Trachyspermum ammi seeds were selected for photochemical study. The crude T. ammi methanol and aqueous extracts showed the presence of alkaloids, saponins, steroids, terpenoids, coumarins, betacyanins, flavonoids and soluble starch. The synthesis of gold nanoparticles (AuNPs) using T. ammi extract was characterized using UV-visible, and FT-IR spectroscopy. The appearance of sharp peak at 520 nm in the UV visible spectra, and the appearance of broad band nanoparticles spectra at 563.21 cm^-1, 516.92 cm^-1 and 462.92 cm^-1 as well as the disappearance of the carboxyl OH bond and carbon-carbon triple bond supported the formation of AuNPs. The crude T. ammi methanol and AuNPs were investigated for antioxidant potential using DPPH· free radical assay, which shows that crude extract has significant antioxidant effect. The synthesized AuNPs was also evaluated for antibacterial activities against staphylococcus aureus, Klebsiella pneumonia and Bacillus subtilis. The crude extract showed activity against Bacillus subtilis, while AuNPs showed activity against staphylococcus aureus. The in vivo sedative effect and analgesic effect were enhanced in AuNPs treated animals in 5 times less dose (i.e., 5, and 10 mg/kg) than that of crude extract. It was concluded that T. ammi extract includes capping and reducing agents, which make it capable to be developed as stable AuNPs. The biological action of AuNPs is either enhanced (sedative and analgesic) or changed (antibacterial activity), when compared with that of plant extract.