Comparing the effect of palm vitamin E alone or in combination with glucosamine on cartilage in a rat model of osteoarthristis

Abstract

Osteoarthritis (OA) is a local joint inflammatory disorder characterised by articular cartilage loss, subchondral bone remodelling and osteophyte formation. Glucosamine is conventionally used as a preventative agent for OA. Palm vitamin E (PVE) is rich in tocotrienol and possesses good anti-inflammatory properties, but data on its effect on the joints are limited. The effects of the combination of glucosamine and PVE in preventing joint degeneration have not been reported thus far. This study aimed to determine the effects of PVE alone or in combination with glucosamine on joint degeneration in a rat model of OA. A total of 35 male Sprague-Dawley rats were randomly divided into five groups, i.e. normal control (NC), monosodium iodoacetate (MIA)-treated group and three MIA-treated groups supplemented with PVE 100 mg/kg/day, glucosamine sulphate 250 mg/kg/day or PVE 100 mg/kg/day plus glucosamine sulphate 250 mg/kg/day. OA was induced by MIA on day 0, and treatments were initiated a day after OA induction. The grip strength of the rats was determined before and every week after OA induction through an inverted mesh wire test, and the retention time of the rats was recorded. Serum was collected at the end of the treatment period to determine cartilage oligomeric matrix protein (COMP) levels. After 4 weeks of treatment, the rats were sacrificed, and their joints were harvested for histological analysis and scoring. Results showed that the retention time of the rats in the grip strength test and their joint histological scores did not differ significantly among the groups (p > 0.05). The COMP level in all the treatment groups was lower than that in the MIA group (p < 0.05). Therefore, PVE alone or in combination with glucosamine elicited potential protective effects against OA as illustrated by COMP level. This effect was likely mediated by the anti-inflammatory effects of PVE and glucosamine.