A. H. M. Khurshid Alam

Effects of the phosphodiesterase IV inhibitor rolipram on Th1 and Th2 immune responses in mice

The present study was designed to investigate the effect of the phosphodiesterase IV inhibitor rolipram on Th1 and Th2 immune responses in mice. Mice were immunized subcutaneously at the base of the tail with ovalbumin (OVA) emulsified with complete Freunds adjuvant (day 0) and were treated daily with oral administration of various doses of rolipram from days 0 to 20. On day 21, production of anti‐OVA IgG and proliferative responses to the antigen were determined. Anti‐OVA IgG2a and interferon‐γ (IFN‐γ), as indicators of Th1 responses, and anti‐OVA IgG1 and interleukin‐10 (IL‐10), as indicators of Th2 responses, were also measured. The results showed that treatment with rolipram failed to affect the production of OVA‐specific IgG but decreased the proliferation of spleen cells to the antigen. Its inhibitory effect on these immune responses was correlated with a marked decrease in IFN‐γ but not IL‐10 production, although neither anti‐OVA IgG2a nor IgG1 production was affected by rolipram. These results suggest that rolipram may preferentially inhibit Th1 responses more effectively than Th2 responses. Administration of rolipram resulted in suppression of antigen (OVA)‐induced arthritis in mice. The suppression of joint inflammation by rolipram was associated with the inhibition of the OVA‐specific proliferative responses of spleen cells and IFN‐γ secretion. These results indicate that rolipram may be effective in regulating Th1‐mediated diseases such as rheumatoid arthritis.

Difference in preventive effects between the phosphodiesterase iv inhibitor rolipram and anti-arthritic drugs on antigen-induced arthritis in mice.

The efficacy of the phosphodiesterase (PDE) IV inhibitor rolipram on antigen-induced arthritis (AIA) in mice was evaluated in comparison with clinically used anti-arthritic drugs. To induce AIA, DBA/1 mice were immunized with ovalbumin (OVA) emulsified with CFA (day 0) followed by intra-articular injection of OVA on day 21. Rolipram and clinically used anti-arthritic drugs including indomethacin (IND), dexamethasone (DEX), methotrexate (MTX), auranofin (AUR), and D-penicillamine (D-PA) were orally administered daily from days 0 to 20. On day 22, anti-OVA IgG in serum, proliferative responses of spleen cells to the OVA, and anti-OVA IgG2a and interferon (IFN)-γ as indicators of Th1 responses, as well as anti-OVA IgG1 and interleukin (IL)-10 as those of Th2 reactions, were measured. Treatment with rolipram was followed by inhibition of the early phase of AIA associated with downregulation of both OVA-specific splenocyte proliferation and decreases of IFN-γ released from the spleen cells but no decreases of the amount of IL-10, or levels of anti-OVA IgG, IgG2a, and IgG1. All clinically used anti-arthritic drugs were more effective in suppressing the late phase of AIA compared with the early phase of joint inflammation. The suppression of AIA by clinically used anti-arthritic drugs was associated with down-regulation of not only Th1 but also Th2 responses. These results suggest that PDE IV inhibitors such as rolipram may exert their suppressive effects on AIA with relatively selective downregulation of antigen-specific Th1 responses compared with anti-arthritic drugs.

N-trans-feruloyl-4-methyldopamine from Achyranthes ferruginea

The aerial parts of Achyranthes ferruginea Roxb. (Amaranthaceae), local name Raktoshirinchi, were collected from Meherchandi, the adjoining area of Rajshahi University Campus, Rajshahi, Bangladesh, in April, 2001. The plant was identified by Professor A.T.M. Naderuzzaman, Department of Botany, Rajshahi University and a voucher specimen representing this collection has been maintained at the Bangladesh National Herbarium (BNH), under the accession number DACB-7398.

In vitro antioxidant and cholinesterase inhibitory activities of Elatostema papillosum leaves and correlation with their phytochemical profiles: a study relevant to the treatment of Alzheimer’s disease

BackgroundAlzheimer’s disease (AD), one of the major causes of dementia, is an overwhelming neurodegenerative disease that particularly affects the brain, leading to memory loss and impairment of language and judgment capacity. The aim of the present study was to investigate the antioxidant and anticholinesterase properties of the leaves of Elatostema papillosum (EPL) and correlate with their phytochemical profiles, which are relevant to the treatment of AD.MethodsThe dried coarse powder of EPL was extracted with 80% methanol (EPL-M80) by cold extraction method. The resultant EPL-M80 was assessed for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity by the Ellman method. The antioxidant activity was determined by DPPH (1, 1-diphenyl-2-picrylhydrazyl) and hydroxyl radical scavenging assays. Quantitative phytochemical (phenolic and flavonoid contents) analysis of endogenous substances in EPL-M80 was performed by standard spectrophotometric methods.ResultsEPL-M80 significantly (p < 0.05) inhibited AChE and BChE activity with IC50 of 165.40 ± 4.01 and 213.81 ± 3.57 μg/mL, respectively in a dose-dependent manner. Additionally, EPL-M80 exhibited strong radical scavenging activity against DPPH (IC50 = 32.35 ± 0.68 μg/mL) and hydroxyl radical (IC50 = 19.67 ± 1.42 μg/mL) when compared to that of standards. EPL-M80 was found to be rich in phenolic (23.74 mg gallic acid equivalent/g of dry extract) and flavonoid (31.18 mg quercetin equivalent/g of dry extract) content. Furthermore, a positive correlation (p < 0.001) was observed between the total phenolics and antioxidant as well as the anticholinesterase potential.ConclusionsThe marked inhibition of AChE and BChE, and potent antioxidant activity of the leaves of Elatostema papillosum highlight its potential to provide an effective treatment for AD.