Hedera rhombea inhibits the biofilm formation of Candida, thereby increases the susceptibility to antifungal agent, and reduces infection

Candida is an opportunistic pathogen and a common cause of fungal infections worldwide. Anti-fungal use against Candida infections has resulted in the appearance of resistant strains. The limited choice of anti-fungal therapy means alternative strategies are needed to control fungal infectious diseases. The aim of this study was to evaluate the inhibition of Candida biofilm formation by Hedera rhombea (Korean name: songak) extract. Biofilm formation was assessed using the crystal violet assay which showed a dose dependent reduction in the presence of extract with the biofilm formation inhibitory concentration of C. albicans (IC50 = 12.5μg/ml), C. tropicalis var. tropicalis (IC50 = 25μg/ml), C. parapsilosis var. parapsilosis (IC50 = 6.25μg/ml), C. glabrata (IC50 = 6.25μg/ml), C. tropicalis (IC50 = 12.5μg/ml), and C. parapsilosis (IC50 = 12.5μg/ml) without directly reducing Candida growth. Treatment with 6.25μg/mL of extract increased the antifungal susceptibility to miconazole from 32% decreasing of fungal growth to 98.8% of that based on the fungal growth assay. Treatment of extract dose-dependently reduced the dimorphic transition of Candida based on the dimorphic transition assay and treatment of 3.125μg/mL of extract completely blocked the adherence of Candida to the HaCaT cells. To know the molecular mechanisms of biofilm formation inhibition by extract, qRT-PCR analysis was done, and the extract was found to dose dependently reduce the expression of hyphal-associated genes (ALS3, ECE1, HWP1, PGA50, and PBR1), extracellular matrix genes (GSC1, ZAP1, ADH5, and CSH1), Ras1-cAMP-PKA pathway genes (CYR1, EFG1, and RAS1), Cph2-Tec1 pathway gene (TEC1) and MAP kinases pathway gene (HST7). In this study, Hedera rhombea extract showed inhibition of fungal biofilm formation, activation of antifungal susceptibility, and reduction of infection. These results suggest that fungal biofilm formation is good screen for developing the antifungal adjuvant and Hedera rhombea extract should be a good candidate against biofilm-related fungal infection.

Discoveries of the genera Baeochila and Idiocysta from Japan, with descriptions of two new species (Hemiptera: Heteroptera: Tingidae)

Two lace bug genera, Baeochila Drake & Poor, 1937 and Idiocysta China, 1930 (Hemiptera: Heteroptera: Tingidae) are recorded from Japan for the first time, and two new species, B. horvathi sp. nov. and I. takarai sp. nov., are described. The former was collected from the vines of Hedera rhombea (Miq.) Bean (Araliaceae) and the bark of Trachycarpus fortunei (Hook.) H.Wendl. (Arecaceae) in suburbanized areas of Honshu, Shikoku and Kyushu, and the latter was collected from the leaves of Freycinetia formosana Hemsl. (Pandanaceae) in the laurilignosa ecosystem of the Ryukyu Islands. The distribution ranges and host plant relationships of the two new species are discussed. Keys to all species of the two genera and photographs of living individuals for the new species are also presented.