Anti-Inflammatory Potential Exhibited by Amomum subulatum Fruits Mitigates Experimentally Induced Acute and Chronic Inflammation in Mice: Evaluation of Antioxidant Parameters, Pro-Inflammatory Mediators and HO-1 Pathway

Abstract

Objective

Conventional anti-inflammatory drugs are associated with serious adverse effects which bring about an ever-increasing demand to supersede them with natural and safe anti-inflammatory agents. Hence, the prime objective of this study was to evaluate the anti- inflammatory potential of an underutilized culinary spice “Amomum subulatum”.

Methods

To assess anti-inflammatory activity of MEAS, acute and chronic inflammation studies were carried out in carrageenan and formalin induced mice paw edema models respectively. Paw volume was measured by vernier caliper. Status of antioxidant enzymes and oxidative stress markers were determined in paw tissue homogenates following standard protocols. Histopathology and immunohistochemistry analysis of paw tissue samples were also performed. Levels of proinflammatory cytokines in serum were quantified by ELISA. Effect of MEAS on vascular permeability was evaluated by evans blue dye extravasation assay. Involvement of heme oxygenase (HO)-1 pathway in anti-inflammatory action of MEAS was investigated by pretreating mice with zinc protoporphyrin (ZnPP) IX, a specific inhibitor of HO-1.

Results

MEAS administration significantly reduced paw edema, as evidenced by paw volume measurement and histopathology analysis. Additionally, pretreatment with MEAS markedly reduced vascular permeability, serum proinflammatory cytokine levels, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Further, the anti-inflammatory mechanism of MEAS showed the involvement of HO-1 pathway when HO-1 was inhibited by ZnPPIX.

Conclusion

Our results manifested strong anti-inflammatory activity of MEAS, suggesting its potential use as a therapeutic alternative for treating inflammatory disorders.

Keywords:

• Amomum subulatum
• paw edema
• carrageenan
• inflammation
• pro-inflammatory mediators

Acknowledgements

The authors are thankful to Dr. Rekha. A. Nair, Director, Regional Cancer Centre (RCC) and Dr. S. Kannan, Head, Division of Cancer Research, RCC for providing valuable support required for the study.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

Drishya Sudarsanan and Dhanisha S S acknowledges Council of Scientific and Industrial Research [09/553(0022)/2016-EMR-1] and University Grants Commission [20/12/2015 (ii) EU-V] respectively for providing support in the form of senior research fellowship for the study.