α-Keto tetrahydrofuran lignan glucosides from the Bangladeshi medicinal plant Terminalia citrina inhibit estradiol (E2) induced proliferation in cancer cells

EtOAc extract from the leaves of Terminalia citrina collected in Bangladesh were separated, and seven previously undescribed α-keto tetrahydrofuran lignan glucosides (terminalosides Q to W) were isolated and characterized. NOESY analysis of ¹H NMR spectra and ECD spectroscopic data analysis revealed the absolute stereochemistry of the tetrahydrofuran ring of the isolated constituents as being a (7S,8R,8'S)- configuration in terminalosides Q to U and a (7R,8R,8'S)- configuration in terminalosides V and W. All of the isolated compounds were evaluated for their estrogenic and anti-estrogenic properties using two types of estrogen-responsive human breast cancer cell lines (MCF-7 and T47D). Terminaloside R, which has a dioxymethylene group in its aromatic ring, inhibited 90% of estradiol-enhanced cell proliferation in T47D and MCF-7 cells at concentrations of 0.01 μM and 0.1 μM, respectively. On the other hand, terminaloside T, the analogous compound which has two oxymethyl groups in place of dioxymethylene, suppressed 90% of cell proliferation selectively in T47D cells at a concentration of 0.01 μM. However, terminaloside W, the 7R-stereoisomer of terminaloside R, only showed moderate activity.

Five furofuranone lignan glucosides from Terminalia citrina inhibit in vitro E2-enhanced breast cancer cell proliferation

Five new polyalkoxylated furofuranone lignan glucosides, terminalosides L-P (1-5), were isolated from EtOAc extracts of the leaves of Terminalia citrina, a Bangladeshi medicinal plant. The structures of the isolates were deduced primarily by NMR spectroscopy, and four of the isolates were found to contain rare tetraoxygenated aryl groups in their structures. The absolute configurations and conformations of the furofuranone ring were confirmed by ECD spectroscopy. All of the isolates were evaluated for their estrogenic and/or antiestrogenic properties using two estrogen responsive breast cancer cell lines, T47D and MCF-7. At a concentration of 10nM, terminaloside L (1) suppressed E2-enhanced T47D cell proliferation by 90%, while terminaloside M (2) showed 90% antiestrogenic activity against MCF-7 cells. Compared to 2, the antiestrogenic activity of terminaloside O (4) and P (5) was weak, possibly due to the different attachment positions of the sugar moiety that they share in common. This is the first report of furofuranone lignans from any Terminalia species, and also of their antiestrogenic activity.

Furofuran Lignan Glucosides with Estrogen-Inhibitory Properties from the Bangladeshi Medicinal Plant Terminalia citrina

Extracts from the leaves of the Bangladeshi medicinal plant Terminalia citrina were prepared, and 13 new furofuran lignan glucosides, terminalosides A-K (1-4, 6-12), 2-epiterminaloside D (5), and 6-epiterminaloside K (13), were characterized using various spectroscopic techniques. Twelve of the isolates were found to contain rare tetraoxygenated aryl groups in their structures. Analysis of the NMR chemical shifts for the oxymethine signals in the furofuran ring suggested a pragmatic approach to determining the relative configuration of these compounds. The ECD and NOESY spectroscopic data obtained allowed for the deduction of the absolute configurations and conformations of the compounds. The isolates were tested for their estrogenic/antiestrogenic activity using the MCF-7 and T47D estrogen-responsive human breast cancer cell lines. Terminalosides B (2) and G (8) exhibited inhibitory effects for both cell lines, and estradiol-enhanced cell proliferation was suppressed by 90% at concentrations lower than 10 μM. Terminaloside E (6) showed inhibitory activity against the T47D cell line, whereas terminalosides C (3), F (7), and I (10) and 6-epiterminaloside K (13) displayed antiestrogenic activity against MCF-7 cells.

Phenolic constituents of the Bangladeshi medicinal plant Pothos scandens and their anti-estrogenic, hyaluronidase inhibition, and histamine release inhibitory activities

Extracts from the stem and roots of the Bangladeshi medicinal plant Pothos scandens L. (Araceae) were isolated, and three hemiterpene glucoside aromatic esters, pothobanosides A (1), B (2), and C (3), and a phenylisobutanoid, pothobanol (4), along with 14 known compounds, were characterized. The isolates were tested for their estrogenic/anti-estrogenic activity using the estrogen-responsive human breast cancer cell lines MCF-7 and T47D, and syringoyl derivatives (2, 3, and canthoside B) showed strong inhibitory activity against both cell lines. Their less oxygenated analogs (1, and markhamioside F) were almost inactive. The isolates were also evaluated for hyaluronidase and histamine release inhibitory activities, and pothobanoside A (1) showed significant hyaluronidase inhibitory activity among the isolated compounds, which was similar to that of the positive control rosmarinic acid. Because hyaluronidase produces an angiogenic response that has been implicated in tumor invasiveness and metastasis, 1 could be valuable as an anti-tumor compound with a different mechanism of action from related compounds (2, 3). Pothobanoside C (3) and pothobanol (4) were also found to inhibit histamine release to a similar degree to the positive control epigallocatechin 3-O-(3"-O-methyl)-gallate. The histamine release inhibitory potency of these isolates may support the traditional uses of this plant in folk medicine.

