Modulation of cerebral malaria by curcumin as an adjunctive therapy

Curcumin as a Stabilizer of Macrophage Polarization during Plasmodium Infection

Malaria is a parasitic infection responsible for high morbidity and mortality rates worldwide. During the disease, phagocytosis of infected red blood cells by the macrophages induces the production of reactive oxygen (ROS) and nitrogen species (RNS), culminating in parasite death. Curcumin (CUR) is a bioactive compound that has been demonstrated to reduce the production of pro-inflammatory cytokines and chemokines produced by macrophages but to reduce parasitemia in infected mice. Hence, the main purpose of this study is to investigate whether curcumin may interfere with macrophage function and polarization after Plasmodium berghei infection in vitro. In our findings, non-polarized macrophage (M0), classically activated (M1), and alternatively activated (M2) phenotypes showed significantly increased phagocytosis of infected red blood cells (iRBCs) when compared to phagocytosis of uninfected red blood cells (RBCs) 3 h after infection. After 24 h, M1 macrophages exposed to RBCs + CUR showed greater elimination capacity when compared to macrophages exposed to iRBCs + CUR, suggesting the interference of curcumin with the microbicidal activity. Additionally, curcumin increased the phagocytic activity of macrophages when used in non-inflammatory conditions (M0) and reduced the inducible nitric oxide synthase (iNOS) and arginase activities in all macrophage phenotypes infected (M0, M1, and M2), suggesting interference in arginine availability by curcumin and balance promotion in macrophage polarization in neutral phenotype (M0). These results support the view of curcumin treatment in malaria as an adjuvant, promoting a balance between pro- and anti-inflammatory responses for a better clinical outcome.

Evaluation of chalcone derivatives for their role as antiparasitic and neuroprotectant in experimentally induced cerebral malaria mouse model

Cerebral malaria is a severe complication of Plasmodium falciparum infection with a complex pathophysiology. The current course of treatment is ineffective in lowering mortality or post-treatment side effects such as neurological and cognitive abnormalities. Chalcones are enormously distributed in spices, fruits, vegetables, tea, and soy-based foodstuffs that are well known for their antimalarial activity, and in recent years they have been widely explored for brain diseases like Alzheimer's disease. Therefore, considering the previous background of chalcones serving as both antimalarial and neuroprotective, the present study aimed to study the effect of these chalcone derivatives on an experimental model of cerebral malaria (CM). CM-induced mice were tested behaviorally (elevated plus maze, rota rod test, and hanging wire test), biochemically (nitric oxide estimation, cytokines (IL-1, IL-6, IL-10, IL-12p70, TNF, IFN-y), histopathologically and immunohistochemically, and finally ultrastructural changes were examined using a transmission electron microscope. All three chalcones treated groups showed a significant (p < 0.001) decrease in percentage parasitemia at the 10th day post-infection. Mild anxiolytic activity of chalcones as compared to standard treatment with quinine has been observed during behavior tests. No pigment deposition was observed in the QNN-T group and other chalcone derivative treated groups. Rosette formation was seen in the derivative 1 treated group. The present derivatives may be pioneered by various research and science groups to design such a scaffold that will be a future antimalarial with therapeutic potential or, because of its immunomodulatory properties, it could be used as an adjunct therapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03676-y.

Neurotransmitters and molecular chaperones interactions in cerebral malaria: Is there a missing link?

