Neuroprotective Effects of Curcumin-Loaded Emulsomes in a Laser Axotomy-Induced CNS Injury Model

Glucuronidation dynamics of curcumin and tetrahydrocurcumin for differential structures and chemical reactivities in human liver microsome and uridine diphosphate glucuronosyltransferase 2B7

THC is the main metabolite of curcumin with better bioactivity. This study aimed to explore the factors that cause differences in the bioactivity of curcumin and THC. We analyzed the metabolic activities of curcumin and THC and the factors responsible for the differences in their activities by glucuronidation activity assay, LC-MS, HPLC, homologous sequence comparisons, and molecular docking. Curcumin has higher metabolic activity than THC in HLM and UGT2B7, while the keto-enol isomers of curcumin and THC were distinctly different under different pH, and their structural transformations were hypothesized. Furthermore, UGT1A and UGT2B are differential sequences of curcumin and THC in UGTs. The binding sites and patterns of curcumin and THC in UGT2B7 are markedly different. In summary, the difference in keto-enolic interconversion isomerism between curcumin and THC is the main factor causing the difference in their activities, which provides a scientific basis for the development of curcumin.

Delivery of curcumin within emulsome nanoparticles enhances the anti-cancer activity in androgen-dependent prostate cancer cell

BACKGROUND

Curcumin, a dietary polyphenol isolated from turmeric, is a potent phytochemical possessing intrinsic anticancer activities against various cancer types including prostate cancer. However, low water solubility and bioavailability of the compound are major challenges against its medical use. The objective of this study is to evaluate the therapeutic potential of curcumin-loaded emulsome nanoparticular system, i.e. CurcuEmulsomes, for the treatment of androgen dependent LNCaP prostate cancer cell line.

METHODS AND RESULTS

The antiproliferative effect of both free curcumin and CurcuEmulsome were investigated comparatively on LNCaP and PNT1A cells. Cell viability data indicates that the inhibition in proliferation of LNCaP cells becomes more effective when curcumin is provided with its emulsome formulation rather than its free form. Corresponding to a therapeutic index of 2.25, Half maximal inhibitory (IC₅₀) and cytotoxic (CC₅₀) concentrations of CurcuEmulsomes for LNCaP and PNT1A cells were estimated as 17.1 µM and 38.6 µM, respectively. The fluorescence signal of autofluorescence curcumin was preserved within the CurcuEmulsomes at 72 h after the treatment. Thus, CurcuEmulsomes prolonged biological activity of curcumin. Induced apoptotic cell death and stimulated cell cycle arrest at G2/M phase were attributed to antiproliferative activity of CurcuEmulsomes. Treatment of LNCaP cells with CurcuEmulsomes increased expression of caspase-3 significantly by 11.76-fold, whereas decreased cyclin D1, Bcl-2 and AR expression levels significantly by of 0.18, 0.06 and 0.46-fold, respectively.

CONCLUSIONS

Presented safety and anticancer activity of CurcuEmulsomes on LNCaP cell line highlights the potential of CurcuEmulsomes to benefit intrinsic anticancer activities of curcumin in androgen dependent prostate cancer therapy.

ATF5 Attenuates Apoptosis in Hippocampal Neurons with Seizures Evoked by Mg2+-Free Medium via Regulating Mitochondrial Unfolded Protein Response

The mitochondrial unfolded protein response (mtUPR)-a stress response pathway for maintaining protein homeostasis-is critical in seizures-induced neuronal injury. The activating transcription factor 5 (ATF5) regulates mtUPR; however, whether ATF5-regulated mtUPR has a role in neuronal injury in epilepsy remains uncertain. Here, we investigated the effects of ATF5-regulated mtUPR on neuronal injury in hippocampal neurons with seizures evoked by Mg²⁺-free medium. HSP60 and ClpP, key proteins of mtUPR, were upregulated, indicating mtUPR activation. ATF5 overexpression by lentiviral vector infection potentiated mtUPR, whereas ATF5 downregulation by lentiviral vector infection attenuated this response. Moreover, ATF5 overexpression elevated mitochondrial membrane potential and reduced reactive oxygen species (ROS) generation, suggesting that ATF5 overexpression protected mitochondrial homeostasis, while ATF5 downregulation had the opposite effect. ATF5 overexpression also reversed Bcl2 downregulation and Bax upregulation and attenuated seizures-induced neuronal apoptosis, while ATF5 downregulation aggravated the injury. Our study demonstrates that ATF5 attenuates seizures-induced neuronal injury, possibly by regulating mtUPR pathways, to prevent mitochondrial dysfunction.

Therapeutic and Preventive Effects of Piperine and its Combination with Curcumin as a Bioenhancer Against Aluminum-Induced Damage in the Astrocyte Cells

Recently, studies conducted with astrocyte cells have drawn attention to neurodegeneration pathologies caused by aluminum exposure. In particular, investigating the potential of herbal therapeutic agents to prevent this effect of aluminum has gained importance. The purpose of this study was to investigate the therapeutic and preventive effects of piperine, curcumin, and the combination of these compounds on reactive primary astrocyte cells. In order to examine the preventive effect, certain concentrations of compounds were applied to the cells before the aluminum application, and to be able to determine the therapeutic effect, the compounds were examined after the aluminum application. The efficacy of the compounds was analyzed in terms of cell viability, apoptosis, necrosis, and cytokine release. In conclusion, the results of the study showed that the use of different concentrations of piperine, curcumin, and their combination had significantly higher % cell viability on aluminum-induced damage in astrocyte cells compared to the damaged control group. In addition, a decrease in the number of apoptotic and necrotic cells was observed in the same groups, which indicated that piperine increased curcumin activity. The decrease in the amount of IL-6 and TGF-β cytokines also supported that piperine increased the effectiveness of curcumin. Considering all these results, it can be said that in terms of aluminum damage in astrocyte cells, the bioavailability-enhancing property of piperine on curcumin was shown for the first time in the literature. In line with these results, it is inevitable to carry out further studies.

