Anti-inflammatory activity of Acanthus ilicifolius.

Acanthus ilicifolius Linn, is a perennial herb (Acanthaceae) widely found in the Sundarban mangroves and is popularly used for its wound healing effects. In the present study an attempt was made to evaluate the anti-inflammatory activity of the Acanthus ilicifolius leaves. The methanolic fraction of Acanthus ilicifolius leaf extract produced significant inhibition of rat paw oedema, when administered both prior to and after carrageenan administration, in a manner similar to BW755C a synthetic cyclooxygenase (COX) and lipoxygenase (LOX) inhibitor. The extract decreased protein exudation and leukocyte migration in the peritoneal fluid, thereby indicating its effectiveness towards inhibiting peritoneal inflammation. It also produced significant inhibition of COX (1 and 2) and 5-LOX activity. Preincubation of the extract inhibited the production of proinflammatory cytokines (TNFalpha and IL-6) in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). The methanolic fraction of the extract was also found to possess significant free radical (DPPH, ABTS, superoxide and hydroxyl radical) scavenging activity. The extract on intraperitoneal administration augmented the endogenous antioxidant status, as evident from the significant increase of ferric reducing ability of plasma (FRAP) and total peroxyl radical trapping activity of plasma (TRAP).

Pharmacological studies on Indian black tea (leaf variety) in acute and chronic inflammatory conditions.

Infusions of Indian black tea (BTI), when administered orally, produced significant inhibition of rat paw oedema, induced with carrageenin (pre and post treatment) and arachidonic acid. BTI was also found to inhibit peritoneal capillary permeability and caused a marked reduction of lipopolysaccharide induced PGE(2) generation. In these models, the observed antioedema effect was similar to that of BW755C (a dual inhibitor of cyclooxygenase and 5-lipoxygenase enzymes). BTI was found to scavenge superoxide and hydroxyl radicals, and also protected rat erythrocytes from the damaging effects of hydrogen peroxide. In chronic studies, BTI inhibited granuloma formation along with the reduction of both lipid peroxidation and hydroxyproline content (in the granuloma tissue). Significant antiarthritic activity was observed with regular administration of BTI in the Freund's adjuvant induced model of arthritis. Chronic treatment with BTI (in arthritic rats) resulted in a decrease of paw diameter and tissue lipid peroxidation, along with a restoration of GSH, catalase and superoxide dismutase levels.

The Gastroprotective Role of Acanthus ilicifolius - A Study to Unravel the Underlying Mechanism of Anti-Ulcer Activity.

Acanthus ilicifolius (Acanthaceae), a mangrove medicinal plant, is widely used by the local inhabitants of the Sundarbans (India) to treat a variety of diseases. As a part of our continued search for novel bioactive products from mangrove medicinal plants, we were able to document the anti-inflammatory effects of this plant. In the present study, we have performed a detailed evaluation of the gastroprotective activity of the methanolic extract of Acanthus ilicifolius using different models of gastric ulceration. Unlike the conventional non-steroidal anti-inflammatory drugs, a methanolic extract of Acanthus ilicifolius leaves (MEAL) possessing significant anti-inflammatory properties, as revealed from our previous studies displayed in rats in dosages of 200 mg and 400 mg/kg BW after intraperitoneal administration, showed significant protective activity (anti-ulcer activity) against the gastric lesions induced by aspirin, indomethacin, stress, ethanol, and pylorus ligation. In pylorus-ligated rats, administration of Methanolic extract of Acanthus ilicifolius leaves (MEAL) significantly decreased gastric volume, acidity, and peptic activity. Moreover, pre-treatment with MEAL significantly restored the levels of reduced glutathione (GSH) and the antioxidant enzyme superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), along with significant inhibition of both lipid peroxidation and myeloperoxidase (MPO) activity in pylorus-ligated animals. Ulceration induced with ethanol was significantly inhibited with MEAL, and the extract also resulted in the reduction of both lipid peroxidation and myeloperoxidase activity. Furthermore, in this experimental model, administration of MEAL improved the activities of SOD, CAT, GSH, and GPX. A similar pattern of action was also noticed in cold-restraint stress-induced (CRS) ulceration, where MEAL pre-treatment inhibited CRS-induced ulceration, improved the status of antioxidant enzymes, and also reduced the level of lipid peroxides. These results suggest that extracts of the leaves of Acanthus ilicifolius may exhibit anti-ulcer activities additional to the anti-inflammatory properties.