which would be mediated through the direct inhibition of thrombin, FXa and TF/FVIIa. The active anticoagulant compound(s) seem to be mainly in the aqueous extract and especially in its aqueous fraction.

Conclusions

This experimental work reported for the first time the anticoagulant effect of leaf extracts from Croton zambesicus. These findings are of particular interest as the leaves from Croton zambesicus are commonly used in infusion by local population and may provide a new natural source for the development of original anticoagulant agents. Furthermore, this activity, associated with the vasorelaxant properties of some of its diterpenes may prove to be interesting for the prevention of cardiovascular diseases in traditional medicine.     

In vitro anti-breast cancer activity of ethanolic extract of Wrightia tomentosa: role of pro-apoptotic effects of oleanolic acid and urosolic acid

Ethnopharmacological relevance

Pterocarpus marsupium Roxb. (PM) is an Ayurvedic traditional medicine well known for its antidiabetic potential.

Aim

To fractionate the antidiabetic constituent(s) of the aqueous of extract of PM hardwood (PME).

Materials and methods

Bio-assay methods including, insulin secretion from mouse pancreas and glucose uptake by mouse skeletal muscle, were used to determine and fractionate the antidiabetic activity of PME. Results obtained from the in vitro experiments were then verified by examining the effect of PME on glucose clearance in normoglycemic, non-diabetic sheep in vivo.

Results

Exposure of mouse pancreatic and muscle tissues to PME stimulated the insulin secretion and glucose uptake, respectively, in a concentration-dependent manner. PME-mediated muscle glucose uptake was not potentiated in the presence of insulin indicating that PME acts via pathways which are utilized by insulin. Bio-assay-guided fractionation of PME yielded a high molecular weight fraction which had potent antidiabetic properties in vitro, and in in vivo.

Conclusions

Our findings, we believe for the first time, provide novel insights for the antidiabetic constituents of PM and demonstrate that a high molecular weight constituent(s) of PM has potent insulinotrophic and insulin-like properties.     

Alpha-amylase inhibitory activity of two Anthocleista species and in vivo rat model anti-diabetic activities of Anthocleista djalonensis extracts and fractions

Ethnopharmacological relevance

Anthocleista djalonensis (A. Chev) and Anthocleista vogelii Planch are plants being used in West Africa traditionally to treat various diseases such as malaria, hernia, hypertension, stomach aches, hemorrhoids, syphilis, and diabetes. Diabetes causes about 5% of all deaths globally each year. Chemotherapeutic agents such as biguanides, sulfonylureas, and thiozolidinediones are available for the treatment of diabetes, however, they have undesirable side effects. The need for newer, more effective and less toxic drugs is imperative and the biodiversity of Nigeria has a high potential for drug discovery based on plants used in the ethnomedicine.

Aim of the study

To investigate the leaves, stem bark and roots of these plants for their probable alpha-amylase inhibitory activities and establish their anti-diabetic activities. The overall goal is do bioassay-guided fractionation and isolation of active anti-diabetic compounds.

Materials and methods

Powdered samples (leaves, stem bark and roots) macerated with 80% aqueous methanol were evaluated in vitro using alpha-amylase inhibitory assay while in vivo investigations were carried out on hyperglycemic rats. Diabetes was induced in albino rats by an intraperitoneal injection of alloxan monohydrate (80 mg/kg). Plant extracts (1 g/kg) were given orally for 7 days, while blood glucose levels were monitored using a one touch glucometer. The crude methanol extracts found to be most active were further partitioned into hexane and ethyl acetate fractions which were also tested in vivo on the diabetic animals.

Results

The leaves and stem bark crude methanol extracts of Anthocleista djalonensis gave comparable α-amylase inhibition of 73.66% and 72.90%, respectively which were quite higher than the 38.93% and 22.90% of the same plant parts given by Anthocleista vogelii. The crude stem bark extract of Anthocleista djalonensis exhibited significant peak blood glucose reduction on day 6 (72.59%, p<0.05) which was higher than the leaves or roots which gave 45.73% and 47.46% (p<0.05), respectively The stem bark ethyl acetate fraction of Anthocleista djalonensis gave reduction in blood glucose level of 60.86% (p<0.05).

