Novel dual-function GC/MS aided ultrasound-assisted hydrodistillation for the valorization of Citrus sinensis by-products: phytochemical analysis and anti-bacterial activities

A huge-amount of citrus by-products is being wasted every-year. There is a high-need to utilize these by-products with high-efficiency. This study focuses on the essential oil (EO) isolation from the zest of Citrus sinensis (CS) by-products, using a novel dual-function gas-chromatography mass-spectrometry optimized ultrasound-assisted hydrodistillation-prototype (DF-GC/MS-HUS). The CS-EO was GC-analyzed by MS-detector (GC/MS) and optimized by flame-ionization detector (GC/FID). Ultrasound-assisted hydrodistillation (HUS) had a dual-function in CS-EO isolation by utilizing an adequate-energy to break-open the oil-containing glands, and by functioning-as a dispersing-agent to emulsify the organic-phase. The most effective DF-GC/MS-HUS optimized-conditions were isolation under 38 °C and 10 min of 28.9 Hz sonication. The main-components of CS-EO were limonene, β-myrcene, and α-pinene (81.32%, 7.55%, and 4.20%) in prototype, compared to (60.23%, 5.33%, and 2.10%) in the conventional-method, respectively. The prototype CS-EO showed natural antibacterial-potentials, and inhibited the bio-film formation by Staphylococcus aureus, Listeria monocytogenes, and E. coli more-potent than the conventional-method. Compared to conventional-method, the prototype-method decreased the isolation-time by 83.3%, lowered energy-consumption, without carbon-dioxide production, by reducing isolation-temperatures by more-than half, which protected the thermolabile-components, and increased the quantity by 2514-folds, and improved the quality of CE-EO composition and its antibacterial-potentials. Therefore, the DF-GC/MS-HUS prototype method is considered a novel green-technique that minimized the energy-utilization with higher-efficiency.

Modulators of diabetic neuropathy and inflammation from Saponaria officinalis: Isolation of active phytochemicals and potential mechanisms of action

Background and aim

Natural metabolites are rich in neuroactive and anti-inflammatory phytochemicals. Soapwort or Saponaria officinalis (Sap) has been utilized for its immunomodulatory and ant-rheumatic properties. Thus, the aim is to exploit Sap phytochemically and to investigate Sap isolated active phytochemicals effect to modulate diabetic neuropathy and inflammation, and their possible mechanisms of action.

Experimental procedure

Bio-guided chromatographic fractionation and phytochemical isolation of the most abundant Sap phytochemicals utilizing RP-HPLC, ¹³C, and ¹H NMR, in-vivo models of diabetes, diabetic neuropathy, and inflammation were used. Glucometers, HbA1c micro-columns, in-vivo hind-paw edema, tail-flick, hot plate, and Von-Frey filaments methods were utilized to investigate the acute, subchronic, and long term diabetes, inflammation, hyperalgesia, and mechanical allodynia. In-vivo antioxidant, inhibitory alpha-amylase, and alpha-glucosidase, and serum insulin levels, IL-6, IL-10, and TNF-alpha cytokines levels were utilized to investigate Sap mechanisms of action.

Results and conclusion

The phytochemical post-hydrolysis RP-HPLC investigation results show six major peaks; Quillaic acid (12.5%), Quillaic acid 22 β-OH (11.25%), Gypsogenin (21.25%), Phytolaccinic acid (18.75%), Phytolaccinic acid (17.50%), and Echynocystic acid (15.10%). The bio-guided chromatographic fractionation investigation utilizing reversed phase HPLC, ¹³C and ¹H NMR has shown that Quillaic acid (QA) is the most abundant and biologically active compound. Sap 20 mg/kg has shown the highest potency in normalization of blood glucose level (BGL) acutely (6-h), subchronically (eight-days), and longer-term (eight-weeks) correlated to Sap 10 and 7 mg/kg, and QA 0.7, 1.0, 2.0 mg/kg. The highest amelioration of diabetic neuropathy (thermal hyperalgesia and mechanical allodynia) was Sap 20 mg/kg. The anti-inflammatory potentials of Sap 20 mg/kg have shown dominance in decreasing carrageenan-induced in-vivo hind-paw edema. The anti-nociceptive mechanism of action might be due to Sap insulin secretagogue and the in-vivo antioxidant potentials. The reduction of IL-6 cytokines and TNF-alpha, along with the elevation of the IL-10 cytokine level might be the underlying Sap anti-inflammatory mechanism. Phytochemically, QA has shown to be the most abundant and biologically active compound in Sap extract. Sap has shown significant (p < 0.05) anti-diabetic, anti-diabetic neuropathy, and anti-inflammatory effects. Our results provide new insights into the potential effects of Saponaria and Quillaic acid as future alternative therapies against diabetic neuropathy and inflammation.

