Anti-inflammatory activity and chemical characterisation of Opuntia ficus-indica seed oil cultivated in Saudi Arabia

The fruits of Opuntia ficus-indica (L.) Mill. (OFI), a member of the family Cactaceae, are cultivated in Saudi Arabia and considered as a functional food with anti-inflammatory activity. The aim of current study was to chemically characterise OFI growing in Saudi Arabia by GC–MS and evaluate its anti-inflammatory activity in rat models via carrageenan-induced paw oedema and croton oil-induced ear oedema at two doses 100 and 200 mg/kg. Palmitic acid (10.68%), linoleic acid (5.9%), oleic acid (8.16%) and β-sitosterol (24.98%) are the major constituents in OFI seed oil. In carrageenan-induced rats, the OFI seed oil (100 and 200 mg/kg) produced significant inhibition of oedema by approximately 46% and 62%, respectively, and reduced prostaglandin (PGE2) concentrations in exudates by 54% and 67%, respectively. Also, it significantly decreased the weight of punch from challenged ears by 20% and 33% and myeloperoxidase (MPO) activity by 54% and 62% of the induced ear, respectively. This was accompanied by amelioration of croton oil-induced histopathological changes. In conclusion, the anti-inflammatory activity of the OFI seed oil might be attributed to the presence of unsaturated fatty acids (USFA) such as oleic acid (omega-9) in addition to β-sitosterol through decreasing PGE2 and MPO activity in the inflamed tissues which was supported by histopathological examination.