Shaikh Jamal Uddin

Effect of citrus flavonoids, naringin and naringenin, on metabolic syndrome and their mechanisms of action

Flavonoids are important natural compounds with diverse biologic activities. Citrus flavonoids constitute an important series of flavonoids. Naringin and its aglycone naringenin belong to this series of flavonoids and were found to display strong anti-inflammatory and antioxidant activities. Several lines of investigation suggest that naringin supplementation is beneficial for the treatment of obesity, diabetes, hypertension, and metabolic syndrome. A number of molecular mechanisms underlying its beneficial activities have been elucidated. However, their effect on obesity and metabolic disorder remains to be fully established. Moreover, the therapeutic uses of these flavonoids are significantly limited by the lack of adequate clinical evidence. This review aims to explore the biologic activities of these compounds, particularly on lipid metabolism in obesity, oxidative stress, and inflammation in context of metabolic syndrome.

Cytotoxic Effects of Bangladeshi Medicinal Plant Extracts

To investigate the cytotoxic effect of some Bangladeshi medicinal plant extracts, 16 Bangladeshi medicinal plants were successively extracted with n-hexane, dichloromethane, methanol and water. The methanolic and aqueous extracts were screened for cytotoxic activity against healthy mouse fibroblasts (NIH3T3) and three human cancer-cell lines (gastric: AGS; colon: HT-29; and breast: MDA-MB-435S) using the MTT assay. Two methanolic extracts (Hygrophila auriculata and Hibiscus tiliaceous) and one aqueous extract (Limnophila indica) showed no toxicity against healthy mouse fibroblasts, but selective cytotoxicity against breast cancer cells (IC50 1.1–1.6 mg mL−1). Seven methanolic extracts from L. indica, Clerodendron inerme, Cynometra ramiflora, Xylocarpus moluccensis, Argemone mexicana, Ammannia baccifera and Acrostichum aureum and four aqueous extracts from Hygrophila auriculata, Bruguiera gymnorrhiza, X. moluccensis and Aegiceras corniculatum showed low toxicity (IC50 > 2.5 mg mL−1) against mouse fibroblasts but selective cytotoxicity (IC50 0.2–2.3 mg mL−1) against different cancer cell lines. The methanolic extract of Blumea lacera showed the highest cytotoxicity (IC50 0.01–0.08 mg mL−1) against all tested cell lines among all extracts tested in this study. For some of the plants their traditional use as anticancer treatments correlates with the cytotoxic results, whereas for others so far unknown cytotoxic activities were identified.

Antioxidant, antinociceptive activity and general toxicity study of Dendrophthoe falcata and isolation of quercitrin as the major component

Plants have been used in traditional medicinal system for centuries. Bangladeshi medicinal plants have received considerable attention from the researchers for evaluation of their bioactivity. As a part of our ongoing research of screening the Bangladeshi medicinal plants, the ethanolic extract of Dendrophthoe falcata have been chosen for the present study. The ethanolic extract of the leaves of the plant have been assessed for their antioxidant, antinociceptive, and general toxicity. The extract showed potent antioxidant activity (IC50 5.1 μg/ml) using DPPH radical scavenging assay, which is comparable to the standard ascorbic acid (IC50 4.6 μg/ml). The extract significantly and dose dependently inhibited the acetic acid induced writhing in mice (71.2%, P < 0.001 and 28.0%, P < 0.05 for 500 and 250 mg/kg body weight, respectively). A general toxicity was assessed by a simple and low cost assay using brine shrimp lethality as an indicator. The extract showed low level of toxicity (LC50 100 μg/ml). Using different chromatographic techniques, quercitrin (quercetin 3-O-α-rhamnoside) was separated as the major component from the extract. The structure was elucidated by detailed 1D and 2D NMR and mass spectral analysis.

