Polymethoxyflavones from Nicotiana plumbaginifolia (Solanaceae) Exert Antinociceptive and Neuropharmacological Effects in Mice.

Polymethoxylavones (PMFs) are known to exhibit significant anti-inflammatory and neuroprotective properties. Nicotiana plumbaginifolia, an annual Bangladeshi herb, is rich in polymethoxyflavones that possess significant analgesic and anxiolytic activities. The present study aimed to determine the antinociceptive and neuropharmacological activities of polyoxygenated flavonoids namely- 3,3',5,6,7,8-hexamethoxy-4',5'-methylenedioxyflavone (1), 3,3',4',5',5,6,7,8-octamethoxyflavone (exoticin) (2), 6,7,4',5'-dimethylenedioxy-3,5,3'-trimethoxyflavone (3), and 3,3',4',5,5',8-hexamethoxy-6,7-methylenedioxyflavone (4), isolated and identified from N. plumbaginifolia. Antinociceptive activity was assessed using the acetic-acid induced writhing, hot plate, tail immersion, formalin and carrageenan-induced paw edema tests, whereas neuropharmacological effects were evaluated in the hole cross, open field and elevated plus maze test. Oral treatment of compounds 1, 3, and 4 (12.5-25 mg/kg b.w.) exhibited dose-dependent and significant (p < 0.01) antinociceptive activity in the acetic-acid, formalin, carrageenan, and thermal (hot plate)-induced pain models. The association of ATP-sensitive K+ channel and opioid systems in their antinociceptive effect was obvious from the antagonist effect of glibenclamide and naloxone, respectively. These findings suggested central and peripheral antinociceptive activities of the compounds. Compound 1, 3, and 4 (12.5 mg/kg b.w.) demonstrated significant (p < 0.05) anxiolytic-like activity in the elevated plus-maze test, while the involvement of GABAA receptor in the action of compound 3 and 4 was evident from the reversal effects of flumazenil. In addition, compounds 1 and 4 (12.5-25 mg/kg b.w) exhibited anxiolytic activity without altering the locomotor responses. The present study suggested that the polymethoxyflavones (1-4) from N. Plumbaginifolia could be considered as suitable candidates for the development of analgesic and anxiolytic agents.

Analgesic and anti-inflammatory activities of Polygonum stagninum.

The n-hexane, ethyl acetate (EtOAc), and methanol extracts of the aerial parts of Polygonum stagninum Buch.-Ham. ex Meissn. (Polygonaceae), a Bangladeshi medicinal plant, were assessed for analgesic and anti-inflammatory properties in experimental mice and/or rat models. In the acetic-acid-induced writhing test in mice, all extracts displayed a dose dependent analgesic effect. The most potent analgesic activity was observed with the EtOAc extract at the dose of 400 mg/kg body weight, with an inhibition of writhing response of 50.3% compared to 62.2% for the positive control aminopyrine. Among the extracts, n-hexane extract at the doses of 200 and 400 mg/kg body weight showed the highest levels of anti-inflammatory activity after 2 h, with the inhibition of paw edema of 60.1% and 64.1%, respectively, and this effect was much better than that of the conventional anti-inflammatory agent phenylbutazone (maximum inhibition of 38.3% after 4 h).

Analgesic and diuretic properties of alpha-santalone from Polygonum flaccidum.

Polygonum flaccidum Meissn. is an annual herb, native to Bangladesh, and well known for its analgesic, anti-inflammatory, diuretic, purgative and insecticidal properties, and also for its use against snake-bites. The analgesic and the diuretic properties of alpha-santalone (1), isolated from the aerial parts of Polygonum flaccidum, were assessed by the acetic-acid-induced writhing method and the Lipschitz test, respectively. Complete (1)H and (13)C NMR data of 1 are also presented.