Conclusion

From our results, the leaves, stem bark and whole root of both plants exhibited α-amylase inhibitory activities with Anthocleista djalonensis also showing good anti-diabetic activities in vivo indicating that they contain active principles for the management of diabetes. There is justification for the use of the plants traditionally to manage diabetes.     

In vitro and in vivo hepatoprotective and antioxidant activity of ethanolic extract from Meconopsis integrifolia (Maxim.) Franch

Ethnopharmacological relevance

Meconopsis integrifolia (Maxim.) Franch is a high mountain endemic species used as a traditional Tibetan and Mongolian herb to treat hepatitis, pneumonia, and edema. This study aims to investigate the hepatoprotective and antioxidant effects of Meconopsis integrifolia ethanolic extract (MIE) in vitro and in vivo.

Materials and methods

The in vitro antioxidant property of MIE was investigated by employing various established systems. Rats with carbon tetrachloride (CCl₄)-induced liver injury were used to assess the hepatoprotective and antioxidant effect of MIE in vivo. The level or activity of alkaline phosphatase (ALP), glutamate pyruvate transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) in the blood serum and thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in the liver and kidney of the rats were assayed using standard procedures.

Results

MIE exhibited strong antioxidant ability in vitro. In the rats with CCl₄-induced liver injury, the groups treated with MIE and silymarin showed significantly lower levels of ALT, AST, ALP, and TB. MIE demonstrated good antioxidant activities in both the liver and kidney of the rats in vivo.

Conclusions

MIE exhibits excellent hepatoprotective effects and antioxidant activities in vitro and in vivo, supporting the traditional use of Meconopsis integrifolia in the treatment of hepatitis.     

Insulin releasing and alpha-glucosidase inhibitory activity of ethyl acetate fraction of Acorus calamus in vitro and in vivo

Ethnopharmacological relevance

The radix of Acorus calamus L. (AC) is widely used in the therapy of diabetes in traditional folk medicine of America and Indonesia, and we previously reported the insulin sensitizing activity of the ethyl acetate fraction of AC (ACE).

Aim of the study

To investigate the insulin releasing and alpha-glucosidase inhibitory activity of ACE in vitro and in vivo.

Materials and methods

Insulin releasing and alpha-glucosidase inhibitory effects of different fractions from AC were detected in vitro using HIT-T15 cell line and alpha-glucosidase enzyme. Furthermore, effects of ACE orally on serum glucose were detected in fasted and glucose/amylum challenged normal mice.

Results

AC and ACE increased insulin secretion in HIT-T15 cells as gliclazide did. As in vivo results, ACE (400 and 800 mg/kg) significantly decreased fasting serum glucose, and suppressed the increase of blood glucose levels after 2 g/kg glucose loading in normal mice. In addition, ACE as a mixed-type inhibitor inhibited alpha-glucosidase activity in vitro with an IC₅₀ of 0.41 μg/ml, and 100 mg/kg of it clearly reduced the increase of blood glucose levels after 5 g/kg amylum loading in normal mice.

Conclusions

Apart from its insulin sensitizing effect, ACE may have hypoglycemic effects via mechanisms of insulin releasing and alpha-glucosidase inhibition, and thus improves postprandial hyperglycemia and cardiovascular complications.     

In vivo anti-inflammatory activities of Ocimum suave in mice

Ethnopharmacological relevance

Ocimum suave has been used in the Ethiopian traditional medicine to relieve pain, fever, inflammation and other disease conditions.

Aim of the study

The aim of the present study was to investigate the anti-inflammatory activities of the aqueous and ethanol leaf extracts and some fractions of Ocimum suave in mice.