Free radical scavenging activity of some Bangladeshi plant extracts

A number of plants from different geographical origins have been shown to possess antioxidant activity. Some of them have been developed as natural antioxidant formulations for food, cosmetic and other applications. Bangladeshi flora is a rich source of a range of plant species, many of which are medicinal plants, and have been used in the preparations of the Unani and Ayurvedic traditional medicines. There are no, or just a few, reports on any systematic screening of the extracts of Bangladeshi plants for free radical scavenging activity using DPPH assay available to date. As part of our on-going search for biological activity in Bangladeshi plants, Kadam (Anthocephalus chinensis), Goran (Ceriaps decandra), Swarnalata (Cuscuta reflexa), Gab (Diospyros peregrina), Sundari (Heritiera fomes), Dhundul (Xylocarpus granatum) and Possur (Xylocarpus mekongensis) have been selected for the assessment of their free radical scavenging activity, and studies on the contents of alkaloids, anthraqunones, flavonoids and tannins in these extracts. Most of these species have been used in traditional medicine in Bangladesh and other countries for the treatment of various illnesses ranging from common cold to cancer. All extracts, except the methanol extract of Cuscuta reflexa, displayed significant free radical scavenging activity in the DPPH assay values within the range of . Among these extracts, the methanol extract of Xylocarpus granatum exhibited the most potent activity and that of Cuscuta reflexa had the least activity . While none of these plants showed positive tests with Dragendorffs reagent, presence of low to moderate amounts of phenolic compounds, e.g. anthraquinones, flavonoids and tannins was evident in all of these plants, except for the methanolic extracts of C. reflexa and the barks of D. peregrina, which did not display any evidence for the presence of flavonoids and anthraquinones, respectively.

Antinociceptive activity of the ethanolic extract of Ficus racemosa Lin. (Moraceae)

The ethanolic extract of Ficus racemosa Lin. (Moraceae) bark and fruit were tested for its possible antinociceptive activity study on acetic acid induced writhing method in mice. Both the bark and fruit extracts at a dose of 500 mg/kg body weight showed significant antinociceptive activity on the experimental animals. The fruit extract showed most potent inhibition of acetic acid induced writhing in mice (61.38%, P < 0.001) where as the bark extract showed inhibition only 42.6% (P < 0.001) and all the result were statistically significant.

Swarnalin and cis -swarnalin, two new tetrahydrofuran derivatives with free radical scavenging activity, from the aerial parts of Cuscuta reflexa

The reversed-phase HPLC analysis of a methanol extract of the aerial parts of Cuscuta reflexa afforded a non-separable mixture (55 : 45) of two novel tetrahydrofuran derivatives, named swarnalin (1) and cis-swarnalin (2), and a known coumarin, 5,6,7-trimethoxycoumarin (3). The structures of the compounds were elucidated unequivocally by UV, HRFABMS and a series of 1D and 2D NMR analyses. The mixture of 1 and 2 showed significant free radical scavenging activity in the DPPH assay and the RC50 value was found to be 3.80 × 10−4 mg mL−1 for the mixture, compared to 2.88 × 10−5 mg mL−1 for the positive control, quercetin.

An ethnobotanical study of medicinal plants used by tribal and native people of Madhupur forest area, Bangladesh.

ETHNOPHARMACOLOGICAL RELEVANCE Madhupur forest area, Tangail is one of early human settlements in Bangladesh. Having abode in the vicinity of the forest, a strong ethnobotanical practice has prevailed in this area since ancient time. Due to the rapid deforestation during the last few decades, many plants have already disappeared or are facing extinction. Thus we attempted to document the medicinal plant use of Madhupur forest area with a view to preserve the ethnobotanical knowledge and in order to protect the biodiversity of this area. MATERIALS AND METHODS The fieldwork was conducted during a period of 1 year. Data was collected by interview, questionnaire, and group discussion with randomly selected informants including indigenous, tribal people, and Traditional Health Practitioners (THPs) living in the study area. Recorded plants are listed along with their indication, part used, form of preparation and use value (UV). Results were also analysed to determine informant consensus factor (ICF) and fidelity level (FL) of the plants on the basis of their use under various ailment categories. RESULTS The present study has documented 78 medicinal plant species from 45 families used for the treatment of at least 77 different major and minor ailments and conditions. Medicinal plant species were categorised as tree, shrub, tuber, herb, and climber. Leaves were found to be the most frequently used plant part while decoction is the major form of preparation. In most cases preparations are either administered orally or applied topically. CONCLUSION The present study revealed that some of the well-known medicinal plants are used extensively demonstrating an effective ethnobotanical practice in the study area. Plants with high ICF and FL values can be subjected to bioassay guided investigation while plants which scored low UVs require bioactivity screening to justify their use for the reported ailment.