Transdermal Delivery of Capsaicin Nanoemulgel: Optimization, Skin Permeation and in Vivo Activity Against Diabetic Neuropathy

Purpose: Diabetic somatic neuropathy is one of the most prevalent complications in type 1 diabetes mellitus. Many treatments were investigated to alleviate the pain associated with this condition. Capsaicin is a naturally occurring lipophilic alkaloid that proved to be an effective and safe treatment of chronic painful disorders. Despite the known therapeutic benefits of capsaicin, the conventional topical formulations have limited bioavailability. Therefore, the current study aims to develop capsaicin nanoemulgel to increase skin permeation and enhance its activity against neuropathic pain. Methods: Low-energy emulsification method was used to prepare nanoemulsions, using eucalyptus oil as the oily phase, tween 80 as a surfactant, propylene glycol, ethanol and isopropyl alcohol as co-surfactants. Pseudo-ternary phase diagrams were constructed to investigate and optimize the formulation. Subsequently, the optimum formulation was formulated as a nanoemulgel and investigated for, skin permeation using Franz diffusion cell, and diabetic neuropathy management using alloxan-induced diabetic mice. Results: The selected nanoemulsion containing 0.05% capsaicin is composed of 8 % oil, 24 % Smix (Tween 80: isopropyl alcohol 2:1 w/w) and 68 % water. It is characterized by nanosized globules (28.15±0.24 nm) with a relatively low polydispersity index (0.27±0.05). The nanoemulgel revealed circa 4-fold increase in capsaicin cumulative permeation when compared to the conventional gel, and an improvement in its antinociceptive properties was observed in the treated diabetic mice (p<0.05). Conclusion: The selected capsaicin nanoemulgel would be a promising transdermal formulation that may alleviate diabetic neuropathy in type 1 diabetes mellitus patients.

Identification of phytochemicals from North African plants for treating Alzheimer's diseases and of their molecular targets by in silico network pharmacology approach

BACKGROUND

The global social expenses of Alzheimer's disease (AD) have been increased to US$1 trillion due to high cost, side-effects, and low efficiency of the current AD-therapies. Another reason is the lack of preventive drugs and the low-income situation of Asian and African countries. Accordingly, patients rather prefer traditional herbal remedies. Network-pharmacology has been a well-established method for the visualization and the construction of disorder target protein-drug framework. This could aid in the identification of drugs molecular-mechanisms.

AIM

The aim of this study is to investigate the phytochemical constituents that could target Alzheimer's disease from the North African plants. This could be done by exploring their possible mechanisms of action through molecular network pharmacology-based approach.

EXPERIMENTAL PROCEDURE

The Phytochemical-compounds of North-African plants (NAP) have been accessed from open-databank. ADME-screening has been conducted for filtering of the NAP phytochemical-constituents utilizing Qikprop-software. The open STITCH databank has been utilized for the prediction of the phytochemical-constituents target-proteins; UniProt and TDD-DB databanks have been utilized for distinguishing AD-related proteins. Phytochemical constituent-target protein (C-T) and plant-phytochemical constituent-target protein (P-C-T) frameworks have been assembled utilizing Cytoscape to interpret the anti-Alzheimer's disease mechanism of action of the targeted phytochemical constituents.

RESULTS

The NAP 6842 phytochemical-constituents (from more than 1000 plants) have been exposed to ADME and CNS modulating filtration, generating 94 phytochemical-constituents which have been subjected to target-prediction investigation. The 94 phytochemical-constituents and the 4 AD-identified targets have been associated through 155 edges which formed the main pathways related to AD. Cuparene, alpha-selinene, beta-sesquiphellandrene, calamenene, 2-4-dimethylheptane, undecane, n-tetradecane, hexadecane, nonadecane, n-eicosane, and heneicosane have had C-T network highest combined-score, whilst the proteins MAO-B, HMG-CoA, BACE1, and GCR have been the most enriched ones by comprising the uppermost combined-scores of C-T. Hypericum perforatum, Piper nigrum, Juniperus communis, Levisticum officinale, Origanum vulgare acquired the uppermost number of P-C-Target interactions.

