Rosmarinic acid attenuates inflammation in experimentally induced arthritis in Wistar rats, using Freund's complete adjuvant

AIM

The purpose of our investigation is to evaluate the anti-arthritic potential of isolated rosmarinic acid from the rind of Punica granatum.

METHOD

Rosmarinic acid was isolated by bioactivity-guided isolation from butanolic fraction of Punica granatum and acute toxicity of rosmarinic acid was carried out. The experiment was conducted at doses of 25 and 50 mg/kg, in Freund's complete adjuvant (FCA)-induced arthritic rats. Various parameters, that is arthritic score, paw volume, thickness of paw, hematological, antioxidant and inflammatory parameters such as glutathione (GSH), superoxide dismutase (SOD), malonaldehyde (MDA) and tumor necrosis factor-α (TNF-α) were also estimated.

RESULTS

Rosmarinic acid significantly decreased the arthritic score, paw volume, joint diameter, white blood cell count and erythrocyte sedimentation rate. It also significantly increased body weight, hemoglobin and red blood cells. The significantly decreased levels of TNF-α were observed in treated groups as compared to arthritic control rats (P < 0.001). At the same time antioxidant parameters (like GSH and SOD) were increased significantly while levels of MDA were significantly decreased (P < 0.001).

CONCLUSION

The outcome of the present research concludes that rosmarinic acid showed significant anti-arthritic potential in FCA-induced arthritis in Wistar rats. This study represented the therapeutic role of rosmarinic acid from Punica granatum for the management of arthritis/rheumatoid arthritis/osteoarthritis and related inflammatory complications with negligible side effects which was still far from complete mitigation with available conventional medicines.

Fluorescent Visualisation of Oxytocin in the Hypothalamo-neurohypophysial/-spinal Pathways After Chronic Inflammation in Oxytocin-Monomeric Red Fluorescent Protein 1 Transgenic Rats

Oxytocin (OXT) is a well-known neurohypophysial hormone that is synthesised in the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus. The projection of magnocellular neurosecretory cells, which synthesise OXT and arginine vasopressin in the PVN and SON, to the posterior pituitary plays an essential role in mammalian labour and lactation through its peripheral action. However, previous studies have shown that parvocellular OXTergic cells in the PVN, which project to the medulla and spinal cord, are involved in various physiological functions (e.g. sensory modulation and autonomic). In the present study, we examined OXT expression in the PVN, SON and spinal cord after chronic inflammation from adjuvant arthritis (AA). We used transgenic rats that express OXT and the monomeric red fluorescent protein 1 (mRFP1) fusion gene to visualise both the magnocellular and parvocellular OXTergic pathways. OXT-mRFP1 fluorescence intensity was significantly increased in the PVN, SON, dorsal horn of the spinal cord and posterior pituitary in AA rats. The levels of OXT-mRFP1 mRNA were significantly increased in the PVN and SON of AA rats. These results suggested that OXT was up-regulated in both hypothalamic magnocellular neurosecretory cells and parvocellular cells by chronic inflammation, and also that OXT in the PVN-spinal pathway may be involved in sensory modulation. OXT-mRFP1 transgenic rats are a very useful model for visualising the OXTergic pathways from vesicles in a single cell to terminals in in vitro preparations.