Identification of α-Glucosidase-Inhibitors in Edgeworthia gardneri (Wall.) Meisn. Using UPLC-Q-TOF-MS/MS Analysis

Edgeworthia gardneri (Wall.) Meisn., a member of the genus Edgeworthia in the family Thymelaeaceae, has long been applied as an edible and medicinal plant in China. E. gardneria has a hypoglycemic effect and is used to prepare daily drinks for the prevention and treatment of diabetes. However, the hypoglycemic substances involved remain unknown. The present study aimed to screen the α-glucosidase-inhibitors of E. gardneri and analyze its chemical profile using a ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) method. As a result, the ethyl acetate fraction (EAF) had significant α-glucosidase-inhibitory and antioxidant activities but did not show an α-amylase-inhibitory activity. A total of 67 compounds were identified in the EAF by UPLC-Q-TOF-MS/MS analysis; among them, 48 compounds were first discovered in the genus Edgeworthia. Additionally, five flavonoids, namely, isoorintin, secoisolaricirinol, tiliroside, chrysin, and kaempferol, had α-glucosidase-inhibitory activities. Rutin had a α-amylase-inhibitory activity. Daphnoretin, a kind of coumarin, has α-glucosidase and α-amylase-inhibitory activities. These findings enrich the chemical library of E. gardneria. EAF has a selective α-glucosidase-inhibitory activity, and flavonoids and coumarins may be the active components of EAF. E. gardneria has important value for developing multiple-target hypoglycemic drugs.

Microencapsulated antioxidant stevia fraction fortifies whey protein and enhances its antidiabetic activity

Whey protein was fortified with a microencapsulated fraction of Stevia rebaudiana, in the proportion 1:4 (w/w), with maltodextrin from the elite variety of Stevia UEM-13, rich in antioxidant compounds, and evaluated its antioxidant and antidiabetic potential in vitro. The fraction in ethyl acetate, the microencapsulated fraction, the whey protein obtained by membrane and a commercial whey protein were characterized and were also investigated solubility, microencapsulation efficiency and stability and digestion in vitro. In addition, these products and two formulations of the icroencapsulated fraction with the obtained whey protein were tested for their potential to inhibit the α-amylase and α-glucosidase enzyme (antidiabetic activity). The microencapsulated fraction (0.5%) and the supplement fortified with the 20% fraction microencapsulated showed inhibitory potential for the enzyme. As for the α-glucosidase enzyme, all products tested showed inhibition, with the formulation with 1.6% microencapsulated fraction added to whey protein being significantly higher. The microencapsulated fraction showed better solubility and stability, including in vitro digestion analysis, and showed antioxidant and antidiabetic capacity. A sensory evaluation was performed with panelists who regularly consume whey protein supplements and products with stevia and the supplement formulation with 1.6 g microencapsulated stevia per 100 g of whey protein have good sensory acceptance.

The diuretic effect of ethyl acetate fractions of Artocarpus altilis, Artocarpus champeden, and Artocarpus heterophyllus leaves in normotensive Wistar rats

BACKGROUND

Artocarpus altilis, A. Champeden, and Artocarpus heterophylus are popular species in Indonesia, and are commonly used as traditional medicine.

OBJECTIVE

This study aims to evaluate the diuretic effects of the ethyl acetate fraction of these three species on normotensive Wistar rats.

METHODS

The ethyl acetate fraction was prepared by a liquid-liquid extraction method. To evaluate diuretic effects, the sixty rats were divided into normal (distilled water), negative (4.5% NaCl), positive control (furosemide 5 mg/kg), and the testing groups. The testing groups were orally given the ethyl acetate fraction of A. altilis, Artocarpus champeden, and A. heterophylus at three dose levels of 25, 50, and 100 mg/kg. All animals were orally given 4.5% NaCl at a dose of 2 mL/200 g except the normal group; then the animals were given drugs according to group doses. Urine volume and electrolyte levels produced by the testing groups were compared to those of the control group. The concentration and ratio of ions were calculated to determine the natriuretic and carbonic anhydrase activities.

