Chemical characterization, anti-nociceptive and anti-inflammatory activities of Plukenetia conophora seed oil in experimental rodent models.

ETHNOPHARMACOLOGICAL RELEVANCE: The seed of the African walnut, Plukenetia conophora Mull.-Arg is well-known for its nutritional and medicinal values. The seed oil is widely used in massages to relieve pain, as nerve tonic and to enhance sexual performance. OBJECTIVE: The study aimed at investigating the chemical profile, antinociceptive and anti-inflammatory activities of P. conophora oil (PCO). METHODS: Seed oil of P. conophora was characterized using Gas-Liquid Chromatographic method (GC-MS) and oral acute toxicity evaluated at 2000 mg/kg. Antinociceptive effects were evaluated in hot plate, acetic acid and formalin-induced paw licking tests. The anti-inflammatory effects were investigated in egg albumin and carrageenan-, formalin and complete Freund adjuvant (CFA)-induced paw oedema models. The levels of pro-inflammatory cytokines in the fluid exudates were also evaluated in carrageenan air pouch model. RESULTS: PCO exhibited high content of alpha linolenic acid (ALA). No toxicity was observed at 2000 mg/kg of PCO. PCO (50-200 mg/kg) demonstrated significant anti-nociceptive activity in pain models. PCO exhibited anti-inflammatory activity against oedema formation by phlogistic agents. The increased inflammatory oedema and oxidative stress in CFA-treated rats were also attenuated by PCO. The PCO (100 and 200 mg/kg) significantly reduced the levels of TNF-α (59.3% and 85.2%) and IL-6 (27.5% and 72.5%) in carrageenan-induced air pouch model. CONCLUSION: The results of this study suggest that ALA-rich seed oil of Plukenetia conophora demonstrated anti-nociceptive and anti-inflammatory activities via inhibition of pro-inflammatory cytokines and oxidative stress, lending supportive evidences for its use in painful inflammatory conditions.

High-fat diet-induced memory impairment and anxiety-like behavior in rats attenuated by peel extract of Ananas comosus fruit via atheroprotective, antioxidant and anti-inflammatory actions.

BACKGROUND: Pineapple peel is a waste component of pineapple with valuable source of metabolites as phytoactive compounds in ameliorating metabolic-related disorders. This study investigated the atheroprotective and neuroprotective effects of peel extract of Ananas comosus fruit (PEAC) in normal diet (ND) and high-fat diet (HFD) fed rats. METHODS: Male Wistar rats were fed ND or HFD for 9 weeks, and beginning from the 6th week animals were also orally treated with PEAC (200 mg/kg). Memory performance was assessed using Y-maze test (YMT) and novel object recognition test (NORT) while anxiolytic-like effect was assessed on the elevated plus maze (EPM). Serum cholesterol, triglycerides and HDL-C were determined, while LDL-C and atherogenic risk calculated. Serum and brain tissue malondialdehyde, reduced glutathione, catalase were determined. Brain acetylcholinesterase activity and interleukin-6 level were also determined. RESULTS: PEAC significantly attenuated HFD-induced reduction in correct alternation in YMT, and discrimination index in NORT. Also, PEAC demonstrated anxiolytic-like activity in EPM test. PEAC significantly improved lipid profile and decreased risk of atherogenicity in ND and HFD-fed rats. In addition, PEAC improves serum and brain antioxidant status by decreasing malondialdehyde and increasing GSH and catalase. PEAC significantly impaired HFD-induced brain acetylcholinesterase activity and IL-6 levels. CONCLUSION: These findings suggest that peel extract of Ananas comosus fruit may protect against diet-induced behavioral disturbances via atheroprotective, antioxidants and anti-inflammatory activities.