Phytochemical screening, cytotoxicity and antibacterial activities of two Bangladeshi medicinal plants

The objectives of the present study were to investigate phytochemical screening and to assay cytotoxicity and antibacterial activities of ethanolic extracts of leaves of two medicinal plants, Aglaonema hookerianum Schott (Family: Araceae) and Lannea grandis Engl. (Family: Anacardiaceae) available in Bangladesh. The brine shrimp lethality bioassay showed that the ethanolic extracts of Aglaonema hookerianum and Lannea grandis possessed cytotoxic activities with LC50 5.25 (microg mL(-1)) and 5.75 (microg mL(-1)) and LC90 10.47 (microg mL(-1)) and 9.55 (microg mL(-1)), respectively. Two extracts obtained from leaves were examined for their antibacterial activities against some gram positive bacteria such as Bacillus subtilis, Bacillus megaterium and Staphylococcus aureus, also gram negative strains of Pseudomonas aeruginosa, Escherichia coli, Shigella dysenteriae, Salmonella typhi, Salmonella paratyphi and Vibrio cholerae. Agar disc diffusion method was applied to observe the antibacterial efficacy of the extracts. Results indicated that both plant extracts (500 microg disc(-1)) displayed antibacterial activity against all of the tested microorganisms. These results were also compared with the zones of inhibition produced by commercially available standard antibiotic, Amoxicillin at concentration of 10 microg disc(-1). Observed antibacterial properties of the ethanolic extract of Aglaonema hookerianum Schott and Lannea grandis Engl. showed that both plants might be useful sources for the development of new potent antibacterial agents.

Parental knowledge, attitude and practice related to blindness of children in some selected Upazilla of Bangladesh

Early detection of blind children at the household and community level is critical in reducing the global burden of visual impairment and childhood blindness. The aim of the study is to identify a range of potential issues relating to parental awareness and perceptions of common eye diseases affecting children. It was a descriptive and cross sectional study. Parents were recruited from four selected Upazillas ('pouroshoba' - 25% and rural - 75%) in the Naogaon district of Bangladesh. The method used in this study to assess parental knowledge and belief was by means of a questionnaire. The selected subjects were interviewed in detail using a structured questionnaire. It is mentionable that among common eye disease, about three-fourth of the parents informed that vitamin-A deficiency was the leading cause of blindness and more than one quarter believed that eye infection was the important cause of childhood blindness. Very few reported that injury in eye was the cause of childhood blindness. Analysis of respondents of this study revealed that half of the parents believed that childhood cataract is untreatable. Approximately 90% those surveyed were unaware of schooling systems for blind children and only 5% sought treatment from an ophthalmologist. This study also demonstrates that the health seeking behavior of parents and their extended families is poor. The mean age of the parents was 32.5±9.3 years, about 75% of parents had education up to primary level, and only 3.7% of them had graduation degree and above. The findings reinforce the necessity of parental awareness of common eye diseases in children and the importance of seeking timely advice including treatment based on informed decisions.

Prevalence and causes of childhood blindness in camps for displaced persons in Khartoum: results of a household survey

The prevalence and causes of visual impairment and blindness were determined in 29 048 children < 16 years in all households of 5 camps for internally displaced people in Khartoum State, Sudan. After house-to-house visits by trained health care workers, 916 children received further assessment, 2.7% of whom were found to be blind, 1.6% to be severely visually impaired and 5.5% to be visually impaired, according to World Health Organization criteria. The prevalence of blindness in children in the camps was estimated as 1.4 per 1000 children. The leading causes of blindness were found to be corneal opacities (40.0%), mainly due to vitamin A deficiency, followed by amblyopia (32.5%).

Causes of severe visual impairment and blindness in Bangladesh: a study of 1935 children

OBJECTIVE

To identify the anatomical site and underlying aetiology of severe visual impairment and blindness (SVI/BL) in children in Bangladesh.

DESIGN

A national case series.

METHODS

Children were recruited from all 64 districts in Bangladesh through multiple sources. Causes were determined and categorised using standard World Health Organization methods.

RESULTS

1935 SVI/BL children were recruited. The median age was 132 months, and boys accounted for 63.1% of the sample. The main site of abnormality was lens (32.5%), mainly unoperated cataract, followed by corneal pathology (26.6%) and disorders of the whole eye (13.1%). Lens-related blindness was the leading cause in boys (37.0%) compared with corneal blindness in girls (29.8%). In 593 children, visual loss was due to childhood factors, over 75% being attributed to vitamin A deficiency. Overall 1338 children (69.2%) had avoidable causes. Only 2% of the country's estimated SVI/BL children have access to education and rehabilitation services.

CONCLUSIONS

This is the first large-scale study of SVI/BL children in Bangladesh over two-thirds of whom had avoidable causes. Strategies for control are discussed.