Samir K. Samanta

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).

Medicinal Plants, Human Health and Biodiversity: A Broad Review

Biodiversity contributes significantly towards human livelihood and development and thus plays a predominant role in the well being of the global population. According to WHO reports, around 80 % of the global population still relies on botanical drugs; today several medicines owe their origin to medicinal plants. Natural substances have long served as sources of therapeutic drugs, where drugs including digitalis (from foxglove), ergotamine (from contaminated rye), quinine (from cinchona), and salicylates (willow bark) can be cited as some classical examples.Drug discovery from natural sources involve a multifaceted approach combining botanical, phytochemical, biological, and molecular techniques. Accordingly, medicinal-plant-based drug discovery still remains an important area, hitherto unexplored, where a systematic search may definitely provide important leads against various pharmacological targets.Ironically, the potential benefits of plant-based medicines have led to unscientific exploitation of the natural resources, a phenomenon that is being observed globally. This decline in biodiversity is largely the result of the rise in the global population, rapid and sometimes unplanned industrialization, indiscriminate deforestation, overexploitation of natural resources, pollution, and finally global climate change.Therefore, it is of utmost importance that plant biodiversity be preserved, to provide future structural diversity and lead compounds for the sustainable development of human civilization at large. This becomes even more important for developing nations, where well-planned bioprospecting coupled with nondestructive commercialization could help in the conservation of biodiversity, ultimately benefiting mankind in the long run.Based on these findings, the present review is an attempt to update our knowledge about the diverse therapeutic application of different plant products against various pharmacological targets including cancer, human brain, cardiovascular function, microbial infection, inflammation, pain, and many more.

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.

In vitro hemolysis and lipid peroxidation-inducing activity of the tentacle extract of the sea anemone (Paracondylactis indicus Dave) in rat erythrocytes

Objective : In vitro hemolytic activity of the tentacle extract of Paracondylactis indicus (Dave), a sea anemone found in the eastern coastal region of West Bengal (India), was determined in rat erythrocytes. Materials and Methods : Acute toxicity study was carried out with the tentacle extract followed by detailed biochemical studies to evaluate the direct and indirect hemolytic activities of the extract. The effects of pH, temperature, divalent cations and chelating agents on hemolysis were also evaluated. Efforts were also made to elucidate the mechanism of the hemolytic activity of the extract. Results : The tentacle extract of P. indicus (Dave) produced significant hemolysis (both direct and indirect) in washed rat erythrocytes. The direct hemolytic activity of the tentacle extract was found to be both temperature- and pH-dependent. Divalent cations (Ca 2+ , Mg 2+ ) produced significant enhancement of direct hemolytic activity. Hemolysis (both direct and indirect) was significantly diminished in the presence of Zn 2+ , EDTA and p-bromophenacyl bromide. The tentacle extract was found to induce lipid peroxidation in washed erythrocytes, which was inhibited by chlorpromazine. The tentacle extract demonstrated significant proteolytic activity, which was found to decrease in the presence of protease inhibitors (EDTA, EGTA and PMSF). Conclusion : P. indica tentacle extract (and in particular, the 60% cut fraction) probably contains enzymatic components like phospholipase(s) along with proteases, which may be the contributing factors for its observed hemolytic activity.

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 PGE2 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 Freunds 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. Copyright

Antimicrobial properties of Kalanchoe blossfeldiana: a focus on drug resistance with particular reference to quorum sensing-mediated bacterial biofilm formation

This study attempts to investigate the antimicrobial properties of Kalanchoe blossfeldiana with a particular reference to quorum sensing (QS)‐mediated biofilm formation.

