Objective: To explore the immunomodulatory, anti-inflammatory,
anti-oxidant and anti-arthritic activity of aqueous and methanolic extracts of
Nauclea pobeguinii
stem bark.
Methods: For
in vitro assays, the
production of
reactive oxygen species (
chemiluminescence technique ), the proliferation of
T cells (liquid
scintillation counter method ), as well as the inhibition of
cyclooxygenase ,
lipoxygenase ,
protein denaturation , and
free radicals [DPPH, ABTS and
nitric oxide (NO) inhibition
methods ] were evaluated. For in vivo assays, a
polyarthritis model was induced by complete
Freund's adjuvant in
rats . The aqueous and methanolic extracts of
Nauclea pobeguinii
stem bark were administered orally at 150 and 300 mg/kg. After 28 days of
treatment , the total
blood was taken to quantify the hematological
parameters and the
serum was used to evaluate the biochemical
parameters (
alanine aminotransferase ,
aspartate transaminase , phenylalnine ammonialyase, and
proteins ) and
oxidative stress parameters (
malondialdehyde ,
catalase ,
superoxide dismutase ,
glutathione and NO), and then the
knee joint was removed for histological
analysis .
Results: The extracts of
Nauclea pobeguinii significantly reduced the
production of intra- and extracellular
reactive oxygen species and decreased
T cell proliferation. They had an inhibitory effect on
cyclooxygenase ,
lipoxygenase , and
protein denaturation , and both extracts had
antioxidant capacity on DPPH, ABTS and NO. Both extracts alleviated
joint inflammation and
pain sensitivity after complete
Freund's adjuvant injection , reduced
alanine aminotransferase ,
aspartate transaminase ,
alkaline phosphatase , NO and
malondialdehyde levels, increased
protein concentration,
superoxide dismutase ,
catalase and
glutathione activity, and restored the cytoarchitecture of the
joint after complete
Freund's adjuvant injection .
Conclusions: The aqueous and methanolic extracts of
Nauclea pobeguinii have immunomodulatory, anti-inflammatory,
anti-oxidant and anti-arthritic properties.