Zuraini Zakaria

Antioxidant activity and phytochemical screening of the methanol extracts of Euphorbia hirta L

OBJECTIVE To assess antioxidant activities of different parts of Euphorbia hirta (E. hirta), and to search for new sources of safe and inexpensive antioxidants. METHODS Samples of leaves, stems, flowers and roots from E. hirta were tested for total phenolic content, and flavonoids content and in vitro antioxidant activity by diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power was measured using cyanoferrate method. RESULTS The leaves extract exhibited a maximum DPPH scavenging activity of (72.96±0.78)% followed by the flowers, roots and stems whose scavenging activities were (52.45±0.66)%, (48.59±0.97)%, and (44.42±0.94)%, respectively. The standard butylated hydroxytoluene (BHT) was (75.13±0.75)%. The IC(50) for leaves, flowers, roots, stems and BHT were 0.803, 0.972, 0.989, 1.358 and 0.794 mg/mL, respectively. The reducing power of the leaves extract was comparable with that of ascorbic acid and found to be dose dependent. Leaves extract had the highest total phenolic content [(206.17±1.95) mg GAE/g], followed by flowers, roots and stems extracts which were (117.08±3.10) mg GAE/g, (83.15±1.19) mg GAE/g, and (65.70±1.72) mg GAE/g, respectively. On the other hand, total flavonoids content also from leave had the highest value [(37.970±0.003) mg CEQ/g], followed by flowers, roots and stems extracts which were (35.200±0.002) mg CEQ/g, (24.350±0.006) mg CEQ/g, and (24.120±0.004) mg CEQ/g, respectively. HPTLC bioautography analysis of phenolic and antioxidant substance revealed phenolic compounds. Phytochemical screening of E. hirta leaf extract revealed the presence of reducing sugars, terpenoids, alkaloids, steroids, tannins, flavanoids and phenolic compounds. CONCLUSIONS These results suggeste that E. hirta have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidant agents, which can be used to treat various oxidative stress-related diseases.

Acute Oral Toxicity of Methanolic Seed Extract of Cassia fistula in Mice

Background and objective: Cassia fistula is widely used in traditional medicine to treat various types of ailments. The evaluation of toxic properties of C. fistula is crucial when considering public health protection because exposure to plant extracts can result in undesirable effects on consumers. Hence, in this study the acute oral toxicity of C. fistula seeds extract was investigated in mice. Results: Oral administration of crude extract at the highest dose of 5000 mg/kg resulted in no mortalities or evidence of adverse effects, implying that C. fistula in nontoxic. Throughout 14 days of the treatment no changes in behavioural pattern, clinical sign and body weight of mice in both control and treatment groups. Also there were no any significant elevations observed in the biochemical analysis of the blood serum. Further, histopathological examination revealed normal architecture and no significant adverse effects observed on the kidney, heart, liver, lung and spleen. Conclusions: Overall, the results suggest that, the oral administration of C. fistula methanolic seeds extract did not produce any significant toxic effect in mice. Hence, the extract can be utilized for pharmaceutical formulations.

The antimicrobial efficacy of Elaeis guineensis: characterization, in vitro and in vivo studies.

The urgent need to treat multi-drug resistant pathogenic microorganisms in chronically infected patients has given rise to the development of new antimicrobials from natural resources. We have tested Elaeis guineensis Jacq (Arecaceae) methanol extract against a variety of bacterial, fungal and yeast strains associated with infections. Our studies have demonstrated that E. guineensis exhibits excellent antimicrobial activity in vitro and in vivo against the bacterial and fungal strains tested. A marked inhibitory effect of the E. guineensis extracts was observed against C. albicans whereby E. guineensis extract at ½, 1, or 2 times the MIC significantly inhibited C. albicans growth with a noticeable drop in optical density (OD) of the bacterial culture. This finding confirmed the anticandidal activity of the extract on C. albicans. Imaging using scanning (SEM) and transmission (TEM) electron microscopy was done to determine the major alterations in the microstructure of the extract-treated C. albicans. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the yeast cells. In vivo antimicrobial activity was studied in mice that had been inoculated with C. albicans and exhibited good anticandidal activity. The authors conclude that the extract may be used as a candidate for the development of anticandidal agent.

Bioassay-Directed Isolation of Active Compounds with Antiyeast Activity from a Cassia fistula Seed Extract

Background and objective: Cassia fistula L belongs to the family Leguminosae, and it is one of the most popular herbal products in tropical countries. C. fistula seeds have been used as a herbal medicine and have pharmacological activity which includes anti-bacterial, anti-fungal, and antioxidant properties. The goal of this study was to identify compounds from C. fistula seeds which are responsible for anti-Candida albicans activity using bioassay-directed isolation. Results: The preliminary phytochemical screening of the plant seed revealed the presence of anthraquinones, flavonoids, saponins, tannins and terpenoids. The isolation of active compounds was carried out in four steps: multiple extractions, fractionation using column chromatography and purification using preparative thin-layer chromatography (TLC) and liquid chromatography/mass spectrometry (LC/MS). The structure of separated compounds was determined on the basis of mass spectrometry data. One compound was identified is roseanone. Conclusions: The MS analysis on the active fraction from seed extract of C. fistula confirmed the presence of roseanone with antiyeast activity.