Plasmodium falciparum is responsible for the most severe and deadliest human malaria infection. The most serious complication of this infection is cerebral malaria. Among the proposed hypotheses that seek to explain the manifestation of the neurological syndrome in cerebral malaria is the vascular occlusion/sequestration/mechanic hypothesis, the cytokine storm or inflammatory theory, or a combination of both. Unfortunately, despite the increasing volume of scientific information on cerebral malaria, our understanding of its pathophysiologic mechanism(s) is still very limited. In a bid to maintain its survival and development, P. falciparum exports a large number of proteins into the cytosol of the infected host red blood cell. Prominent among these are the P. falciparum erythrocytes membrane protein 1 (PfEMP1), P. falciparum histidine-rich protein II (PfHRP2), and P. falciparum heat shock proteins 70-x (PfHsp70-x). Functional activities and interaction of these proteins with one another and with recruited host resident proteins are critical factors in the pathology of malaria in general and cerebral malaria in particular. Furthermore, several neurological impairments, including cognitive, behavioral, and motor dysfunctions, are known to be associated with cerebral malaria. Also, the available evidence has implicated glutamate and glutamatergic pathways, coupled with a resultant alteration in serotonin, dopamine, norepinephrine, and histamine production. While seeking to improve our understanding of the pathophysiology of cerebral malaria, this article seeks to explore the possible links between host/parasite chaperones, and neurotransmitters, in relation to other molecular players in the pathology of cerebral malaria, to explore such links in antimalarial drug discovery.

Recent updates on applications of Lipid-based nanoparticles for site-specific drug delivery

BACKGROUND

Site-specific drug delivery is a widespread and demanding area nowadays. Lipid-based nanoparticulate drug delivery systems have shown promising effects for targeting drugs among lymphatic systems, brain tissues, lungs, and skin. Recently, lipid nanoparticles are used for targeting the brain via the mucosal route for local therapeutic effects. Lipid nanoparticles (LNPs) can help in enhancing the efficacy and lowering the toxicities of anticancer drugs to treat the tumors, particularly in lymph after metastases of tumors. LNPs contain a non-polar core that can improve the absorption of lipophilic drugs into the lymph node and treat tumors. Cellular uptake of drugs can also be enhanced using LNPs and therefore, LNPs are the ideal carrier for treating intracellular infections such as leishmaniasis, tuberculosis and parasitic infection in the brain, etc. Furthermore, specific surface modifications with molecules like mannose, or PEG could improve the macrophage uptake and hence effectively eradicate parasites hiding in macrophages.

METHOD

An electronic literature search was conducted to update the advancements in the field of site-specific drug delivery utilizing lipid-based nanoparticles. A search of the Scopus database (https://www.scopus.com/home.uri) was conducted using the following keywords: lipid-based nanoparticles; site specific delivery.

CONCLUSION

Solid lipid nanoparticles have shown site-specific targeted delivery to various organs including the liver, oral mucosa, brain, epidermis, pulmonary and lymphatic systems. These lipid-based systems showed improved bioavailability as well as reduced side effects. Therefore, the focus of this article is to review the recent research studies on LNPs for site-specific or targeting drug delivery.

Molecular Targets of Natural Compounds with Anti-Cancer Properties

Cancer is the second leading cause of death in humans. Despite rapid developments in diagnostic methods and therapies, metastasis and resistance to administrated drugs are the main obstacles to successful treatment. Therefore, the main challenge should be the diagnosis and design of optimal therapeutic strategies for patients to increase their chances of responding positively to treatment and increase their life expectancy. In many types of cancer, a deregulation of multiple pathways has been found. This includes disturbances in cellular metabolism, cell cycle, apoptosis, angiogenesis, or epigenetic modifications. Additionally, signals received from the microenvironment may significantly contribute to cancer development. Chemical agents obtained from natural sources seem to be very attractive alternatives to synthetic compounds. They can exhibit similar anti-cancer potential, usually with reduced side effects. It was reported that natural compounds obtained from fruits and vegetables, e.g., polyphenols, flavonoids, stilbenes, carotenoids and acetogenins, might be effective against cancer cells in vitro and in vivo. Several published results indicate the activity of natural compounds on protein expression by its influence on transcription factors. They could also be involved in alterations in cellular response, cell signaling and epigenetic modifications. Such natural components could be used in our diet for anti-cancer protection. In this review, the activities of natural compounds, including anti-cancer properties, are described. The influence of natural agents on cancer cell metabolism, proliferation, signal transduction and epigenetic modifications is highlighted.

