The anti-inflammatory and antioxidant potential of pistachios (Pistacia vera L.) in vitro and in vivo

Several reports have demonstrated the effectiveness of pistachio against oxidative stress
and inflammation. In this study, we investigate if polyphenols extracts from natural raw shelled
pistachios (NP) or roasted salted pistachio (RP) kernels have anti-inflammatory and antioxidant
properties at lower doses than reported previously, in both in vitro and in vivo models. The
monocyte/macrophage cell line J774 was used to assess the extent of protection by NP and RP
pistachios against lipopolysaccharide (LPS)-induced inflammation. Moreover, antioxidant activity
of NP and RP was assessed in an in vivo model of paw edema in rats induced by carrageenan
(CAR) injection in the paw. Results from the in vitro study demonstrated that pre-treatment with
NP (0.01, 0.1 and 0.5 mg/mL) and RP (0.01 and 0.1 mg/mL) exerted a significant protection against
LPS induced inflammation. Western blot analysis showed NP reduced the degradation of IB-,
although not significantly, whereas both NP and RP decreased the TNF- and IL-1 production
in a dose-dependent way. A significant reduction of CAR-induced histological paw damage,
neutrophil infiltration and nitrotyrosine formation was observed in the rats treated with NP. These
data demonstrated that, at lower doses, polyphenols present in pistachios possess antioxidant and
anti-inflammatory properties. This may contribute toward a better understanding of the beneficial
health effects associated with consumption of pistachios.