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Oral squamous cellular carcinoma (OSCC) is considered a life-threatening disease with detection in late stages, which forces us to opt for dangerous treatment with a combination of chemotherapy and radiotherapy. Herbal components such as piperine and quercetin are derived from edible sources, proving their anticancer potential against oral cancer cells in vitro. Encapsulation into lipid matrix-mediated nanostructured lipid carriers (NLCs) can make both drugs bio-accessible. NLCs were synthesised using the high shear homogenisation method and characterised for their physicochemical properties, followed by in vitro cellular evaluation in FaDu oral cancer cells. NLCs showed negatively charged particles smaller than 180 nm with a polydispersity index (PDI) of <0.3. Both drugs were found to encapsulate sufficiently, with >85% entrapment efficiency and an improved drug release profile compared to their pristine counterparts. Differential scanning calorimetry (DSC) thermograms showed conversion into an amorphous matrix in lyophilized NLCs, which was supported by X-ray diffraction (XRD) analysis. The cytotoxicity assay showed the IC 50 concentration for dual drug-loaded NLCs, which was more effective than the pure drug solution. NLCs were found to be internalised in cells in a short time with an almost 95% co-localization rate. Dual drug-loaded NLCs showed maximum depolarisation of the mitochondrial membrane along with more apoptotic changes. Improved apoptosis was confirmed in NLCs using flow cytometry. The in vivo biodistribution of Coumarin-6 labelled NLCs in rats confirmed their efficient distribution in various parts of the oral cavity through oral administration. Optimised dual drug-loaded NLCs provide a better option for delivering both drugs through a single lipid matrix against oral cancer., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Piperine (PIP), the major alkaloid component from Piper longum L. and Piper nigrum L., could enhance the bioavailabilities of other drugs including rosuvastatin, peurarin and docetaxel (DOX) via inhibition of CYP3A and P-glycoprotein activity. Nevertheless, the effect of such drug combination usage on the in vivo exposure of PIP has not been investigated due to lack of assay for the simultaneous determination of PIP and other drugs such as DOX. Besides, the reported pharmacokinetics of PIP varied a lot without appropriate bioavailability determined from the same dose. In the current study, an LC/MS/MS method has been developed to simultaneously determine the plasma concentrations of PIP and DOX and further applied to investigate the pharmacokinetics properties of PIP after oral and intravenous administrations as well as the pharmacokinetics interactions between PIP and DOX after their co-administration. A simple protein precipitation method was employed for plasma sample treatment by adding a mixture of methanol and acetonitrile (1:1, v/v) with glibenclamide as internal standard (IS). The LC/MS/MS system consisted of Agilent 6430 series LC pumps and auto-sampler. The chromatographic separation was carried out in 15min on a Waters C18 column (150×3.9mm i.d., 4μm) with a mobile phase containing 0.2% formic acid and acetonitrile (1:1, v/v) at a flow rate of 0.4ml/min. The detection was performed using the positive ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode with precursor-to-product ion transitions at m/z 286.1→201.1 for PIP, m/z 830.3→548.9 for DOX and m/z 494.2→369.0 for IS. The method demonstrated good linearity for both PIP and DOX over the concentration range of 2.5-1280ng/ml with LLOD at 2.5ng/ml. The intra-day and inter-day precisions were less than 13.34% and relative error (R.E.) representing accuracy was in the range of -11.38 to 3.15%. The recoveries of PIP, DOX and IS were above 75% and there was no matrix effect. PIP and DOX exhibited good stabilities under various conditions. PIP was administrated via intravenous bolus at 3.5mg/kg and via oral administration at 35mg/kg and 3.5mg/kg, while DOX was intravenously administrated at 7mg/kg to Sprague-Daley rats. The plasma concentrations of PIP and DOX were determined using the above developed and validated method. At the dose of 3.5mg/kg, the bioavailability of PIP was calculated to be 25.36%. Its AUC0→t was unproportionally increased with doses, indicating a potential non-linear pharmacokinetics profile of PIP. It was found that the AUC0→t and C0 of DOX and t1/2 of PIP were significantly