Effect of ethanol and aqueous extracts of seed pod of Copaifera salikounda (Heckel) on complete Freund's adjuvant-induced rheumatoid arthritis in rats

Phytochemicals from medicinal plants from African forests with potentials in rheumatoid arthritis management

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammation, pain, and cartilage and bone damage. There is currently no cure for RA. It is however managed using nonsteroidal anti-inflammatory drugs, corticosteroids and disease-modifying anti-rheumatic drugs, often with severe side effects. Hidden within Africa's lush vegetation are plants with diverse medicinal properties including anti-RA potentials. This paper reviews the scientific literature for medicinal plants, growing in Africa, with reported anti-RA activities and identifies the most abundant phytochemicals deserving research attention. A search of relevant published scientific literature, using the major search engines, such as Pubmed/Medline, Scopus, Google Scholar, etc. was conducted to identify medicinal plants, growing in Africa, with anti-RA potentials.

KEY FINDINGS

Twenty plants belonging to 17 families were identified. The plants are rich in phytochemicals, predominantly quercetin, rutin, catechin, kaempferol, etc., known to affect some pathways relevant in RA initiation and progression, and therefore useful in its management.

SUMMARY

Targeted research is needed to unlock the potentials of medicinal plants by developing easy-to-use technologies for preparing medicines from them. Research attention should focus on how best to exploit the major phytochemicals identified in this review for the development of anti-RA 'green pharmaceuticals'.

Styphnolobium japonicum (L.) Schott Flower Extract Alleviates Oxidative Stress and Inflammatory Factors in the Adjuvant-Induced Arthritis Rat Model

Introduction

This research was to evaluate the beneficial effects of Styphnolobium japonicum (L.) Schott flower extract (SJF) on the adjuvant-induced arthritis rat model.

Methods

Arthritis was evoked by injection of complete Freund's adjuvant (CFA) in the hind paw. SJF (150 or 300 mg/kg/day) or Celecoxib (5 mg/kg/day) were administered intragastrically from the 0th day to the 28th day. The arthritis symptoms (paw edema, arthritic scores, mechanical hyperalgesia, and thermal hyperalgesia), inflammation biomarkers (RT and CRP), related enzymes (MMP1 and MMP13), oxidative stress markers (CAT, SOD, GPx, and MDA), and inflammatory cytokines (IL-6, IFN-γ, TNF-α, and IL-1β) of SJF-treated CFA rats were evaluated.

Results

CFA rats exhibited severe arthritis symptoms, increased oxidative stress, and inflammatory cytokines. Interestingly, SJF treatment relieving arthritis symptoms and restored body weight gain compared with those in the CFA group. SJF treatment decreased the levels of CRP, RF, MMP1, and MMP13 in the CFA group. Besides, SJF treatment increased the activities of antioxidant enzymes and decreased the MDA content and inflammatory cytokines compared with those in the CFA group. Moreover, SJF could increase the mRNA expression of GPx-1 and CAT and inhibit the mRNA expression of IL-6 and TNF-α in the ankle tissue of CFA rats.

Anti-inflammatory effect of stevioside abates Freund's complete adjuvant (FCA)-induced adjuvant arthritis in rats

Adjuvant arthritis is a chronic, autoimmune and inflammatory disorder of the joints. The occurrence of disorder causes a severe damage to the connective tissue eventually leading to progressive physical disability and eventual death. The recent years of evidence suggests the anti-inflammatory properties of stevioside, a diterpene glycoside. However, the effect of stevioside against adjuvant arthritis, a chronic inflammatory disorder is not known. Hence, the present study was designed to study the effect of stevioside against Freund's complete adjuvant induced arthritis model in rats. The acute anti-inflammatory effect of stevioside also studied by employing carrageenan-induced paw oedema model in rats. The biochemical markers, haematological parameters, lipid peroxidation, myeloperoxidase activity, lipoxygenase activity, the levels of PGE2 and pro-inflammatory (TNF-α, IL-6 & IL-1β) and anti-inflammatory cytokine (IL-10) were analysed. The protein expression of NF-κB (p65) COX-2 and iNOS in paw tissues were estimated by western blotting. Stevioside treatment significantly ameliorates the adjuvant induced arthritic scoring, histological alterations, paw volume, elevation of biochemical (AST, ALT, ALP and glucose levels) and haematological (haemoglobin, differential and platelet count) parameters and restored the endogenous anti-oxidant (SOD, CAT, GSH and GST) activities. Treatment with stevioside also significantly prevented the adjuvant induced elevation of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), pro-inflammatory protein expressions (iNOS, COX-2, NF-κB (p65) and pIκB/IκB ratio), prevented the increase in myeloperoxidase activity and significantly restored the anti-inflammatory (IL-10) cytokine level in paw tissues. Collectively, our findings suggest that stevioside may serve as anti-inflammatory agent and could serve as a potential adjunct therapeutic option in treating adjuvant arthritis.

