Anti-infective activities of 11 plants species used in traditional medicine in Malaysia.

Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC50 < 50 µg/mL. Extracts of U. grandiflora, C. costatus, T. peduncularis, L. eugenifolius, A. subulatum, and C. aeruginosa had good activities against P. falciparum K1 with IC50 < 10 µg/mL. Pinoresinol isolated from C. costatus was inactive against L. donovani and P. falciparum. C. costatus extract and pinoresinol increased the sensitivity of Staphylococcus epidermidis to cefotaxime. Pinoresinol demonstrated moderate activity against influenza virus (IC50 = 30.4 ±â€¯11 µg/mL) and was active against Coxsackie virus B3 (IC50 = 7.1 ±â€¯3.0 µg/mL). ß-Amyrin from L. eugenifolius inhibited L. donovani with IC50 value of 15.4 ±â€¯0.01 µM. Furanodienone from C. aeruginosa inhibited L. donovani and P. falciparum K1 with IC50 value of 39.5 ±â€¯0.2 and 17.0 ±â€¯0.05 µM, respectively. Furanodienone also inhibited the replication of influenza and Coxsackie virus B3 with IC50 value of 4.0 ±â€¯0.5 and 7.2 ±â€¯1.4 µg/mL (Ribavirin: IC50: 15.6 ±â€¯2.0 µg/mL), respectively. Our study provides evidence that medicinal plants in Malaysia have potentials as a source of chemotypes for the development of anti-infective leads.

Antibacterial effects of ellagitannins from Acalypha wilkesiana var. macafeana hort.: surface morphology analysis with environmental scanning electron microscopy and synergy with antibiotics.

The present study served to gain further insight into the bactericidal effects of ellagitannins from Acalypha wilkesiana var. macafeana hort. against pathogenic bacteria. Ellagitannins from the aerial parts of A. wilkesiana var. macafeana hort. (EAW) inhibited the growth of Bacillus cereus (ATCC 11778), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 11632) and Methicillin-resistant Staphylococcus aureus (MRSA) clinical strain with inhibition zones equal to 11.01 ± 1.53 mm, 16.63 ± 0.11 mm, 11.40 ± 1.10 mm and 8.22 ± 0.19 mm, respectively. The minimal inhibition concentration and the minimal bactericidal concentration of ellagitannins from A. wilkesiana var. macafeana hort. (EAW) against MRSA were 750 µg/mL and 3000 µg/mL, respectively. We then examined the synergistic effect of EAW with three antibiotics, i.e. ampicillin, streptomycin and tetracycline, via the checkerboard assay and time-kill assay and observed that EAW is synergistic with ampicillin against S. aureus (ATCC 11632). Environmental electron scanning microscopy analysis showed cell lysis against S. aureus (ATCC 11632) upon treatment with the ellagitannin fraction. The ellagitannin fraction from A. wilkesiana var. macafeana hort. is bactericidal against gram-positive bacteria tested and works synergistically with ampicillin against S. aureus. Morphology analysis of the cell suggests that the bactericidal property of the ellagitannin fraction mechanism involves lysis of the cell wall. In summary, our studies demonstrate that A. wilkesiana var. macafeana hort. produces bactericidal ellagitannins of clinical and/or cosmetological value.

In vitro 5-LOX inhibitory and antioxidant activities of extracts and compounds from the aerial parts of Lopholaena coriifolia (Sond.) E. Phillips & C.A. Sm.

The aim of this study was to investigate the antioxidant and anti-inflammatory potentials of crude extracts of Lopholaena coriifolia (Sond.) E. Phillips & C.A. Sm. and its isolated compounds. Separation and structure elucidation of Lopholaena coriifolia (Sond.) E. Phillips & C.A. Sm. were conducted using chromatographic and spectroscopic method. The antioxidant activities of the extracts in this study were determined by the ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ß-carotene bleaching assays meanwhile the anti-inflammatory activity was evaluated using the 5-lipoxygenase assay. Seven known compounds quercetin 3-O-glucoside (1), naringenin 7-O-glucoside (2), seneciphylline-O-glucoside (3), chrysoeriol (4), retrorsine (5), adonifiline (6) and 5,4'-di-O-methyl alpinumisoflavone (7) were isolated from ethanol extract of Lopholaena coriifolia (Sond.) E. Phillips & C.A. Sm. The ethanol and water extracts of Lopholaena coriifolia (Sond.) E. Phillips & C.A. Sm. elicited potent antioxidant and anti-inflammatory properties. Amongst the isolated compounds quercetin 3-O-glucoside gave strong antioxidant activity and adonifiline strongly inhibited 5-lipoxygenase activity.

Antibacterial and antioxidant activities of Synedrella nodiflora (L.) Gaertn. (Asteraceae).

The hexane, ethyl acetate, ethanol and water extracts of Synedrella nodiflora (L.) Gaertn. (Asteraceae) were assessed for their antibacterial and antioxidant capacities. The antioxidant capacities were evaluated using the ferric reducing antioxidant power (FRAP) and ß-carotene bleaching assays. The antimicrobial activities were assessed using the classical pour-plate disc diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and death kinetic assays, against six bacterial strains. The ethanol extract displayed significant antioxidant capacities both in the FRAP and ß-carotene bleaching assays. The ethanol extract abrogated the growth of all the bacteria tested. Folin-Ciocalteu and aluminium chloride spectrometry assays indicated the presence phenolic compounds, including flavonoids in the ethanol extract.