RESULTS

The ethyl acetate fractions of the three Artocarpus species at 100 mg/kg dose were more active than the standard furosemide (p < 0.05) to increase urinary excretion. Furthermore, at doses of 50 and 100 mg/kg, the fraction significantly increased the excretion of Na+, K+, and Cl- ions more than the standard (p < 0.05). The testing groups showed good natriuretic and carbonic anhydrase activities.

CONCLUSIONS

The ethyl acetate fraction of A. altilis, A. champeden, and A. heterophylus leaves performed good diuretic and natriuretic activities. Therefore, the fractions can be considered as potential natural diuretic medicines.

Anti-inflammatory, antinociceptive effects and involvement of opioid receptors in the antinociceptive activity of Eugenia uniflora leaves obtained with water, ethanol, and propylene glycol mixture

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia uniflora (Myrtaceae) is a species native to Brazil and has a traditional use in the treatment of inflammation.

AIM OF THE STUDY

To evaluate the anti-inflammatory and antinociceptive effects, and the involvement of opioid receptors in the antinociceptive activity of extract and fractions from Eugenia uniflora leaves.

MATERIALS AND METHODS

TLC and HPLC were used to characterize the spray-dried extract (SDE) and fractions. In the in vivo assays, Swiss (Mus musculus) mice were used. Carrageenan-induced hind-paw edema and carrageenan-induced peritonitis models were used to determine the anti-inflammatory effect of the extract (50, 100, or 200 mg/kg). Acetic acid-induced writhing, tail-flick, and formalin tests were used to determine the antinociceptive effect of the extract (50, 100, or 200 mg/kg). The aqueous (AqF) and ethyl acetate (EAF) fractions (6.25, 12.5, and 25 mg/kg) were then combined with naloxone to evaluate the involvement of opioid receptors in the antinociceptive activity.

RESULTS

In this work, the TLC and HPLC analysis evidenced the enrichment of EAF, which higher concentration of gallic acid (5.29 ± 0.0004 %w/w), and ellagic acid (1.28 ± 0.0002 %w/w) and mainly myricitrin (8.64 ± 0.0002 %w/w). The extract decreased the number of total leukocytes and neutrophils in the peritoneal cavity (p < 0.05), at doses of 100 and 200 mg/kg and showed significant inhibition in the increase of paw edema volume (p < 0.05). The treatment per oral route (doses of 50, 100, and 200 mg/kg) significantly reduced the nociceptive response in acetic acid-induced abdominal writhing (p < 0.05). The effect of the extract on the tail-flick test showed a significant increase in latency time of animals treated at doses of 200 and 100 mg/kg (p < 0.05). The extract and ethyl acetate fraction reduced the nociceptive effect in both phases of formalin at all tested doses. The naloxone reversed the antinociceptive effect of EAF, suggesting that opioid receptors are involved in mediating the antinociceptive activity of EAF of E. uniflora in the formalin test.

CONCLUSION

The current study demonstrates the anti-inflammatory and analgesic activities of water: ethanol: propylene glycol spray-dried extract from E. uniflora leaves using in vivo pharmacological models in mice. Our findings suggest that spray-dried extract and ethyl acetate fraction exhibit peripheral and central antinociceptive activity with the involvement of opioid receptors that may be related to the presence of flavonoids, mainly myricitrin.

Elsholtzia rugulosa: Phytochemical Profile and Antioxidant, Anti-Alzheimer's Disease, Antidiabetic, Antibacterial, Cytotoxic and Hepatoprotective Activities

Elsholtzia rugulosa Hemsl., a species of the Labiatae family, has a long history of use as a honey plant, herbal tea, and folk medicine in China. However, little is known about its composition and biological activities. The present study aimed to investigate the total phenol and flavonoid contents, phytochemical composition, and multiple biological activities of this plant. The total flavonoid content of the ethyl acetate fraction (EAF) was higher than those of the petroleum ether fraction (PEF), n-butanol fraction (NBF), and water fraction (WF). The EAF also had much stronger antioxidant, cytotoxic, hepatoprotective, and acetylcholinesterase (AChE) and α-glucosidase inhibitory activities than the PEF, NBF, and WF. More importantly, the IC₅₀ values of the EAF and NBF against α-glucosidase were much lower than that of the positive control acarbose, indicating their potent α-glucosidase inhibitory activities. The isolation of the EAF led to the acquisition of 9 compounds, four of which (β-daucosterol, methyl rosmarinate, betulinic acid, and oleanolic acid) possessed significant α-glucosidase inhibitory activities. Maltol 6'-O-(5-O-p-coumaroyl)-β-D-apiofuranosyl-β-D-glucopyranoside and rosmarinic acid were the major phenolic compounds in the EAF according to the HPLC-DAD analysis. All these findings indicate that the EAF, NBF, and some isolated compounds have the potential to be developed as antidiabetic drugs. Moreover, the dual inhibition of AChE and butyrylcholinesterase (BChE) of certain fractions indicates their potential in the development of anti-Alzheimer's disease drugs. The present study provides a new understanding of the phytochemistry and bioactivity of E. rugulosa.

