Z. Zuraini

Assessment of Euphorbia hirta L. Leaf, Flower, Stem and Root Extracts for Their Antibacterial and Antifungal Activity and Brine Shrimp Lethality

The antimicrobial activities of the methanolic extracts of Euphorbia hirta Lleaves, flowers, stems and roots were evaluated against some medically important bacteria and yeast using the agar disc diffusion method. Four Gram positive (Staphylococcus aureus, Micrococcus sp., Bacillus subtilis and Bacillus thuringensis), four Gram negative (Escherichia coli, Klebsiella pneumonia, Salmonella typhi and P. mirabilis) and one yeast (Candida albicans) species were screened. Inhibition zones ranged between 16–29 mm. Leaves extract inhibited the growth of all tested microorganisms with large zones of inhibition, followed by that of flowers, which also inhibited all the bacteria except C. albicans. The most susceptible microbes to all extracts were S. aureus and Micrococcus sp. Root extract displayed larger inhibition zones against Gram positive bacteria than Gram negative bacteria and had larger inhibition zones compared to stem extract. The lowest MIC values were obtained with E. coli and C. albicans (3.12 mg/mL), followed by S. aureus (12.50 mg/mL) and P. mirabilis (50.00 mg/mL). All the other bacteria had MIC values of 100.00 mg/mL. Scanning Electron Microscopic (SEM) studies revealed that the cells exposed to leaf extract displayed a rough surface with multiple blends and invaginations which increased with increasing time of treatment, and cells exposed to leaf extract for 36 h showed the most damage, with abundant surface cracks which may be related to final cell collapse and loss of function. Time-kill assay of C. albicans indicated a primarily fungicidal effect at 1- and 2-fold MIC. E. hirta extracts had LC50 values of 0.71, 0.66, 0.41 and 0.03 mg/mL for stems, leaves, roots and flowers, respectively against Artemia salina. Hence, these plants can be used to discover new bioactive natural products that may serve as leads in the development of new pharmaceuticals.

In situ TEM and SEM studies on the antimicrobial activity and prevention of Candida albicans biofilm by Cassia spectabilis extract

The inhibitory effect of Cassia spectabilis methanol leaf extract was evaluated against biofilm forming Candida albicans, which was sensitive to 6.25 mg/ml concentration of the extract. Transmission (TEM) and scanning electron microscope (SEM) observations were used to study the anticandidal activity and prevention of biofilm formation by the C. spectabilis extract. SEM analysis further revealed reduction in C. albicans biofilm in response to the extract. The main abnormalities noted via TEM study was the alterations in morphology and complete collapse of the yeast cells after 36 h of exposure to the extract. The significant antifungal activity shown by this methanol extract of C. spectabilis suggests its potential against infections caused by C. albicans.

Pharmacological activity, phytochemical analysis and toxicity of methanol extract of Etlingera elatior (torch ginger) flowers.

Abstract Objective To elucidate its pharmacological activities and medicinal potential of extract of Etlingera elatior ( E. elatior ). Methods Phytochemical screening of the flower extract was done to determine the phytochemical in the extract. The pharmacological study included the determination of antimicrobial activity and minimum inhibitory concentration (MIC) of metabolic flower extract. The antimicrobial activity of the extract was tested against medically important bacterial, yeast and fungal strains. Apart from that, the methanolic extract of E. elatior flower was further tested in vivo toxicity using the brine shrimp lethality test. Moreover, the flower extract was qualitatively screened for their free radical scavenging activity by 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. Results The extract was effective on tested microorganisms and MIC values were in the range of 1.563-50.000 mg/mL. The brine shrimp lethality test exhibited no significant toxicity (LC 50 = 2.52 mg/mL) against Artemia salina . The E. elatior flower extract with high LC 50 value signified that this plant is not toxic to humans. While the phytochemical screening of the flower extract revealed the presence of the following compounds: flavonoids, terpenoids, saponin, tannins and carbohydrates whereas, alkaloids, anthraquinone and reducing sugars were absent. The concentration of the flower extract required for 50% inhibition of DPPH radical scavenging effect (IC 50 ) were 9.14 mg/mL and 8.08 mg/mL for butylated hydroxytoluene 8.08 mg/mL. Conclusions These findings indicate that the extract of E. elatior flower possesses pharmacological properties and potential to develop natural products based pharmaceuticals products.

