Effect of Fimbristylis ovata on receptor for advanced glycation end-products, proinflammatory cytokines, and cell adhesion molecule level and gene expression in U937 and bEnd.3 cell lines

Evaluation of the anti-inflammatory, antipyretic and antinociceptive activities of the hydroalcoholic extract of Rhynchospora nervosa (Vahl) Boeckeler (Cyperaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Rhynchospora nervosa (Vahl) Boeckeler (Cyperaceae), popularly known as "capim-estrela", is a native species widely distributed in Brazil. The whole plant has been used in local traditional medicine in the form of teas or syrups to treat inflammation, flu, nasal congestion, fever, swelling, and venereal disease. This is the first study to investigate the pharmacological properties of this species.

AIM OF THE STUDY

The present study aimed to evaluate the in vivo anti-inflammatory, antipyretic and antinociceptive potential of the lyophilized hydroalcoholic extract of R. nervosa in heterogenic Swiss mice. In addition to pharmacological studies, the total phenol and flavonoid contents of the extract were determined.

MATERIAL AND METHODS

The anti-inflammatory effect was evaluated through carrageenan-induced paw edema and peritonitis models. For the antinociceptive assay, the number of acetic acid-induced writhing responses in the animals was counted. Antipyretic activity was tested by yeast-induced pyrexia in mice and evaluated for 4 h. Nitric oxide (NO) concentration and leukocyte migration in the peritoneal fluid were quantified. The acute toxicity of the extract was also calculated. Quantitative analyses of total phenols and flavonoids in the extract were performed by spectrophotometric methods.

RESULTS

In short, the lyophilized hydroalcoholic extract of R. nervosa showed low acute toxicity in the preclinical tests (LD₅₀ = 3807 mg/kg). A significant anti-inflammatory effect was observed, with an average reduction of carrageenan-induced paw edema of 96.37%. Comparatively, indomethacin inhibited the development of the carrageenin paw edema by 97.52%. In the peritonitis test, a significant reduction in NO levels was recorded. A reduction in the number of white cells, notably monocytes, was also observed, confirming the anti-inflammatory effect. Writhing was reduced by 86.53%, which indicates antinociceptive activity. As for antipyretic activity, no positive effects of the extract were observed. The lyophilized hydroalcoholic extract of R. nervosa presented a high content of phenolic compounds (322.47 μg GAE/mg) and total flavonoids (440.50 μg QE/mg).

CONCLUSION

The lyophilized hydroalcoholic extract of R. nervosa showed significant in vivo anti-inflammatory and antinociceptive activity in mice. These preliminary findings support the indication of the use of this species in folk medicine in Brazil for the treatment of inflammation.

Fimbristylis ovata extract and its ability to encounter AGEs-induced neurotoxicity in SH-SY5Y

Abstract

Advanced glycation end products (AGEs) upon binding to its receptor (receptor for AGEs, RAGE) trigger several pathological processes involving oxidative stress and inflammatory pathway which play a pivotal role in various degenerative diseases including Alzheimer's disease. Fimbristylis ovata (F. ovata) has long been reported to be used as a traditional herbal medicine; nonetheless, very few studies have been reported. In this study, the protective effects of F. ovata extract on neurotoxicity of hippocampal neuronal cells (SH-SY5Y) was investigated. When compared to normal control, AGEs treatment significantly induced oxidative stress level and enhanced NF-κB translocation to nucleus in the neuronal cells (p < 0.05). The increase in NF-κB translocation leads to increase in transcription level of the target genes including RAGE and pro-inflammatory cytokines which include interleukin 1 beta (IL1B), tumor necrosis factor-alpha (TNFA) and interleukin 6 (IL6). Pre-treatment of SH-SY5Y with the extracts of F. ovata shows favorable results by significantly suppressing oxidative stress level (p < 0.05) as well transcriptional level of RAGE (p < 0.05) and pro-inflammatory cytokines (p < 0.05). Chemical analysis of F. ovata extracts using High Resolution Liquid Chromatograph Mass Spectrometer (HR-LCMS) and Gas Chromatograph with high resolution Mass Spectrometer (GC-HRMS) suggested some potential active phytochemical compounds. The results from this study may provide possible alternative treatment for prevention and/or therapy of neurodegenerative disorders by targeting the above-mentioned pathways. The role of the phytochemical active ingredient (s) in inhibiting the AGEs-triggered signaling inflammatory pathway should be investigated in future study.

Graphic abstract