Protective effect of ethyl acetate fraction from Semen sojae germinatum, the processed sprout of Chinese black soybean, on rat experimental osteoarthritis

BACKGROUND

Our previous in vitro study reported that the ethyl acetate fraction (EAF) of Semen sojae germinatum (SSG), the processed sprout of Chinese black soybean, possessed the potent anti-inflammatory and chondroprotective properties. The aim of the present work was to verify the in vivo antiosteoarthritic effect of EAF from SSG on a rat osteoarthritis (OA) model .

METHODS

A classical rat OA model was surgically induced by anterior cruciate ligament transaction (ACLT). The OA rats were intra-articularly administered EAF from SSG for 8 weeks. The cartilage and synovial tissues were stained with hematoxylin and eosin (HE) to observe the histopathological changes. Safranin O/fast green staining was used to assess the glycosaminoglycan content in cartilage tissue sections. The expression of type II collagen and matrix metalloproteinase (MMP)-13 in cartilage was measured by immunohistochemistry. The apoptotic chondrocytes in the cartilage sections were detected using TUNEL assay. The concentrations of interleukin (IL)-1β and tumor necrosis factor (TNF)-ɑ in synovial fluid were determined using ELISA.

RESULTS

Intra-articular administration of EAF from SSG well retained the structure and superficial layer of cartilage tissues, ameliorated cartilage lesion and the degradation of cartilage matrix, including proteoglycan and type II collagen, induced by ACLT operation. The ACLT-induced upregulation of MMP-13 expression in the cartilage tissues was resisted by EAF from SSG. Moreover, EAF from SSG inhibited the ACLT-induced chondrocyte apoptosis. Compared to OA model group, the inflammatory status of synovial membrane was improved, the levels of inflammatory cytokines IL-1β and TNF-ɑ in synovial fluid were decreased in rats administrated with EAF from SSG.

CONCLUSION

These data suggested that EAF from SSG displayed in vivo protective effect on OA development via preventing the degeneration of articular cartilage, inhibiting chondrocyte apoptosis and suppressing synovial inflammation.

Antibacterial Activity of Lidah Mertua (Sansevieria Trifasciata Prain.) Leaves Extract on Escherichia coli and Staphylococcus aureus

BACKGROUND:

Infection is the most common diseases in developing country, including Indonesia. Bacteria that often causes infection is Escherichia coli and Staphylococcus aureus. One of the traditional plants that can be used as an antibacterial is lidah mertua.

AIM:

The purpose of this study was to find out the profile of chemical compounds by thin layer chromatography method and determine the antibacterial activity of Lidah Mertua leaves by in vitro.

METHODS:

This research conducted an experimentally using non-polar, semipolar, and polar as solvents to get extract against E. coli and S. aureus as bacterial testing. The antibacterial activity using agar diffusion method to get minimum inhibitory concentration (MIC).

RESULTS:

The result of the research on thin layer chromatography showed that the compounds contained in the Lidah Mertua leaves were polifenol, steroids and alkaloids. The data obtained were tabulated and analysed descriptively. The antibacterial activity show that n-hexane extract does not provide inhibitory activity. MIC value show that aethyl acetate extract of lidah mertua leaves inhibited the growth of E. coli and S. aureus at concentration 50 mg/mL and 25 mg/mL with diameters of inhibition zone is 8.50 mm and 8.20 mm and methanol extract of lidah mertua leaves inhibited the growth of E. coli and S. aureus at concentration 12.5 mg/mL and 25 mg/mL with diameters of inhibition zone is 8.46 mm and 8.32 mm.

