BackgroundPersicaria hydropiper (Linn.) Delarbre is a common plant of Polygonaceae family commonly called Bishkatali in Bangladesh. Leaves of the plant are traditionally used in the treatment of rheumatic pain, gout, and skin diseases such as ringworms, scabies, boils, abscesses, carbuncles, bites of snakes, dogs or insects. This study evaluated the antinociceptive effect of the methanol extract of P. hydropiper leaves (MEPH).MethodsThe antinociceptive activity of MEPH was investigated using heat-induced (hot-plate and tail-immersion test) and chemical-induced (acetic acid, formalin, glutamic acid, cinnamaldehyde) nociception models in mice at 25, 50, and 75 mg/kg doses. Involvement of opioid system, cyclic guanosine monophosphate (cGMP) pathway, and ATP-sensitive K+ channel pathway were also tested using naloxone, methylene blue and glibenclamide respectively.ResultsMEPH showed antinociceptive activity in both heat- and chemical induced pain models. In both hot plate and tail immersion tests MEPH significantly increases the latency to the thermal stimuli. In acetic acid-induced writhing test the extract inhibited the number of abdominal writhing. Likewise, MEPH produced significant dose-dependent inhibition of paw licking in both neurogenic and inflammatory pain induced by intraplantar injection of formalin. Besides, MEPH also significantly inhibited the glutamate-induced pain and cinnamaldehyde-induced pain in mice. It was also clear that pretreatment with naloxone significantly reversed the antinociception produced by MEPH in hot plate and tail immersion test suggesting the involvement of opioid system in its effect. In addition, administration of methylene blue, a non specific inhibitor of NO/guanylyl cyclase, enhanced MEPH induced antinociception while glibenclamide, an ATP-sensitive K+ channel antagonist, could not reverse antinociceptive activity induced by MEPH.ConclusionBased on the results of the current study it can be said that MEPH possesses significant antinociceptive activity which acts in both peripheral and central mechanisms.

Background Dalbergia sissoo DC. (Family: Fabaceae) is a medium to large deciduous tree, is locally called “shishu” in Bangladesh. It is used to treat sore throats, dysentery, syphilis, bronchitis, inflammations, infections, hernia, skin diseases, and gonorrhea. This study evaluated the antinociceptive effect of the methanol extract of D. sissoo leaves (MEDS) in mice.MethodsThe extract was assessed for antinociceptive activity using chemical and heat induced pain models such as hot plate, tail immersion, acetic acid-induced writhing, formalin, glutamate, and cinnamaldehyde test models in mice at the doses of 100, 200, and 400 mg/kg (p.o.) respectively. Morphine sulphate (5 mg/kg, i.p.) and diclofenac sodium (10 mg/kg, i.p.) were used as reference analgesic drugs. To confirm the possible involvement of opioid receptor in the central antinociceptive effect of MEDS, naloxone was used to antagonize the effect.ResultsMEDS demonstrated potent and dose-dependent antinociceptive activity in all the chemical and heat induced mice models (p < 0.001). The findings of this study indicate that the involvement of both peripheral and central antinociceptive mechanisms. The use of naloxone verified the association of opioid receptors in the central antinociceptive effect.ConclusionsThis study indicated the peripheral and central antinociceptive activity of the leaves of D. sissoo. These results support the traditional use of this plant in different painful conditions.

Adenanthera pavonina is a deciduous tree commonly used in the traditional medicine to treat inflammation and rheumatism. The aim of this study was to evaluate the antinociceptive activity of ethanol extract of leaves of A. pavonina (EEAP). EEAP was investigated using various nociceptive models induced thermally or chemically in mice including hot plate and tail immersion test, acetic acid-induced writhing, and glutamate- and formalin-induced licking tests at the doses of 50, 100, and 200 mg/kg body weight (p.o.). In addition, to assess the possible mechanisms, involvement of opioid system was verified using naloxone (2 mg/kg) and cyclic guanosine monophosphate (cGMP) signaling pathway by methylene blue (MB; 20 mg/kg). The results have demonstrated that EEAP produced a significant and dose-dependent increment in the hot plate latency and tail withdrawal time. It also reduced the number of abdominal constrictions and paw lickings induced by acetic acid and glutamate respectively. EEAP inhibited the nociceptive responses in both phases of formalin test. Besides, the reversal effects of naloxone indicated the association of opioid receptors on the exertion of EEAP action centrally. Moreover, the enhancement of writhing inhibitory activity by MB suggests the possible involvement of cGMP pathway in EEAP-mediated antinociception. These results prove the antinociceptive activity of the leaves of A. pavonina and support the traditional use of this plant.