CONCLUSION

The phytochemical-targets prediction of NAP utilizing molecular-network pharmacology-based investigation has paved the way for networking multi-target, multi-constituent, and multi-pathway mechanisms. This may introduce potential future targets for the regulation and the management of Alzheimer's disease.

TAXONOMY CLASSIFICATION BY EVISE

Alzheimer's disease, Network pharmacology, In-silico computer based approach.

Antihyperglycemic and hepatoprotective properties of miracle fruit (Synsepalum dulcificum) compared to aspartame in alloxan-induced diabetic mice

OBJECTIVE

This study was undertaken to investigate the antihyperglycemic potential of miracle fruit (MF) as well as its hepatic safety as compared to aspartame in alloxan-induced diabetic mice.

METHODS

MF extracts were prepared and screened for their phytochemical composition using high-performance liquid chromatography (HPLC). Total phenolic, flavonoid and tannin contents and antioxidant potential were also determined. Additionally, MF was evaluated for its sensory attributes. For in vivo work, MF ethanol extract at high (MFH: 500 mg/kg body weight [BW]) and low (MFL: 250 mg/kg BW) doses as well as aspartame were injected intraperitoneally into alloxan-induced diabetic mice. Blood glucose levels were determined following acute and subchronic treatment. At the end of the study, animals were sacrificed, serum was collected for biochemical analysis and liver tissues were obtained for histopathological examination.

RESULTS

MF ethanol extract contained more flavonoids and tannins, and had higher 1,1-diphenyl-1-picrylhydrazyl radical-scavenging activity (79.61%) compared to MF aqueous extract (P < 0.05). HPLC analysis of MF ethanol extract also revealed the presence of 10 antioxidants with quercetin comprising the major polyphenol. Additionally, sensory analysis of MF showed that its intake is effective in masking undesirable sourness. Subchronic administration of MFH proved amelioration of hyperglycemia in mice as compared to aspartame. Moreover, aspartame treatment significantly elevated (P < 0.05) the level of alanine aminotransferase and had destructive effects on the liver histopathology; however, hepatic architecture was restored by low and high doses of MF.

CONCLUSION

MF is an effective antihyperglycemic with hepatoprotective properties that can be used as a healthier alternative sweetening agent in place of aspartame for sour beverages.

In Vitro and In Vivo Evaluation of the Protective Potential of Moringa oleifera Against Dietary Acrylamide-induced Toxicity

Background:

A c rylamide (AA) in food is a public health concern that has attracted scientists’ attention worldwide.

Objective:

This study was carried out to investigate the efficiency of Moringa oleifera (M. olifera) leaves in the reduction of AA in French fries in vitro and its hepato-protective properties against AA-induced liver toxicity in vivo.

Materials and Methods:

Total phenolic, flavonoid, tannin contents and antioxidant potential of M. oleifera leaves were evaluated and the phenolic constituents characterized via HPLC. AA content was also monitored in French fries using LC-MS/MS. For in vivo assay, mice were treated with AA alone or in combination with M. oleifera (150 and 250 mg/kg IP).

Results:

Phytochemical screening showed that gallic acid, ellagic acid, epicatechin, and quercetin were the most abundant phenolic compounds identified. This work also demonstrated a nearly 37% reduction in AA when French fries were soaked in 1% M. oleifera. Moreover, AA-intoxicated mice resulted in a significant (P < 0.05) elevation in the liver enzyme alanine aminotransferase (ALT), which was restored when pre-treated with M. oleifera.

Conclusion:

This study proved that M. olifera could be effective in reducing AA levels in French fries and that treatment with M. oleifera extract can restore the hepatic damage in AA-intoxicated mice.

Phytochemical and anti-neuropathic investigations of Crocus sativus via alleviating inflammation, oxidative stress and pancreatic beta-cells regeneration

Objective

The aim of this study is to investigate the phytochemical and the long-term anti-neuropathic potentials of Crocus sativus cultivated in the University botanical garden, and explore its most bioactive compounds and their underlying mechanisms of action.

Methods

Phytochemical analysis and bio-guided isolation-procedures including RP-HPLC and ¹H and ¹³C NMR utilizing biological models of diabetes, inflammation, and diabetic-neuropathy were used. Cultivated saffron (S-RCED) and Spanish-saffron stigma (S-SP) alone or in combination with Camellia sinus (CS) were investigated.

