Macrophage activation plays a significant role in homeostasis of organisms. Various internal and external stress factors may affect their function, leading to adverse effects on the body. ‘In vitro macrophage activation techniques provide us with a window to understand the mechanisms of inflammation and response of macrophages to the modulating interventions. Apart from infectious diseases, inflammation is also the major culprit in pathogenesis of many noncommunicable diseases such as arthritis, obesity, metabolic syndrome, diabetes, cancer, cardiovascular disease etc. In vitro macrophage activation allows us to study the role of polarized macrophages in the process of pathogenesis. This emerging technique leads to newer diagnostics, understanding pathophysiological mechanism/s, drug development and management of chronic inflammatory diseases. We, at MRC-KHS, use this technique for screening of medicinal plant-derived phytomolecules for their anti-inflammatory, immunomodulatory and anticancer activities. This review briefly outlines the different experimental models of in vitro macrophage activation and their applications for understanding the pathophysiological mechanisms of underlying chronic inflammation and screening of therapeutic activity of plant-based phytomolecules.

Anacardium occidentale L. (Anacardiaceae) is used in South Cameroon as well as in other tropical countries by traditional practitioners as a folk remedy for treatment of diabetes mellitus. We demonstrated the antidiabetic potential of the plant extracts in n-streptozotocin diabetic rats. The aim of the current study was to investigate the antidiabetic effects of ethanol extract of leaves of A. occidentale on neonatal streptozotocin diabetic rats. Two day old neonates were injected with 100 mg/kg of streptozotocin. At the end of the experimental period of 30 days, reduction in the fasting blood glucose levels, serum insulin, glycated hemoglobin levels, serum lipid parameters, and renal function biomarkers were estimated in the control and treated rats. Histopathological examination of liver, kidney and pancreas were also carried out. On administration of 100 mg/kg of plant extract, blood glucose levels of the rats showed 8.01% and 19.25% decrease in the fasting blood glucose levels on day 15 and day 30, respectively. The administration of extract showed that the effects of extract treatment are comparable to treatment with the standard drug Pioglitazone. These results demonstrate significant antidiabetic potential of the ethanol extract of leaves of A. occidentale, justifying the use of plant in the indigenous system of medicine. Further studies for investigating the specific compound(s) responsible for such beneficial role in diabetes would open new outlook in the therapy of type 2 diabetes.

Background. Efficacy of standard dose of primaquine (PQ) as antirelapse for P. vivax has decreased. We aimed to assess efficacy of different PQ regimens. Methods. It was an open label, randomized, controlled, parallel group, assessor blind study comparing antirelapse efficacy of 3 PQ regimens (B = 15 mg/day × 14 days, C = 30 mg/day × 7 days, and D = 30 mg/day × 14 days) with no PQ group (A) in P. vivax patients. Paired primary and recurrence samples were subjected to 3 methods: (i) month of recurrence and genotyping, (ii) by PCR-RFLP, and (iii) PCR sequencing, to differentiate relapse and reinfection. The rates of recurrence relapse and reinfection were compared. Methods were compared for concordance between them. Results. The recurrence rate was 16.39%, 8.07%, 10.07%, and 6.62% in groups A, B, C, and D, respectively (P = 0.004). The relapse rate was 6.89%, 1.55%, 4%, and 3.85% as per the month of recurrence; 8.2%, 2%, 4.58%, and 3.68% (P = 0.007) as per PCR-RFLP; and 2.73%, 1.47%, 1.55%, and 1.53% as per PCR sequencing for groups A, B, C, and D, respectively. The concordance between methods was low, 45%. Conclusion. The higher recurrence rate in no PQ as compared to PQ groups documents PQ antirelapse activity. Regimens tested were safe. However, probable resistance to PQ warrants continuous monitoring and low concordance and limitations in the methods warrant caution in interpreting.

OBJECTIVE:To determine whether Curcuma longa Linn extract, NBFR-03, can arrest low-grade squamous intraepithelial neoplasia (LSIL) a 12 week intervention study was performed.METHODS:Of a total of 1473 women undergoing Pap smear screening, 88 cases had LSIL. Only those with persistent LSIL subsequent to antimicrobial therapy, and willing to follow the protocol (N=21), were included for clinical examination, Pap smears, colposcopy, clinical biochemistry, urinalysis and assessment of serum IL-6, being conducted before and after treatment. Standardised NBFR-03 (0.2gm) capsules were administered, twice daily, for 12 weeks.RESULTS:None progressed to higher grade lesion as assessed by Pap smears and colposcopy. Sixteen cases regressed to atypia, ASCUS or inflammatory pattern; 3 persisted as LSIL, 1 discontinued early because of itching, and 1 did not start. None developed any significant abnormality clinically or biochemically. Micrometry showed a significant reduction in nuclear diameter and nucleocytoplasmic ratio after treatment (p<0.02, and <0.05 respectively). Serum IL-6 levels showed a significant decline (mean 248∓ 156 (SEM) vs 27.7∓ 10.5 (SEM) pg/ ml; p<0.05).CONCLUSION:Use of NBFR-03 for 12 weeks was associated with an arrest or regression of LSIL in Pap smears and colposcopy, with reduction in the circulating IL-6 levels.

