In vitro and in vivo targeting effect of folate decorated paclitaxel loaded PLA–TPGS nanoparticles

Paclitaxel is one of the most effective chemotherapeutic agents for treating various types of cancer. However, the clinical application of paclitaxel in cancer treatment is considerably limited due to its poor water solubility and low therapeutic index. Thus, it requires an urgent solution to improve therapeutic efficacy of paclitaxel. In this study, folate decorated paclitaxel loaded PLA–TPGS nanoparticles were prepared by a modified emulsification/solvent evaporation method. The obtained nanoparticles were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared (FTIR) and Dynamic Light Scattering (DLS) method. The spherical nanoparticles were around 50 nm in size with a narrow size distribution. Targeting effect of nanoparticles was investigated in vitro on cancer cell line and in vivo on tumor bearing nude mouse. The results indicated the effective targeting of folate decorated paclitaxel loaded copolymer nanoparticles on cancer cells both in vitro and in vivo.     

Cardioprotective effects of an active metabolite of furnidipine in 2 models of isolated heart and on in vivo ischemia–induced and reperfusion-induced arrhythmias in rats

Dihydropyridines are known not only to have antiarrhythmic effects but also to exert a significant cardiac depressive influence. We previously showed that M-2, an active and final metabolite of furnidipine, had cardioprotective effects without the marked cardiac depression seen with this dihydropyridine. We studied the influence of M-2 infusion (10(-7) M) on hemodynamics during low-flow and regional ischemia in the rat working heart. We examined the protection conferred by M-2 infusion (10(-7) M) against effects of veratridine-induced intracellular calcium overload in the Langendorff heart. Additionally, we performed an in vivo study to explore the effects of oral administration of M-2 at different times and doses, in the ischemia- and reperfusion-induced arrhythmias model. M-2 improved coronary flow during low-flow and regional ischemia while favorably maintaining aortic pressure parameters. M-2 provided outstanding protection against deleterious effects of calcium overloading by significantly preventing rise in left ventricular diastolic pressure and decrease in coronary flow. M-2 reduced mortality and incidence and duration of severe arrhythmias while exhibiting differential influence on blood pressure, which depended on dose and time of administration and could suggest its clinical indication. The results of our entire study establish a beneficial cardioprotective role of M-2, which exhibited pleiotropic effects on the ischemic heart by imparting protection in various ways. This combined with good tolerance, long duration of action, low toxicity, and relatively large therapeutic window makes M-2 a promising candidate as a precursor for a new chemical class of cardioprotective drugs.     

Orthostatic hypotensive effect of antipsychotic drugs in Wistar rats by in vivo and in vitro studies of α1-adrenoceptor function

Rationale It has been suggested that the increase in serotonin transmission induced by indirect agonists such as fenfluramine and fluoxetine attenuates cue-elicited reinstatement of cocaine-seeking in rats through a 5-HT_2C receptor-dependent mechanism. Objective We investigated whether Ro 60-0175, a nonselective 5-HT_2B–2C agonist, influences cue-elicited reinstatement of cocaine-seeking behavior. We evaluated the 5-HT_2C receptor’s role in Ro 60-0175 by studying its interaction with SB-242,084, a selective 5-HT_2C antagonist. The study also explored whether Ro 60-0175 influences cue-elicited seeking behavior associated with sucrose, a highly palatable nutritive reinforcer. Materials and methods Different groups of free-feeding rats were trained to associate discriminative stimuli (S^Ds) with the availability of cocaine or a sucrose pellet or no-reward in two-lever operant cages. Cocaine and sucrose pellets were available under an FR1 schedule of reinforcement, and each reinforcer was followed by a 20-s timeout signaled by a cue light coming above the active lever. After extinction of reinforced responding in the absence of cue, the reinforcer-associated stimuli were reintroduced in reinstatement sessions in which reinforcers were withheld. Results Ro 60-0175, at IP doses from 0.1 to 1 mg/kg, dose-dependently reduced cocaine-seeking behavior, while 1 mg/kg had no such effect for the sucrose pellet. Pretreatment with 1 mg/kg SC SB-242,084 completely prevented the effect on cocaine-seeking behavior. Conclusions These findings, provided they can be extrapolated to abstinent human addicts, suggest therapeutic potential for the selective 5-HT_2C agonist in preventing cue-controlled cocaine-seeking and relapse. An erratum to this article can be found at     

α-Glucosidase inhibition, 15-lipoxygenase inhibition,and brine shrimp toxicity of extracts and isolated compounds from Terminalia macroptera leaves

Context: Terminalia macroptera Guill. &; Perr. (Combretaceae), a tree that grows in West Africa, has been used in traditional medicine against a variety of diseases such as hepatitis, gonorrhea, skin diseases, and diabetes.

