Effects of Clinacanthus nutans leaf extract on lipopolysaccharide - induced neuroinflammation in rats: A behavioral and 1H NMR-based metabolomics study

Objective: This research revealed the biochemical outcomes of metabolic dysregulation in serum associated with physiological sickness behavior following lipopolysaccharide (LP S)-induced neuroinflammation in rats, and treatment with Clinacanthus nutans (CN). Verification of H-1 NMR analysis of the CN aqueous extract proved the existence of bioactive phytochemical constituents' in extract. Materials and Methods: Twenty-five rats were subjected to unilateral stereotaxic injection of 10 mu L LPS (1 mg/mL), while another ten rats were injected with phosphate-buffered saline (PBS, 10 mu L) as control. Then, 29 parameters of rat behavior related to sickness were tracked by a device software (SMART 3.0.1) on days 0 and 14 of CN treatment. The acquired and accumulated data were analyzed using multivariate data analysis with the SIMCA Software package (version 13, Umetrics AB; UmeA, Sweden). The pattern trends of related groups were documented using PCA and OPLS analysis. Results: A similar ameliorated correlation pattern was detected between improvement in physiological sickness behavior and anti-inflammatory biomarkers by the H-1 NMR spectra of the sera following treatment with CN (500 and 1000 mg/kg body weight (bw)) and the control drug (dextromethorphan hydrobromide, 5 mg/kg of rats bw) in rats. Here, 21 biomarkers were detected for neuroinflammation. Treatment with the aqueous CN extract resulted in a statistically significant alteration in neuroinflammation metabolite biomarkers, including ethanol, choline, and acetate. Conclusion: This result denotes that the metabolomics approach is a reliable tool to disclose the relationship between central neuroinflammation, and systemic metabolic and physiological disturbances which could be used for future ethno-pharmacological assessments.