Acute toxicity impacts of Euphorbia hirta L extract on behavior, organs body weight index and histopathology of organs of the mice and Artemia salina.

Background: The methanol extract of Euphorbia hirta L (Euphorbiaceae), which is used in traditional medicines, was tested for in vivo toxicity. Materials and Methods: In vivo brine shrimp lethality assay and oral acute toxicity study at single high dose of 5000 mg/kg and observation for 14 days in mice were used to study the toxic effect of E. hirta. Results: Brine shrimp lethality assay was used to calculate the median lethal concentration (LC50) of E. hirta (for leaves, stems, flowers and roots) methanolic extracts at concentrations from 100 to 0.07 mg/ml. The LC50 values of 1.589, 1.420, 0.206 and 0.0827 mg/ml were obtained for stems, leaves, flowers and roots, respectively. Potassium dichromate (the positive control) had LC50 value of 0.00758 mg/ml. The acute oral toxicity study of the leaf extract resulted in one third mortality and mild behavioral changes among the treated mice. No significant statistical differences found between body weight, relative (%) and absolute (g) organ weights of treated and untreated groups (P> 0.05). Gross and microscopic examination of the vital organ tissues revealed no differences between control and treated mice. All the tissues appeared normal. Conclusions: E. hirta leaves methanol extract has exhibited mild toxic effects in mice.

In vitro and in vivo antifungal activity of Cassia surattensis flower against Aspergillus niger

Invasive aspergillosis (IA) in immunocompromised host is a major infectious disease leading to reduce the survival rate of world population. Aspergillus niger is a causative agent causing IA. Cassia surattensis plant is commonly used in rural areas to treat various types of disease. C. surattensis flower extract was evaluated against the systemic aspergillosis model in this study. Qualitative measurement of fungal burden suggested a reduction pattern in the colony forming unit (CFU) of lung, liver, spleen and kidney for the extract treated group. Galactomannan assay assessment showed a decrease of fungal load in the treatment and positive control group with galactomannan index (GMI) value of 1.27 and 0.25 on day 28 but the negative control group showed high level of galactomannan in the serum with GMI value of 3.58. Histopathology examinations of the tissues featured major architecture modifications in the tissues of negative control group. Tissue reparation and recovery from infection were detected in extract treated and positive control group. Time killing fungicidal study of A. niger revealed dependence of the concentration of C. surattensis flower extract.

Students’ awareness and attitudes toward archaeological conservation: Bujang Valley

Purpose Like other components of cultural heritage, the preservation of archaeological sites is important because they constitute a unique and irreplaceable legacy, something that has been received from the ancestors and that should be passed on to future generations. The purpose of this paper is to explore how well secondary school students in Bujang Valley, Malaysia, understand the concept and value of archaeology and to what extent they are interested in archaeology. Design/methodology/approach A questionnaire survey was administered to 110 students, aged 14 and 15 years, from secondary schools in the Bujang Valley area. Findings The results showed that most of the students were interested in archaeology and had a moderately accurate understanding of what archaeology entailed. Their main information sources included museum visits and participating in local archaeological projects. Participants demonstrated a sense of archaeological responsibility in objecting to the illegal trafficking of artefacts. Practical implications Moreover, these findings have significant implications for heritage and education authorities in the Bujang Valley in terms of planning for educational programmes to raising the awareness of local communities. Originality/value These findings expand upon the knowledge of students’ attitudes towards archaeology.

Developing and Evaluating Rapid E-learning Mathematics Materials for Distance Learners

Rapid e-learning authoring tool has made the development of e-learning materials much easier for teachers. This exploratory study was design to evaluate Mathematics e-learning material developed using Articulate Presenter. Using Keller’s Model of Motivation, a questionnaire was designed and distributed to 20 respondents. The Mean analysis was carried out to assess the respondents’ perception of Mathematics e-learning materials. This study suggests that respondents perceived Mathematics e-learning materials create confident in learning. The practical implications of these findings were discussed.

Adaptation of Candida albicans for Growth Within the Host

One of the most important attributes of microorganisms is their ability to biologically adapt to every environment on earth. Microorganisms possess sophisticated signaling systems that enable them to sense and respond to environmental changes and challenges. Typically, this response results in morphological, physiological and even genetic differentiations. The genetic information associated with a microbe is capable of alterations which are sometimes reversible, and disappearing when the particular pressure is lifted. Other alterations are maintained and can even be passed on to succeeding generations of bacteria. This fact may well indicate that the structure can be modified to maintain function under environmental stress. Candida albicans, commonly found as a component of the normal flora of humans, residing in the gastrointestinal tract, in the genitourinary tract and on the skin, is the most common opportunistic human pathogen. The yeast is a harmless commensal in most healthy people, but it causes superficial as well as life-threatening systemic infections in immunocompromised patients. The ability of C. albicans to be virulent depends completely on its yeast-to-hyphae switch where the organism changes from a unicellular yeast form to a multicellular hyphal form. This switch may likely be induced by environmental conditions like temperature, pH and nutrients. This chapter presents the regulatory adaptation mechanisms that make C. albicans the most successful fungal pathogen of humans.