Plasmodium chabaudi-infected mice spleen response to synthesized silver nanoparticles from Indigofera oblongifolia extract.

Malaria is a worldwide serious-threatening infectious disease caused by Plasmodium and the parasite resistance to antimalarial drugs has confirmed a significant obstacle to novel therapeutic antimalarial drugs. In this article, we assessed the antioxidant and anti-inflammatory activity of nanoparticles prepared from Indigofera oblongifolia extract (AgNPs) against the infection with Plasmodium chabaudi caused in mice spleen. AgNPs could significantly suppress the parasitaemia caused by the parasite to approximately 98% on day 7 postinfection with P. chabaudi and could improve the histopathological induced spleen damage. Also, AgNPs were able to increase the capsule thickness of the infected mice spleen. In addition, the AgNPs functioned as an antioxidant agent that affects the change in glutathione, nitric oxide and catalase levels in the spleen. Moreover spleen IL1ß, IL-6 and TNF-α-mRNA expression was regulated by AgNPs administration to the infected mice. These results indicated the anti-oxidant and the anti-inflammatory protective role of AgNPs against P. chabaudi-induced spleen injury.

Morphological and release characterization of nanoparticles formulated with poly (dl-lactide-co-glycolide) (PLGA) and lupeol: In vitro permeability and modulator effect on NF-κB in Caco-2 cell system stimulated with TNF-α.

Lupeol exhibits anti-inflammatory effects; unfortunately it shows low water solubility. An alternative to overcome this is the development of nanomaterials. Several methods for nanomaterial production are available. One of them is emulsification/solvent-evaporation. The objective of the present work was to evaluate physical properties, transport and in vitro modulator effects on NF-κB of poly (lactide-co-glycolide) (PLGA) nanoparticles loaded with lupeol. Nanonutraceuticals were prepared with 16% (w/v) of lupeol. Size distribution and morphology were measured by particle size analyzer and TEM. In vitro release of lupeol was studied by three different models: Higuchi, Siepmann & Peppas, and Power law. Transport of nanonutraceutical was studied in a Caco-2 cell model and by GC-MS. Modulator effect on NK-κB was studied by western blot analysis. Nanonutraceuticals were 10% larger than the nanoparticles without lupeol (372 vs 337 nm) and presented a broader size distribution (0.28 vs 0.22). TEM results displayed spherical structures with a broader size distribution. Entrapment efficiency of lupeol was 64.54% and it in vitro release data fitted well to the Power law and Higuchi equation (R > 0.84-0.84). Strong regulation of NF-κB of nanonutraceutical was observed. It was not observed any transport across the Caco-2 cell model at the different experimental conditions.

Inhibition of liver carcinogenesis in Wistar rats by consumption of an aqueous extract from leaves of Ardisia compressa.

This study evaluates the chemopreventive effect of an aqueous extract of dried leaves of Ardisia compressa against liver cancer. A rat liver assay that mimics progressive forms of human disease was used as a carcinogenesis model. Forty-five male Wistar rats (180-200 g body weight) were injected intraperitoneally on day 1 with a single dose (100 mg/kg) of diethylnitrosamine (DEN), and also received via gavage 20 mg/kg acetylaminofluorene (2-AAF), on days 7, 8 and 9. The rats were randomly divided into four groups (n=15). Control groups (Group 1 and Group 2) had free access to water. Group 3 received 0.5% (w/v) of A. compressa tea for 10 days before treatment and during the study as the sole source of fluid until the rats were killed. A fourth group of 15 rats received no carcinogen or promoter but did receive 0.5%, (w/v) of A. compressa tea. All animals had 70% partial hepatectomy at day 10. The incidences of hepatocellular foci, nodules and carcinoma were significantly smaller in Group 3 than in Group 2 (P<0.01). A. compressa tea consumption alone (Group 4) did not induce the development of foci, nodules or carcinomas (P<0.01). The striking observation of this study was that consumption of A. compressa tea resulted in complete inhibition of the chemically-induced hepatocarcinogenesis in Wistar rats.

Ontogeny constrains systemic protease inhibitor response in Nicotiana attenuata.

Protease inhibitors (PIs) are plant compounds that can inhibit proteases of mammal, insect, or pathogen origin and are frequently induced by mechanical wounding, insect feeding, or pathogen infection. Nicotiana attenuata is a species that induces nicotine, volatiles, and phenolics in response to damage. Here we examine the distribution of PIs in N. attenuata to determine if they are part of the induced response in this species and if this response is ontogenetically constrained. We found that N. attenuata shoot extracts inhibited trypsin (Tryp) and chymotrypsin (Chym) activities, while root extracts inhibited Tryp, Chym, and the bacterial protease subtilisin (Sub). The highest TrypPI levels were found at midday in the source-sink transition leaf, while older or younger leaves contained lower TrypPI levels and did not show significant diurnal fluctuations. Rosette plants, bolting plants, and flowering plants all contained TrypPIs in leaves, stems, and flowers, while seed capsules, seeds, and young seedlings did not contain any PIs. PIs in N. attenuata rosette plants were induced by Manduca sexta larval feeding, methyl jasmonate (MeJA) treatment, wounding, and application of M. sexta oral secretion and regurgitant. The response to MeJA application was stronger and longer lasting than to mechanical wounding. The direction and magnitude of the systemic response to mechanical wounding or larval damage depended on the age of the leaf that was damaged and the frequency of wounding. The systemic signal for TrypPI induction appears to follow source-sink relations in the plant and to be regulated by the octadecanoid pathway. Interestingly, by the time plants reach the flowering stage, they had lost the ability to increase PI levels after MeJA treatment. We concluded that plant ontogeny constrains both constitutive and inducible PI production in N. attenuata.

Crystallization and preliminary crystallographic study of cathepsin D inhibitor from potatoes.

Single crystals of the glycosylated inhibitor of cathepsin D and trypsin isolated from potato tubers were obtained using the hanging drop vapor diffusion method and ammonium nitrate as precipitant. The crystals exhibit strong F222 pseudo symmetry but belong to the orthorhombic space group C222 or C222(1), with cell parameters a = 73.8 A, b = 119.9 A and c = 133.2 A with two molecules per asymmetric unit. The crystals diffract to a resolution of 2.4 A.

Primary structure of cathepsin D inhibitor from potatoes and its structure relationship to soybean trypsin inhibitor family.

A novel effective procedure for the purification of cathepsin D inhibitor from potatoes (PDI) was developed. The amino acid sequence of PDI was determined by analysis of the cyanogen bromide digest and of the limited tryptic and chymotryptic digest of the protein. The inhibitor is a single polypeptide chain protein consisting of 188 residues with a simple sugar moiety attached to Asn-19. The tentative disulfide pairings are also suggested. The sequence data clearly indicate that PDI is homologous with the soybean trypsin inhibitor (STI) (Kunitz) family. The active center of PDI for trypsin inhibition was identified as Pro-Val-Arg-Phe in analogy to STI.