Materials and methods

The crude extracts were screened for their anti-inflammatory activities on carrageenan-induced mouse paw edema at three dose levels. The butanol and aqueous fractions of the aqueous extract were also evaluated for their anti-inflammatory activities using carrageenan, histamine and serotonin-induced mouse paw edema at three dose levels. Normal saline and aspirin were employed as negative and positive control groups, respectively.

Results

Both ethanol and aqueous extracts significantly decreased carrageenan-induced inflammation at all the three doses used. However, greater paw edema inhibition was observed with the aqueous extract. The two fractions also showed significant reduction of inflammation against inflammatory models in which the aqueous residue exhibited the highest inhibition.

Conclusions

From the present findings, it can be concluded that the ethanol and aqueous leaf extracts as well as butanol and aqueous fractions of Ocimum suave have shown anti-inflammatory properties.     

Neuroprotective effects of Fructus Chebulae extracts on experimental models of cerebral ischemia

Objective

To investigate the neuroprotective effects of Fructus Chebulae extract using both in vivo and in vitro models of cerebral ischemia.

Methods

As an in vitro model, oxygen glucose deprivation followed by reoxygenation (OGD-R) and hydrogen peroxide (H₂O₂) induced cellular damage in rat pheochromocytoma (PC12) cells was used to investigate the neuroprotective effects of extract of Fructus Chebulae. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to calculate cell survival. For in vivo, occlusion of left middle cerebral artery on rats was carried out as a focal cerebral ischemic model.

Results

Fructus Chebulae extract increases the PC12 cell survival against OGD-R and H₂O₂ by 68% and 91.4% respectively. Fructus Chebulae also decreases the cerebral infarct volume by 39% and extent of hemisphere swelling from 17% in control group to 10% in Fructus Chebulae treated group.

Conclusion

Fructus Chebulae, as a traditional medicine, can rescue the neuronal cell death against ischemia related damage. The possible mechanism for the neuroprotection might be the inhibition of oxidative damages occurring after acute phase of cerebral ischemia.     

Anticancer potential of aqueous extract of alocasia macrorrhiza against hepatic cancer in vitro and in vivo

Ethnopharmacological relevance

Alocasia macrorrhiza has been used as a folk medicine for cancer treatment in the Southwest of China.

Aim of the study

The purpose of this study is to confirm the anticancer activity of aqueous extract of alocasia macrorrhiza against hepatic cancer and to elucidate its mechanism of action.

Materials and methods

Human normal liver cells and hepatocellular carcinoma cells were tested in vitro for cytotoxicity, colony formation inhibition, EdU incorporation, AO/EB staining apoptotic cells, apoptotic DNA fragmentation, and cell cycle distribution in response to alocasia macrorrhiza extract. The mRNA and protein expressions of PPARγ, Cyclin D1, Rb, P21, Bax, Bcl-2 and caspase-3 were detected through RT-PCR and Western blotting; the tumor growth inhibition in vivo was tested by oral administration of the extract.

Results

Alocasia macrorrhiza aqueous extract exhibited proliferation inhibition and apoptosis effects on human hepatocellular carcinoma cells in vitro, inhibited hepatoma growth in vivo.

Conclusion

Alocasia macrorrhiza extract has potential cytotoxic and apoptotic effect on human hepatocellular carcinoma cells and inhibits hepatoma growth in vivo, its mechanism of action might be associated with the inhibition of DNA synthesis, cell cycle (G₀/G₁) arrest, apoptosis induction through up-regulation the mRNA and protein expressions of PPARγ, Rb, Bax and capase-3genes and down-regulation of the expressions of Cyclin D1 and Bcl-2 genes.     

