Hydroethanolic Leaf Extract of Persicaria Lanigera R. Br. Soják (Polygonaceae) Exhibits Anti-Inflammatory Effects in Experimental Models of Inflammation

Abstract

Persicaria lanigera extract (PLE) is traditionally used to manage inflammatory disorders. This study aimed at evaluating the anti-inflammatory and oral safety of a hydroethanolic (70 % 𝑣𝑣⁄) leaf extract of Persicaria lanigera. The anti-inflammatory effects of the extract were assessed using both acute and chronic inflammatory models while the toxicity profile was performed using acute and sub-acute toxicity studies. From the acute inflammatory studies, PLE (100-600 mg kg-1, p.o.) administered pre-emptively suppressed the mean maximal oedema to 59.10±4.94 %, 56.08±3.65 %, and 48.62±3.27 % at 100, 300 and 600 mg kg-1, and total inflamed paw by 43.72 %, 52.34 % and 61.58 % at the same doses in carrageenan-induced paw oedema. In the chronic inflammatory studies, PLE suppressed the disease activity index (DAI) score in acetic acid-induced colitis from 84.00±5.09 to 58.00±5.39, 50.00±7.07 and 43.00±5.38 at 100, 300 and 600 mg kg-1, and similarly inhibited the granuloma tissue formation by 20.65 %, 22.61 % and 30.14 % at the same doses respectively. PLE significantly suppressed the Complete Freund’s Adjuvant (CFA)-induced arthritic ipsilateral paw to 126.58±10.91 %, 113.82±11.46 % and 106.45±34.85 % at 100, 300 and 600 mg kg-1 respectively when administered prophylactically. In the therapeutic study, PLE decreased the CFA-induced inflammation in the ipsilateral limb to 568.50±91.18 %, 545.50±71.88 % and 541.83±70.21 % dose-dependently at the same doses respectively. In the toxicity studies, PLE was confirmed to be relatively safe and non-toxic with no clinical signs or treatment related toxic effects including haematological, biochemical, histological changes and death.