Coumarins from Angelica decursiva inhibit lipopolysaccharideinduced nitrite oxide production in RAW 264.7 cells

Ishrat Jahan Ishita,Md. Nurul Islam,김영식,최란주,손희숙,정현아,최재수 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.1

Angelica decursiva has long been used in Korean traditional medicine as an antitussive, analgesic, antipyretic, and cough remedy. In this study, the anti-inflammatory activity of 9 coumarin derivatives isolated from a 90 % methanol fraction was evaluated via inhibition of production of nitric oxide (NO) and tumor necrosis factor-a (TNF-a), as well as the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX- 2) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Among the tested compounds, edulisin II (1) exhibited the most potent NO production inhibitory activity, followed by decursidin (2), Pd–C-III (3), 4-hydroxy Pd–CIII (4), Pd–C-I (5), and Pd–C-II (6). In contrast, (?)-transdecursidinol (7) did not exhibit NO suppressive effects on LPS-stimulated RAW 264.7 cells. Structure-activity relationships revealed that esterification of the hydroxyl at C-30 or C-40 of 7 with an angeloyl/senecioyl/acetyl group is essential for its inhibitory activity against NO production, while the number of angeloyl or senecioyl groups, and their positions greatly affect the potency of these coumarins. Coumarins 1-6 also inhibited TNF-a production and iNOS protein expression, while compounds 1-4 inhibited COX-2 protein expression in LPS-stimulated RAW 264.7 cells. These results suggest that coumarins isolated from A. decursiva might be used as potential leads for the development of therapeutic agents for inflammation-associated disorders.

Evaluation of anti-inflammatory and antioxidant potential of the kernel root of Xylocarpus mekongensis (Lamk.) M. Roem

Jahan, Ismet Ara,Hossain, Md. Hemayet,Nimmi, Ishrat,Islam, Siblara,Kawsar, Md. Hassan,Islam, Md. Amirul 경희한의학연구센터 2012 Oriental Pharmacy and Experimental Medicine Vol.12 No.3

Anti-inflammatory and antioxidant activities of the crude ethanolic extract of the kernel root of Xylocarpus mekongenesis (Lamk.) M. Roem. (Meliaceae) was evaluated in different methods. The extract showed significant antiinflammatory activity in carrageenan-induced oedema test in rats showing 69.42 % reduction in the paw volume (P<0.01) comparable to that produced by the standard drug indomethacin (70.25 %) at 24 h when the extract was fed at the dose of 400 mg/kg body weight. The percentage inhibition of the oedema paw volume was statistically significant (p<0.05) when compared with the indomethacin treated animals at 0.5, 1, 2, 4 and 6 h. The extract exhibited $IC_{50}$ value 4.78 ${\mu}g/ml$ in DPPH free radical scavenging activity test that was found to be very significant and comparable to that of the standard antioxidants ascorbic acid and BHA (1.9372 and 4.81 ${\mu}g/ml$) respectively. In nitric oxide radical scavenging test, the $IC_{50}$ value was also found fairly significant 57.37 ${\mu}g/ml$ when compared to standard ascorbic acid (36.81 ${\mu}g/ml$). In reducing power test, the maximum absorbance of the same extract was observed as 1.923 at 100 ${\mu}g/ml$ and that of ascorbic acid and BHA were 2.8111 and 1.0314 respectively. The extract showed highest antioxidant capacity at 100 ${\mu}g/ml$ concentration expressed as equivalents of ascorbic acid (1.44). The total phenolic content of the extract was also found quite high ($342.15{\pm}0.92$ mg/g of gallic acid equivalent). Therefore, the results of this study suggest the probable anti-inflammatory and antioxidant activities of the ethanolic extract of X. mekongenesis kernel root and justify its use in traditional medicines.

The Impact of Voluntary Disclosure on Firm’s Value

Md,QAMRUZZAMAN,Ishrat JAHAN,Salma KARIM 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.6

Financial reporting includes disclosures as prescribed by regulators, but few companies go beyond mandatory requirements and provide additional information voluntarily. This study evaluates the potential impact of voluntary information disclosure on the value of firms listed on the Dhaka Stock Exchange for the period 2017–2019. The study applies GLS and system-GMM (Two-stage) estimation for detecting the magnitude of voluntary disclosure information on the firms’ value. Study findings reveal a positive and significant relationship between voluntary disclosure relating to financial statistics, social responsibility information, corporate governance, and the firms’ value as measured by Tobin’s Q. However, there is a negative and significant relationship between company information, accounting policies, and the firms’ value as measured by Tobin’s Q. Study findings suggest that the impact of voluntary disclosure on the value of the firms varies with the appropriate selection of proxy measures. Nonetheless, it is believed that voluntary disclosure plays a major role in projecting a clean image in the market and in attracting potential investors with a positive note about the company’s prospects.

COVID-19, Remittance Inflows, and the Stock Market: Empirical Evidence from Bangladesh

Md,QAMRUZZAMAN,Salma KARIM,Ishrat JAHAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

This study’s motivation is to investigate the association between the stock market, remittance, and the pandemic of COVID-19 for the period from March 3, 2020, to December 14, 2020. For evaluating the impact of COVID-19 and remittances on stock market behaviour during the pandemic, the study applies Autoregressive Distributed lagged (ARDL) for magnitudes estimation and directional association through the Toda-Yamamoto causality test. Study findings from ARDL estimation revealed that COVID-19 measured by detecting new cases negatively influences the stock market both in the long-term and short-term. Remittance positively influences the stock market behaviour, particularly in the long-term. Furthermore, the directional causality test disclosed unidirectional causal effects between COVID-19 and the stock market behaviour, which establishes all proxy measures for the equation’s stock market. The hypothesis results explain the causal relationship between remittance inflows and the stock market in Bangladesh. The study’s application will help policymakers rethink the policies for channelizing remittances for productive investment areas. Furthermore, the study’s findings will reinstate the widely perceived notions, which is the critical role of remittance in the economy even though the economy passes through a great pandemic.