Results

The RP-HPLC analyses showed the presence of picrocrocin, crocin I, crocin II, crocin I’, crocin II’, and safranal (SAF) in both S-SP and S-RCED extracts with higher-concentrations. It had been shown that SAF was the most bioactive-compound in Crocus sativus. Both S-SP and S-RCED possessed significant (P < 0.05) anti-diabetic activities in acute (6 h), subchronic (8 d) and chronic (8 weeks) models. S-RCED had been proven with more hypoglycemic potentials when compared to S-SP and SAF. S-SP, S-RCED, and SAF produced significant anti-inflammatory and anti-nociceptive activities against carrageenan-induced inflammatory, hyperalgesic and tactile diabetic-neuropathy models, respectively. S-SP, S-RCED, and SAF elevated serum catalase, reduced glutathione, and insulin serum levels, ameliorated lipid peroxidation and HbA1c levels, and histopathologically regenerated the pancreatic beta-cells. Combinations with CS showed more significant efficacy than the single component.

Conclusion

The oxidative stress reduction, insulin secretagogue, and pancreatic beta-cells regeneration potentials might be responsible for the mechanism underlying the anti-diabetic, anti-inflammatory and anti-diabetic neuropathy activities. Thus, the cultivated Crocus sativus might be clinically useful for protecting against many serious-disorders.

Phytochemical analysis of Ficus carica L. active compounds possessing anticonvulsant activity

The anticonvulsant potential of Ficus carica methanol-extract (Fc) has been studied. It was found that Fc most active fraction is rich in oligosaccharides (OFG). ¹H, ¹³C NMR and Nano-ESI, MALDI MS, and LC-MS techniques proved that OFG contains alpha-glucopyranoside oligomer in high amounts. Both Fc and OFG reduced strychnine (STR) convulsion-action. Fc and OFG fully protected the experimental-animals from STR-lethality. The intracerebroventricular-administration (ICV) of Fc or OFG in combination with glycine in ethanol-treated mice caused a dose-dependent returning to a 2nd-loss of righting-reflex (LORR), and was antagonized by STR. FC and OFG ICV injection counteracted STR-inhibition, confirming that Fc/OFG anticonvulsant mechanism of action was mediated by potentiation of glycine receptor. These results support Fc and OFG potential anticonvulsant-activity with good safety-profile.

Combination of Rheum ribes and Metformin Against Diabetes, Thermal Hyperalgesia, and Tactile Allodynia in a Mice Model

CONTEXT

The prevalence of diabetes mellitus (DM) is increasing. Because of its progressive nature, therapeutic shifts and combinations are often required to reduce the risk of glucose toxicity and avoid serious side effects. To treat DM and its related complications, a combination therapy may offer a promising remedy to counteract those issues.

OBJECTIVES

The study was established to evaluate the phytochemical content of a standardized aqueous extract of Rheum ribes (RR) and to determine the antidiabetic, antihyperalgesic, and antimechanical allodynic effects of 50 mg/kg of RR alone, 25 mg/kg of metformin (MTF) alone, and a combination of the 2 substances (MTF+RR) in mice with alloxan-induced diabetes.

DESIGN

The research team designed an animal study.

SETTING

The study was performed at the facilities of the faculty of pharmacy at Beirut Arab University (Beirut, Lebanon).

ANIMALS

The animals were male, Swiss-Webster mice, weighing 22-30 g and aged 12-16 wk.

INTERVENTION

DM was induced in experimental animals by an IP injection of alloxan every 48 h for 3 injections at a total dose of 180 mg/kg. Substudy A measured the acute-0, 0.5, 2, and 6 h-and subchronic-1, 3, 5, and 8 d-effects of a water extract of the RR alone, of the MTF alone, and of the MTF+RR combination on blood-glucose levels (BGLs), body weights, and catalase (CAT) serum levels. The mice were divided into 6 groups of 7 mice each, and each group received various IP injections of the tested samples: (1) group 1, a vehicle control group of normal mice (NORM group) received sterile, cold, 0.9% saline; (2) group 2, a vehicle control group of diabetic mice (VEH group) received sterile, cold, 0.9% saline; (3) group 3, a positive control group of diabetic mice (GB group) received 5 mg/kg of glibenclamide; (4) group 4, an intervention group of diabetic mice (MTF group) received 25 mg/kg of MTF only; (5) group 5, an intervention group of diabetic mice (RR group) received 50 mg/kg of RR only; and (6) group 6, an intervention group (MTF+RR group) of diabetic mice received 25 mg/kg of MTF and 50 mg/kg of RR. Substudy B measured the subchronic-0, 2, 4, 6, and 8 wk-effects of the RR only, of the MTF only, and of the MTF+RR combination on the hot plate and tail flick latencies and on the von Frey paw withdrawal thresholds. Again, they were divided into 6 groups of 7 mice each (groups 7 through 12), and each group received various IP injections of the tested samples, with all of the groups receiving the same treatments as for substudy A, except that group 9, a positive control group of diabetic mice, received 10 mg/kg of tramadol.