Transcriptome-based analysis of blood samples reveals elevation of DNA damage response, neutrophil degranulation, cancer and neurodegenerative pathways in Plasmodium falciparum patients

BACKGROUND

Malaria caused by Plasmodium falciparum results in severe complications including cerebral malaria (CM) especially in children. While the majority of falciparum malaria survivors make a full recovery, there are reports of some patients ending up with neurological sequelae or cognitive deficit.

METHODS

An analysis of pooled transcriptome data of whole blood samples derived from two studies involving various P. falciparum infections, comprising mild malaria (MM), non-cerebral severe malaria (NCM) and CM was performed. Pathways and gene ontologies (GOs) elevated in the distinct P. falciparum infections were determined.

RESULTS

In all, 2876 genes were expressed in common between the 3 forms of falciparum malaria, with CM having the least number of expressed genes. In contrast to other research findings, the analysis from this study showed MM share similar biological processes with cancer and neurodegenerative diseases, NCM is associated with drug resistance and glutathione metabolism and CM is correlated with endocannabinoid signalling and non-alcoholic fatty liver disease (NAFLD). GO revealed the terms biogenesis, DNA damage response and IL-10 production in MM, down-regulation of cytoskeletal organization and amyloid-beta clearance in NCM and aberrant signalling, neutrophil degranulation and gene repression in CM. Differential gene expression analysis between CM and NCM showed the up-regulation of neutrophil activation and response to herbicides, while regulation of axon diameter was down-regulated in CM.

CONCLUSIONS

Results from this study reveal that P. falciparum-mediated inflammatory and cellular stress mechanisms may impair brain function in MM, NCM and CM. However, the neurological deficits predominantly reported in CM cases could be attributed to the down-regulation of various genes involved in cellular function through transcriptional repression, axonal dysfunction, dysregulation of signalling pathways and neurodegeneration. It is anticipated that the data from this study, might form the basis for future hypothesis-driven malaria research.

Zwitterionic self-assembled nanoparticles as carriers for Plasmodium targeting in malaria oral treatment

The current decline in antimalarial drug efficacy due to the evolution of resistant Plasmodium strains calls for new strategies capable of improving the bioavailability of antimalarials, especially of those whose lipophilic character imparts them a low solubility in biological fluids. Here we have designed, synthesized and characterized amphiphilic zwitterionic block copolymers forming nanoparticles capable of penetrating the intestinal epithelium that can be used for oral administration. Poly(butyl methacrylate-co-morpholinoethyl sulfobetaine methacrylate) (PBMA-MESBMA)-based nanoparticles exhibited a specific targeting to Plasmodium falciparum-infected vs. parasite-free red blood cells (74.8%/0.8% respectively), which was maintained upon encapsulation of the lipophilic antimalarial drug curcumin (82.6%/0.3%). The in vitro efficacy of curcumin upon encapsulation was maintained relative to the free compound, with an IC50 around 5 μM. In vivo assays indicated a significantly increased curcumin concentration in the blood of mice one hour after being orally fed PBMA-MESBMA-curcumin in comparison to the administration of free drug (18.7 vs. 2.1 ng/ml, respectively). At longer times, however, plasma curcumin concentration equaled between free and encapsulated drug, which was reflected in similar in vivo antimalarial activities in Plasmodium yoelii yoelii-infected mice. Microscopic analysis in blood samples of fluorescently labeled PBMA-MESBMA revealed the presence of the polymer inside P. yoelii yoelii-parasitized erythrocytes one hour after oral administration to infected animals.

Eugenol disrupts Plasmodium falciparum intracellular development during the erythrocytic cycle and protects against cerebral malaria

BACKGROUND

Malaria is a parasitic disease that compromises the human host. Currently, control of the Plasmodium falciparum burden is centered on artemisinin-based combination therapies. However, decreased sensitivity to artemisinin and derivatives has been reported, therefore it is important to identify new therapeutic strategies.

METHOD

We used human erythrocytes infected with P. falciparum and experimental cerebral malaria (ECM) animal model to assess the potential antimalarial effect of eugenol, a component of clove bud essential oil.