CONCLUSION:

The profile of chemical compounds by thin layer chromatography method showed that the compounds contained in the Lidah Mertua leaves were polifenol, steroids and alkaloids. The antibacterial activity show that n-hexane extract does not provide inhibitory activity, but aethyl acetate extract of lidah mertua leaves inhibited the growth of E. coli and S. aureus.

Adventitious root cultures of Oplopanax elatus inhibit LPS-induced inflammation via suppressing MAPK and NF-κB signaling pathways

Bioreactor-cultured adventitious roots (ARs) of the endangered medicinal plant Oplopanax elatus Nakai is a novel alternative plant material. To utilize ARs in the product production, the present study investigated the anti-inflammatory effect of O. elatus ARs. In the in vivo experiment, lipopolysaccharide (LPS)-induced acute lung injury disease model was established and several inflammatory indexes were determined. For the LPS-stimulated mice, after pretreatment of AR crude extract (200 mg/kg), cell infiltration in lungs was decreased, the production of proinflammatory mediators, including nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6, and 1β in the bronchoalveolar lavage fluid was evidently reduced, which indicated that O. elatus ARs had an anti-inflammatory effect. In the in vitro experiment, ethyl acetate (EtOAc) fractions (12.5, 25, and 50 μg/mL) were used to treat LPS-induced peritoneal macrophages (PMs) of mice. The production of NO, prostaglandin E₂, TNF-α, IL-6, and IL-1β in LPS-stimulated PMs was obviously inhibited (p < 0.05) after pretreatment with EtOAc fractions, and the expression of the inducible nitric oxide synthase and cyclooxygenase were also suppressed. To clarify the anti-inflammatory mechanism, effects of EtOAc fraction on changes of proteins related to the pathways of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) were investigated. The phosphorylation of extracellular regulated protein kinases, c-jun n-terminal kinase, and p38 MAPK in LPS-induced PMs was inhibited after pretreatment of EtOAc fractions. In addition, EtOAc fractions enhanced inhibitor of nuclear factor-kappa B-α expression and decreased nuclear translocation of p65 NF-κB. Thus, EtOAc from O. elatus ARs is involved in regulating MAKP and NF-κB signaling pathways to inhibit LPS-induced inflammation.

Inhibition of lipid accumulation by the ethyl acetate fraction of Distylium racemosum in vitro and in vivo

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Lipid accumulation in the 3T3-L1 cells were inhibited by treatment with DRE.

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The expression levels of SREBP1c, PPARγ, C/EBPα, and FAS were decreased by DRE.

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HFD induced fat mice showed lower rate of weight gain and serum TG level through DRE administration.

This study confirms the anti-obesity effect of the ethyl acetate fraction of Distylium racemosum (DRE), a member of Hamamelidaceae, that naturally grows on Jeju Island, on adipocyte differentiation in 3T3-L1 cells. This study further demonstrated that DRE exhibits anti-obesity effects in C57BL/6 obese mice. The degree of adipocyte differentiation was determined using Oil red O stain; results indicated a decrease in fat globules, which was dependent on DRE concentration, when pre-adipocytes were treated with differentiation-inducing agents. In addition, this significantly reduced the expression of the adipogenic transcription factor and related genes. C57BL/6 obese mice treated with DRE showed a lower rate of body weight gain than the high-fat diet (HFD) group mice. Further, the level of serum triglyceride in the DRE treatment group was lower than that in the HFD group. The findings show that DRE are capable of suppressing adipocyte accumulation; therefore, DRE may represent a promising source of functional materials for the anti-obesity.

