ABSTRACT
Shilajit, a blackish-brown exudation obtained from steep rocks of different mountains, has been longly used as a therapeutic agent in traditional medicine. The present study was designed to evaluate the antioxidant, cytotoxic and hyperalgesia-suppressing activity of the aqueous and DMSO extracts of a native Shilajit. The antioxidant and cytotoxic effects of Shilajit extracts was determined using DPPH scavenging activity and MTT assay methods, respectively. In order to examine the hyperalgesia-suppressing activity of the Shilajit aqueous extract the STZ-induced diabetic animals were subjected to oral administration of the extract (50, 100 and 200 mg/kg daily) for six weeks followed by evaluating the behavioral examination (hot plate and tail flick tests) compared to those of diabetic control (Sham) and vehicle groups. The obtained results of antioxidant evaluation of Shilajit represented scavenging activity of 50% at concentration of 2500 µg/mL and 6000 µg/mL in the case of aqueous and DMSO extracts, respectively. Cytotoxic study of water extract of Shilajit revealed IC50 of 727.5±1.9 µg/mL and 1103±3.2 µg/mL on cell lines of MCF-7 (breast cancer) and A549 (lung cancer), respectively. Thermal pain response examination of diabetic rats treated with aqueous extract of Shilajit (100 mg/kg and 200 mg/kg) for six weeks reduced hyperalgesia compared to vehicle and Sham groups. To sum up, considering the moderate antioxidant and hyperalgesia-suppressing activity of this native Shilajit make it as a suitable candidate for further investigation after isolation and characterization of the active compounds.