RESULTS

Plasmodium falciparum cultures treated with increasing concentrations of eugenol reduced parasitemia in a dose-dependent manner, with IC₅₀ of 532.42 ± 29.55 μM. This effect seems to be irreversible and maintained even in the presence of high parasitemia. The prominent effect of eugenol was detected in the evolution from schizont to ring forms, inducing important morphological changes, indicating a disruption in the development of the erythrocytic cycle. Aberrant structural modification was observed by electron microscopy, showing the separation of the two nuclear membrane leaflets as well as other subcellular membranes, such as from the digestive vacuole. Importantly, in vivo studies using ECM revealed a reduction in blood parasitemia and cerebral edema when mice were treated for 6 consecutive days upon infection.

CONCLUSIONS

These data suggest a potential effect of eugenol against Plasmodium sp. with an impact on cerebral malaria.

GENERAL SIGNIFICANCE

Our results provide a rational basis for the use of eugenol in therapeutic strategies to the treatment of malaria.

Macrophage plasticity, polarization and function in response to curcumin, a diet-derived polyphenol, as an immunomodulatory agent

Monocytes and macrophages are important cells of the innate immune system that have diverse functions, including defense against invading pathogens, removal of dead cells by phagocytosis, antigen presentation in the context of MHC class I and class II molecules, and production of various pro-inflammatory cytokines and chemokines such as IL-1β, IL-6, TNF-α and MCP-1. In addition, pro-inflammatory (M1) and anti-inflammatory (M2) macrophages clearly play important roles in the progression of several inflammatory diseases. Therefore, therapies that target macrophage polarization and function by either blocking their trafficking to sites of inflammation, or skewing M1 to M2 phenotype polarization may hold clinical promise in several inflammatory diseases. Dietary-derived polyphenols have potent natural anti-oxidative properties. Within this group of polyphenols, curcumin has been shown to suppress macrophage inflammatory responses. Curcumin significantly reduces co-stimulatory molecules and also inhibits MAPK activation and the translocation of NF-κB p65. Curcumin can also polarize/repolarize macrophages toward the M2 phenotype. Curcumin-treated macrophages have been shown to be highly efficient at antigen capture and endocytosis via the mannose receptor. These novel findings provide new perspectives for the understanding of the immunopharmacological role of curcumin, as well as its therapeutic potential for impacting macrophage polarization and function in the context of inflammation-related disease. However, the precise effects of curcumin on the migration, differentiation, polarization and immunostimulatory functions of macrophages remain unknown. Therefore, in this review, we summarized whether curcumin can influence macrophage polarization, surface molecule expression, cytokine and chemokine production and their underlying pathways in the prevention of inflammatory diseases.

Antimalarial Activity of Orally Administered Curcumin Incorporated in Eudragit®-Containing Liposomes

Curcumin is an antimalarial compound easy to obtain and inexpensive, having shown little toxicity across a diverse population. However, the clinical use of this interesting polyphenol has been hampered by its poor oral absorption, extremely low aqueous solubility and rapid metabolism. In this study, we have used the anionic copolymer Eudragit® S100 to assemble liposomes incorporating curcumin and containing either hyaluronan (Eudragit-hyaluronan liposomes) or the water-soluble dextrin Nutriose® FM06 (Eudragit-nutriosomes). Upon oral administration of the rehydrated freeze-dried nanosystems administered at 25/75 mg curcumin·kg−1·day−1, only Eudragit-nutriosomes improved the in vivo antimalarial activity of curcumin in a dose-dependent manner, by enhancing the survival of all Plasmodium yoelii-infected mice up to 11/11 days, as compared to 6/7 days upon administration of an equal dose of the free compound. On the other hand, animals treated with curcumin incorporated in Eudragit-hyaluronan liposomes did not live longer than the controls, a result consistent with the lower stability of this formulation after reconstitution. Polymer-lipid nanovesicles hold promise for their development into systems for the oral delivery of curcumin-based antimalarial therapies.