Objective: To investigate enzyme inhibitory activity against α-glucosidase and 15-lipoxygenase (15-LO) and toxicity against brine shrimp of extracts and compounds from T. macroptera leaves.

Materials and methods: Methanol extract, ethyl acetate, and butanol extracts obtained from the methanol extract, six isolated polyphenols (chebulagic acid, chebulic acid trimethyl ester, corilagin, methyl gallate, narcissin, and rutin), and shikimic acid were evaluated for enzyme inhibition and toxicity.

Results: In enzyme inhibition assays, all extracts showed high or very high activity. Chebulagic acid showed an IC₅₀ value of 0.05?µM towards α-glucosidase and 24.9?±?0.4?µM towards 15-LO, in contrast to positive controls (acarbose: IC₅₀?201?±?28?µM towards α-glucosidase, quercetin: 93?±?3?µM towards 15-LO). Corilagin and narcissin were good 15-LO and α-glucosidase inhibitors, as well, while shikimic acid, methyl gallate, and chebulic acid trimethyl ester were less active or inactive. Rutin was a good α-glucosidase inhibitor (IC₅₀ ca. 3?µM), but less active towards 15-LO. None of the extracts or the isolated compounds seemed to be very toxic in the brine shrimp assay compared with the positive control podophyllotoxin.

Conclusion: Inhibition of α-glucosidase in the gastrointestinal tract may be a rationale for the medicinal use of T. macroptera leaves against diabetes in traditional medicine in Mali. The plant extracts and its constituents show strong inhibition of the peroxidative enzyme 15-LO.     

In vivo and in vitro studies of Danzhi Jiangtang capsules against diabetic cardiomyopathy via TLR4/MyD88/NF-κB signaling pathway

ObjectivesDanzhi Jiangtang capsule (DJC) is widely used for preventing and treating diabetic cardiomyopathy (DCM). However, the underlying mechanisms of the anti-inflammatory and antiapoptotic activities are unclear.MethodsIn the in vivo diabetic cardiomyopathy rat model, cardiac function was measured through echocardiography, histological changes in the myocardium were visualized using HE staining, and cardiomyocyte apoptosis was detected using TUNEL. The serum levels of anti-inflammatory cytokines were detected using ELISA. Finally, TLR4, MyD88, and NF-κB mRNA expressions were analyzed using RT-qPCR. In the in vitro experiments, the apoptosis rate of the H9c2 cells was detected using FCM; moreover, TLR4, MyD88 and NF-κB mRNA expressions were measured using RT-qPCR and related protein levels were investigated using Western blotting.ResultsIn vivo, DJC effectively improved cardiac function, alleviated the pathological changes, and reduced the apoptosis rate. Moreover, DJC reduced TNF-α, IL-1β, and IL-6 activities, with significant inhibition of the TLR4, MyD88 and NF-κB p65 mRNA expression. Moreover, in vitro, DJC effectively inhibited high-glucose-induced H9c2 apoptosis-an effect similar to that for TAK242. Finally, both the DJC and TAK242 considerably reduced TLR4, MyD88, NF-κB, Bax, and caspase-3 protein expression but increased that of BCL-2.ConclusionsDJC prevented the overactivation of the TLR4/MyD88/NF-κB signaling pathway and regulate cardiomyocyte apoptosis against DCM.     

