Pengaruh Bubuk Daun Kenikir (Cosmos Caudatus) Terhadap Kadar Malondialdehyde Plasma Tikus Wistar Diabetes Diinduksi Streptozotocin

Latar Belakang: Komplikasi vaskular diabetes terjadi akibat meningkatnya pembentukan radikal bebas sehingga menyebabkan stress oksidatif. Parameter tingkat stress oksidatif paling stabil adalah malondialdehyde (MDA). Stress oksidatif dapat dikendalikan dengan meningkatkan konsumsi antioksidan nonenzimatik. Daun kenikir memiliki zat antioksidan nonenzimatik potensial golongan flavonoid yaitu kuersetin. Penelitian ini bertujuan menganalisis pengaruh bubuk daun kenikir terhadap kadar malondialdehyde plasma tikus Wistar diabetes diinduksi streptozotocin.Metode: Jenis penelitian ini adalah true experimental dengan post-test only randomized control group design. Subjek penelitian yaitu 21 ekor tikus Wistar jantan dibagi menjadi 3 kelompok, K+, P1, dan P2. Seluruh kelompok diinduksi streptozotocin 65 mg/kg dan nicotinamide 230 mg/kg, kelompok perlakuan diberi bubuk daun kenikir dosis 700 mg/200gBB/hari dan 1400 mg/200gBB/hari selama 21 hari. Pemeriksaan kadar MDA plasma dengan metode 2-Thiobarbituric Acid Reactive Substance (TBARS). Data dianalisis menggunakan uji One Way Anova dan Post-hoc LSD.Hasil: Dosis 700 mg (P1) dan 1400 mg (P2) bubuk daun kenikir mampu menurunkan kadar MDA plasma tikus Wistar diabetes diinduksi streptozotocin (p<0,05). Rerata kadar MDA plasma kelompok kontrol positif sebesar 7,7±0,61, perlakuan 1 sebesar 6,1±0,58 dan perlakuan 2 sebesar 2,8±0,50. Secara statistik terdapat perbedaan rerata kadar MDA plasma antar kelompok (p<0,05).Simpulan: Bubuk daun kenikir dosis 700 mg/200gBB/hari dan 1400 mg/200gBB/hari selama 21 hari mampu menurunkan kadar MDA plasma tikus Wistar diabetes diinduksi streptozotocin. Dosis 1400 mg/200gBB/hari bubuk daun kenikir lebih efektif menurunkan kadar MDA plasma

Molecular Mechanism: The Human Dopamine Transporter Histidine 547 Regulates Basal and HIV-1 Tat Protein-Inhibited Dopamine Transport

Abnormal dopaminergic transmission has been implicated as a risk determinant of HIV-1-associated neurocognitive disorders. HIV-1 Tat protein increases synaptic dopamine (DA) levels by directly inhibiting DA transporter (DAT) activity, ultimately leading to dopaminergic neuron damage. Through integrated computational modeling prediction and experimental validation, we identified that histidine547 on human DAT (hDAT) is critical for regulation of basal DA uptake and Tat-induced inhibition of DA transport. Compared to wild type hDAT (WT hDAT), mutation of histidine547 (H547A) displayed a 196% increase in DA uptake. Other substitutions of histidine547 showed that DA uptake was not altered in H547R but decreased by 99% in H547P and 60% in H547D, respectively. These mutants did not alter DAT surface expression or surface DAT binding sites. H547 mutants attenuated Tat-induced inhibition of DA transport observed in WT hDAT. H547A displays a differential sensitivity to PMA- or BIM-induced activation or inhibition of DAT function relative to WT hDAT, indicating a change in basal PKC activity in H547A. These findings demonstrate that histidine547 on hDAT plays a crucial role in stabilizing basal DA transport and Tat-DAT interaction. This study provides mechanistic insights into identifying targets on DAT for Tat binding and improving DAT-mediated dysfunction of DA transmission

Development of NanoART for HIV Treatment: Minding the Cytochrome P450 (CYP) Enzymes

Sustained suppression of HIV viral load is the primary objective for HIV treatment, which successfully achieved by the use of a wide array of antiretroviral therapies (ART). Despite this enormous success low level of virus persists in the anatomical and cellular reservoirs of the body causing a multitude of immunological and neurocognitive deficits. Towards this, nano-formulations are gaining attention to solve these problems by delivering ART to the targeted locations such as brain, lymphoid tissues, and monocytes/macrophages. As cytochrome P450 (CYP) enzymes play a critical role in the metabolism of drugs and other xenobiotics, it is expected that the interaction of nanoparticles with CYP enzymes may result in adverse drug reactions, cellular toxicity, and alterations in CYP-mediated metabolism of other drug molecules. Considering these potential adverse outcomes it is imperative to design the nano-carriers that will have minimal impact on CYP enzymes. Therefore, developing a long-acting nanoART regimen with minimal side effects is an essential step to improve patient\u27s adherence to the treatment paradigm, effective treatment strategy, and to combat the HIV infection & AIDS