A transmission electron microscopy study of the diversity of Candida albicans cells induced by Euphorbia hirta L. leaf extract in vitro.

OBJECTIVE To determine the major changes in the microstructure of Candida albicans (C. albicans) after treatment with Euphorbia hirta (E. hirta) L. leaf extract. METHODS Transmission electron microscopy was used to study the ultrastructural changes caused by E. hirta extract on C. albicans cells at various exposure time. RESULTS It was found that the main abnormalities were the alterations in morphology, lysis and complete collapse of the yeast cells after 36 h of exposure to the extract. Whereas the control cultures showed a typical morphology of Candida with a uniform central density, typically structured nucleus, and a cytoplasm with several elements of endomembrane system and enveloped by a regular, intact cell wall. CONCLUSIONS The significant antifungal activity shown by this methanol extract of E. hirta L. suggests its potential against infections caused by C. albicans. The extract may be developed as an anticandidal agent.

Fungicidal Effect and Oral Acute Toxicity of Psophocarpus tetragonolobus. Root Extract

Abstract The methanol extract of Psophocarpus tetragonolobus. (L.) DC (Leguminosae) root was screened for antimicrobial activity against Candida albicans. (Berkhout). The extract showed a favorable antimicrobial activity against C. albicans. with a minimum inhibitory concentration (MIC) value of 3.13 mg/mL. Apart from the fungicidal effects, imaging using scanning electron microscopy (SEM) was done to determine the major alterations in the microstructure of C. albicans.. The main abnormalities noted via SEM studies were the alterations in morphology and complete collapse of the yeast cells after 36 h of exposure to the extract. The effect of the extract on the growth profile of the yeast was also examined. It changed the normal growth profile of C. albicans., thus confirming the fungicidal effect of the extract on C. albicans.. In an acute toxicity study using rats, death was not observed, so the acute minimum fatal dose of the extract was greater than 2000 mg/kg, and we found no pathologic changes in macroscopic examination by necropsy of rats treated with extract. We conclude that the extract may be safely used as an antimicrobial agent.

Antibacterial Activity and Toxicity of Psophocarpus tetragonolobus.

Abstract A methanol extract of the Psophocarpus tetragonolobus. (L.) DC (Leguminosae) leaves was screened for antimicrobial activity against Pseudomonas aeruginosa.. Antimicrobial tests were carried out using the disk diffusion assay and broth dilution method against Pseudomonas aeruginosa.. The extract showed favorable antimicrobial activity against Pseudomonas aeruginosa. with a minimum inhibitory concentration (MIC) value of 2.55 mg/mL. Apart from the antibacterial effects, imaging using scanning electron microscopy (SEM) was done to determine the major alterations in the microstructure of the Pseudomonas aeruginosa.. The main abnormalities noted via SEM studies were alterations in morphology and complete collapse of the bacterial cells after 36 h of exposure to the extract. The effect of the extract on the growth profile of the bacteria was also examined. The extract changed the normal growth profile of Pseudomonas aeruginosa., thus confirming the bactericidal effect of the extract on Pseudomonas aeruginosa.. Furthermore, the extract was also tested against brine shrimp for toxicity. The extract exhibited no significant toxicity (LC50 = 1.30 mg/mL) against Artemia salina. L. (Artemiidae).

Antimicrobial activities of Psophocarpus tetragonolobus (L.) DC extracts.

Consecutive chloroform, ethanol, and ethyl acetate partitions of extracts from winged bean [Psophocarpus tetragonolobus (L.) DC] root, stem, leaf, and pod extracts were tested for their antimicrobial activity against 19 microbial species, including 11 bacterial pathogens, four yeasts, and four molds using the disk diffusion assay technique. The pod extract was found to be most effective against all of the tested organisms, followed by the stem, root, and leaf extracts, and the ethanol fraction showed the most significant (p < 0.05) antimicrobial activity against all of the tests among three soluble fractions of extract, followed by the ethyl acetate and chloroform fractions. The minimum inhibitory concentrations (MICs) of extracts determined by the broth dilution method ranged from 1.25 to 10.0 mg/mL. The MIC of ethanol fraction of pod extracts was the lowest by comparison with the other two extracts. The MIC for fungi was at or below 2.5 mg/mL and for bacteria was at or above 2.5 mg/mL.