Curculigoside and polyphenol-rich ethyl acetate fraction of Molineria latifolia rhizome improved glucose uptake via potential mTOR/AKT activated GLUT4 translocation

Adipose tissue is one of the major organs responsible for rapid restoration of postprandial glucose fluxes. Being the major isoform of glucose transporter in adipose tissue, regulations of insulin-dependent GLUT4 trafficking have always been of research interest. The present study aimed to examine the molecular mechanisms underlying the efficacy of curculigoside and polyphenol-rich ethyl acetate fraction (EAF) of Molineria latifolia rhizome in triggering glucose uptake. We assessed the adipogenic potential and glucose uptake stimulatory activity of curculigoside and EAF by employing a murine 3T3-L1 adipocyte model. The transcriptional and translational expressions of selected intermediates in the insulin signalling pathway were evaluated. While curculigoside neither promoted adipogenesis nor activated peroxisome proliferator activated receptor gamma, treatment with polyphenol-rich EAF resulted otherwise. However, both treatments enhanced insulin-stimulated uptake of glucose. This was coupled with increased availability of GLUT4 at the plasma membrane of the differentiated adipocytes although the total GLUT4 protein level was unaffected. In addition, the treatment increased the phosphorylation of both AKT and mTOR, which have been reported to be associated with GLUT4 translocation. The present findings proposed that curculigoside and EAF increased glucose transport activity of 3T3-L1 adipocytes via GLUT4 translocation as a result of potential mTOR/AKT activation. The more potent efficacy observed with EAF suggested potential synergistic and multi-targeted action.

The gastroprotective effect of ethyl acetate fraction of hot water extract of Trichosanthes cucumerina Linn and its underlying mechanisms

BACKGROUND

Antacids, anticholinergic drugs, histamine H2- receptor antagonists and irreversible proton pump inhibitors have been used for the treatment of gastric ulcers. However, prolonged use of these drugs may lead to series of adverse effects such as diarrhea, headache, rash, hypertension, muscular and joint pain. Therefore, there is an urgent need of more effective and safer treatments with fewer side effects. The aim of the present study was to scientifically evaluate the gastroprotective activity of fractions of the hot water extract of Trichosanthes cucumerina Linn (Family: Cucurbitaceae) aerial parts with a view to identifying the fraction with the best gastroprotective activity and the possible mechanism/s by which this fraction exert gastroprotection.

METHODS

Gastroprotective activity of hexane fraction (HF), ethyl acetate fraction (EF), butanol fraction (BF) and aqueous fraction (AF) were evaluated by the assessment of ability to reduce the ulcer index in ethanol-induced rat model and the mode of action by which the most active fraction mediating gastroprotection.

RESULTS

EF showed the maximum gastroprotection effect followed by BF and AF. EF (75 mg/kg) exhibited significantly higher gastroprotection compared to the reference drugs. Further investigations with two lower doses of EF confirmed that EF can mediated a significant and dose dependent gastroprotection. The rats treated with the EF showed significant reduction in free acidity (45%), total acidity (by 48%) in the gastric juice, increased the amount of mucus produced by the rat gastro mucosa and potent antihistamine activity (by 25.6%). EF was also rich in phenolic compounds and flavonoids.

CONCLUSION

Gastroprotective mechanism of EF is possibly involves inhibition of acidity, elevation in mucus content, inhibition of histamine and antioxidant mechanisms.

Protective effect of ethyl acetate fraction of Biophytum sensitivum extract against sodium oxalate-induced urolithiasis in rats

The methanolic whole plant extract of Biophytum sensitivum (感应草gǎnyìng cǎo) has been found to possess antiurolithiatic effect. The present study was undertaken to evaluate the antiurolithiatic effect of some fractions of methanolic whole plant extract of B. sensitivum (MBS) in rats as a step toward activity-directed isolation of antiurolithiatic component. The MBS was successively extracted with dichloromethane, ethyl acetate, ethanol and water to obtain fractions. Sodium oxalate (70 mg/kg, i.p.) was administered to rats for seven days to develop calcium oxalate urolithiasis. These rats were treated with two doses (20 and 40 mg/kg, p.o.) of the fractions, 1 h before sodium oxalate injections. Antiurolithiatic activity was assessed by estimating biochemical changes in urine, serum and kidney homogenate along with histological changes in kidney tissue. Sodium oxalate administration caused biochemical alterations in urine which was found to be prevented significantly by the ethyl acetate fraction. Supplementation with ethyl acetate fraction prevented the elevation of serum creatinine, uric acid and blood urea nitrogen levels. The elevated calcium, oxalate and phosphate levels in the kidney tissue homogenate of lithiatic rats were significantly reduced by the treatment with ethyl acetate fraction. The ethyl acetate fraction also caused significant decrease in lipid peroxidation activity, accumulation of calcium oxalate deposits and histological changes in the kidney tissue. The results showed that the antiurolithiatic component of the methanolic whole plant extract of the plant is contained in the ethyl acetate fraction. The effect is attributed to its diuretic, antioxidant, nephroprotective properties and effect on lowering the concentration of urinary stone-forming constituents.

