Effects of Clinacanthus nutans Lindau extracts on hyperuricemic mice

Abstract

Clinacanthus nutans or Sabah Snake Grass (Acanthaceae) has been commercialised locally as an anti-gout, and anti-hyperuricemia. However, the scientific evidences that supports its efficacy in treating these illnesses is still insufficient. The study aims to investigate the effect of different extracts and doses of C. nutans leaf in the normalisation of uric acid levels in hyperuricemic mice, conduct a metabolite fingerprinting on the mice serum through an LC-MS-based metabolomics approach, and to evaluate the acute toxicity effect of the C. nutans extract on kidney and liver samples of the mice of the selected doses. The dried leaves were extracted by soaking in different solvents with different concentrations of ethanol in water (0, 20, 50, 70, 100%, v/v). These extracts were tested in vivo using a potassium oxonate-induced hyperuricemia mice model. The results showed that the administration of the aqueous and 50% ethanolic extract with the dose 800 mg/kg b.w. for 4 weeks significantly (P<0.05) reduced and normalised the serum uric acid level of the mice starting from week 3. The same effect was also noticed for allopurinol whereby uric acid levels were potently normalised throughout the experiment (week 1 to 4). However, the data obtained from the LC-MS based fingerprinting showed that the metabolite profile of the mice serum treated with allopurinol was affected negatively in comparison with the healthy group starting from week 2. Interestingly, the metabolite profile of the mice treated with the C. nutans aqueous extracts at 800 mg/kg b.w. dose was better than that of allopurinol whereby they normalised the metabolic profile of the mice in week 4. The treatment with allopurinol, C. nutans aqueous and 50% ethanol extracts did not cause any histopathological or behavioural side effects to the mice with zero mortality up to 4 weeks of treatment. Moreover, the identification of the serum metabolites involved in the treatment is necessary to understand the mechanism of action of the C. nutans extracts. This study concludes that the C. nutans leaf extract has a potential in treating hyperuricemia and gout.