Cytotoxic and Antibacterial Evaluation of Coumarins and Chromanone Acid from Calophyllum symingtonianum.

Calophyllum symingtonianum is a rare species from the Calophyllum genus that belongs to the Guttiferae family. Calophyllum has been recognized as a potential medicinal plant due to its many bioactive phytochemicals especially coumarins and chromanone acids. In this study, the cytotoxic activities against MCF-7 and A-549 and antibacterial activities towards S. aureus, B. subtilis, P. aeruginosa and E. Coli of three coumarins known as inophyllum D, inophyllum H and calanone as well as chromanone acid identified as isocordato-oblongic acid isolated from this plant were evaluated. Inophyllum H exhibited the highest IC50 values against MCF-7 at 25.56 μg/mL and A-549 at 26.41μg/mL. Isocordato-oblongic acid showed moderate antibacterial activity against S. aureus and B. subtilis at 125μg/mL and 62.5μg/mL, respectively. This study suggests C. symingtonianum as a potential plant for cytotoxic and antibacterial phytochemicals.

Isolation and Identification of Potential Antineoplastic Bioactive Phenolic Compounds in Malaysian Honeys.

The role of honeys as chemopreventive agents was inferred from their phenolic composition. The present study aims to isolate and identify such phenolic compounds with anticarcinogenic potential from the sugar matrix of Malaysian honeys. Phenolic compounds in Malaysian Acacia, Gelam and Tualang honey samples were isolated using octadecyl (C18) silica solid phase extraction (SPE) technique and identification was performed using high-performance liquid chromatography (HPLC) with diode array detector (DAD). Identification of phenolic compounds was achieved by comparing chromatographic retention times of honey samples with those of authentic standard compounds. HPLC analysis confirmed the presence of anticancer phenolic compounds in all honey samples with considerable variation observed among both different and the same types of honey. Six flavonoids (quercetin, naringenin, kaempferol, rutin, hesperetin, and apigenin), two phenolic acids (p-coumaric acid, and ferulic acid) and two tannins (ellagic acid, and penta-O-galloyl-β-D-glucose [PGG]) were the bioactive anticancer compounds identified. The presence of PGG in Malaysian honey was described for the first time. This study concludes that these three types of Malaysian honey possessed anticancer properties at varying degrees. Their potential usage as natural anticancer therapeutic agents with numerous health benefits could be further explored and considered as an alternative for current anticancer drugs.

Antibacterial properties of Persicaria minor (Huds.) ethanolic and aqueous-ethanolic leaf extracts.

Persicaria minor known as small water-pepper is used traditionally for the treatment of dandruffs and stomach indigestion. Therefore, this study was designed to evaluate the antibacterial activity of plant leaf material. 30% aqueous-ethanol and 100% aqueous were used for solvent extraction. Both extracts were evaluated for total protein and polysaccharide contents and results were compared. The extracts were then tested against four strains of bacteria; Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 11229, Staphylococcus aureus ATCC 6538and Pseudomonas aeruginosa ATCC 1544,at different concentrations using disc-diffusion and microplate dilution assays with penicillin being used as a positive control standard. Both extracts showed antibacterial activity against S. aureus, E. faecalis, and E. coli, respectively with aqueous-ethanolic extract being more potent. However, none of the extracts were active against P. aeruginosa. Results from this study truly illustrated high potential of P. minor leaves to be used topically as antibacterial agent for controlling of tested colony.

Antioxidant and tyrosinase inhibition activities of α- mangostin and Garcinia mangostana Linn. pericarp extracts.

The methanol, ethyl acetate and petroleum ether crude extracts of mangosteen pericarp and α- mangostin were evaluated for the antioxidant capacity and tyrosinase inhibition properties. The ferric reducing antioxidant power (FRAP) assay was used to investigate their antioxidant capacity. Tyrosinase inhibition effect was evaluated using mushroom tyrosinase inhibition assay. Methanol extract has higher antioxidant reducing capacity (m= 1.621), compared to the rest of the extracts. Meanwhile, ethyl acetate extract and α- mangostin showed potent tyrosinase inhibition activities as compared to Kojic acid, a well- known tyrosinase inhibitor. It is observed that tyrosinase inhibition effect is antioxidant independent as ethyl acetate extract possessed low antioxidant capacity. This study suggests direct tyrosinase inhibition by ethyl acetate extract of Garcinia mangostana.

Antioxidant and tyrosinase inhibition activities of Eurycoma longifolia and Swietenia macrophylla.

Extract from plants have been reported to contain valuable bioactive compounds that have potential in promoting antioxidant activity. The present study was aimed to investigate the extracts of two plants available in Southeast Asia, Eurycoma longifolia and Swietenia macrophylla for their primary metabolite contents, phenolic contents, antioxidant and anti- tyrosinase activity. Two types of solvents were utilised in the extraction process of both plants. Ethyl acetate found to be a better solvent for isolation of primary metabolite compound compared to methanol. For Folin-Ciocalteu assay, methanol extract of Swietenia macrophylla possed higher phenolic content while for Eurycoma longifolia, ethyl acetate extract had higher phenolic content. In DPPH assay, the radical scavenging activity of extracts were strongly correlated to the total phenolic content based on the percentage of DPPH radical scavenging of each extracts (p<0.05). In tyrosinase inhibition assay, the activity of each extracts were very low compared to standard Kojic acid. It was assumed that, the ability of plant extracts to inhibit tyrosinase are partly contributed by antioxidant potential of the extracts (p<0.01).

Cytotoxic effect of Annona muricata Linn leaves extract on Capan-1 cells.

Annona muricata Linn has been reported to contain valuable bioactive compounds known as Annonaceous acetogenins.Theselong chain fatty acids were widely discussed for its potential in promoting anticancer and antiproliferative activity in various cancer cell lines. However, little study has been done on A. muricata effect in pancreatic cancer cells. In this study, the viability of Capan-1 after treatment with A. muricata extracts was determined by using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results displayed that only hexane and commercialized extract inhibited cell proliferation in a concentration-dependent manner with IC25 varied ~7.8-8μg/ml and ~0.9-1.0μg/ml respectively. The data demonstrate that A. muricata hexane and commercialized extracts induced mild cytotoxicity in pancreatic cancer cells (Capan-1).