Asish Kumar Das

Anti-inflammatory, antinociceptive and diuretic activities of Amoora cucullata Roxb.

The crude methanolic extract of the leaves of Amoora cucullata Roxb. was investigated for its possible anti-inflammatory activity using carrageenin induced rat paw edema model and cotton pellet implantation method in rat. The extract was also studied for its antinociceptive activity using acetic acid induced writhing model in mice. At the doses of 200 and 400 mg/kg body weight, the extract showed significant anti-inflammatory activity in both models. At the same doses, the extract also significantly reduced the number of acetic acid-induced abdominal constriction (writhing) in mice. The crude extract also showed significant diuretic activity in albino mice.

The isolation and synthesis of a novel benzofuran compound from Tephrosia purpurea, and the synthesis of several related derivatives, which suppress histamine H1 receptor gene expression

A novel naturally occurring compound with a benzofuran skeleton was isolated from a plant, Tephrosia purpurea collected in Bangladesh. The chemical synthesis of this compound confirmed its structure, and preliminary biological results showed its suppressive activity towards histamine H1 gene expression. One isomer and four derivatives were also synthesized, and their suppression activity was investigated. Although only small quantities of this compound can be isolated from its natural source, a 10 g scale synthesis was demonstrated by the newly developed method.

In Vivo and In Vitro Evaluation of Pharmacological Potentials of Secondary Bioactive Metabolites of Dalbergia candenatensis Leaves

Background. Dalbergia species has wide range of secondary metabolites and is traditionally used in treatment of painful micturition, swelling, and leprosy and as blood tonic. The study evaluates membrane stabilizing, anticoagulant, analgesic, cytotoxic, subacute anti-inflammatory, and depression potentials of D. candenatensis leaves metabolites. Methods. Membrane stabilizing activity was evaluated by hypotonic induced hemolysis assay, whereas anticoagulant activity is done through extrinsic pathway by measuring prothrombin time. Analgesic action, cytotoxic effect, and subacute anti-inflammatory activity were determined by acetic acid induced writhing model, brine shrimp lethality bioassay, and formaldehyde induced model, respectively. Depression activity was measured by the Open Field, Hole Cross, Hole Board, and thiopentone induced sleeping time measuring methods. Results. D. candenatensis contains phenolic, flavonoid, and tannin, quantified as 416.25u2009mg, 330.00u2009mg, and 432.22u2009mg Gallic Acid Equivalent/100u2009g of dry extract, respectively. Extract showed maximum inhibition of writhe, hemolysis, and edema, approximate to 57.14%, 36.62%, and 34.1%, respectively. LC50 value for nauplii was 151.499u2009μg/ml. Mean prothrombin time was approximate to 31.0 ± 2.31 seconds at 1.0u2009mg/ml. Extract showed depression activity, and maximum sleeping time was noted to be about 141 minutes. Conclusion. D. candenatensis leaves show dose dependent membrane stabilizing, anticoagulant, depression, analgesic, moderate cytotoxic, and subacute anti-inflammatory activities.

A systematic review on the neuroprotective perspectives of beta-caryophyllene: Neurobiological effects of β-caryophyllene

Beta (β)‐caryophyllene (BCAR) is a major sesquiterpene of various plant essential oils reported for several important pharmacological activities, including antioxidant, anti‐inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, antimicrobial, and immune‐modulatory activity. Recent studies suggest that it also possesses neuroprotective effect. This study reviews published reports pertaining to the neuropharmacological activities of BCAR. Databases such as PubMed, Scopus, MedLine Plus, and Google Scholar with keywords “beta (β)‐caryophyllene” and other neurological keywords were searched. Data were extracted by referring to articles with information about the dose or concentration/route of administration, test system, results and discussion, and proposed mechanism of action. A total of 545 research articles were recorded, and 41 experimental studies were included in this review, after application of exclusion criterion. Search results suggest that BCAR exhibits a protective role in a number of nervous system‐related disorders including pain, anxiety, spasm, convulsion, depression, alcoholism, and Alzheimers disease. Additionally, BCAR has local anesthetic‐like activity, which could protect the nervous system from oxidative stress and inflammation and can act as an immunomodulatory agent. Most neurological activities of this natural product have been linked with the cannabinoid receptors (CBRs), especially the CB2R. This review suggests a possible application of BCAR as a neuroprotective agent.

Bioactivity studies on Zanthoxylum budrunga wall (Rutaceae) root bark

BackgroundThe root-bark of the medicinally important plant Zanthoxylum budrunga (ZBRB) brooks a variety of uses in ethnobotanical and ethnomedicinal practice in Bangladesh and thus demands biological investigation to reveal its therapeutic potentiality. So, the present study was perpetrated to explore antioxidant, analgesic, antidiarrhoeal, and a cytotoxic activity of ethanolic root-bark extract of Zanthoxylum budrunga and was also to quantify the major bioactive polyphenolic constituents by HPLC analysis.MethodsTotal phenolic content was measured spectrophotometrically by using Folin Chiocalteu’s reagent while in vitro antioxidant activity was determined by means of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and reducing power assay. HPLC analysis was performed to identify and quantify the major bioactive polyphenolic constituents present in the extract. Acetic acid induced writhing test and hot-plate test were conducted to evaluate the analgesic activity of the crude extract. On the other hand, in vivo antidiarrheal potentiality was investigated by using experimentally castor oil induced diarrhoea in mice and brine shrimp lethality bio-assay was implemented to check the cytotoxic potentiality of the crude extract.ResultsZanthoxylum budrunga showed DPPH scavenging activity (IC50 54.27xa0μg/mL), while the total phenolic content was 647.91xa0mg GAE/100xa0g of extract. ZBRB also showed concentration dependent ferric reducing power activity. At the doses of 250 and 500xa0mg/kg, ZBRB exhibited statistically significant (Pu2009<u20090.001) inhibition of writhing in test mice (64.58 and 77.78%, respectively). In hot-plate test, ZBRB, at the above dose levels, significantly (Pu2009<u20090.001) prolonged pain threshold with response time of 5.80 and 6.81xa0s, respectively. In castor oil induced diarrhoeal episode in mice, ZBRB exhibited 66.56% and 83.39% inhibition of defecation at the doses of 250 and 500xa0mg/kg, respectively (Pu2009<u20090.001). The LC50 (Median lethal concentration) value of ZBRB in brine shrimp lethality bioassay was found to be 21.84xa0μg/mL. In the HPLC analysis, (+)-catechin, caffeic acid and quercetin were detected with the concentration of 17.94xa0mg/100, 3.72xa0mg/100 and 11.95xa0mg/100xa0g of ethanolic extract of ZBRB, respectively.ConclusionThe results rationalize the uses of the plant in traditional medicine for diarrhoeal as well as pain management. Catechin, caffeic acid, and other phenolics constituents might have some function in the observed activity.