Evaluation of the healing effect of Psidium Guajava L. hydro-alcoholic fruit extract on induced osteoarthritis in male rats

Osteoarthritis is a major public health consideration which leads to disability because of chronic pain, stiffness, sleeping disorder and depression. Among the herbal products Psidium Guajava L. fruit could be regarded as a potential natural remedy due to its anti-oxidant characteristics. The aim of this study was to evaluate the healing effect of Psidium Guajava L. fruit on osteoarthritis of the knee in rats.

Forty male Sprague-Dawley rats with induced osteoarthritis by intra-articular injection of 500U of type 2 collagenase in the left knee were recruited in four treatment groups (n=10): (A) control, (B) Piascledine (10mg/kg) as positive control, (C) oral administration of hydro-alcoholic extract of Psidium Guajava L. fruit (500mg/kg), and (D) oral administration hydro-alcoholic extract of Psidium Guajava L. fruit (1000mg/kg). After 8 weeks of daily administration, the outcome was evaluated by histopathological and radiographic assessments. The data were analyzed using Kruskal-Wallis nonparametric in SPSS version 23.00, and P<0.05 was considered statistically significant.

Psidium Guajava extract exhibited good radical scavenging activities with IC50 of 0.46 ± 0.13 mg/mL (quercetin as a positive control). Histopathological assessments of the cartilage showed smooth and continuous articular surface with columnar cell distribution in the experimental group that received 1000mg/kg Psidium Guajava L. fruit hydro-alcoholic extract which healed better than others, especially in the control group (p-value =0.02). The radiological assessments of the knee joints showed similar findings in histopathological assessment. 

Psidium Guajava L. fruit hydro-alcoholic extract might be regarded as an effective complementary and alternative treatment for osteoarthritis of the knee in rats.