Development of Nanoemulsions to Enhance the Antileishmanial Activity of Copaifera paupera Oleoresins

Based on the ethnopharmacological evidences about the antileishmanial activity of Copaifera spp. oleoresins, the effects of crude extracts and fractions of oleoresin of two specimens from Copaifera paupera were evaluated on Leishmania amazonensis and Leishmania infantum strains. The oleoresin rich in α-copaene (38.8%) exhibited the best activity against L. amazonensis (IC₅₀ = 62.5 μg/mL) and against L. infantum (IC₅₀ = 65.9 μg/mL). The sesquiterpene α-copaene isolated was tested alone and exhibited high antileishmanial activity in vitro with IC₅₀ values for L. amazonensis and L. infantum of 17.2 and 11.4 μg/mL, respectively. In order to increase antileishmanial activity, nanoemulsions containing copaiba oleoresin and α-copaene were developed and assayed against L. amazonensis and L. infantum promastigotes. The nanoemulsion containing α-copaene (NANOCOPAEN) showed the best activity against both species, with IC₅₀ of 2.5 and 2.2 μg/mL, respectively. This is the first report about the antileishmanial activity of α-copaene.

Optimization of Curcuma Oil/Quinine-Loaded Nanocapsules for Malaria Treatment

Quinine, a treatment used in chloroquine-resistant falciparum malaria, was loaded into poly(ɛ-caprolactone) or Eudragit^® RS100 nanocapsules using Curcuma oil as the oil-based core. Until now, the effect of cationic nanocapsules on malaria has not been reported. A 2⁴ factorial design was adopted using, as independent variables, the concentration of Curcuma oil, presence of quinine, type of polymer, and aqueous surfactant. Diameter, zeta potential, and pH were the responses studied. The formulations were also evaluated for drug content, encapsulation efficiency, photostability, and antimalarial activity against Plasmodium berghei-infected mice. The type of polymer influenced all of the responses studied. Quinine-loaded Eudragit^® RS100 (F13) and PCL nanocapsules (F9), both with polysorbate 80 coating, showed nanometric particle size, positive zeta potential, neutral pH, high drug content, and quinine photoprotection ability; thus, these nanocapsules were selected for in vivo tests. Both formulations showed lower levels of parasitemia from the beginning of the experiment (5.78 ± 3.60 and 4.76 ± 3.46% for F9 and F13, respectively) and highest survival mean time (15.3 ± 2.0 and 14.9 ± 5.6 days for F9 and F13, respectively). F9 and F13 showed significant survival curve compared to saline, thus demonstrating that nanoencapsulation improved bioefficacy of QN and co-encapsulated curcuminoids, regardless of the surface charge.

Antiplasmodial, anti-complement and anti-inflammatory in vitro effects of Biophytum umbraculum Welw. traditionally used against cerebral malaria in Mali

ETHNOPHARMACOLOGICAL RELEVANCE

Biophytum umbraculum Welw. (Oxalidaceae) is a highly valued African medicinal plant used for treatment of cerebral malaria, a critical complication of falciparum malaria.

AIM OF THE STUDY

To provide additional information about traditional use of B. umbraculum and to test plant extracts and isolated compounds for in vitro activities related to cerebral malaria.

MATERIALS AND METHODS

The traditional practitioners were questioned about indication, mode of processing/application, dosage and local name of B. umbraculum. Organic extracts and some main constituents of the plant were investigated for anti-malaria, anti-complement activity and inhibition of NO secretion in a RAW 264.7 cell line.

RESULTS

Treatment of cerebral malaria was the main use of B. umbraculum (fidelity level 56%). The ethyl acetate extract showed anti-complement activity (ICH50 5.7±1.6μg/ml), inhibition of macrophage activation (IC50 16.4±1.3μg/ml) and in vitro antiplasmodial activity (IC50 K1 5.6±0.13μg/ml, IC50 NF54 6.7±0.03μg/ml). The main constituents (flavone C-glycosides) did not contribute to the activity of the extract.

