UPLC-PDA-ESI/MS metabolic profiling of dill shoots bioactive fraction; evidence of its antioxidant and hepatoprotective effects in vitro and in vivo.

Hydroxyl radical ( OH) scavenging capacity of aqueous dill (Anethum graveolens L.) shoot (ADSh) extract was assessed using electron paramagnetic resonance (EPR) spectroscopy. ADSh extract (at concentrations of 0.5 and 10 mg/ml) exerted high (OH) radical scavenging power. ADSh extract was further fractionated on Diaion HP-20 column to yield five fractions. EPR spin-trapping assay revealed fraction 4 (eluted with 75% aq. MeOH) to possess ( OH) radical scavenging capacity over a concentration range (0.01-10 mg/ml), whereas fraction 2 (eluted with 25% aq. MeOH) appeared to be pro-oxidant at concentration 0.01 mg/ml. UPLC-PDA-ESI-MS metabolite profiling of ADSh extract revealed 87 metabolites, of which 64 compounds were identified in fraction 4, the most active fraction. Furthermore, ADSh extract demonstrated a hepatoprotective effect against acetaminophen (APAP)-induced hepatotoxicity in rats. Pretreatment of rats with ADSh extract (200 mg/kg b.wt) markedly attenuated the increased in the serum hepatic enzyme levels. It also increased free glutathione level and total antioxidant capacity in the serum of treated rats. [Correction added on May 3, 2021, after first online publication: "rates" has been changed to "rats" in the previous sentence.] Additionally, levels of (TNF-α and IL-1β) were back to almost normal levels compared to the control group. The above findings suggest that ADSh extract has a protective effect against APAP-induced liver damage.