(2S,3S)-sulfated pterosin C, a cytotoxic sesquiterpene from the Bangladeshi mangrove fern Acrostichum aureum.

Two new sesquiterpenes, (2R,3S)-sulfated pterosin C (1) and (2S,3S)-sulfated pterosin C (2), along with two known derivatives, (2S,3S)-pterosin C and (2R)-pterosin P, were isolated from a methanolic extract of the aerial parts of Acrostichum aureum. The structures of 1 and 2 were determined by the interpretation of their spectroscopic data. The isolated pterosins were evaluated for their cytotoxic activity against the AGS, HT-29, MDA-MB-231, and MCF-7 human cancer cell lines and the NIH3T3 normal mouse fibroblast cell line, using the MTT assay. Compound 2 showed IC50 values in the range 23.9-68.8 μM. The lowest IC50 value (23.9 μM) was recorded against AGS gastric adenocarcinoma cells. Compound 2 was found to exert an apoptotic effect on AGS cells within 24 h of treatment, which increased with time and was greater than the positive control, cycloheximide. The cytotoxicity of 2 seems to be due in part to the sulfate group on C-14 and the configuration at C-2.

Central nervous system depressant activity of Diospyros peregrina bark

The methanol extract of Diospyros peregrina bark was studied for its effect on the central nervous system (CNS) using the pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract, at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to the control. In open field test, the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed from the second observation period (30 min) and persisted up to fifth observation period (120 min) for 250 mg dose group and up to sixth observation period (180 min) for 500 mg dose group. These results support the finding that D. peregrina bark extract at the above doses has CNS depressing effects and indicate that D. peregrina bark may contain biologically active constituent(s) having CNS depressant activity.

Evaluation of cytotoxic activity of patriscabratine, tetracosane and various flavonoids isolated from the Bangladeshi medicinal plant Acrostichum aureum.

Context: Acrostichum aureumL. (Pteridaceae), a mangrove fern, has been used as a Bangladeshi traditional medicine for a variety of diseases including peptic ulcer. Objective: Isolation and structural elucidation of cytotoxic secondary metabolites from the methanol extract of the aerial parts of A. aureum. Materials and methods: Compounds were isolated using HPLC. The compound structures were elucidated by 1D and 2D NMR, MS and other spectroscopic methods using published data. The compounds were tested for their cytotoxic activity against healthy and cancer cells using the MTT assay. Active compounds were further evaluated for apoptosis–and necrosis-inducing potential against gastric cancer cells (AGS) using the FITC Annexin V apoptosis assay. Results and discussion:Seven known compounds, patriscabratine, tetracosane and 5 flavonoids (quercetin-3-O-β-d-glucoside, quercetin-3-O-β-d-glucosyl-(6→1)-α-l-rhamnoside, quercetin-3-O-α-l-rhamnoside, quercetin-3-O-α-l-rhamnosyl-7-O-β-d-glucoside and kaempferol) were isolated. Patriscabratine was found moderately cytotoxic against AGS, MDA-MB-231 and MCF-7 cells with IC50 values ranging from 69.8 to 197.3 μM. Tetracosane showed some cytotoxic activity against AGS, MDA-MB-231, HT-29 and NIH 3T3 cells with IC50 values ranging from 128.7 to >250 μM. Patriscabratine and tetracosane displayed an apoptotic effect (10%) on AGS cells within 24 h which was increased (20%) after 48 h, and was comparable to, if not greater, than the positive control, cycloheximide. Conclusion:Except for quercetin-3-O-β-d-glucoside and kaempferol; compounds were isolated for the first time from this plant and evaluated for their cytotoxic activity. The results highlight the potential of this plant as a source of bioactive compounds and provide a rationale for its traditional use in peptic ulcer treatment.