Tanzima Yeasmin

Antimicrobial activities of the rhizome extract of Zingiber zerumbet Linn.

OBJECTIVE To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet (Z. zerumbet) (L.) Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi. METHODS The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol (4.0 L) after concentration. The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract (15.0 g), petroleum ether fraction (6.6 g) and chloroform soluble fraction (5.0 g). The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method. Commercially available kanamycin (30 µg/disc) was used as standard disc and blank discs impregnated with the respective solvents were used as negative control. RESULTS At a concentration of 400 µg/disc, all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm. Among the tested samples, the crude ethanol extract showed the highest activity against Vibrio parahemolyticus (V. parahemolyticus). The minimum inhibitory concentration (MIC) of the crude ethanol extract and its fractions were within the value of 128-256 µg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V. parahemolyticus (128 µg/mL). CONCLUSIONS It can be concluded that, potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z. zerumbet (L).

Interaction between chronic arsenic exposure via drinking water and plasma lactate dehydrogenase activity.

Arsenic is a potent environmental pollutant that has caused one of the largest public health poisonings in the history of human civilization, affecting tens of millions of people worldwide especially in Bangladesh. Lactate dehydrogenase (LDH) in blood plays an important role in predicting cell or organ damage and as an important clue to the diagnosis of a variety of cancers. However, effect of chronic arsenic exposure on the LDH level in blood has not yet been documented. Since the chronic arsenic exposure is associated with organ damages and multi-site cancers, this research aimed at assaying the plasma level of LDH activity in the population who were exposed to arsenic chronically in Bangladesh. A total of 185 individuals living in arsenic-exposed areas and 121 individuals living in non-exposed area in Bangladesh were recruited as study subjects. Arsenic content in drinking water, hair and nails were estimated by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) and LDH activity was assayed by a spectrophotometer. Significant increase in LDH activity was observed with increasing concentrations of arsenic in water, hair and nails. Further, the study subjects were split into four groups based on the three ways of each exposure metrics (water, hair and nail arsenic concentrations) where the study subjects in the non-exposed area were used as a reference (lowest exposure) group. LDH activity was found to be increased in the higher exposure groups of water and hair arsenic concentrations. LDH activity was also increased at low to medium exposure groups of nail arsenic concentrations.Thus, the elevated plasma LDH activity might be helpful for the early prognosis of organ or tissue damage in the individuals who were exposed to arsenic chronically.

Cytotoxicity of the rhizome of medicinal plants.

OBJECTIVE To investigate the cytotoxicity of the crude ethanol extract of the rhizome of Zingiber zerumbet (Z. zerumbet) (L) Smith. and Curcuma zedoaria (C. zedoaria) Rosc. against Artemia salina Leach. METHODS Fresh rhizomes of Z. zerumbet (L) Smith. and C. zedoaria Rosc. were extracted separately in cold with ethanol (2.5 L) and after concentration a brownish syrupy suspension of ethanol extracts of Z. zerumbet (L) Smith. and C. zedoaria Rosc. was obtained. The cytotoxic effect of the crude ethanol extracts of both plants was determined by brine shrimp lethality bioassay. RESULTS Crude ethanol extracts of the rhizome of Z. zerumbet (L) Smith. showed the highest cytotoxicity (LC50 was 1.24 µg/mL) against brine shrimp nauplii as compared with C. zedoaria Rosc. (LC50 was 33.593 µg/mL) after 24 h of exposure. CONCLUSIONS It can be concluded that the rhizome of Z. zerumbet (L) Smith. and C. zedoaria Rosc. can be used as a source of cytotoxic agent.

Mosquitocidal triterpenes from the stem of Duranta repens

Two triterpenes, β-amyrin and 12-oleanene 3β, 21β-diol, were isolated as a mixture from the chloroform soluble fraction of an ethanol extract of Duranta repens Linn (Verbenaceae) stem. The structures of the two compounds were confirmed by analysis of their IR, 1H-NMR, 13C-NMR and LC-MS spectral data. The mixture of β-amyrin and 12-oleanene 3β, 21β-diol (compound 1) was highly effective against the larvae of the mosquito, Culex quinquefasciatus Say (Diptera: Culicidae), as a mosquitocide.

Preventive effect of ethanol extract of Alpinia calcarata Rosc on Ehrlich ' s ascitic carcinoma cell induced malignant ascites in mice

OBJECTIVE To explore cytotoxic activity of ethanol extract of Alpinia calcarata Rosc (EEAC) rhizome against Ehrlich ascites carcinoma (EAC) tumor bearing Swiss Albino mice. METHODS In the present study, its anti-neoplastic activity has been studied by monitoring parameters like tumor weight measurement, survival time, tumor cell growth inhibition, haematological characteristics etc. RESULTS It was found that EEAC at dose 8 mg/kg/day (i.p.) significantly decreased tumor weight (62.0%; P <0.01), increased life span (70.25%; P <0.01) and reduced tumor cell growth rate (85.7%; P <0.01) in comparison to those of EAC bearing mice. The plant extract also improved the depleted haematological parameters like RBC, WBC, Hb%, differential counts (e.g. lymphocytes, neutrophils, monocytes etc) of EAC bearing mice towards normal. The host toxic effects were not very high and recovered gradually towards normal within a few days after treatment. CONCLUSIONS EEAC exhibits potent in vivo cytotoxic activity against EAC tumor bearing Swiss Albino mice. So, the plant can be considered as a probable new source of antitumor agents.