OUTCOME MEASURES

The BGLs of the mice were monitored acutely for 6 h and subchronically for 8 d. Glycated hemoglobin (HbA1c), inhibition of α-glucosidase, and effects on serum insulin were evaluated. Using tail flick, hot plate latencies, and von Frey paw withdrawal thresholds, thermal hyperalgesia and tactile allodynia were assessed. Using a natural antioxidant, in vivo antioxidant activity was used to evaluate CAT and lipid peroxide (LPO) levels.

RESULTS

The reductions in blood glucose, HbA1c, α-glucosidase, and LPO were statistically significant for the MTF+RR. The body weight, serum insulin, tail flick, hot plate latencies, paw withdrawal thresholds, and CAT increased significantly in diabetic mice treated with the combination. Consequently, the combination's potent inhibitory effect on α-glucosidase and serum insulin elevation might be responsible for its hypoglycemic potential, whereas its antioxidant effects might be responsible for the amelioration of painful hyperalgesia and allodynia, suggesting that the combination has better antidiabetic and antinociceptive effects and fewer side effects than treatment with MTF alone. No adverse events were reported.

CONCLUSION

When combined with MTF, RR might be a promising adjuvant for amelioration of DM and related nociceptive complications.

Phytochemical Compositions and Antidiabetic Potentials of Salvia sclarea L. Essential Oils

Salvia sclarea (SS) is characterized by its valuable essential oils (Eos) and potent biological activities. This study aimed at investigating the phytochemical composition of SS Eos collected in within the same week, from two different regions in Lebanon, Beirut (SS-Bt) and Taanayel (SS-Tl), utilizing GC-MS methods, and to explore their acute and subchronic antidiabetic potentials. Moreover, studying the phytochemical diversity of twenty SS Eos established on our work and literature descriptions in order to recognize the origin of the Lebanese active chemotype(s). The Eos have been obtained by hydro-distillation and identified via GC-MS analyses. Five chemotypes of SS Eos have been identified. The Lebanese Eos, SS-Bt and SS-Tl, studied here have shown evidence to belong to two different chemotypes 1 and 5, respectively. SS-Bt has shown to belong to chemotype 1, which is characterized by high linalool (LL) concentration (average 40.2%). On the other hand, SS-Tl has shown to belong to chemotype 5, which is characterized by high linalyl acetate (LA) concentration (average 50.4%). The acute and subchronic antidiabetic activities of these EOs have been monitored along with LL and LA, in order to find the most active chemotype. Chemotypes 1 (owned to high LL content), present at low altitude places of Lebanon and Poland, has shown significantly higher acute and subchronic antidiabetic activities than that of chemotype 5 (owned to high LA content). In conclusion, Salvia sclarea Eos have shown potential antidiabetic activities, and their Eos might be used in the future as a complementary or an alternative medicine in the management of diabetes and related complications.

Infrared-Assisted Extraction and HPLC-Analysis of Prunus armeniaca L. Pomace and Detoxified-Kernel and their Antidiabetic Effects

INTRODUCTION

Prunus armeniaca L. (P. armeniaca) is one of the medicinal plants with a high safety-profile.

OBJECTIVES

The aim of this work was to make an infrared-assisted extraction (IR-AE) of P. armeniaca fruit (pomace) and kernel, and analyse them using reverse phase high-performance liquid chromatography (RP-HPLC) aided method.