CONCLUSION

Inhibition of complement activation and anti-inflammatory activity of B. umbraculum observed in this study might be possible targets for adjunctive therapy in cerebral malaria together with its antiplasmodial activity. However, clinical trials are necessary to evaluate the activity due to the complex pathogenesis of cerebral malaria.

Cerebral malaria--clinical manifestations and pathogenesis

One of the most common central nervous system diseases in tropical countries is cerebral malaria (CM). Malaria is a common protozoan infection that is responsible for enormous worldwide mortality and economic burden on the society. Episodes of Plasmodium falciparum (Pf) caused CM may be lethal, while survivors are likely to suffer from persistent debilitating neurological deficits, especially common in children. In this review article, we have summarized the various symptoms and manifestations of CM in children and adults, and entailed the molecular basis of the disease. We have also emphasized how pathogenesis of the disease is effected by the parasite and host responses including blood brain barrier (BBB) disruption, endothelial cell activation and apoptosis, nitric oxide bioavailability, platelet activation and apoptosis, and neuroinflammation. Based on a few recent studies carried out in experimental mouse malaria models, we propose a basis for the neurological deficits and sequelae observed in human cerebral malaria, and summarize how existing drugs may improve prognosis in affected individuals.

Diarylheptanoids Rich Fraction of Alnus nepalensis Attenuates Malaria Pathogenesis: In-vitro and In-vivo Study

Diarylheptanoids from Alnus nepalensis leaves have been reported for promising activity against filariasis, a mosquito-borne disease, and this has prompted us to investigate its anti-malarial and safety profile using in-vitro and in-vivo bioassays. A. nepalensis leaf extracts were tested in-vitro against chloroquine-sensitive Plasmodium falciparum NF54 by measuring the parasite specific lactate dehydrogenase activity. Among all, the chloroform extract (ANC) has shown promising anti-plasmodial activity (IC50 8.06 ± 0.26 µg/mL). HPLC analysis of ANC showed the presence of diarylheptanoids. Efficacy and safety of ANC were further validated in in-vivo system using Plasmodium berghei-induced malaria model and acute oral toxicity in mice. Malaria was induced by intra-peritoneal injection of P. berghei infected red blood cells to the female Balb/c mice. ANC was administered orally at doses of 100 and 300 mg/kg/day following Peter's 4 day suppression test. Oral administration of ANC showed significant reduction of parasitaemia and increase in mean survival time. It also attributed to inhibition of the parasite induced pro-inflammatory cytokines as well as afford to significant increase in the blood glucose and haemoglobin level when compared with vehicle-treated infected mice. In-vivo safety evaluation study revealed that ANC is non-toxic at higher concentration. Copyright © 2016 John Wiley & Sons, Ltd.

Correlation of interleukin-4 levels with Plasmodium falciparum malaria parasitaemia in Sudanese children

OBJECTIVES

This study aimed to measure the level of interleukin-4 (IL-4) in the serum of children patients with falciparum malaria and to correlate the production of this cytokine with the severity of malaria parasitaemia.

METHODS

One hundred ten patients with malaria participated in this study (53 males and 57 females) and their results were compared with that of 60 healthy control subjects. Their ages ranged between 6 months and 15 years. For the detection of parasitaemia, a calibrated thick-smear technique was used with standard Giemsa staining. For designation of the relative parasite count, a simple code from one to four crosses is used according to the criteria mentioned by Gilles and Warrell. The blood samples were assessed for IL-4 using enzyme-linked immunosorbent assay (ELISA) technique.

RESULTS

Thirty-three malaria patients (30.27%) had one cross (+) parasitaemia, 13 patients (11.93%) had (++) parasitaemia, 24 patients (22.02%) had (+++) parasitaemia and 39 patients (35.78%) had (++++) parasitaemia. There was a significant difference (P<0.009) in the concentration of IL-4 between malaria patients (160.74±25.5 pg/ml) and control group (62.136±18.16 pg/ml). Uncomplicated malaria patients showed the highest record of IL-4 level followed by cerebral malaria (CM) group and then severe malaria anaemia group (SMA) (255.8±54.13, 102.7±34.88 and 90.95±20.90 pg/ml respectively, P>0.0001).

