Gold Nanoparticles (AuNPs) Conjugated with Andrographolide Ameliorated Viper (Daboia russellii russellii) Venom-Induced Toxicities in Animal Model.

Andrographolide, a diterpenoid compound found in the aerial parts of Andrographis paniculata (a well known anti snake venom plant) was conjugated with gold nanoparticle (andrographolide-AuNPs) and its efficacy against Daboia russellii russellii venom (DRRV) induced local damage, organ toxicity and inflammatory response was evaluated in animal models. Ethical clearance was obtained before animal experiments. Andrographolide-AuNPs was formed by adsorption method. Physico-chemical characterization of particle was done by dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Swiss albino male mice were divided into 5 groups: Gr. 1-Sham control, Gr. 2-DRRV control, Gr. 3-anti snake venom serum treated, Gr. 4-andrographolide treated and Gr. 4-andrographolide-AuNPs treated. 1/5th minimum lethal dose of DRRV (10 µg/s.c./20 g mice) was induced in animals of group 2, 3, 4 and 5 animals, followed by treatment with anti snake venom serum (2 mg/20 g mice, i.v.) andrographolide (50 µg/20g mice, i.p.) and andrographolide-AuNPs (50 µg/20 g mice, i.v.) in group 3, 4 and 5 animals, respectively. Blood was collected after 18 h, serum was prepared and organ toxicity markers (transaminases, phosphatases, lactate dehydrogenase, creatine phosphate, urea, creatinine, Ca2+, phosphorous), inflammatory markers (interleukin 1ß, 6, 17a, 10, tumor necrosis factor α) and local damage testings (defibrination, edema, hemorrhage) were assessed. Values were expressed as mean ± SEM (n = 4), one way analysis of variance was done, P < 0.05 was considered as statistically significant. Formed andrographolide-AuNPs were pink in color with hydrodynamic diameter 30-50 nm, polydispersity index 0.412 and zeta potential -16.21 mV. XRD data confirmed the presence of crystalline gold in andrographolide-AuNPs. TEM (20-50 nm) and FE-SEM (20-25 nm) indicated the presence of nearly spherical particle. DRRV envenomation followed by treatment with andrographolide-AuNPs provided protection against venom induced edema, hemorrhage, defibrination, organ toxicity and inflammation in animal model. Venom neutralization by andrographolide-AuNPs was > andrographolide, which confirmed the increased efficacy of andrographolide after gold nanoparticle conjugation, may be due to anti-oxidant/anti-inflammatory activity of andrographolide, showing increased efficacy after gold nanoparticle tagging. Thus, andrographolide-AuNPs may serve as a supportive therapy in snakebite (against venom induced local damage, organ toxicity and inflammatory response) subject to further detail studies.

Therapeutic efficacy of artemisinin-loaded nanoparticles in experimental visceral leishmaniasis.

Visceral leishmaniasis (VL) is a fatal vector-borne parasitic syndrome attributable to the protozoa of the Leishmania donovani complex. The available chemotherapeutic options are not ideal due to their potential toxicity, high cost and prolonged treatment schedule. In the present study, we conjectured the use of nano drug delivery systems for plant-derived secondary metabolite; artemisinin as an alternative strategy for the treatment of experimental VL. Artemisinin-loaded poly lactic co-glycolic acid (ALPLGA) nanoparticles prepared were spherical in shape with a particle size of 220.0±15.0 nm, 29.2±2.0% drug loading and 69.0±3.3% encapsulation efficiency. ALPLGA nanoparticles administered at doses of 10 and 20mg/kg body weight showed superior antileishmanial efficacy compared with free artemisinin in BALB/c model of VL. There was a significant reduction in hepatosplenomegaly as well as in parasite load in the liver (85.0±5.4%) and spleen (82.0±2.4%) with ALPLGA nanoparticles treatment at 20mg/kg body weight compared to free artemisinin (70.3±0.6% in liver and 62.7±3.7% in spleen). In addition, ALPLGA nanoparticle treatment restored the defective host immune response in mice with established VL infection. The protection was associated with a Th1-biased immune response as evident from a positive delayed-type hypersensitivity reaction, escalated IgG2a levels, augmented lymphoproliferation and enhancement in proinflammatory cytokines (IFN-γ and IL-2) with significant suppression of Th2 cytokines (IL-10 and IL-4) after in vitro recall, compared to infected control and free artemisinin treatment. In conclusion, our results advocate superior efficacy of ALPLGA nanoparticles over free artemisinin, which was coupled with restoration of suppressed cell-mediated immunity in animal models of VL.

Thermostability, pH stability and dye degrading activity of a bacterial laccase are enhanced in the presence of Cu2O nanoparticles.

The present study relates to a nanotechnology enabled method in which purified laccase from Escherichia coli AKL2 was supplemented with 100 µM copper oxide nanoparticles (Cu(2)O) (NP-laccase). The activity, half life and stability of NP-laccase were enhanced by 4, 42 and 36-fold respectively at high temperature (80 °C) and also over a wide range of pH (4-12) than laccase (in the presence of 0.18 mM CuSO(4)). Thermodynamic analysis of the nanoparticle-induced enzyme stability revealed an enhanced entropy-enthalpy compensation at 80 °C, which reflected the maintenance of its native structure. This was further supported by CD studies. The enhanced activity and thermostability of NP-laccase can be utilized for efficient decolorisation of dyes (both phenolic and azo).

Vitamin C prevents cigarette smoke induced atherosclerosis in guinea pig model.

AIM: Cigarette smoking is a major risk for developing atherosclerosis; however, the underlying mechanism is poorly understood. This paucity of knowledge is largely attributed to the lack of an animal model; therefore, our efforts were targeted towards establishing cigarette smoke (CS)-induced atherosclerosis in guinea pig. To understand the mechanism, we investigated apoptosis, an event implicated in atherosclerosis, in the aorta of CS-exposed animals. Since a major deleterious effect of CS is oxidative stress, we also examined the effect of vitamin C, an antioxidant, on CS- induced atherosclerosis. METHODS AND RESULTS: Guinea pigs on a diet with or without vitamin C supplement were exposed to CS for different time periods. Aortal sections from these animals were examined for atherosclerotic changes by staining with H&E and Oil red O. Atherogenic changes were observed in sections obtained from CS-exposed guinea pigs only. TUNEL assay showed the occurrence of apoptosis in CS-exposed guinea pig aorta. Our results revealed that CS-induced apoptosis could contribute to the progression but not to the initiation of the disease. Immunohistochemical analysis documents that CS-induced apoptosis in aortal sections is mediated at least in part by an increased Bax/Bcl2 ratio. In contrast, CS-exposed guinea pigs fed with vitamin C-supplemented diet exhibit little or no atherogenic changes. This anti-atherosclerotic activity of vitamin C can be attributed partly to its ability to inhibit CS-induced apoptosis and platelet activation. CONCLUSION: Exposure of guinea pigs to cigarette smoke causes the development of atherosclerosis, which can be prevented by vitamin C supplement.