In vitro and animal model estimation of the anti Open Access inflammatory and antinociceptive activities of Abrus precatorius (fabaceae) plant-mediated nanoparticles

Background: Recent research indicates that biosynthesized metal nanoparticles from natural products such as plants often exhibit higher therapeutic efficacy and reduced toxicity compared to natural products at macro-scale or chemically-synthesized nanoparticles. The potential therapeutic compounds in natural products usually act as capping agents on synthesized nanoparticles, facilitating targeted delivery of those compounds at lower, more effective doses. Given the roles of inflammation, oxidative stress, and nociception in diseases, developing novel drugs with enhanced efficacy and reduced toxicity is crucial. Objective: This study aimed to investigate the anti-inflammatory, antioxidant, and antinociceptive activities of Abrus precatorius extracts and their mediated nanoparticles using diverse in vitro and in vivo models. Methods: The anti-inflammatory, antioxidant, and antinociceptive bioactivities of Abrus precatorius (AP) (Rosary pea) extracts were investigated. The extracts, labelled B2 for seeds, A2 for seed coats, and their mediated nanoparticles A1 (silver nanoparticles synthesized from seed coat extracts) and B1 (silver nanoparticles synthesized from seed extracts), were bio-synthesized using the crude extracts. Anti inflammatory activity was assessed using the Carrageenan model and antinociceptive activity was evaluated through acetic acid writhing, hot plate, tail clip tests, and xylene ear oedema in mice, with doses ranging from 10-50 µg/kg. In vitro antioxidant activity was measured with 2,2-Diphenyl-1-picrylhydrazine (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assays at concentrations of 10-50 µg/ml. Results: The results showed that the aqueous extract of Abrus precatorius significantly reduced oedema volume in rats and increased antinociceptive and antioxidant activities, as did the mediated nanoparticle samples A1 and B1. In the acetic acid writhing test, the samples exhibited inhibition ranging from 5.5% to 83.3% at doses of 0.01-0.05 mg/kg, indicating reduced pain responses induced by acetic acid. Among the samples, B1 showed the highest inhibition in the acetic acid writhing test. In the DPPH scavenging radical test, sample B2 demonstrated the greatest inhibition of DPPH radicals at 88.64% at a concentration of 0.05 mg/ml, highlighting strong antioxidant activity. Sample A1 exhibited the highest inhibition at 80.42% for the carrageenan test after 6 hours, indicating potent anti-inflammatory effects. Conclusion: The current research illustrates that the extract of Abrus precatorius, in both its crude and nanoparticle forms, displays notable anti-inflammatory, antioxidant, and antinociceptive properties. The biosynthesized nanoparticles prove to be more effective at lower doses in reducing oedema and scavenging DPPH radicals in rodents compared to the crude extracts.