Inhibition of arachidonic acid metabolism and pro-inflammatory cytokine production by Bruguiera gymnorrhiza leaf

Bruguiera gymnorrhiza is a mangrove plant of the family Rhizophoraceae. The roots and leaves of the plant have traditionally been used for treating burns and mild inflammatory lesions. In the present study an attempt was made to evaluate the anti-inflammatory activity of the Bruguiera gymnorrhiza leaves. The methanolic fraction of Bruguiera gymnorrhiza leaves (BRG) was evaluated using different in vitro and in vivo models to evaluate the anti-inflammatory properties and also to obtain an insight on the probable mechanism of such activity. The leaf extract produced significant inhibition of both carrageenan induced rat paw oedema and acetic Acid induced peritoneal capillary permeability. The above observations were further supported by our findings from in vitro experimental models, where the plant extract produced significant inhibition of both cyclooxygenase (COX) and lipoxygenase (LOX) enzymes. Moreover, BRG inhibited the production of proinflammatory cytokines (TNF- α, IL-6 and IL-1β) in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) in a dose dependent manner. It was also found to possess significant free radical (DPPH, superoxide and oxygen radical) scavenging activity. From the results obtained from the various in vitro and in vivo test models, it may be concluded that the methanolic extract of Bruguiera gymnorrhiza leaves display significant anti-inflammatory properties, probably mediated through blockade of both COX – LOX pathway, coupled with scavenging effect on free radicals.

A report on anti-oedemogenic activity of Byttneria herbacea roots--possible involvement of histamine receptor (type I).

ETHNOPHARMACOLOGICAL RELEVANCE The traditional healers of the Kol tribes of West Bengal, Bihar and Jharkhand (India), widely use the woody rootstock of Byttneria herbacea to reduce the swelling of limbs, due to filariasis. Besides filariasis different part of this plant is used for the treatment of cholera, diarrhoea and asthma. AIM OF THIS STUDY This study is a preliminary attempt to evaluate the anti-oedemogenic activity of the roots of Byttneria herbacea. MATERIALS AND METHODS The anti-oedemogenic activity of the hydroalcoholic extract of the roots of Byttneria herbacea (HBH) was evaluated against carrageenan and histamine induced rat paw oedema, acetic acid induced writhing and histamine induced vascular permeability in mice. Further, the effect of HBH on the expression of human histamine receptor type I (H1R) was studied in HeLa cells. RESULTS HBH exhibited significant dose-dependent inhibition (*p<0.05) against carrageenan and histamine induced rat paw oedema. Similar significant dose-dependent inhibition was observed against acetic acid induced writhing and histamine-induced vascular permeability in mice. Moreover, H1R specific mRNA expression was also significantly (*p<0.05) suppressed by HBH. CONCLUSION HBH was observed to possess anti-oedemogenic activity which is probably mediated through suppression of H1R.

Pharmacological and Biochemical studies on Telescopium telescopium - a marine mollusk from the Mangrove regions

SUMMARY The tissue extract (TTE) of a marine snail Telescopium telescopium, collected from the coastal regions of West Bengal, India, was extensively screened for pharmacological and biochemical properties. Telescopium telescopium (TTE) produced significant lysis of washed rat erythrocytes (both direct and indirect), produced haemorrhagic lesions in the skin and also released haemoglobin (in vitro tissue damage) from different tissue samples. TTE was found to produce pro-inflammatory effects when injected into the rat hind paw and also increased peritoneal vascular permeability. Furthermore, intravenous administration of TTE produced a decrease in blood pressure (hypotensive effect) in anaesthetized rats. The extract produced potent esterase activity, as was evident from the breakdown of FDA with subsequent release of fluorescein (in vitro). TTE also demonstrated prominent cholinesterase, phospholipase, phosphatase and protease activities.

An insight on the neuropharmacological activity of Telescopium telescopium– a mollusc from the Sunderban mangrove

The present study was carried out to evaluate the biological properties of the tissue extract of a marine snail Telescopium telescopium, collected from the coastal regions of West Bengal India. On extensive pharmacological screening, it was found that the biological extract of T. telescopium (TTE) produced significant central nervous system (CNS)‐depressant activity as observed from the reduced spontaneous motility, potentiation of pentobarbitone induced sleeping time, hypothermia and respiratory depression with transient apnoea. The extract significantly decreased both residual curiosity and also muscle coordination. The fraction, obtained following saturation with 60–80% ammonium sulphate (80S), was also found to demonstrate predominant CNS‐depressant activity. It was observed that both TTE and the 80S fraction significantly altered the brain noradrenaline and homovanillic acid levels without affecting the brain gamma amino butyric acid (GABA) concentration. Based on the present observations, it can be suggested that the CNS‐depressant effects produced by TTE and 80S could be attributable to modified catecholamine metabolism in the brain.