Investigational reverse transcriptase inhibitors for the treatment of HIV

INTRODUCTION: While considerable advances have been made in the development of antiretroviral agents, there is still work to be done. Reverse transcriptase inhibitors are important drugs for the treatment of HIV, and considerable research is currently ongoing to develop new agents and to modify currently existing agents. AREAS COVERED: Herein, the authors discuss both investigational nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), including agents that are in various stages of development. They also discuss novel formulations that are being investigated for currently available drugs, and discuss the advantages that these new formulations may provide. EXPERT OPINION: New formulations and co-formulations of currently existing antiretrovirals will represent an important area of development, as a means to improve adherence for HIV-positive individuals. New formulations will continue to be developed, with a focus on allowing for less-frequent administration, as well increasing drug concentrations at local sites such as vaginal tissue, rectal tissue and sites in the immune system

Kinetic characterizations of diallyl sulfide analogs for their novel role as CYP2E1 enzyme inhibitors

Diallyl sulfide (DAS), a selective inhibitor of CYP2E1, has shown protective effects against alcohol- and acetaminophen-induced hepatotoxicity in many studies. However, DAS is also a CYP2E1 substrate that on metabolism produces toxic metabolites and causes cytotoxicity. The objective of this study was to find a potent DAS analog as a CYP2E1 inhibitor and has the characteristic of producing less toxic metabolites. We selected seven commercially available compounds that are similar to DAS (DAS analogs). First, we performed ligand-CYP2E1 docking study to determine the binding mode and binding energy. The analysis suggested a relative potential for these DAS analogs as CYP2E1 inhibitor. We then performed a comprehensive inhibition kinetics of DAS analogs and determined the relative IC50, Ki, and types of inhibition compared to that of DAS. The results showed that compared to DAS, diallyl ether and allyl methyl sulfide have lower Ki values (3.1 and 4.4 μmol/L, respectively, vs. 6.3 μmol/L for DAS) and IC50 values (6.3 and 11.4 μmol/L, respectively, vs. 17.3 μmol/L for DAS). However, allyl methyl sulfide and thiophene showed similar inhibitory capacities to that of DAS, and four other DAS analogs showed lower potency than DAS. In conclusion, we have found relatively more potent inhibitors of CYP2E1, which have lower toxicity than DAS. These compounds can replace DAS not only as a tool for in vitro and in vivo studies that involve CYP2E1 inhibition, but also can lead the way for their use in preventing CYP2E1-mediated hepatic toxicity of alcohol and acetaminophen

Intra-ventral tegmental HIV-1 Tat1-86 attenuates nicotine-mediated locomotor sensitization and alters mesocorticolimbic ERK and CREB signaling in rats

Cigarette smoking prevalence in the HIV-positive individuals is profoundly higher than that in the HIV-negative individuals. We have demonstrated that HIV-1 transgenic rats exhibit attenuated nicotine-mediated locomotor activity, altered cAMP response element binding protein (CREB) and extracellular regulated kinase (ERK1/2) signaling in the mesocorticolimbic regions. This study investigated the role of HIV-1 Tat protein in the alterations of nicotine-mediated behavior and the signaling pathway observed in the HIV-1 transgenic rats. Rats received bilateral microinjection of recombinant Tat1-86 (25 μg/side) or vehicle directed at ventral tegmental area (VTA) followed by locomotor testing in response to 13 daily intravenous injections of nicotine (0.05 mg/kg, freebase, once/day) or saline. Further, we examined the phosphorylated levels of CREB (pCREB) and ERK1/2 (pERK1/2) in the prefrontal cortex, nucleus accumbens (NAc) and VTA. Tat diminished baseline activity in saline control rats, and attenuated nicotine-induced behavioral sensitization. Following repeated saline injection, the basal levels of pERK1 in the NAc and VTA and pERK2 in VTA were lower in the vehicle control group, relative to the Tat group. After repeated nicotine injection, pERK1 in NAc and VTA and pERK2 in VTA were increased in the vehicle group, but not in the Tat group. Moreover, repeated nicotine injections decreased pCREB in the prefrontal cortex and VTA in the Tat group but not in the vehicle group. Thus, these findings indicate that the direct injection of Tat at the VTA may mediate CREB and ERK activity in response to nicotine-induced locomotor activity