Is there a relation between extremely low frequency magnetic field exposure, inflammation and neurodegenerative diseases? A review of in vivo and in vitro experimental evidence

The protein coding sequence of most eukaryotic genes (exons) is interrupted by non-coding parts (introns), which are excised in a process termed splicing. To generate a mature messenger RNA (mRNA) hundreds of combinatorial protein-protein and RNA-protein interactions are required to splice out often very large introns with high fidelity and accuracy. Inherent to splicing is the use of alternative splice sites generating immense proteomic diversity from a limited number of genes. In humans, alternative splicing is a major mode of regulating gene expression, occurs in over 90% of genes and is particularly abundant in the brain. Only recently, it has been recognized that the complexity of the splicing process makes it susceptible to interference by various xenobiotics. These compounds include antineoplastic substances, commonly used drugs and food supplements and cause a spectrum of effects ranging from deleterious inhibition of general splicing to highly specific modifications of alternative splicing affecting only certain genes. Alterations in splicing have been implicated in numerous diseases such as cancer and neurodegeneration. Splicing regulation plays an important role in the execution of programmed cell death. The switch between anti- and pro-apoptotic isoforms by alternative splice site selection and misregulation of a number of splicing factors impacts on cell survival and disease. Here, our current knowledge is summarized on compounds interfering with general and alternative splicing and of the current methodology to study changes in these processes relevant to the field of toxicology and future risk assessments.     

Mechanisms underlying the cardio-protection of total ginsenosides against myocardial ischemia in rats in vivo and in vitro: Possible involvement of L-type Ca2+ channels,contractility and Ca2+ homeostasis

Here we aimed to observe the effects of total ginsenosides (TG) against isoproterenol (ISO) induced myocardial ischemia (MI) and to explore its underlying mechanisms based on L-type Ca²⁺ current (I_Ca-L), intracellular Ca²⁺ ([Ca²⁺]_i) and contraction in isolated rat myocytes. Rat model of MI was induced by subcutaneously injection of ISO (85 mg/kg) for 2 consecutive days. J-point elevation, heart rate, serum levels of creatine kinase (CK) and lactated dehydrogenase (LDH), and heart morphology changes were observed. Influences of TG on I_Ca-L, [Ca²⁺]_i and contraction in isolated rat myocytes were observed by the patch-clamp technique and IonOptix detection system. TG significantly reduced J-point elevation, heart rate, serum levels of CK and LDH, and improved heart pathologic morphology. TG decreased I_Ca-L in concentration-dependent manner with a half-maximal inhibitory concentration (IC₅₀) of 31.65 μg/mL. TG (300 μg/mL) decreased I_Ca-L of normal and ischemic ventricular myocytes by 64.33 ± 1.28% and 61.29 ± 1.38% respectively. At 30 μg/mL, TG reduced Ca²⁺ transient by 21.67 ± 0.94% and cell shortening by 38.43 ± 6.49%. This study showed that TG displayed cardioprotective effects on ISO-induced MI rats and the underlying mechanisms may be related to inhibition of I_Ca-L, damping of [Ca²⁺]_i and decrease of contractility.     

Diuretic effect of extracts,fractions and two compounds 2α,3β,19α-trihydroxy-urs-12-en-28-oic acid and 5-hydroxy-3,6,7,8,4′-pentamethoxyflavone from Rubus rosaefolius Sm. (Rosaceae) leaves in rats

Although diuretics have been widely used to treat hypertension along with others cardiovascular and renal disorders, no scientific data have been recorded to support the diuretic properties of Rubus rosaefolius Sm. (Rosaceae), a plant popularly used in Brazil to treat hypertension. Male Wistar rats were orally treated with: vehicle; hydrochlorothiazide; aqueous (AERR) and methanolic (MERR) extracts; dichloromethane (DCM), hexane (HEX) and ethyl acetate (EA) fractions; and the isolated compounds 2α,3β,19α-trihydroxy-urs-12-en-28-oic acid (TUA) and 5-hydroxy-3,6,7,8,4′-pentamethoxyflavone (PMF). At the end of the experiment (after 8 or 24 h), urine volume and other urine or plasma parameters were measured. AERR and MERR, at 100 and 30 mg/kg, respectively, induced diuretic, natriuretic and kaliuretic effect. Additionally, the DCM and HEX, but not EA, at 10 mg/kg, also increased urine volume and Na⁺ and K⁺ excretion. Both active constituents, TUA and PMF, at doses of 1 and 3 mg/kg, showed an augmented diuretic and natriuretic index. While TUA revealed a kaliuretic action, PMF did not interfere with potassium excretion. The compounds increased urinary creatinine, but not urea, levels. TUA was able to decrease calcium excretion, as well as HCTZ, while PMF effect was associated with increased urinary prostaglandin E₂ levels. The non-selective muscarinic receptor antagonist (atropine) prevented TUA-induced diuresis. In addition, indomethacin (a cyclooxygenase inhibitor) and atropine, exhibited the ability to block the diuretic effects prompted by PMF. Our study demonstrates the diuretic effect of extracts, fractions and two natural compounds obtained from R. rosaefolius leaves in rats.

