LC-MS based metabolite profiling, in-vitro antioxidant and in-vivo antihyperlipidemic activity of Nigella sativa extract

The aim of this study was to identify the bioactive phytoconstituents present in the aqueous extract of Nigella sativa and also, to evaluate the antioxidant and antihyperlipidemic activity in Wistar rats. The LC-MS/MS analysis was assessed for the determination of different bioactive compounds present in N. sativa extract. Total phenolic and flavonoid content were determined by using validated Folin-Ciocalteu and Aluminum chloride colorimetric methods, respectively. The in-vitro antioxidant and in-vivo antihyperlipidemic activity in Wistar rats were also evaluated. Preliminary phytochemical screening of the extract showed the presence of alkaloids, flavonoids, phenols, glycosides, and amino acids in the aqueous extract. The bioactive compounds of the aqueous extract were identified through LC-MS/MS analysis. The in-vitro antioxidant activity of N. sativa showed the highest free radical scavenging capacity in DPPH, H₂O₂, and OH radical scavenging assays with IC₅₀ values 11.916 ± 2.828, 30.294 ± 13.790, and 12.048 ± 2.828 µg/mL, respectively. Evaluation of antihyperlipidemic activity of extract in Wistar rats showed that a high dose (800 mg/kg) of extract significantly decreased total cholesterol (TC) 71.76 ± 6.91 mg/dL, TG 83.6 ± 8.09 mg/dL, low-density lipoproteins (LDL-c) 33.86 ± 6.05 mg/dL, very low-density lipoproteins (VLDL-c) 16.72 ± 1.61 mg/dL level in blood. However, the HDL-C level was significantly improved (21.18 ± 1.80 mg/dL) as compared to HFD-induced control rats (11.76 ± 1.14 mg/dL) after 28 days of treatment. Also, at the same dose, animal body weight was also decreased to 162.6 ± 16.40 g compared with control 184.4 ± 10.24 g. The aqueous extract of N. sativa was found to be an effective natural source of antioxidant and hypolipidemic agents. This activity was attributed to the presence of diverse bioactive compounds in it.