Anti-inflammatory Property of Ethanolic Extract of Cleome spinosa Leaves in an in vivo Model of Delayed-type Hypersensitivity

Objectives: Delayed-type hypersensitivity (DTH) reactions represent a clinically important class of immune responses that have wide-ranging implications in various health and disease conditions. The existing anti-inflammatory drugs to treat DTH have several shortcomings including severe side-effects. Thus, a new plant-derived anti-inflammatory drug with no or less toxicity would be effective in treating DTH. The Cleome genus has been routinely used to cure various ailments including inflammation. This study investigates the anti-inflammatory properties of the ethanolic leaf extract of Cleome spinosa (CSE) in a DTH model for the first time. Materials and Methods: DTH response was induced by 2, 4-di nitro-fluorobenzene in the mouse foot pad. Histological sectioning of the paw was carried out to find changes in the architecture of the tissue. Serum tumour necrosis factor-alpha (TNF-α) was estimated through enzyme linked immunosorbent assay (ELISA), and the bioactive compounds present in CSE were analysed through reversed phase-high-performance liquid chromatography . Results: With CSE treatment, the oedema in the resensitized paw alleviated faster with no loss of digits compared to the controls. Histological study of the resensitized paw showed less dermal and sub-dermal thickening and less collagen deposition that regained normal tissue architecture during the healing process with CSE treatment. CSE treatment did not show any adverse haematological and histopathological changes in the visceral organs of mice. The level of serum TNF-α was found to be significantly lower with CSE treatment. CSE was found to be rich in phenol, flavonoids, tocopherol, carotene and phytosteroids. Conclusion: The anti-inflammatory and immunomodulatory role of CSE against hapten-induced deleterious DTH inflammation suggests its therapeutic potential in treating inflammatory diseases and combating infections.