     

Removal of the 26-methyl group from 19-nor-1α,25-dihydroxyvitamin D₃ markedly reduces in vivo calcemic activity without altering in vitro VDR binding, HL-60 cell differentiation, and transcription

Twelve new analogues of 19-nor-1α,25-dihydroxyvitamin D? (5-16) were prepared by convergent syntheses, employing the Wittig-Horner reaction. The necessary Grundmann type ketones (45-48), possessing fixed configurations of the hydroxyl group at C-25, were obtained by a multistep procedure from commercial vitamin D? and enantiomers of 1,3-butanediol (23 and 24). We have examined the influence of removal of one of the methyl groups located at C-25 on the biological in vitro and in vivo activity. The in vivo tests showed that the synthesized vitamin D compounds (5-16) exhibit reduced calcemic activity both in bone and in the intestine. However, in vitro potency of 2-methylene and 2α-methyl compounds (5-10, 13, and 14) remained similar or enhanced as compared to that of 1α,25-(OH)?D?.     

Anti-inflammatory effect of tricin 4′-O-(threo-β-guaiacylglyceryl) ether,a novel flavonolignan compound isolated from Njavara on in RAW264.7 cells and in ear mice edema

Although recent study has shown tricin 4′-O-(threo-β-guaiacylglyceryl) ether (TTGE), an isolated compound from Njavara rice, to have the most potent anti-inflammatory effects, the action mechanism has not been fully understood. Here, we examined the effect of TTGE on the inflammation and elucidated the potential mechanism. We demonstrated that TTGE significantly inhibited LPS-induced NO and ROS generation in RAW264.7 cells, which was correlated with the down-regulating effect of TTGE on the iNOS and COX-2 expression via NF-κB and STAT3. TPA-induced ear edema was also efficiently inhibited by the TTGE treatment. TTGE blocked the induction of iNOS and COX-2 through the regulation of NF-κB and STAT3, which could explain the reduced TPA-induced edema symptoms. Moreover, the introduction of ERK inhibitor abrogated the anti-inflammatory effect of TTGE via the recovery of NF-κB and STAT3 signalings. Taken together, these results suggest that TTGE has anti-inflammatory properties through down-regulation of NF-κB and STAT3 pathways.     

A 20S combined with a 22R configuration markedly increases both in vivo and in vitro biological activity of 1α,25-dihydroxy-22-methyl-2-methylene-19-norvitamin D3

Six new analogues of 1α,25-dihydroxy-19-norvitamin D(3) (3a-4b, 5, and 6) were prepared by a convergent synthesis applying the Wittig-Horner reaction as a key step. The influence of methyl groups at C-22 on their biological activity was examined. It was established that both in vitro and in vivo activity is strongly dependent on the configuration of the stereogenic centers at C-20 and C-22. Introduction of the second methyl group at C-22 (analogues 5 and 6) generates the compounds that are slightly more potent than 1α,25-(OH)(2)D(3) in the in vitro tests but much less potent in vivo. The greatest in vitro and in vivo biological activity was achieved when the C-20 is in the S configuration and the C-22 is in the R configuration. The building blocks for the synthesis, the respective (20R,22R)-, (20R,22S)-, (20S,22R)-, and (20S,22S)-diols, were obtained by fractional crystallization of mixtures of the corresponding diastereomers. Structures and absolute configurations of the diols 21a, 21b, and 22a as well as analogues 3a, 5, and 6 were confirmed by the X-ray crystallography.     