Antinociceptive, anti-inflammatory and diuretic properties of Polygonum barbatum (L.) Hara var. barbata / Propriedades antinociceptiva, antiinflamatória e diurética dos extratos de P. barbatum (L.) Hara var. barbata

The antinociceptive, anti-inflammatory and diuretic properties of the extracts of P. barbatum (L.) Hara var. barbata, Polygonaceae, at the doses of 200 and 400 mg/kg body weight, were evaluated in mice/rat models using, respectively, the acetic-acid-induced writhing method, the carrageenan-induced edema test and the Lipschitz method. In the acetic-acid-induced writhing test in mice, all extracts displayed a dose dependent analgesic effect. The most potent analgesic activity was observed with the petroleum ether extract at the dose of 400 mg/kg body weight with an inhibition of writhing response 46.8 percent compared to 62.2 percent for the positive control aminopyrine. Petroleum ether extract at the dose of 400 mg/kg body weight also displayed the highest levels of anti-inflammatory activity after 2 h with the 39.3 percent inhibition of paw edema, and this effect was better than the effect observed by the conventional anti-inflammatory agent phenylbutazone (maximum inhibition of 38.3 percent after 4 h). All extracts increased urine volume in a dose-dependent manner, and the ethyl acetate extract showed a significant level of diuresis comparable to that of the standard diuretic agent furosemide.

As propriedades antinociceptiva, antiinflamatória e diurética dos extratos de P. barbatum (L.) Hara var. barbata, Polygonaceae, nas doses de 200 e 400 mg/kg de peso corpóreo foram avaliadas em modelos utilizando camundongos/ratos, respectivamente, o método de contorções induzidas por ácido acético, o teste de edema induzido por carragenina e o método de Lipschitz. No método de contorções induzidas por ácido acetic, todos os extratos apresentaram efeito nociceptivo dose dependente. O efeito nociceptivo mais potente foi observado com o extrato de éter de petróleo na dose de 400 mg/kg com uma inibição das contorções de 46,8 por cento comparado com o controle positivo de aminopirina de 62,2 por cento. O extrato de éter de petróleo na dose de 400 mg/kg também mostrou maior atividade antiinflammatoria após 2 h com 39,3 por cento de inibição do edema de pata, e este efeito foi maior que o observado para o agente antiinflamatório convencional fenilbutazona (inibição máxima de 38,4 por cento após 4 h). Todos os extratos aumentaram o volume de urina de maneira dose dependente e o extrato acetato de etila mostrou um nível de significância de diurese comparável ao agente diurético padrão, furosemida.

Total synthesis and analgesic activity of 6-fluoroindan-1-acetic acid and its 3-oxo derivative.

6-Fluoro-3-oxo-indan-1-acetic acid (5) and 6-fluoroindan-1-acetic acid (6) were conveniently synthesised from 3-fluorobenzaldehyde in four and five steps, respectively. The structures of these new compounds and two other intermediates, 3-fluorobenzylidine-bis-acetoacetate (2) and 3-fluoro-beta-phenyl glutaric acid (3) were elucidated by spectroscopic means, notably, HRMS, 1D and 2D NMR. The analgesic activity of compounds 5 and 6 were assessed by the acetic acid induced writhing in Swiss albino mice.

Hepatoprotective activity of Phyllanthus reticulatus.

Two partially purified organic fractions designated by PR1 and PR2 of the fat free ethanol (95%) extract of aerial parts of Phyllanthus reticulatus were tested for the hepatoprotective activity in rats against CCl(4)-induced liver damage. The rats receiving the fractions showed promising hepatoprotective activity as evident from significant changes of pentobarbital-induced sleeping time, changes in serum levels of sGPT, sGOT, sALP and bilirubin and also from histopathological changes as compared to CCl(4)-intoxicated rats.

Anti-inflammatory activity of indanyltetrazole derivatives.

A number of indanyl tetrazolederivatives namely 5-(6'-chloroindan-1'-yl)tetrazole (CIT), 5-(6'-bromoindan-1'-yl)tetrazole (BIT), 5-(6'-chloroindan-1'-yl)methyltetrazole (CIMT), 5-(6'-bromoindan-1'-yl)methyl-tetrazole (BIMT) were evaluated for the anti-inflammatory activity in carragennan induced rat paw edema in Swiss albino Wister rats for 24-hour period at the dose of 100 mg/kg of body weight by intraperitoneal route where phenylbutazone (PBZ) was used as the standard. All of these compounds exhibited inhibition on rat paw edema with peak actions observed following 3 hours after administration. Moreover, compounds CIMT and BIMT were further evaluated at dose of 50 mg/kg of body weight. Among the compounds, CIMT showed higher activity than others and was very close to standard phenylbutazone.