Phytochemical, pharmacological evaluation of Morinda pubescens J.E.Sm. bark extract for nephroprotective activity

Background

Morinda pubescens J.E.Sm. (Rubiaceae) is an important medicinal plant used in indigenous system of medicine i.e., Ayurveda, Siddha and Unani.

Objective

The aim of this study is to evaluate the nephroprotective effect of M. pubescens in gentamicin induced acute renal failure in rats.

Methods

Nephrotoxicity was induced in male Wistar rats by administration of gentamicin (100 mg/kg, i.p.) once daily for 10 days. Simultaneously, the treatment was conducted with water extract bark of M. pubescens (200 mg/kg, p.o.) and its ethyl acetate fractions (100 mg/kg, p.o.) once daily for ten days. Silymarin (50 mg/kg, p.o.) is used as standard drug. Using renal biochemical markers creatinine, urea, uric acid, BUN, albumin, protein, and other parameters are kidney weight, body weight, urine volume and histopathology of the kidney. Statistical analysis was performed by using one - way ANOVA followed by Dunnett's test.

Results

It was observed that the water extract and its ethyl acetate fractions bark of M. pubescens has brought back the altered levels of biochemical markers and other parameters to the near normal levels. Histopathological study revealed treatment groups also shows the normal texture of kidney.

Conclusions

The present study possessed nephroprotective activity but ethyl acetate fraction was found to exhibit greater nephroprotective activity than the water extract.

Ethyl acetate fraction of Aframomum melegueta fruit ameliorates pancreatic β-cell dysfunction and major diabetes-related parameters in a type 2 diabetes model of rats

ETHNOPHARMACOLOGICAL RELEVANCE

In West Africa, various preparations of the fruit, seed and leaf of Aframomum melegueta K. Schum. are reputably used for the management of diabetes mellitus (DM) and other metabolic disorders. The present study evaluated the anti-diabetic effects of A. melegueta ethyl acetate fraction (AMEF) from fruit ethanolic extract in a type 2 diabetes (T2D) model of rats.

MATERIALS AND METHODS

T2D was induced in rats by feeding a 10% fructose solution ad libitum for two weeks followed by a single intraperitoneal injection of streptozotocin (40 mg/kg body weight) and the animals were orally treated with 150 or 300 mg/kg body weight (bw) of the AMEF once daily for four weeks.

RESULTS

At the end of the intervention, diabetic untreated animals showed significantly higher serum glucose, serum fructosamine, LDH, CK-MB, serum lipids, liver glycogen, insulin resistance (HOMA-IR), AI, CRI and lower serum insulin, pancreatic β-cell function (HOMA- β) and glucose tolerance ability compared to the normal animals. Histopathological examination of their pancreas revealed corresponding pathological changes in the islets and β-cells. These alterations were reverted to near-normal after the treatment of AMEF at 150 and 300 mg/kg bw when, the effects were more pronounced at 300 mg/kg bw compared to the 150 mg/kg bw.

CONCLUSION

The results of our study suggest that AMEF treatment at 300 mg/kg bw showed potent anti-diabetic effect in a T2D model of rats.

Effects and molecular mechanisms of the antidiabetic fraction of Acorus calamus L. on GLP-1 expression and secretion in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

The radix of Acorus calamus L. (AC) is widely used in diabetes therapies in traditional folk medicine from America and Indonesia, and we have previously reported that the ethyl acetate fraction of AC (ACE) acts as an antidiabetic through insulin sensitizing, insulin releasing and alpha-glucosidase inhibitory activities. The present study is designed to investigate the effects and molecular mechanisms of ACE on glucagon-like peptide-1 (GLP-1) expression and secretion related to its hypoglycemic effects.

