Marine algae: chemistry and potential

Seaweeds or macroalgae are valuable marine plants that have garnered much attention from the public due to their high bioactive, nutrients and minerals content. They are classified into three higher taxa, namely Chlorophyta (green seaweed), Phaeophyta (brown seaweed) and Rhodophyta (red seaweed), based on their pigmentation. Due to their the valuable nutrition and bioactive components, seaweeds have been used in multiple applications, including in cosmeceutical, nutraceutical and pharmaceutical industries as well as in fine chemical and enzymes production. The extraction of these components is influenced by various process parameters such as drying methods, solvent extraction, pH, temperature, extraction time, solid to solvent ratio etc. Thus, it is important to design the experimental to get the optimised condition to get the significant amount of the interest components. Response surface methodology (RSM) is one of the economically efficient experimental procedure for optimising this complex process. Compared to using ‘one to one factor’ method, RSM is far better since in RSM the several process variables simultaneously interact with each other. Therefore, in this presentation underlying the approach of our research on the optimisation of the extraction of valuable components in seaweeds will be discussed

In-vivo toxicity of Prophet's medicinal plant, lawsonia inermis (henna) leaves

Lawsonia inermis (henna) is always being explored solely for its scientific components, not for its usage as the Prophetic medicine. Although henna is a popular medicinal plant around the world, only scant toxicity studies have been reported about Malaysia henna and hardly any study that investigated histopathological changes of liver and kidneys of mice due to administration of henna leaves extracts. Antiurolithiatic effect of Malaysian henna in-vitro had been proven and in order to continue study the effect in-vivo, toxicity of the henna towards kidneys should be determined first. The objectives of this study are to observe acute oral toxicity effect of the hydroethanolic (75 % ethanol) extract of henna leaves on behavioural and clinical patterns of the mice and to compare the histopathological changes between control and treatment groups of the mice. Leaves were extracted using soxhlet with hydroethanolic solvent. Single oral dose of 2000 mg/kg henna leaves extracts diluted with distilled water were assigned to treatment group of mice while control group was given distilled water only. Observations were done for 14 days and the mice were sacrificed. Selected organs were taken and weighed but only livers and kidneys were taken for histological assessments. Overall, the behavioral and clinical patterns of the mice were observed to be normal. Biostatistically, all selected organs’ means weight between control and treatment groups are not statistically significant (p>0.05). Furthermore, the irregularities found were not very apparent when histopathological examinations were done. Even though there was not death occurred during the experimental period and no gross changes were observed, there were degeneration of connective tissues between the tubules of the kidneys and pyknotic nuclei within hepatocytes. In conclusion, it is scientifically proven that single dose of hydroethanolic extract of L. inermis (henna) leaves can cause toxicity towards liver and kidneys of the mice

Synergistic effects of antibiotics in combination with essential oils against pathogenic bacterial strains

The incidence of epidemics due to drug resistant bacteria had posed public health concern. Thus, a novel antibacterial approach to synergize antibiotics in combination with essential oils of selected zingiberaceae plants was chosen in this study to aid in increasing the susceptibility of bacteria. The aim was to evaluate the in vitro interaction between the essential oils and five types of antibiotics against two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and two gram-negative bacteria (Esherichia coli and Pseudomonas aeruginosa). Essential oils from rhizomes of Curcuma mangga Val., Zingiber officinale var. rubrum Thelaide and Zingiber zerumbet (L.) Smith were extracted by hydrodistillation. The antibacterial testing employed was Minimum Inhibitory Concentration (MIC) using broth microdilution method. The interaction of essential oils and antibiotics was determined by Fractional Inhibitory Concentration (FIC) using chequerboard technique. Results revealed that essential oil of Curcuma mangga Val. synergized with erythromycin and tetracycline against B. cereus, and with streptomycin against E. coli. Essential oil of Z. officinale synergized with erythromycin and tetracycline against B. cereus and E. coli. Combination with penicillin also produced synergism against E.coli. Essential oil of Z. zerumbet when combined with tetracycline acted synergistically towards S. aureus, B. cereus and P. aeruginosa. Combination with penicillin acted synergistically towards B. cereus, E. coli and P. aeruginosa. When combined with streptomycin, it synergized against S. aureus and E. coli, while with ampicillin it synergized against B. cereus. From the results, all three essential oils exhibit antibacterial properties. Z. zerumbet has the most potent antibacterial property as it produced synergistic effects towards all four types of bacteria

A new sesquiterpene from Knema patentinervia

A new widdrane sesquiterpene was isolated from Knema patentinervia by chromatographic methods. The structure was elucidated by spectroscopic methods, including 1H–1H COSY, HMQC, HMBC, and NOESY NMR experiments. The compound showed no inhibition of leukemia cancer cell growth and no inhibition towards bacterial growth of Staphylococcus aureus, Bacillus anthracis, Pseudomonas aeruginosa, and Escherichia coli

Antimicrobial and cytotoxicity activities of sterculia parviflora

In this modern world, plants and natural resources are being so significant in various pharmacological and drug research. The search for new antimicrobial and anticancer remedies is among the most prominent research fields nowadays. The aims of the present study are to evaluate the antimicrobial and cytotoxic activity of Sterculiaparviflora against the selected microorganisms and breast cancer cell line (MCF-7) respectively. S. parviflora’s leaves were extracted with n-hexane, ethyl acetate and methanol by using Soxhlet apparatus. At first, the extracts were analyzed for their phytochemical constituents such as alkaloids, flavonoids, saponins, steroids, terpenoids and phenolic. In the antimicrobial screening, the crude extracts were evaluated through disc diffusion and micro dilution methods against two Gram-positive bacteria (S. aureus and B. cereus), two Gram-negative bacteria (P. aeruginosa and E. coli) and two fungi (C. albicanand Aspergillus spp.). In disc diffusion method, the methanol extract exhibited antimicrobial potency against S. aureus and B. cereus which ranged within 8 to 10.7 mm of inhibition zone while ethyl acetate only inhibited B. cereus ranged within 14.7 to 26.3 mm. The Minimum Inhibitory Concentration (MIC) values of methanol extract against both S. aureus and B. cereus is 25 mg/mL while 50 mg/mL against B. cereus for ethyl acetate. The Minimum Bactericidal Concentration (MBC) values which indicated completely inhibition without visible growth of bacteria is at concentration of 50 mg/mL for methanol extract against both S. aureus and B. cereus while 100 mg/mL for ethyl acetate extract against B. cereus. In cytotoxicity study, MTT assay and tryphan blue exclusion methods were done to assess the percentage of viable cells of MCF-7 cell line after being treated with S. parviflora extracts. The results showed that all extracts did not exhibit significant cytotoxic effect on MCF-7 cancer cell line at concentrations of 100, 50, 25, 12.5, 6.25 and 3.125 mg/mL after 24 hours incubation. Moreover, the IC50 values of each extracts also would not be determined due to inability of extracts to reduce the viable cells percentage to be lower than 50%. In conclusion, the S. parviflora extracts exhibited potential antimicrobial activity against S. aureus and B. cereus while possessed no cytotoxic potency against MCF-7 breast cancer cell line