Studies on the drying characteristics of Cashew leaves are scarce in the literature; particularly the traditional sun drying properties as well as oven drying properties of plants are not adequately investigated. The aim of the work was to determine the sun, oven, shade dried and fresh leaves drying characteristics of Cashew and to compare the effect of the same on the antioxidant property of the extracts.

The causative agents of malaria have developed a sophisticated machinery for entering multiple cell types in the human and insect hosts. In this machinery, a critical interaction occurs between the unusual myosin motor MyoA and the MyoA-tail Interacting Protein (MTIP). Here we present one crystal structure that shows three different conformations of Plasmodium MTIP, one of these in complex with the MyoA-tail, which reveal major conformational changes in the C-terminal domain of MTIP upon binding the MyoA-tail helix, thereby creating several hydrophobic pockets in MTIP that are the recipients of key hydrophobic side chains of MyoA. Because we also show that the MyoA helix is able to block parasite growth, this provides avenues for designing antimalarials.

Malaria is an ancient disease that has influenced human evolution and history. Though the malaria parasite cycle was discovered in 1897 and the concept of eradication was adopted by the World Health Organization in 1955, the disease continues to remain a major public health problem. Most estimates suggest the global annual estimate of 300-500 million clinical cases and 2-3 million deaths.([1]) Four parasite species account for most human malaria infections worldwide-P falciparum, P. vivax, P malariae and P ovale. The biology of each parasite presents unique challenges for diagnosis, management, drug development and policy-making. The present issue of the journal contains five articles by participants at a National Consultation on Drug Resistance - malaria, TB and HIV-AIDS held in September 2005 in Mumbai (Bombay), which touch upon a multitude of challenges in malaria control.

A 70-year-old male scientist, who had returned 5 weeks earlier from Ethiopia, was admitted to the hospital with symptoms consistent with malaria. On physical examination, he had orthostatic hypotension. He was dehydrated and showed a mild clinical delirium. Abdominal examination revealed a possible spleen tip, and he had petechial lesions bilaterally below his knees. Laboratory data revealed his white blood cell count to be 4,500/mL, with 67% polymorphonuclear cells and 15% band forms. The hemoglobin level was 13.9 g/dL, and the platelet count was low, at 32,000/mL.

The key to reducing mortality and morbidity associated with malaria is rapid diagnosis and early, effective therapy. Berberine, a plant alkaloid, has been used for fluorescent staining of the Y chromosome. We evaluated whether berberine can be used for staining of malarial parasites in 40 selected peripheral blood smears from patients with clinical symptoms of malaria; smears were evaluated with OptiMal (DiaMed, Miami, FL) and Giemsa stain. Twenty were positive with both OptiMal and Giemsa (Plasmodium vivax, 14; Plasmodium falciparum, 6); 10 were negative with both. The remainder were positive by OptiMal but negative by Giemsa and, therefore, were classified as equivocal. All slides were processed simultaneously, stained with berberine, and read under a fluorescent microscope. P vivax and P falciparum DNA fluoresced with berberine. The positives and negatives by berberine concurred with the Giemsa staining. Of the 10 equivocal smears, 5 were confirmed positive by berberine. Gametocytes were easily identifiable. This test has high sensitivity and high positive predictive value and, once standardized, can be used as a potential screening and diagnostic tool.

Mitochondria in Plasmodium parasites have many characteristics that distinguish them from mammalian mitochondria. Selective targeting of malaria parasite mitochondrial physiology has been exploited in successful antimalarial chemotherapy. At present, our understanding of the functions served by the parasite mitochondrion is somewhat limited, but the availability of the genomic sequences makes it possible to develop a framework of possible mitochondrial functions by providing information on genes encoding mitochondrially targeted proteins. This review aims to provide an overview of mitochondrial physiology in this post-genomic era. Although in many cases direct experimental proof for their mitochondrial functions may not be available at present, descriptions of these potential mitochondrial proteins can provide a basis for experimental approaches.

