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 1β, 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.