Anti-tumor activity and relative mechanism of ethanolic extract of Marsdenia tenacissima (Asclepiadaceae) against human hematologic neoplasm in vitro and in vivo

Ethnopharmacological relevance

Marsdenia tenacissima, a traditional Chinese medicinal herb, endemic to Yunnan Province is widely used to treat cough, asthma, expectorant, esophageal cancer, gastric cancer, lung cancer, and hepatocellular carcinoma. The aim of this study was to evaluate in vitro and in vivo anti-hematologic neoplasm potential of the ethanolic extract of this herb (crude ethanolic extract of Marsdenia tenacissima, CME) and by using different assays to elucidate its possible mechanism of action.

Materials and methods

The cytotoxicity of CME on tumor cells and peripheral blood mononuclear cells (PBMCs) was evaluated using MTT and apoptosis assays. We also tested the effect of CME on colony formation inhibition and cell cycle distribution of tumor cells. The protein expressions of Cyclin D1, Bax, Bcl-2, caspase-3 and caspase-9 were detected through Western blotting. In vivo anti-tumor effect was evaluated by measuring tumor volume changes, measuring tumor weight, evaluation of tumor microvessel density (MVD) and TUNEL staining by using immunohistochemistry staining in tumor models of nude mice.

Results

Marsdenia tenacissima ethanolic extract exhibited effects of proliferation inhibition and induction of apoptosis on human hematologic neoplasm tumor cells in vitro, as well as hematologic neoplasm growth in vivo.

Conclusion

This study clearly indicated that the ethanolic extract of Marsdenia tenacissima displayed strong anti-tumor effects against hematologic neoplasm cells and could induce tumor cells apoptosis in vitro and in vivo, and also had a significant anti-angiogenic effect in vivo against tumor cell apoptosis. Its multi-mechanism of action might be associated with the cell cycle (G0/G1) arrest, induction of apoptosis through up-regulation protein expressions of Bax, caspase-9 and caspase-3 genes and down-regulation of the expressions of Cyclin D1 and Bcl-2 genes, a decrease in tumor microvessel density and an increase of TUNEL-positive cells in vivo. These findings provided the molecular theoretical basis of clinical application.     

HPLC-based activity profiling for antiplasmodial compounds in the traditional Indonesian medicinal plant Carica papaya L

Ethnopharmacological relevance

Leaf decoctions of Carica papaya have been traditionally used in some parts of Indonesia to treat and prevent malaria. Leaf extracts and fraction have been previously shown to possess antiplasmodial activity in vitro and in vivo.

Materials and methods

Antiplasmodial activity of extracts was confirmed and the active fractions in the extract were identified by HPLC-based activity profiling, a gradient HPLC fractionation of a single injection of the extract, followed by offline bioassay of the obtained microfractions. For preparative isolation of compounds, an alkaloidal fraction was obtained via adsorption on cationic ion exchange resin. Active compounds were purified by HPLC–MS and MPLC–ELSD. Structures were established by HR-ESI-MS and NMR spectroscopy. For compounds 5 and 7 absolute configuration was confirmed by comparison of experimental and calculated electronic circular dichroism (ECD) spectroscopy data, and by X-ray crystallography. Compounds were tested for bioactivity in vitro against four parasites (Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum), and in the Plasmodium berghei mouse model.

Results

Profiling indicated flavonoids and alkaloids in the active time windows. A total of nine compounds were isolated. Four were known flavonols – manghaslin, clitorin, rutin, and nicotiflorin. Five compounds isolated from the alkaloidal fraction were piperidine alkaloids. Compounds 5 and 6 were inactive carpamic acid and methyl carpamate, while three alkaloids 7–9 showed high antiplasmodial activity and low cytotoxicity. When tested in the Plasmodium berghei mouse model, carpaine (7) did not increase the survival time of animals.

Conclusions

The antiplasmodial activity of papaya leaves could be linked to alkaloids. Among these, carpaine was highly active and selective in vitro. The high in vitro activity could not be substantiated with the in vivo murine model. Further investigations are needed to clarify the divergence between our negative in vivo results for carpaine, and previous reports of in vivo activity with papaya leaf extracts.     