CONCLUSION

It was concluded that elevation of serum IL-4 in Sudanese children suffering from Plasmodium falciparum malaria is correlated with the severity of malaria hyperparasitaemia rather than with the severity of the disease.

Plants as antimalarial agents in Sub-Saharan Africa

Although the burden of malaria is decreasing, parasite resistance to current antimalarial drugs and resistance to insecticides by vector mosquitoes threaten the prospects of malaria elimination in endemic areas. Corollary, there is a scientific departure to discover new antimalarial agents from nature. Because the two antimalarial drugs quinine and artemisinin were discovered through improved understanding of the indigenous knowledge of plants, bioprospecting Sub-Saharan Africa's enormous plant biodiversity may be a source of new and better drugs to treat malaria. This review analyses the medicinal plants used to manage malaria in Sub-Saharan Africa. Chemical compounds with antiplasmodial activity are described. In the Sub-Saharan African countries cited in this review, hundreds of plants are used as antimalarial remedies. While the number of plant species is not exhaustive, plants used in more than one country probably indicate better antimalarial efficacy and safety. The antiplasmodial data suggest an opportunity for inventing new antimalarial drugs from Sub-Saharan-African flora.

Simultaneously targeting inflammatory response and parasite sequestration in brain to treat Experimental Cerebral Malaria

Malaria afflicts around 200 million people annually, with a mortality number close to 600,000. The mortality rate in Human Cerebral Malaria (HCM) is unacceptably high (15–20%), despite the availability of artemisinin-based therapy. An effective adjunct therapy is urgently needed. Experimental Cerebral Malaria (ECM) in mice manifests many of the neurological features of HCM. Migration of T cells and parasite-infected RBCs (pRBCs) into the brain are both necessary to precipitate the disease. We have been able to simultaneously target both these parameters of ECM. Curcumin alone was able to reverse all the parameters investigated in this study that govern inflammatory responses, CD8⁺ T cell and pRBC sequestration into the brain and blood brain barrier (BBB) breakdown. But the animals eventually died of anemia due to parasite build-up in blood. However, arteether-curcumin (AC) combination therapy even after the onset of symptoms provided complete cure. AC treatment is a promising therapeutic option for HCM.

HPLC method for simultaneous quantitative detection of quercetin and curcuminoids in traditional chinese medicines

OBJECTIVES

Quercetin and curcuminoids are important bioactive compounds found in many herbs. Previously reported high performance liquid chromatography ultraviolet (HPLC-UV) methods for the detection of quercetin and curcuminoids have several disadvantages, including unsatisfactory separation times and lack of validation according the standard guidelines of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use.

METHODS

A rapid, specific, reversed phase, HPLC-UV method with an isocratic elution of acetonitrile and 2% v/v acetic acid (40% : 60% v/v) (pH 2.6) at a flow rate of 1.3 mL/minutes, a column temperature of 35°C, and ultraviolet (UV) detection at 370 nm was developed. The method was validated and applied to the quantification of different types of market available Chinese medicine extracts, pills and tablets.

RESULTS

The method allowed simultaneous determination of quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin in the concentration ranges of 0.00488 ─ 200 μg/mL, 0.625 ─ 320 μg/mL, 0.07813 ─ 320 μg/mL and 0.03906 ─ 320 μg/mL, respectively. The limits of detection and quantification, respectively, were 0.00488 and 0.03906 μg/mL for quercetin, 0.62500 and 2.50000 μg/mL for bisdemethoxycurcumin, 0.07813 and 0.31250 μg/mL for demethoxycurcumin, and 0.03906 and 0.07813 μg/mL for curcumin. The percent relative intra day standard deviation (% RSD) values were 0.432 ─ 0.806 μg/mL, 0.576 ─ 0.723 μg/mL, 0.635 ─ 0.752 μg/mL and 0.655 ─ 0.732 μg/mL for quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively, and those for intra day precision were 0.323 ─ 0.968 μg/mL, 0.805 ─ 0.854 μg/mL, 0.078 ─ 0.844 μg/mL and 0.275 ─ 0.829 μg/mL, respectively. The intra day accuracies were 99.589% ─ 100.821%, 98.588% ─ 101.084%, 9.289% ─ 100.88%, and 98.292% ─ 101.022% for quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively, and the inter day accuracy were 99.665% ─ 103.06%, 97.669% ─ 103.513%, 99.569% ─ 103.617%, and 97.929% ─ 103.606%, respectively.