MATERIALS AND METHODS

The hypoglycemic effect of ACE (100mg/kg, i.g.) was confirmed by testing blood glucose levels or via oral glucose tolerance test (OGTT) in streptozotocin (STZ) induced hyperglycemic mice, db/db diabetic mice and diet-induced obese (DIO) mice. Plasma insulin, GLP-1 levels and intestinal GLP-1 related gene expression were determined in STZ-induced and db/db diabetic mice. The in vitro effects of ACE (12.5μg/ml) on the expression and secretion of GLP-1 were detected in NCI-H716 intestinal L-cells, and the correlation between ACE and molecules in the Wnt signaling pathway was further explored.

RESULTS

ACE (100mg/kg) significantly lowered fasting blood glucose in STZ-induced and db/db diabetic mice and improved the OGTT in DIO mice. Insulin releasing and islet protective effects, along with the increased secretion of GLP-1, were observed. The expression of proglucagon gene (gcg) and post-translational processing gene prohormone convertase 3 (pc3) and the GLP-1 content in the culture medium of L-cells notably increased after the ACE treatment (12.5μg/ml). At the same time, β-catenin nuclear translocation occurred, and its downstream protein cyclin D1 was activated, showing the involvement of Wnt signaling.

CONCLUSIONS

ACE might activate Wnt signaling to increase the gene expression of gcg and pc3 and exert incretin effects, including insulinotropic and islet protection, to lower blood glucose levels via elevated GLP-1 secretion either directly or indirectly.

Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats

Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ)-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), and serum alkaline phosphatase (SALP) were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). It was found that administration of ethyl acetate fraction (200 and 400 mg/kg) produced a significant (P < 0.001) fall in fasting blood glucose level, TBARS, bilirubin, AST, ALT, and SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats.

Herbs in association with drugs: Enhancement of the aminoglycoside-antibiotic activity by Pityrogramma calomelanos (L.) Link

AIMS

In this work, the ethyl acetate and hexane fractions of Pityrogramma calomelanos (L.) were evaluated to antibacterial and antifungal activity against strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, Candida krusei and Candida tropicalis.

METHODS

The study was performed aiming to assess the antimicrobial effect with the method of dilution in HIA. The hexane and ethyl acetate fractions were named HFPC and EAFPC, respectively.

RESULTS

Both fractions of specie P. calomelanos displayed good activity against S. aureus when associated with gentamicin. When associated with the antifungal, the fractions did not exhibit relevant activity against species of Candida.

CONCLUSIONS

These results indicate that this specie can be used as a possible source of natural products of antibacterial interest, mainly when combined with aminoglycosides.

on 4-Nitroquinoline-1-Oxide Injected Mice

Antioxidant effects of ethyl acetate fraction of Mentha spicata (L.) were evaluated against 4-nitroquinoline-1-oxide injected mice. For this study, experiment setup consisted of 36 albino mice of either sex divided into 6 groups: Control (25% DMSO in water), ethyl acetate fraction (EAF) alone group (80, 160 mg/Kg body weight-bwt), 4-NQO (7.5 mg/Kg bwt-IP) alone and 4-NQO + EAF. EAF and vehicles were administered orally for five consecutive days. 4-NQO (7.5 mg/Kg bwt) was injected intraperitoneally on the 6(th) day. After 24 h, the animals were killed; liver sample was extracted and used for bio-assay. 4-NQO alone treated group decreased (27-60%) the antioxidant activities and promoted lipid peroxidation (LPO-60%) over their respective control values. Pretreatment with EAF, at the maximum dose (160 mg/Kg bwt) brought down the LPO up to 87% enhanced by 4-NQO. Among the enzymatic antioxidants, glutathione S-transferase (GST) was the most affected enzyme with 4-NQO and the least was catalase (CAT). Pretreatment with EAF (160 mg/Kg bwt), the restoration of antioxidants like glutathione peroxidase, superoxide dismutase, and CAT were found equal or less than 1.2 fold higher than that of the respective control values whereas, GST was observed to be the most restored antioxidant. Be reduced glutathione (GSH) and the least vitamin C over their control values. EAF restored the GSH and Vitamin E levels were found to be 1.2 fold higher than the respective control values.