Investigational protease inhibitors as antiretroviral therapies

INTRODUCTION: Highly Active Antiretroviral Therapy (HAART) has tremendously improved the life expectancy of the HIV-infected population over the past three decades. Protease inhibitors have been one of the major classes of drugs in HAART regimens that are effective in treating HIV. However, the emergence of resistance and cross-resistance against protease inhibitors encourages researchers to develop new PIs with broad-spectrum activity, as well as novel means of enhancing the efficacy of existing PIs. AREAS COVERED: In this article we discuss recent advances in HIV protease inhibitor (PI) development, focusing on both investigational and experimental agents. We also include a section on pharmacokinetic booster drugs for improved bioavailability of protease inhibitors. Further, we discuss novel drug delivery systems using a variety of nanocarriers for the delivery of PIs across the blood-brain barrier to treat the HIV in the brain. EXPERT OPINION: We discuss our opinion on the promises and challenges on the development of novel investigational and experimental PIs that are less toxic and more effective in combating drug-resistance. Further, we discuss the future of novel nanocarriers that have been developed to deliver PIs to the brain cells. Although these are promising findings, many challenges need to be overcome prior to making them a viable option

Monocyte-derived exosomes upon exposure to cigarette smoke condensate alter their characteristics and show protective effect against cytotoxicity and HIV-1 replication

Abstract Smoking is known to exacerbate HIV-1 pathogenesis, especially in monocytes, through the oxidative stress pathway. Exosomes are known to alter HIV-1 pathogenesis through inter-cellular communication. However, the role of exosomes in smoking-mediated HIV-1 pathogenesis is unknown. In this study, we investigated the effect of cigarette smoke condensate (CSC) on the characteristics of monocyte-derived exosomes and their influence on HIV-1 replication. Initially, we demonstrated that CSC reduced total protein and antioxidant capacity in exosomes derived from HIV-1-infected and uninfected macrophages. The exosomes from CSC-treated uninfected cells showed a protective effect against cytotoxicity and viral replication in HIV-1-infected macrophages. However, exosomes derived from HIV-1-infected cells lost their protective capacity. The results suggest that the exosomal defense is likely to be more effective during the early phase of HIV-1 infection and diminishes at the latter phase. Furthermore, we showed CSC-mediated upregulation of catalase in exosomes from uninfected cells, with a decrease in the levels of catalase and PRDX6 in exosomes derived from HIV-1-infected cells. These results suggest a potential role of antioxidant enzymes, which are differentially packaged into CSC-exposed HIV-1-infected and uninfected cell-derived exosomes, on HIV-1 replication of recipient cells. Overall, our study suggests a novel role of exosomes in tobacco-mediated HIV-1 pathogenesis

Novel elvitegravir nanoformulation approach to suppress the viral load in HIV-infected macrophages

Purpose: Monocytes serve as sanctuary sites for HIV-1 from which virus is difficult to be eliminated. Therefore, an effective viral suppression in monocytes is critical for effective antiretroviral therapy (ART). This study focuses on a new strategy using nanoformulation to optimize the efficacy of ART drugs in HIV-infected monocytes. Methods: Poly(lactic-co-glycolic acid) (PLGA)-based elvitegravir nanoparticles (PLGA-EVG) were prepared by nano-precipitation technique. The physicochemical properties of PLGA-EVG were characterized using transmission electron microscopy, dynamic light scattering, and Fourier-transform infrared spectroscopy. Cellular uptake study was performed by fluorescence microscopy and flow cytometry. All in vitro experiments were performed by using HIV-infected monocytic cell lines U1 and HIV-infected primary macrophages. Elvitegravir quantification was performed using LC-MS/MS. HIV viral replication was assessed by using p24 ELISA. Results: We developed a PLGA-EVG nanoparticle formulation with particle size of ~ 47 nm from transmission electron microscopy and zeta potential of ~ 6.74 mV from dynamic light scattering. These nanoparticles demonstrated a time- and concentration-dependent uptakes in monocytes. PLGA-EVG formulation showed a ~ 2 times higher intracellular internalization of EVG than control group (EVG alone). PLGA-EVG nanoparticles also demonstrated superior viral suppression over control for a prolonged period of time. Conclusions: PLGA-based EVG nanoformulation increased the intracellular uptake of EVG, as well as enhanced viral suppression in HIV-infected macrophages, suggesting its potential for improved HIV treatment in monocytic cells