METHODS

IR-AE is a novel-technique aimed at increasing the extraction-efficiency. The antidiabetic-potentials of the P. armeniaca pomace (AP) and the detoxified P. armeniaca kernel extract (DKAP) were monitored exploring their possible hypoglycemic-mechanisms. Acute (6 h), subchronic (8 days) and long-term (8 weeks) assessment of Diabetes mellitus (DM) using glucometers and glycated hemoglobin (HbA1c) methods were applied.

RESULTS

Serum-insulin levels, the inhibitory effects on alpha-glucosidase, serum-catalase (CAT) and lipid peroxidation (LPO) levels were also monitored. AP was shown to be rich in polyphenolics like trans-lutein (14.1%), trans-zeaxanthin (10.5%), trans-ß-cryptoxanthin (11.6%), 13, cis-ß-carotene (6.5%), trans 9, cis-ß-carotene (18.4%), and ß-carotene (21.5%). Prunus armeniaca kernel extract before detoxification (KAP) was found to be rich in amygdaline (16.1%), which caused a high mortality rate (50.1%), while after detoxification (amygdaline, 1.4%) a lower mortality rate (9.1%) was found. AP showed significant (p ≤ 0.05, n = 7/group) antidiabetic-activity more prominent than DKAP acutely, subchronically and on longer-terms. IR-AEs displayed more efficient acute and subchronic blood glucose level (BGL) reduction than a conventional extraction method, which might be attributed to IR-AE superiority in extraction of active ingredients. AP showed more-significant and dose-dependent increase in serum-insulin, CAT-levels and body-weights more prominent than those of DKAP. Alpha-glucosidase and LPO levels were inhibited with AP-groups more-significantly.

CONCLUSION

In comparison to conventional-methods, IR-AE appeared to be an efficient and time-conserving novel extraction method. The antidiabetic-potentials of pomace and detoxified-kernels of P. armeniaca were probably mediated via the attenuation of glucose-provoked oxidative-stress, the inhibition of alpha-glucosidase and the marked insulin-secretagogue effect. Copyright © 2017 John Wiley & Sons, Ltd.

Neuroprotective effects of Moringa oleifera: Bio-guided GC-MS identification of active compounds in diabetic neuropathic pain model

OBJECTIVES

To explore the phytotherapeutic-activities of Moringa oleifera (MO) seeds on painful diabetic neuropathy in alloxan-induced diabetic mice.

METHODS

The bio-guided fractionation of MO utilizing column chromatography aided with GC-MS was used to detect the most active constituent of MO. Hyperalgesia, using tail-flick and hot-plate latency experiments, and mechanical-allodynia, utilizing von-Frey filaments, were evaluated before and after 8 weeks of intraperitoneal alloxan administration (180 mg/kg). Serum catalase and insulin levels, body weight and blood glucose levels (BGL), alpha-glucosidase inhibition, lipid peroxidation and glycated hemoglobin (HbA1c) were measured to evaluate both alloxan-induced diabetes mellitus and diabetic painful neuropathy (DPN).

RESULTS

Beta-sitosterol (BSL) was proved to be the most active constituent of MO. The administration of MO (40, 60 and 80 mg/kg) or BSL (18, 25 and 35 mg/kg) significantly attenuated hyperalgesia and tactile allodynia (P⩽0.05), compared with tramadol (10 mg/kg) acting as a positive control, in alloxan-treated animals (n=7 per group). Moreover, MO and BSL have improved insulin secretion, in vivo antioxidant catalase, lipid peroxidation, acute and subchronic BGL, and normalized alpha-glucosidase and HbA1c levels.

CONCLUSIONS

The observed insulin secretagogue, alpha-glucosidase inhibition, hypoglycemic and antioxidant potentials might be responsible for MO and BSL antinociception and neuroprotective mechanism. MO and BSL have shown good glycemic-control and powerful neuroprotective properties which might serve as potential lead-compounds for further analysis.

Prunella vulgaris L. active components and their hypoglycemic and antinociceptive effects in alloxan-induced diabetic mice

