Authors: Haroon ur Rasheed , Kauser Ismail , Muhammad Owais Ismail , Akhtar Ali , Humaira Arif , Syeda Zehra Ahmed

Abstract

Background and objective: Conventional disease-modifying anti-rheumatic drugs (DMARDs) used for the treatment of rheumatoid arthritis are known for their steady onset of action and multiple adverse effects. The objective of this study is to evaluate the anti-arthritic activity of ethanolic extract of Solanum nigrum in Complete Freund’s adjuvant-induced arthritic rat model.

Methods: 30 male Wistar albino rats were used in a 4-week pre-clinical experimental study. The animals were divided into 5 groups; Group-I Negative (healthy) control (0.9% normal saline), Group-II positive (diseased) control (0.9% normal saline), Group-III Standard group (Methotrexate 1.5mg/kg), Group-IV (Solanum nigrum 100mg/kg), Group-V (Solanum nigrum 200mg/kg). To develop arthritis, 0.1mL of Complete Freund’s Adjuvant (CFA) was administered intraarticularly in the right knee joints of all groups except Group-I at day 0. Knee joint circumference was assessed by using a Vernier calliper once weekly for 4 weeks. For euthanasia, 100mg/kg pentobarbital was injected intraperitoneally in all animals on the 29^th day for the assessment of histopathological changes in knee joints. SPSS version 22 was used to analyse the results and ANOVA was applied for intergroup and intragroup comparisons. A P-value less than 0.05 was considered significant at a 95% confidence interval.

Results: Edema in the positive controls (group-II) increased continuously throughout the study duration. While group-III (MTX) showed initial increase in edema but slight reduction was observed in the last two weeks. Group-V (SN200) with higher dose of herbal extract showed maximum reduction in edema. Histological assessment showed maximum arthritic score (3) in group-II. While 66% of animals in group-III (MTX) and group-IV (SN100) showed mild scoring exhibiting scattered inflammatory cells. Group-V showed maximum improvement in the histopathological changes and 66% of animals showed normal scoring while 33% animals showed few inflammatory cells.

Conclusion: Ethanolic extract of Solanum nigrum has decreased knee joint edema and improved histopathological outcomes.

Keywords: Arthritis, Inflammation, Histology, Methotrexate, Solanum nigrum, Herbal Medicine