Anti-angiogenic activity of methanol extract of Phellinus linteus and its fractions

Aim of the study

The aim of the present study was to investigate the effects of MeOH extract of PL (PLME) and its fractions on angiogenesis.

Materials and methods

PLME and its subsequent fractions (methylene chloride, ethyl acetate, n-butanol and aqueous fractions) were evaluated in vitro. Specifically, the anti-angiogenic activities of PLME and its fractions were investigated by measuring their effects on the proliferation, migration, tube formation and phosphorylation of vascular endothelial growth factor receptor (VEGFR)-2 in human umbilical vein endothelial cells (HUVECs). In addition, the in vivo Matrigel plug model was applied to evaluate new vessel formation.

Results

The results revealed that PLME and its subsequent fractions, except for the aqueous fraction, led to significant inhibition of the proliferation, migration, tube formation and VEGFR-2 phosphorylation of HUVECs as well as in vivo angiogenesis.

Conclusions

These findings indicate the potential for the use of PLME in pathological situations involving stimulated angiogenesis, such as inflammation and tumor development.     

Panaxatriol saponins extracted from Panax notoginseng induces thioredoxin-1 and prevents 1-methyl-4-phenylpyridinium ion-induced neurotoxicity

Aim of the study

Thioredoxin-1 has various biologic activities, including the control of redox balance and the inhibition of apoptosis. The current study was designed to examine the effects of panaxatriol saponins (PTS) extracted from Panax notoginseng on thioredoxin-1 expression and 1-methyl-4-phenylpyridinium ion-induced injury.

Materials and methods

Using PC12 cells and Kunming mice, we test thioredoxin-1 expression after PTS treatment by Western blot. The protective effect of PTS against 1-methyl-4-phenylpyridinium ion-induced injury was assessed by MTT assay and LDH release assay.

Results

PTS induced thioredoxin-1 expression in vitro and in vivo, and attenuated 1-methyl-4-phenylpyridinium ion-induced cell death of PC12 cells.

Conclusions

PTS is a new inducer of thioredoxin-1 and has a possible potential as a therapeutic agent for neurodegenerative diseases including Parkinson's disease.     

Walnut leaf extract inhibits PTP1B and enhances glucose-uptake in vitro

Ethnopharmacological relevance

Walnut, Juglans regia L. (Juglandaceae), is one of the medicinal plants used to treat diabetic symptoms in Austrian folk medicine. The air-dried green leaves are either used as aqueous decoctions or liquor preparations and are consumed on a daily basis. We investigated the hypoglycemic effect of a methanolic Juglans regia leaf extract on glucose uptake, protein tyrosine phosphatase 1B (PTP1B) inhibition and peroxisome proliferator-activated receptor gamma (PPARγ) activation.

Material and methods

Hypoglycemic activity was assessed by glucose-uptake in C2C12 myocytes, inhibition of PTP1B and activation of PPARγ. Phytochemical characterization of the extract was carried out by LC–MS and GC–MS.

Results

Methanolic Juglans regia leaf extract enhanced the glucose uptake rate in C2C12 myocytes at concentrations of 25 µg/mL compared to untreated cells. This activity may partly be explained by the inhibition of PTP1B but not PPARγ agonism. LC–MS analyses revealed chlorogenic acid (1), 3-p-coumaroylquinic acid (2), a trihydroxynaphthalene-hexoside (3), as well as eight flavonoids (4–11) as main phenolic constituents in the active extract.

Conclusions

The finding that Juglans regia leaf extract enhances glucose uptake and inhibits PTP1B provides an in vitro-based rationale for the traditional use of walnut leaf preparations against elevated blood-glucose levels.     

Regulation effects of TZQ-F on adipocyte differentiation and insulin action

Ethnopharmacological relevance

TZQ has been used in traditional Chineses medicine for treating diabetes. Based on the recipe of traditional anti-diabetic formula TZQ, we have developed TZQ-F which has been in phase 2 clinical trails. To study the mechanisms by which TZQ-F ameliorates diabetes, we examined whether treatment with TZQ-F improves hyperinsulinemia, hyperglycemia and obesity in type 2 diabetic KKA^y mice and whether this is associated with an improvement of adipocyte differentiation and insulin action.

