Immunomodulatory and antiparasitic effects of garlic-arteether combination via nitric oxide pathway in Plasmodium berghei-infected mice.

Many reports indicate medicinal value of garlic (Allium sativum), a popular herbal medicine used worldwide, and its therapeutic effect against several diseases. Earlier studies in our laboratory have shown a potential therapeutic role of garlic-artemisinin combination in mice infected with Plasmodium berghei. A single dose of α, ß-arteether with three oral doses of garlic provides almost 95% protection. The present study aims to understand the mode of action of this combination. We have documented the level of nitric oxide (NO), a key molecule of protection and have seen in the reversal of organ morphology caused by malaria infection. The combination effects on the (a) survival rate and degree of parasitemia and (b) NO levels in blood, liver, spleen and thymus of malaria-infected mice were investigated. During the study, liver, spleen and thymus cell suspensions were assessed for immunobiochemical alterations of NO levels. The increase in NO level after infection appears to be unable to protect, whereas striking increase in spleen and thymus leads to protection against infection, and is further confirmed by detection of increased inducible nitric oxide synthase mRNA expression levels in different organs by RT-PCR. In addition, the role of T cell subsets during combination treatment was also studied. All these results indicate a potential mechanism of protection through NO pathway in combination-treated animals after malaria infection and may lead to an immunotherapy trial of malaria disease.

Advances in nanomedicines for malaria treatment.

Malaria is an infectious disease that mainly affects children and pregnant women from tropical countries. The mortality rate of people infected with malaria per year is enormous and became a public health concern. The main factor that has contributed to the success of malaria proliferation is the increased number of drug resistant parasites. To counteract this trend, research has been done in nanotechnology and nanomedicine, for the development of new biocompatible systems capable of incorporating drugs, lowering the resistance progress, contributing for diagnosis, control and treatment of malaria by target delivery. In this review, we discussed the main problems associated with the spread of malaria and the most recent developments in nanomedicine for anti-malarial drug delivery.

Widespread occurrence of the Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene haplotype SVMNT in P. falciparum malaria in India.

The Plasmodium falciparum chloroquine resistance transporter (Pfcrt) K76T mutation and haplotype (amino acids 72-76) and the P. falciparum multidrug resistance 1 (Pfmdr1) mutation (N86Y) were analyzed as markers of chloroquine resistance in the DNAs of 73 blood samples from patients with P. falciparum malaria in India. Seventy of the 73 DNAs had the Pfcrt K76T mutation. Of these, 66 had the SVMNT haplotype and four had CVIET, the African/Southeast Asian haplotype. Only 20 of 69 DNAs had the Pfmdr1 N86Y mutation. It is surprising that the Pfcrt haplotype in India is predominantly SVMNT, rather than that seen in Southeast Asia. The widespread prevalence of the Pfcrt K76T mutation is a cause for concern.

Phenobarbitone-mediated translocation of the cytosolic proteins interacting with the 5'-proximal region of rat liver CYP2B1/B2 gene into the nucleus.

The positive element (PE) (-69 to -98 bp) within the 5'-proximal region of the CYP2B1/B2 gene (+1 to -179 bp) of rat liver is essential for phenobarbitone (PB) response and gives a single major complex with the rat liver cytosol in gel shift analysis. This complex corresponds to complex I (top) of the three complexes given by the nuclear extracts. PB treatment of rats leads to a decrease in complex I formation with the cytosol and PE and an increase in the same with the nuclear extract in gel shift analysis. Both the changes are counteracted by simultaneous okadaic acid administration. The nuclear protein giving rise to complex I has been isolated and has an M(r) of 26 kDa. The cytosolic counterpart consists of two species, 26 and 28 kDa, as revealed by Southwestern blot analysis using labeled PE. It is concluded that PB treatment leads to the translocation accompanied by processing of the cytosolic protein species into the nucleus that requires protein dephosphorylation. It is suggested that PB may exert a global regulation on the transcription of many genes by modulating the phosphorylation status of different protein factors involved in transcriptional regulation.

Receptor-mediated gene delivery approach demonstrates the role of 5'-proximal DNA region in conferring phenobarbitone responsiveness to CYP2B2 gene in rat liver in vivo.

The phenobarbitone (PB) responsiveness of the 5'-proximal region of the CYP2B1/B2 gene was examined in detail with plasmid DNA constructs containing G-free cassette as reporter, using in vivo targeting of the same DNA constructs into rat liver as galactosylated-polylysine complexes. The contribution of the proximal region (-1 to -179 bp) and the positive element (-69 to -98 bp) identified earlier in this laboratory to PB responsiveness was assessed. The results obtained on PB treatment of rats subjected to receptor-mediated gene delivery to liver were conclusive and dramatic, with the control (saline-treated) rats manifesting very little expression of the reporter, reflecting the in vivo picture of CYP2B1/B2 gene expression. The positive element conferred PB responsiveness to homologous and heterologous promoters. Deletion of the positive element led to elimination of PB response. The entire -179 bp region was significantly more effective in responding to PB treatment than the region up to -98 bp, both containing one copy of the positive element. Thus, the positive element and its flanking sequences in the 5'-proximal region are involved in conferring PB responsiveness to the CYP2B1/B2 gene.