CONCLUSION

The method was found to be simple, accurate and precise and is recommended for routine quality control analysis of commercial Chinese medicine products containing the flour flavonoids as their principle components in the extracts.

Neurological and behavioral manifestations of cerebral malaria: An update

Neglected tropical diseases are a group of tropical diseases endemic in poor countries even though medical treatment and cures are available. They are considered a global health problem due to the severity of the physiological changes they induce in their hosts. Malaria is a disease caused by Plasmodium sp. that in its cerebral form may lead to acute or long-term neurological deficits, even with effective antimalarial therapy, causing vascular obstruction, reduced cerebral blood flow and many other changes. However, Plasmodium falciparum infection can also develop into a cerebral malaria (CM) disease that can produce neurological damage. This review will discuss the mechanisms involved in the neuropathology caused by CM, focusing on alterations in cognitive, behavior and neurological functions in human and experimental models.

Optimization of artemether-loaded NLC for intranasal delivery using central composite design

The objective of the study was to optimize artemether-loaded nanostructured lipid carriers (ARM-NLC) for intranasal delivery using central composite design. ARM-NLC was prepared by microemulsion method with optimized formulation having particle size of 123.4 nm and zeta potential of -34.4 mV. Differential scanning calorimetry and powder X-ray diffraction studies confirmed that drug existed in amorphous form in NLC formulation. In vitro cytotoxicity assay using SVG p12 cell line and nasal histopathological studies on sheep nasal mucosa indicated the developed formulations were non-toxic and safe for intranasal administration. In vitro release studies revealed that NLC showed sustained release up to 96 h. Ex vivo diffusion studies using sheep nasal mucosa revealed that ARM-NLC had significantly lower flux compared to drug solution (ARM-SOL). Pharmacokinetic and brain uptake studies in Wistar rats showed significantly higher drug concentration in brain in animals treated intranasally (i.n.) with ARM-NLC. Brain to blood ratios for ARM-NLC (i.n.), ARM-SOL (i.n.) and ARM-SOL (i.v.) were 2.619, 1.642 and 0.260, respectively, at 0.5 h indicating direct nose to brain transport of ARM. ARM-NLC showed highest drug targeting efficiency and drug transport percentage of 278.16 and 64.02, respectively, which indicates NLC had better brain targeting efficiency compared to drug solution.

Intranasal therapeutic strategies for management of Alzheimer's disease

Alzheimer's disease (AD) is a chronic and progressive age-related irreversible neurodegenerative disorder that represents 70% of all dementia with 35 million cases worldwide. Successful treatment strategies for AD have so far been limited, and present therapy is based on cholinergic replacement therapy and inhibiting glutamate excitotoxicity. In this context, role of neuroprotective drugs has generated considerable interest in management of AD. Recently, direct intranasal (IN) delivery of drug moieties to the central nervous system (CNS) has emerged as a therapeutically viable alternative to oral and parenteral routes. IN delivery bypasses the blood-brain barrier by delivering and targeting drugs to the CNS along the olfactory and trigeminal neural pathways which are in direct contact with both the environment and the CNS. In an attempt to understand how neurotherapeutics/nanoparticulate delivery systems can be transported from the nose to the CNS, the present review sets out to discuss the mechanism of transport from nose to brain. The aim of this review is to discuss and summarize the latest findings of some of the major studies on IN drug delivery in AD models, with a focus on the potential efficacy of neuroprotective treatments.