The present research focuses to examine the meristic and landmark-based morphometric variations of barred spiny eel Macrognathus pancalus from four populations namely Dhakuria beel, Jessore (DBJ); Bohnni boar, Gopalgonj (BBG); the Arial kha river, Madaripur (AKRM) and the Nabaganga river, Jhenidah (NRJ) in Bangladeshi freshwaters. Six meristic counts were compared among four populations and significant differences were observed in number of caudal fin rays and number of pelvic fin rays in all meristic characters. The truss protocol was used in the present study based on six general morphometrics and fifteen truss measurements. Univariate statistics showed that five (standard length (SL), upper jaw length (UJL), lower jaw length (LJL), head depth (HD) and inter orbital (IO)) of six morphometric and eleven truss networks (viz. 2-3, 3-4, 5-6, 6-7, 7-8, 1-8, 2-8, 3-8, 3-7, 4-7 and 5-7) among fifteen truss measurements differed significantly. Cannonical discriminate function analyses were conducted among samples and the populations were fully intermingled. Pooled within-group correlation showed morphometric and landmark measurements; the first discriminant function (DF) accounted for 79%, the second DF accounted for 15.9% and third DF accounted for 5.1% of group variability. An euclidian dendrogram was prepared based on morphometric and truss measurements in four populations, where two clusters were mainly formed, in which first cluster formed by NRJ population was fully separated, and the second cluster was formed by two populations of AKRM and DBJ. Additionally, a subcluster BBG was formed with AKRM. On the basis of morphometric and truss measurements, 68.8%, 83.6%, 55.6% and 80% of original grouped cases were correctly classified in NRJ, AKRM, DBJ and BBG, respectively. These results specify the presence of different stocks of fish from four aquatic habitats. This study is highly significant for proper conservation and effective management of M. pancalus populations as well as for the scientific community for further research.

The present study was carried out to investigate the possible analgesic, neuropharmacological and cytotoxic activities of the methanolic extract of Trigonella foenum-graecum Linn. leaves. The analgesic and neuropharmacological activities of Trigonella foenum-graecum Linn. were investigated at the doses of 100mg/kg, 200mg/kg and 400mg/kg of body weight in mice. Analgesic potential of the extract was evaluated for centrally acting analgesic property using tail immersion method and peripheral analgesic actions using acetic acid-induced writhing test. In acetic acid-induced writhing test, extract produced a significant (p < 0.001) inhibition of writhing response in a dose dependent manner but maximum inhibition (93.46%) of writhing was found at 400mg/kg dose. In tail immersion method, extract caused a significant (p < 0.001) increase in latency time and the results were comparable to the standard drug Diclofenac- Sodium. In addition, neuropharmacological property of crude extract was carried out by Hole cross and Open field test. The extract significantly (p < 0.05-0.001) displayed a dose dependent suppression of motor activity, exploratory behaviour. Furthermore, the extract was subjected to Brine Shrimp lethality bioassay for primary evaluation of cytotoxicity, where the extract was found to be highly toxic to Brine Shrimp nauplii, having LC50 values of 10μg/ml while the LC50 of the reference anticancer drug vincristine sulphate was 0.66μg/ml. The results of this present study suggest that the extract possesses analgesic, cytotoxic and CNS depressant activities. Key Words: Trigonella foenum-graecum Linn.; cytotoxicity; neuropharmacological; analgesic activity. DOI: http://dx.doi.org/10.3329/icpj.v1i1.9218 International Current Pharmaceutical Journal 2011, 1(1): 6-11