Prunella vulgaris L. (Lamiaceae) (PV) is a herbaceous plant traditionally utilized in management of diabetes and it has immunomodulatory activity. In this study, acute and subchronic antidiabetic, in-vivo antioxidant and antinociceptive effects of PV were evaluated in alloxan-induced type 1 diabetes (T1D) in a mouse model. Bio-guided fractionation, isolation, RP-HPLC, and ¹H and ¹³C NMR identification of the active components responsible for PV effects were determined. RP-HPLC analysis showed that PV contained rosmarinic acid (RA) 4.5%, caffeic acid (CA) 9.8% and p-coumaric acid (pCA) 11.6%. Bio-guided fractionation showed that PV most active fraction was rich in caffeic acid, hence named, caffeic acid-rich fraction (CARF). RP-HPLC, and ¹H and ¹³C NMR experiments showed that CARF contained CA (93.4%) and RA (6.6%). CARF reduced blood glucose levels and improved in-vivo oxidative-stress. It also inhibited the carbohydrate-hydrolyzing enzymes (alpha-amylase and alpha-glucosidase) and reduced HbA1c levels more significantly (p≤0.05) than that of PV and equivalent amounts of CA or RA. For longer times, CARF had significantly (p≤0.05) increased serum-insulin, ameliorated thermal hyperalgesia and tactile allodynia more significantly (p≤0.05) than the effects of PV and equivalent amounts of CA or RA. Moreover, the tested compounds showed potential restoration of the lipid peroxide levels. Consequently, CARF and PV observed increase in serum-insulin, attenuation of alpha-amylase and alpha-glucosidase, and their antioxidant potentials might be responsible for their antidiabetogenic and antinociceptive properties. In conclusion, CARF isolated from PV could be a potential therapeutic agent to ameliorate T1D and related complications.

Anti-Inflammatory and Antioxidant Activities of Salvia fruticosa: An HPLC Determination of Phenolic Contents

Objectives. Salvia fruticosa Mill. (S. fruticosa) is widely used in folk medicine. Accordingly, the present study was designed to evaluate the antioxidant and anti-inflammatory activities of S. fruticosa, and to determine the phenolic constituents of its extracts. Methods. The antioxidant activity was determined using 2,2-diphenylpicrylhydrazyl assay. Total phenolic contents were estimated using Folin-Ciocalteu reagent, and high-performance liquid chromatography was performed to identify phenolic constituents. To evaluate the anti-inflammatory activity, carrageenan-induced mouse paw edema was determined plethysmographically. Key Findings. Different plant extracts demonstrated strong radical scavenging activity, where the ethyl acetate extract had the highest value in the roots and the lowest in the aerial parts. This antioxidant activity was correlated to the total phenolic content of different extracts, where rutin and luteolin were the most abundant constituents. Interestingly, both the roots and aerial parts revealed a significant anti-inflammatory activity comparable to diclofenac. Conclusions. This study is the first to demonstrate pharmacologic evidence of the potential anti-inflammatory activity of S. fruticosa. This activity may partly be due to the radical scavenging effects of its polyphenolic contents. These findings warrant the popular use of the East Mediterranean sage and highlight the potential of its active constituents in the development of new anti-inflammatory drugs.

Mechanisms of insulin resistance in experimental hyperinsulinemic dogs

This study was undertaken to characterize the insulin resistance and the mechanism thereof caused by chronic hyperinsulinemia produced in dogs by surgically diverting the veins of the pancreas from the portal vein to the vena cava. Pancreatic venous diversion (PVD, n = 8) caused a sustained increase in arterial insulin and decrease in portal insulin concentration compared with the control group (n = 6). Hyperinsulinemic euglycemic clamps were conducted 4 wk after surgery. The increase in the glucose disposal rate (GDR) was significantly less in the PVD group (39.0+/-5.0 vs. 27.9+/-3.2 micromol/kg/min, P < 0.01) compared with the control group, but the suppression of hepatic glucose production by insulin was similar for both groups. Muscle insulin receptor tyrosine kinase activity (IR-TKA) increased from 6.2+/-0.4 to 20.3+/-2.7 in the control group, but from 5.8+/-0.5 to only 12.7+/-1.7 fmol P/fmol IR in the PVD group (P < 0.01). With respect to the periphery, the time to half-maximum response (t1/2a) for arterial insulin was the same for both groups, whereas the t1/2a for lymph insulin (30+/-3 vs. 40+/-4 min, P < 0.05) and GDR (29+/-3 vs. 66+/-10 min, P < 0.01) were greater for the PVD group. Chronic hyperinsulinemia led to marked peripheral insulin resistance characterized by decreased insulin-stimulated GDR, and impaired activation of GDR kinetics due, in part, to reduced IR-TKA. Transendothelial insulin transport was impeded and was responsible for one third of the kinetic defect in insulin-resistant animals, while slower intracellular mechanisms of GDR were responsible for the remaining two thirds.