[58] The effect of β-caryophyllene on renal dysfunction following ischaemia–reperfusion injury

Objective To investigate the effect of β-caryophyllene (BCP) on renal ischaemia–reperfusion injury (IRI)-induced renal dysfunction, as IRI causes renal functional alterations that might lead to permanent renal impairment and BCP (a natural bicyclic sesquiterpene and constituent of many essential oils and spices) has been shown to exhibit anti-inflammatory, antioxidant, antispasmodic and chemopreventive activities in several organs. BCP is a USA Food and Drug Administration (FDA)-approved food additive and its effect on IRI has not been investigated. Methods Wistar rats underwent left renal warm ischaemia for 40 min. The G-BCP group ( n  = 13) received oral BCP (50 mg/kg/day) dissolved in a vehicle starting 7 days before IRI and continued 7 days thereafter when the renal functions of both kidneys and the tissue level of some oxidative stress markers and pro-inflammatory cytokines were measured. The G-Vx group ( n  = 13) underwent the same protocol but received vehicle only. Results IRI effected haemodynamic (renal blood flow and glomerular filtration rate) and tubular (urine volume, total and fractional urinary sodium excretion) parameters in the left ischaemic kidney in the G-Vx group. BCP did not affect any of these alterations in the ischaemic kidney (all P > 0.05). However, it attenuated the alterations in malondialdehyde (MDA) and glutathione (GSH) in the left ischaemic kidney in the G-BCP group compared to the G-Vx group, at a mean (SD) MDA level of 9.3 (2.1) vs 4.8 (1.0) μ mol/L ( P  = 0.047) and GSH level of 18.1 (2.5) vs 13.6 (1.7) mmoL/L, ( P  = 0.09). Conclusion BCP appears to have no significant protective effect on the haemodynamic and tubular glomerular functions when measured 7 days after IRI, despite the attenuation in the alterations in some of the oxidative stress markers indicating a weak reno-protective effect of BCP in this condition.