Preclinical evaluations of Norcantharidin liposome and emulsion hybrid delivery system with improved encapsulation efficiency and enhanced antitumor activity

BACKGROUND

Norcantharidin (NCTD) has a certain degree of hydrophilicity and poor lipophilicity, and has some side-effects, including short t_1/2, vascular irritation, cardiotoxicity and nephrotoxicity, which bring difficulties for formulation research. In this study, we aim to develop a novel nanocarrier to improve encapsulation efficiency, increase sterilization stability and enhance antitumor activity.

METHODS

Phospholipid complexes methods were used for increasing the lipophilicity of norcantharidin (NCTD), then NCTD phospholipid complexes were not only loaded in the oil phase and oil-water interface surface, but also encapsulated in phospholipid bilayers to obtain NCTD liposome-emulsion hybrid (NLEH) delivery system. The in vitro cytotoxicity and apoptosis, in vivo tissue distribution, tumor penetration, heterotopic and orthotopic antitumor studies were conducted to evaluate therapeutic effect.

RESULTS

NLEH exhibited an improved encapsulation efficiency (89.3%) and a better sterilization stability, compared to NCTD liposomes and NCTD emulsions. NLEH can achieve a better antitumor activity by promoting absorption (1.93-fold), prolonging blood circulation (2.08-fold), enhancing tumor-targeting accumulation (1.19 times), improving tumor penetration, and increasing antitumor immunity.

CONCLUSIONS

The liposome-emulsion hybrid (LEH) delivery system was potential carrier for NCTD delivery, and LEH could open opportunities for delivery of poorly soluble anticancer drugs, especially drugs that are more hydrophilicity than lipophilicity.

Antileishmanial Activity of BNIPDaoct- and BNIPDanon-loaded Emulsomes on Leishmania infantum Parasites

Among bisnaphthalimidopropyl (BNIP) derivatives, BNIPDaoct and BNIPDanon recently came forward with antileishmanial activities beyond the standard, commercialized antileishmanial therapies. However, high-level toxicity on macrophages plus poor aqueous solubility and poor bioavailability of the compounds limit their application in therapies. Addressing these limitations, the present study introduces BNIPDaoct- and BNIPDanon-loaded emulsomes as lipid-based nanocarrier systems. Accordingly, emulsome formulations were prepared with the presence of BNIP compounds. The average diameters of BNIPDaoct- and BNIPDanon-loaded emulsomes were found as 363.1 and 337.4 nm, respectively; while empty emulsomes differed with a smaller average particle diameter, i.e., 239.1 nm. All formulations exhibited a negative zeta potential value. The formulations achieved the encapsulation of BNIPDaoct and BNIPDanon at approximately 0.31 mg/ml (501 µM) and 0.24 mg/ml (387 µM), respectively. The delivery of BNIP within the emulsomes improved the antileishmanial activity of the compounds. BNIPDaoct-loaded emulsome with 50% inhibitory concentration (IC50) value of 0.59 ± 0.08 µM was in particular effective against Leishmania infantum promastigotes compared to free BNIPDaoct (0.84 ± 0.09 µM), free BNIPDanon (1.85 ± 0.01 µM), and BNIPDanon-loaded emulsome (1.73 ± 0.02 µM). Indicated by at least ≥ 2-fold higher 50% cytotoxic concentration (CC50) values, the incorporation of BNIP into emulsomes significantly reduced the toxicity of BNIPs against macrophages, corresponding to up to 16-fold improvement in selectivity index (CC50/IC50) for L. infantum promastigotes. The infection rates of macrophages were determined using dual-fluorescent flow cytometry as 68.6%. Both BNIP formulations at concentration of 1.87 µM reduced the parasitic load nearly to 40%, whereas BNIPDaoct-loaded emulosmes could further decrease the parasitic load below 20% at 7.5 µM and above. In conclusion, the incorporation of BNIPDaoct and BNIPDanon into emulsomes results in water-soluble dispersed emulsome formulations that do not only successfully facilitate the delivery of BNIP compounds into the parasites and the Leishmania-infected macrophages in vitro but also enhance antileishmanial efficacy as proven by the decline in IC50 values. The selectivity of the formulation for L. infantum parasites further contributes to the challenging safety profile of the compounds. The promising in vitro antileishmanial efficacy of BNIP-loaded emulsomes highlights the potential of the system for the future in vivo studies.

Novel bioemulsomes for baicalin oral lymphatic targeting: development, optimization and pharmacokinetics

Aim: The aim of this study was to elaborate on 'bioemulsomes,' novel biocompatible lipoprotein analogs for effective lymphatic transport of baicalin (BCL). Methods: BCL bioemulsomes were developed and optimized and in vitro physicochemical characterization performed. The bioavailability of BCL bioemulsomes compared with free BCL was investigated using in vivo pharmacokinetics studies. Finally, BCL lymphatic transport was assessed via cycloheximide blockade assay. Results: Optimized BCL-loaded nanoemulsomes showed promising in vitro characteristics that favor lymphatic targeting. In vivo pharmacokinetics showed a significant improvement in bioavailability over free BCL. A significant decrease in BCL emulsome absorption (33%) was exhibited after chemical blockage of the lymphatic pathway, confirming the lymphatic transport potential. Conclusion: Bioemulsomes could be a promising tool for bypassing BCL oral delivery hurdles as well as lymphatic transport, paving the way for potential treatment of lymphoma.