increased after their combination use, suggesting potential enhanced bioavailability of not only DOX but also PIP, which may lead to the overall enhanced pharmacological effects., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Organophosphorus anticholinesterases (OPs) elicit acute toxicity by inhibiting acetylcholinesterase (AChE), leading to acetylcholine accumulation and overstimulation of cholinergic receptors. Endocannabinoids (eCBs, e.g., arachidonoyl ethanolamide [AEA] and 2-arachidonoyl glycerol [2-AG]) are neuromodulators that regulate neurotransmission by reducing neurotransmitter release. The eCBs are degraded by the enzymes fatty acid amide hydrolase (FAAH, primarily involved in hydrolysis of AEA) and monoacylglycerol lipase (MAGL, primarily responsible for metabolism of 2-AG). We previously reported that the cannabinoid receptor agonist WIN 55,212-2 reduced cholinergic toxicity after paraoxon exposure. This study compared the effects of the cannabinoid receptor antagonist AM251 on acute toxicity following either paraoxon (PO) or chlorpyrifos oxon (CPO). CPO was more potent in vitro than PO at inhibiting AChE (≈ 2 fold), FAAH (≈ 8 fold), and MAGL (≈ 19 fold). Rats were treated with vehicle, PO (0.3 and 0.6 mg/kg, sc) or CPO (6 and 12 mg/kg, sc) and subsets treated with AM251 (3mg/kg, ip; 30 min after OP). Signs of toxicity were recorded for 4h and rats were then sacrificed. OP-treated rats showed dose-related involuntary movements, with AM251 increasing signs of toxicity with the lower dosages. PO and CPO elicited excessive secretions, but AM251 had no apparent effect with either OP. Lethality was increased by AM251 with the higher dosage of PO, but no lethality was noted with either dosage of CPO, with or without AM251. Both OPs caused extensive inhibition of hippocampal AChE and FAAH (>80-90%), but only CPO inhibited MAGL (37-50%). These results provide further evidence that eCB signaling can influence acute OP toxicity. The selective in vivo inhibition of MAGL by CPO may be important in the differential lethality noted between PO and CPO with AM251 co-administration., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Besides the suggested role of a putative endocannabinoid membrane transporter mediating the cellular uptake of the endocannabinoid anandamide (AEA), this process is intrinsically coupled to AEA degradation by the fatty acid amide hydrolase (FAAH). Differential blockage of each mechanism is possible using specific small-molecule inhibitors. Starting from the natural product-derived 2E,4E-dodecadiene scaffold previously shown to interact with the endocannabinoid system (ECS), a series of diverse N-alkylcarbamates were prepared with the aim of generating novel ECS modulators. While being inactive at cannabinoid receptors and monoacylglycerol lipase, these N-alkylcarbamates showed potent to ultrapotent picomolar FAAH inhibition in U937 cells. Overall, a highly significant correlation (Spearman's rho=0.91) was found between the inhibition of FAAH and AEA cellular uptake among 54 compounds. Accordingly, in HMC-1 cells lacking FAAH expression the effect on AEA cellular uptake was dramatically reduced. Unexpectedly, 3-(4,5-dihydrothiazol-2-yl)phenyl carbamates and the 3-(1,2,3-thiadiazol-4-yl)phenyl carbamates WOBE490, WOBE491 and WOBE492 showed a potentiation of cellular AEA uptake inhibition in U937 cells, resulting in unprecedented femtomolar (hyperpotent) IC50 values. Potential methodological issues and the role of cellular accumulation of selected probes were investigated. It is shown that albumin impacts the potency of specific N-alkylcarbamates and, more importantly, that accumulation of FAAH inhibitors can significantly increase their effect on cellular AEA uptake. Taken together, this series of N-alkylcarbamates shows a FAAH-dependent inhibition of cellular AEA uptake, which can be strongly potentiated using specific head group modifications. These findings provide a rational basis for the development of hyperpotent AEA uptake inhibitors mediated by ultrapotent FAAH inhibition., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Echinacea preparations were the top-selling herbal supplements or medicines in the past decade; however, there is still frequent misidentification or substitution of the Echinacea plant species in the commercial Echinacea products with not well chemically defined compositions in a specific preparation. In this report, a comparative metabolomics study, integrating supercritical fluid