Comparative study of selective in vitro and in silico BACE1 inhibitory potential of glycyrrhizin together with its metabolites, 18α- and 18β-glycyrrhetinic acid,isolated from <Emphasis Type="Italic">Hizikia fusiformis</Emphasis>

Hizikia fusiformis (Harvey) Okamura is a brown seaweed widely used in Korea and Japan, and it contains different therapeutically active constituents. In the present study, we investigated the activities of glycyrrhizin isolated from H. fusiformis, including its metabolites, 18α- and 18β-glycyrrhetinic acid against Alzheimer’s disease (AD) via acetyl and butyrylcholinesterase and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibition. Among these three compounds, 18β-glycyrrhetinic acid (IC₅₀?=?8.93?±?0.69 µM) demonstrated two fold potent activity against BACE1 compared to the positive control, quercetin (IC₅₀?=?20.18?±?0.79 µM). Additionally, glycyrrhizin with an IC₅₀ value of 20.12?±?1.87 µM showed similarity to quercetin, while 18α-glycyrrhetinic acid showed moderate activity (IC₅₀?=?104.35?±?2.84 µM). A kinetic study revealed that glycyrrhizin and 18β-glycyrrhetinic acid were non-competitive and competitive inhibitiors of BACE1, demonstrated via K _i values of 16.92 and 10.91 µM, respectively. Molecular docking simulation studies evidently revealed strong binding energy of these compounds for BACE1, indicating their high affinity and capacity for tighter binding to the active site of the enzyme. These data suggest that glycyrrhizin isolated from the edible seaweed, H. fusiformis and its metabolite, 18β-glycyrrhetinic acid demonstrated selective inhibitory activity against BACE1 to alleviate AD.     

Protective effect of 2-dodecyl-6-methoxycyclohexa-2, 5-diene-1, 4-dione,isolated from Averrhoa carambola L., against Aβ1–42-induced apoptosis in SH-SY5Y cells by reversing Bcl-2/Bax ratio

Psychopharmacology - Aβ1–42-induced neurotoxicity has been considered as a possible mechanism to aggravate the onset and progression of Alzheimer’s disease (AD). In this study, we...     

Syringol isolated from Eleusine coracana (L.) Gaertn bran suppresses inflammatory response through the down-regulation of cPLA2, COX-2, IκBα, p38 and MPO signaling in sPLA2 induced mice paw oedema

Inflammopharmacology - Eleusine coracana (L.) Gaertn (E. coracana) is one of the highest consuming food crops in Asia and Africa. E. coracana is a plant with several medicinal values including...     

(3α)-3-(tiglinoyloxy)-ent-kaur-16-en-19-oic acid,isolated from Wedelia trilobata L., exerts an anti-inflammatory effect via the modulation of NF-κB,MAPK and mTOR pathway and autophagy in LPS-stimulated macrophages

(3α)-3-(tiglinoyloxy)-ent-kaur-16-en-19-oic acid (WT-26) is an ent-kaurane dieterpenoid extracted from Wedelia trilobata L., a widely cultivated ornamental plant with several scientific reports supporting its anti-inflammatory activity. WT-26 has better anti-inflammatory activity than its analog Kaurenoic acid (ent-kaur-16-en-19-oic acid). Nevertheless, the participation of WT-26 in the main signaling pathway associated with inflammation is lack of study. We aimed to study the anti-inflammatory effect of WT-26 and related signaling cascade in lipopolysaccharide (LPS)-stimulated macrophages. Here, we showed that WT-26 suppressed nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in LPS-stimulated macrophages by downregulating the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in mRNA and protein level. WT-26 down-regulated tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) and IL-1β production as well. Moreover, WT-26 inhibited the activation of nuclear factor-κB (NF-κB) p65 and its upstream signaling. WT-26 also reduced phosphorylation of mitogen-activated protein kinases (MAPKs) and mTOR. Besides, WT-26 decreased the overproduction of reactive oxygen species (ROS) and protected the mitochondrial integrity in stimulated macrophages. Our study also demonstrated that the autophagy induced by LPS was attenuated by WT-26. Collectively, our data indicated that WT-26 has the potential to be developed as a novel therapeutic agent for inflammatory-related diseases.