Methods

TZQ-F, fenofibrate, rosiglitazone or distilled water was administered to 7-week-old diabetic KKA^y and nondiabetic C57BL/6J mice for 8 weeks. Insulin resistance index, body weight and levels of serum blood glucose, leptin, insulin and adiponectin were evaluated. The expression of peroxisome proliferator-activated receptor γ (PPARγ) in skeletal muscle and liver tissues were determined with real-time PCR and western boltting. The mRNA expressions of insulin receptor (InsR), insulin receptor substrate-1 (IRS-1), insulin receptor substrate-2 (IRS-2), glucose transporter-1 (Glut-1) and Phosphoenolpyruvate 3-kinases (PI3K) in skeletal muscle and liver tissues were determined with real-time PCR. Histopathology of liver has been observed.

Results

Treatment of TZQ-F for 8 weeks ameliorated hyperglycemia, hyperinsulinemia, hyperleptinemia and hypoadiponectinemia in KKA^y mice. TZQ-F also up-regulated expression of PPARγ in liver tissue. However, it had no effect on regulation of expression of PPARγ in muscle tissue. In addition, TZQ-F upregulates InsR, IRS-1, IRS-2, Glut-1, and PI3K mRNA expression. Consistent with the in vivo results, histology study demonstrated that TZQ-F alleviated pathologic changes of the liver induced by high-fat diet.

Conclusions

These results first indicate that TZQ-F can be beneficial for reducing hyperinsulinemia, hyperglycemia and obesity through its potency of regulating adipocyte differentiation and insulin action.     

In vitro and in vivo antioxidant activity of the ethanolic extract from Meconopsis quintuplinervia

Aims of the study

Meconopsis quintuplinervia, a medicinal herb endemic to the Tibetan region, is used to treat hepatitis. The aim of this study is to evaluate the antioxidant potential of the ethanolic extract of this herb using different assays.

Materials and methods

The antioxidant capacity of Meconopsis quintuplinervia was investigated using various established in vitro systems. An in vivo study of carbon tetrachloride (CCl₄)-induced antioxidant activity in mice was also conducted by examining the levels of malondialdehyde (MDA) and the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH).

Results

The extract showed strong in vitro antioxidant ability. In the in vivo study, CCl₄-induced oxidative stress caused significant decreases in the SOD, CAT, and GSH levels and a significant increase in the MDA level, most of which were significantly reversed (except for SOD in the liver.) by treatment with the extract and standard Vitamin E.

Conclusion

This study clearly indicates that the ethanolic extract of Meconopsis quintuplinervia is a valuable source of natural antioxidants. These findings provide scientific support for the traditional use of this herb as a Tibetan medicine for liver diseases.     

Serviceberry [Amelanchier alnifolia (Nutt.) Nutt. ex. M. Roem (Rosaceae)] leaf extract inhibits mammalian α-glucosidase activity and suppresses postprandial glycemic response in a mouse model of diet-induced obesity and hyperglycemia

Ethnopharmacological relevance

Serviceberry or Saskatoon berry [Amelanchier alnifolia (Nutt.) Nutt. ex. M. Roem (Rosaceae)], native to the North Glacier forests of the Rocky Mountains in Montana, has been used by the Blackfeet Indian tribe in alleviation of diabetes. Anecdotally, tea made from twigs and leaves have been used for optimum health and diabetes management. However, such traditional knowledge of the medicinal properties of Amelanchier alnifolia has not been validated by scientific studies. The goal of this study was to identify potential antidiabetic mechanisms of serviceberry.