Evaluation of rohitukine-enriched fraction of Dysoxylum binectariferum Hook.f. (leaves) as anti-arthritic phytopharmaceutical candidate: Chemical standardization, in-vivo validation, formulation development and oral pharmacokinetics

ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis is a chronic inflammatory disease of joints. Dysoxylum binectariferum Hook.f (Family: Meliaceae) is a Indian medicinal plant which is traditionally being used to heal inflammation of joints.

AIM OF THE STUDY

This work was aimed to carry out chemical standardization, in-vitro/in-vivo validation, oral pharmacokinetics and formulation development of anti-arthritic botanical lead, the rohitukine-enriched fraction of D. binectariferum.

MATERIALS AND METHODS

The rohitukine-enriched fraction of D. binectariferum was standardized using four chemical markers and was checked for microbial load, heavy metal content, aflatoxins and pesticides. Its in-vitro inhibitory effect on the lipopolysaccharide (LPS) induced production of pro-inflammatory cytokines TNF-α and IL-6 was studied in THP-1 cells. The in-vivo anti-arthritic activity was investigated in collagen-induced arthritis model in DBA/1J mice. The sustained release capsule formulation was developed and characterized for physicochemical and pharmacokinetic properties.

RESULTS

Rohitukine and schumaniofioside A were found to be major chemical constituents of the botanical lead. The rohitukine-enriched fraction of D. binectariferum significantly reduced the production of both pro-inflammatory cytokines TNF-α and IL-6 (>50% inhibition at 3.12 μg/mL) in THP-1 cells. In LPS-treated wild-type mice model, the rohitukine-enriched fraction at 200 mg/kg (PO, QD) completely reduced serum TNF-α levels. In transgenic mice model (collagen-induced arthritis in DBA/1J mice), rohitukine-enriched fraction at 100 mg/kg (PO, QD) dose has resulted in >75% reduction of TNF-α/IL-6 serum levels, 68% reduction in anti-mouse type II collagen IgG1 antibody levels, decreased joint proteoglycan loss and reduced paw edema in DBA/1J mice. The sustained release capsule formulation of rohitukine-enriched fraction showed sustained-release of rohitukine over the period of 24 h, and resulted in an improved plasma-exposure of rohitukine in SD rats.

CONCLUSIONS

The data presented herein demonstrated anti-arthritic potential of rohitukine-enriched fraction of D. binectariferum and this study will serve as the benchmark for further research on this botanical lead and developed sustained release capsule formulation.

Wogonin ameliorate complete Freund's adjuvant induced rheumatoid arthritis via targeting NF-κB/MAPK signaling pathway

Rheumatoid arthritis (RA) is a chronic and accelerated autoimmune illness with proliferative and damaging synovitis, resulting in joint death and cartilage and bone erosion. This study focused on the potential therapeutic effect of wogonin on complete Freund's adjuvant (CFA) induced RA in rats and the underlying mechanisms. Arthritis was experimentally caused in rats by subcutaneously injecting 0.1 mL of CFA into the subplantar area of the left hind paw under moderate anesthesia on day zero. The regular oral doses of indomethacin/wogonin began on day zero and proceeded after injection to day 35. Wogonin reduced arthritic score considerably, enhanced body weight, and reduced paw thickness. Wogonin also boosted red blood cell considerably along with hemoglobin and reduced white blood cell count and erythrocyte sedimentation rate. Wogonin substantially improved an altered level of oxidative stress markers, antioxidant proteins, and inflammatory cytokines in a dose-dependent way. Wogonin inhibited p38 phosphorylation triggered by CFA and p65 nuclear translocation.