extraction, gas chromatography/mass spectrometry and data mining, demonstrates that the three most used medicinal Echinacea species, Echinacea purpurea, E. pallida, and E. angustifolia, can be easily classified by the distribution and relative content of metabolites. A mitogen-induced murine skin inflammation study suggested that alkamides were the active anti-inflammatory components present in Echinacea plants. Mixed alkamides and the major component, dodeca-2E,4E,8Z,10Z(E)-tetraenoic acid isobutylamides, were then isolated from E. purpurea root extracts for further bioactivity elucidation. In macrophages, the alkamides significantly inhibited cyclooxygenase 2 (COX-2) activity and the lipopolysaccharide-induced expression of COX-2, inducible nitric oxide synthase and specific cytokines or chemokines [i.e., TNF-α, interleukin (IL)-1α, IL-6, MCP-1, MIP-1β] but elevated heme oxygenase-1 protein expression. Cichoric acid, however, exhibited little or no effect. The results of high-performance liquid chromatography/electron spray ionization/mass spectrometry metabolite profiling of alkamides and phenolic compounds in E. purpurea roots showed that specific phytocompound (i.e., alkamides, cichoric acid and rutin) contents were subject to change under certain post-harvest or abiotic treatment. This study provides new insight in using the emerging metabolomics approach coupled with bioactivity assays for medicinal/nutritional plant species classification, quality control and the identification of novel botanical agents for inflammatory disorders., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Fatty acid amide hydrolase (FAAH) is one of the main enzymes responsible for terminating the signaling of endocannabinoids, including anandamide. This paper is the first report of the synthesis, [123I]-labeling and in vitro and in vivo evaluation of anandamide analogues as potential metabolic trapping radioligands for in vivo evaluation of brain FAAH. N-(2-iodoethyl)linoleoylamide (2) and N-(2-iodoethyl)arachidonylamide (4) were synthesized with good yields (75% and 86%, respectively) in a two steps procedure starting from their respective acids. In vitro analyses, performed using recombinant rat FAAH and [3H]-anandamide, demonstrated interaction of 2 and 4 with FAAH (IC50 values of 5.78 microM and 3.14 microM, respectively). [123I]-2 and [123I]-4 were synthesized with radiochemical yields of 21% and 12%, respectively, and radiochemical purities were > 90%. Biodistribution studies in mice demonstrated brain uptake for both tracers (maximum values of 1.23%ID/g at 3 min pi for [123I]-2 and 0.58%ID/g at 10 min pi for [123I]-4). However, stability studies demonstrated the sensitivity of both tracers to dehalogenation.

Lack of involvement of the opioid system with the endocannabinoid, arachidonylethanolamide (anandamide) was possibly due to hydrolysis by fatty acid amide hydrolase (FAAH). Cyclohexylcarbamic acid 3'-carbamoyl-biphenyl-3-yl ester (URB597) is an inhibitor of FAAH, increases brain anandamide levels and enhances anandamide-induced antinociception in male ICR mice (25-30 g). The combination of URB597 (10 mg/kg, i.p.) and anandamide (40 mg/kg, i.p.) produced maximal antinociception in the mouse tail-flick test [68.7+/-16.8 percent maximum possible effect (%MPE)], versus either substance alone (27.3+/-7.9%MPE and 4.6+/-2.3%MPE, respectively) and is significantly blocked (p<0.05) by the cannabinoid CB(1) receptor antagonist, SR141716A (rimonabant), the kappa opioid receptor-selective antagonist, nor-Binaltorphimine (10 microg i.t.; 12.7+/-4.0%MPE) and the mu opioid receptor antagonist, naloxone (1 mg/kg, s.c.; 6.0+/-3.8%MPE), but not by the delta opioid receptor-selective antagonist, naltrindole (2 mg/kg, s.c.; 29.7+/-8.2%MPE) or the cannabinoid CB(2) receptor antagonist, SR144528. In addition, nor-BNI (10 microg i.t) administration to FAAH(-/-) knockout mice produced a nociceptive response. The URB597/anandamide combination was not active in the CB(1)(-/-) knockout mice, but retained activity in the MOR(-/-) knockout mice. The sub-active combination of (URB597 10 mg/kg, i.p/anandamide 10 mg/kg, i.p.; 15.5+/-4.3%MPE) shifted the dose response curve of morphine to the left (morphine alone ED(50)=4.6 mg/kg [3.7-5.6] versus morphine/URB597/anandamide (ED(50)=2.5 mg/kg [1.9-3.4]). These data are the first demonstration that anandamide, if protected from degradation, acts via the CB(1) receptor to interact with kappa opioid receptor systems in opioid analgesia.