Materials and Methods

Serviceberry plant samples consisting of leaves, twigs, and leaves with berries were extracted and fractionated. Ethyl acetate and water fractions were tested for inhibition of α-glucosidase activity in vitro. Diet-induced obese, hyperglycemic C57Bl6 mice were administered serviceberry leaf extract prior to sucrose-, starch-, or glucose-loading to test for α-glucosidase inhibition and decreased post-prandial glycemic response.

Results

In the course of screening for potential antidiabetic mechanisms, serviceberry leaf extracts and subfractions demonstrated potent inhibitory activity against mammalian intestinal α-glucosidase activity (EC 3.2.1.20). Further, in an animal model of diet-induced obesity and hyperglycemia, serviceberry leaf subfraction demonstrated significant inhibition of intestinal α-glucosidase activity, and delayed the absorption of carbohydrates, resulting in significant lowering of post-prandial blood glucose concentrations, similar to the antidiabetic drug Acarbose™.

Conclusions

These findings indicating that serviceberry leaf extract may lower post-prandial glycemic response corroborate traditional knowledge of the Blackfeet Indians of Montana, and potentially offer a complementary approach in the treatment of diabetes.     

Antidiabetic effects of Justicia spicigera Schltdl (Acanthaceae)

Ethnopharmacological importance

Justicia spicigera is a plant species used for the Teenak (Huesteca Potosina) and Mayan (Yucatan peninsula) indigenous for the empirical treatment of diabetes, infections and as stimulant.

Aim of the study

To evaluate the cytotoxicity, antioxidant and antidiabetic properties of J. spicigera.

Materials and methods

The effects of ethanolic extracts of J. spicigera (JSE) on the glucose uptake in insulin-sensitive and insulin-resistant murine 3T3-F442A and human subcutaneous adipocytes was evaluated. The antioxidant activities of the extract of JSE was determined by ABTS and DPPH methods. Additionally, it was evaluated the antidiabetic properties of JSE on T2DM model.

Results

JSE stimulated 2-NBDG uptake by insulin-sensitive and insulin-resistant human and murine adipocytes in a concentration-dependent manner with higher potency than rosiglitazone 1 mM. JSE showed antioxidant effects in vitro and induced glucose lowering effects in normoglycemic and STZ-induced diabetic rats.

Conclusion

The antidiabetic effects of administration of J. spicigera are related to the stimulation of glucose uptake in both insulin-sensitive and insulin-resistant murine and human adipocytes and this evidence justify its empirical use in Traditional Medicine. In addition, J. spicigera exerts glucose lowering effects in normoglycemic and STZ-induced diabetic rats.     

Rhizoma Paridis ethanol extract selectively inhibits the proliferation of HUVECs comparing to Lovo cells and shows anti-angiogenesis effects in a mouse model

Ethnopharmacological relevance

Rhizoma Paridis, a traditional Chinese Medicine, was identified to be cytotoxic to cancer cells. The present study was designed to investigate the potential anti-angiogenic and antitumor effect of the ethanol extract of Rhizoma Paridis (RPE) in vitro and in vivo.

Materials and methods

The cytotoxic effect of RPE against human colon cancer Lovo cells and human umbilical vein endothelial cells (HUVECs) was examined using MTT assay. We also tested the effect of RPE on tube formation, migration, apoptosis and cell cycle of HUVECs. Moreover, Lovo subcutaneous xenograft was applied to study the antitumor and anti-angiogenesis effect of RPE in vivo.

Results

RPE exerted a higher inhibition effect on the proliferation of HUVECs than Lovo cells. The tube formation and cell migration were also significantly inhibited in the presence of RPE in a concentration-dependent manner though the significant inhibition effects were observed at the cytotoxic dose. RPE induced cell apoptosis and G0–G1 cell cycle arrest of HUVECs. In vivo, significant tumor growth inhibition was observed in human colon cancer xenografts established by Lovo cells, accompanying by a marked decrease in MVD.

Conclusions

Our current study exhibited that RPE has a selective cytotoxity against HUVECs comparing to Lovo cells and also demonstrated significant anti-angiogenic effect in vivo.