Anti-inflammatory and antioxidant activities of the ethanolic extract of Ceriops decandra (Griff.) Ding Hou bark

Hemayet Hossain,Sk. Moniruzzaman,Ishrat Nimmi,Hassan Kawsar,Akbor Hossain,Amirul Islam,Ismet Ara Jahan 경희대학교 융합한의과학연구소 2011 Oriental Pharmacy and Experimental Medicine Vol.11 No.4

The crude ethanolic extract of the bark of Ceriops decandra (Griff.) Ding Hou (Family: Rhizophoraceae)was evaluated for its possible anti-inflammatory and antioxidant activities in different methods. At the dose of 400 mg/kg body weight, the extract showed a significant anti-inflammatory activity in the carrageenan-induced oedema test in rats showing 67.72% reduction in the paw volume (P<0.01) comparable to that produced by the standard drug indomethacin (69.29%) at 24 h. The percentage inhibition of the oedema paw volume by the 400 mg/kg body weight of the extract was also statistically significant (*P<0.05 and **p<0.01) compared favorably with the indomethacin treated animals at 1, 2, 4, 6 and 24 h. Three complementary test systems for determining the antioxidant activities of the ethanolic extract of C. decandra,namely DPPH free radical scavenging, reducing power, total phenolic contents determination were used for the analysis. In DPPH free radical scavenging test, IC_(50) value for the ethanolic crude extract was found fairly significant (12.90 μg/ml) while compared to the IC_(50) value of the reference standards ascorbic acid and butylated hydroxy anisole (2.9372 and 4.81 μg/ml) respectively. In reducing power test the absorbance for ethanolic extract was found to be 1.0900 at 100 μg/ml concentration while compared to 2.8111 and 1.0314 for standard ascorbic acid and BHA respectively at the same concentration. The amount of total phenolic content was also determined and calculated as quite high in the ethanolic extract (309.86 mg/g of gallic acid equivalent). Therefore, the obtained results tend to suggest the probable anti-inflammatory and antioxidant activities of the ethanolic extract of C. decandra bark and justify its use in folkloric remedies.

Anti-inflammatory Activity of Edible Brown Alga Saccharina japonica and its Constituents Pheophorbide a and Pheophytin a in LPS-stimulated RAW 264.7 Macrophage Cells

Md Nurul Islam,Ishrat Jahan Ishita,Seong Eun Jin,Ran Joo Choi,Chan Mee Lee,Yeong Shik Kim,Hyun Ah Jung,Jae Sue Choi 한국식품영양과학회 2013 한국식품영양과학회 학술대회발표집 Vol.2013 No.11

Anti-inflammatory and antioxidant activities of the ethanolic extract of $Ceriops$ $decandra$ (Griff.) Ding Hou bark

Hossain, Hemayet,Moniruzzaman, Sk.,Nimmi, Ishrat,Kawsar, Hassan,Hossain, Akbor,Islam, Amirul,Jahan, Ismet Ara 경희한의학연구센터 2011 Oriental Pharmacy and Experimental Medicine Vol.11 No.4

The crude ethanolic extract of the bark of $Ceriops$ $decandra$ (Griff.) Ding Hou (Family: Rhizophoraceae) was evaluated for its possible anti-inflammatory and antioxidant activities in different methods. At the dose of 400 mg/kg body weight, the extract showed a significant anti-inflammatory activity in the carrageenan-induced oedema test in rats showing 67.72% reduction in the paw volume ($P$ <0.01) comparable to that produced by the standard drug indomethacin (69.29%) at 24 h. The percentage inhibition of the oedema paw volume by the 400 mg/kg body weight of the extract was also statistically significant ($^*P$ <0.05 and $^{**}p$ <0.01) compared favorably with the indomethacin treated animals at 1, 2, 4, 6 and 24 h. Three complementary test systems for determining the antioxidant activities of the ethanolic extract of $C.$ $decandra$, namely DPPH free radical scavenging, reducing power, total phenolic contents determination were used for the analysis. In DPPH free radical scavenging test, $IC_{50}$ value for the ethanolic crude extract was found fairly significant (12.90 ${\mu}g$/ml) while compared to the $IC_{50}$ value of the reference standards ascorbic acid and butylated hydroxy anisole (2.9372 and 4.81 ${\mu}g$/ml) respectively. In reducing power test the absorbance for ethanolic extract was found to be 1.0900 at 100 ${\mu}g$/ml concentration while compared to 2.8111 and 1.0314 for standard ascorbic acid and BHA respectively at the same concentration. The amount of total phenolic content was also determined and calculated as quite high in the ethanolic extract (309.86 mg/g of gallic acid equivalent). Therefore, the obtained results tend to suggest the probable anti-inflammatory and antioxidant activities of the ethanolic extract of $C.$ $decandra$ bark and justify its use in folkloric remedies.