The key to reducing mortality and morbidity associated with malaria is rapid diagnosis and early, effective therapy. Berberine, a plant alkaloid, has been used for fluorescent staining of the Y chromosome. We evaluated whether berberine can be used for staining of malarial parasites in 40 selected peripheral blood smears from patients with clinical symptoms of malaria; smears were evaluated with OptiMal (DiaMed, Miami, FL) and Giemsa stain. Twenty were positive with both OptiMal and Giemsa ( Plasmodium vivax , 14; Plasmodium falciparum , 6); 10 were negative with both. The remainder were positive by OptiMal but negative by Giemsa and, therefore, were classified as equivocal. All slides were processed simultaneously, stained with berberine, and read under a fluorescent microscope. P vivax and P falciparum DNA fluoresced with berberine. The positives and negatives by berberine concurred with the Giemsa staining. Of the 10 equivocal smears, 5 were confirmed positive by berberine. Gametocytes were easily identifiable. This test has high sensitivity and high positive predictive value and, once standardized, can be used as a potential screening and diagnostic tool.

ABSTRACTImmunization withPlasmodium yoeliimerozoite surface protein-8 (PyMSP-8) has been shown to protect mice against lethalP. yoelii17XL malaria. Here we demonstrate that PyMSP-8-specific antibodies preferentially suppressP. yoelii17XL growth in mature erythrocytes compared to growth in reticulocytes and do not suppress the growth of nonlethalP. yoelii17X, a parasite that primarily replicates in reticulocytes. The protection against normocyte-associatedP. yoeliimalaria parasites is mediated by antibodies that recognize conformational epitopes of PyMSP-8 that are nonpolymorphic. We examined changes in gene expression in reticulocyte-restrictedP. yoelii17XL parasites that escaped neutralization by PyMSP-8-specific antibodies usingP. yoeliiDNA microarrays. Of interest,Pymsp-8gene expression decreased, while the expression ofmsp-1,msp-7, and several rhoptry protein genes increased. Breakthrough parasites also exhibited increases in the expression of a subset ofyirandPyst-agenes that are predicted to encode polymorphic antigens expressed on the surface of infected erythrocytes. These data suggest that changes in the expression of parasite proteins expressed on the merozoite surface, as well as the surface of infected erythrocytes, may alter host cell tropism and contribute to the ability of malaria parasites to evade merozoite-specific, neutralizing antibodies.

A male gametocyte defect in the Plasmodium falciparum Dd2 parasite was previously discovered through the observation that all progeny clones in a Dd2 x HB3 genetic cross were the result of fertilization events between Dd2 female and HB3 male gametes. A determinant linked to the defect in Dd2 was subsequently mapped to an 800-kb segment on chromosome 12. Here, we report further mapping of the determinant to an 82-kb region and the identification of a candidate gene, P. falciparum male development gene 1 (pfmdv-1), that is expressed at a lower level in Dd2 compared with the wild-type normal male gametocyte-producing ancestor W2. Pfmdv-1 protein is sexual-stage specific and is located on the gametocyte plasma membrane, parasitophorous vacuole membrane, and the membranes of cleft-like structures within the erythrocyte. Disruption of pfmdv-1 results in a dramatic reduction in mature gametocytes, especially functional male gametocytes, with the majority of sexually committed parasites developmentally arrested at stage I. The pfmdv-1-knockout parasites show disturbed membrane structures, particularly multimembrane vesicles/tubes that likely derive from deformed cleft-like structures. Mosquito infectivity of the knockout parasites was also greatly reduced but not completely lost. The results suggest that pfmdv-1 plays a key role in gametocyte membrane formation and integrity.

Atovaquone is an antiparasitic drug that selectively inhibits electron transport through the parasite mitochondrial cytochrome bc1 complex and collapses the mitochondrial membrane potential at concentrations far lower than those at which the mammalian system is affected. Because this molecule represents a new class of antimicrobial agents, we seek a deeper understanding of its mode of action. To that end, we employed site-directed mutagenesis of a bacterial cytochrome b, combined with biophysical and biochemical measurements. A large scale domain movement involving the iron-sulfur protein subunit is required for electron transfer from cytochrome b-bound ubihydroquinone to cytochrome c1 of the cytochrome bc1 complex. Here, we show that atovaquone blocks this domain movement by locking the iron-sulfur subunit in its cytochrome b-binding conformation. Based on our malaria atovaquone resistance data, a series of cytochrome b mutants was produced that were predicted to have either enhanced or reduced sensitivity to atovaquone. Mutations altering the bacterial cytochrome b at its ef loop to more closely resemble Plasmodium cytochrome b increased the sensitivity of the cytochrome bc1 complex to atovaquone. A mutation within the ef loop that is associated with resistant malaria parasites rendered the complex resistant to atovaquone, thereby providing direct proof that the mutation causes atovaquone resistance. This mutation resulted in a 10-fold reduction in the in vitro activity of the cytochrome bc1 complex, suggesting that it may exert a cost on efficiency of the cytochrome bc1 complex.

Comment on Alkhalil et al, page [4279][1] A careful study suggests that the major nutrition uptake channel in the malaria parasite-infected erythrocyte plasma membrane is a product of the parasite genome rather than a modified erythrocyte molecule. H aving chosen to make its living off a red