Bioactive Composition, Antioxidant Activity, and Anticancer Potential of Freeze-Dried Extracts from Defatted Gac (Momordica cochinchinensis Spreng) Seeds.

Background: Gac (Momordica cochinchinensis Spreng) seeds have long been used in traditional medicine as a remedy for numerous conditions due to a range of bioactive compounds. This study investigated the solvent extraction of compounds that could be responsible for antioxidant activity and anticancer potential. Methods: Defatted Gac seed kernel powder was extracted with different solvents: 100% water, 50% methanol:water, 70% ethanol:water, water saturated butanol, 100% methanol, and 100% ethanol. Trypsin inhibitors, saponins, phenolics, and antioxidant activity using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) assays; and anticancer potential against two melanoma cancer cell lines (MM418C1 and D24) were analysed to determine the best extraction solvents. Results: Water was best for extracting trypsin inhibitors (581.4 ± 18.5 mg trypsin/mg) and reducing the viability of MM418C1 and D24 melanoma cells (75.5 ± 1.3 and 66.9 ± 2.2%, respectively); the anticancer potential against the MM418C1 cells was highly correlated with trypsin inhibitors (r = 0.92, p < 0.05), but there was no correlation between anticancer potential and antioxidant activity. The water saturated butanol had the highest saponins (71.8 ± 4.31 mg aescin equivalents/g), phenolic compounds (20.4 ± 0.86 mg gallic acid equivalents/g), and antioxidant activity, but these measures were not related to anticancer potential. Conclusions: Water yielded a Gac seed extract, rich in trypsin inhibitors, which had high anticancer potential against two melanoma cell lines.

Functional and genetic diversity of mycorrhizal fungi from single plants of Caladenia formosa (Orchidaceae).

BACKGROUND AND AIMS: Mycorrhizal associations are essential to the plant kingdom. The largest flowering plant family, the Orchidaceae, relies on mycorrhizal fungi for germination, growth and survival. Evidence suggests varying degrees of fungal-host specificity based on a single fungal isolate from a single plant. This paper shows for the first time the diversity of endophytes colonizing in a single plant over consecutive years and the functional significance of this diversity. METHODS: Stem-collars of Caladenia formosa were collected in different seasons and years. Mycorrhizal fungi isolated were tested for their efficacy to induce leafing and genetically determined using ITS-RFLP and sequencing. RESULTS: Multiple mycorrhizal fungi were repeatedly isolated from a single collar that displayed varying effectiveness in germination percentages and adult leaf length. Additional factors contributed to the isolation of effective mycorrhizal fungi; fungal collection season, year of collection and individual isolates. Surface sterilization only improved the number of isolated mycorrhizal fungi. Dual inoculation did not increase germination. All 59 mycorrhizal fungi effective in germinating seed belonged to one clearly defined ITS (internal transcribed spacer) clade and clustered close to Sebacina vermifera (79-89 % homology). Isolates resulting in the greatest germination were not necessarily those resulting in the greatest survival and growth 1 year after germination. CONCLUSION: Single orchid plants contained multiple mycorrhizal fungal strains of one species that had diverse functional differences. These results suggest that our current knowledge of fungal-host specificity may be incomplete due to experimental and analytical limitations. It also suggests that the long-term effectiveness of a mycorrhizal fungus or fungi could only be found by germination and longer-term growth tests rather than genetically.

Effect of ultraviolet radiation on the expression of pp38MAPK and furin in human keratinocyte-derived cell lines.

BACKGROUND: Ultraviolet radiation (UVR) is known to induce the activation of stress-inflammation signal transduction pathways, and to induce the activity of many proteases in skin cells. It is unknown whether the activation of proteases such as furin is related to changes in the phosphorylation status of p38MAPK. METHODS: The effect of UVR on immortalized keratinocyte (HaCaT) and squamous cell carcinoma (Colo16) cells was investigated with respect to cell survival, phosphorylation of p38MAPK, and the proprotein convertase, furin. The cells were exposed to either a low or a high dose of UVA and/or UVB and the viability was monitored over 48 h, along with changes in the intracellular expression of p38MAPK and furin. RESULTS: Low-dose UVA (2 kJ/m(2)) and/or UVB (0.2 kJ/m(2)) radiation had no effect on cell viability, except in UVA-irradiated Colo16 cells. High UVA (20 kJ/m(2)) caused a loss of cell viability in HaCaT cells, but not in Colo16 cells. The opposite effect was seen in cells exposed to a high UVB dose (2 kJ/m(2)). The viability of both cell cultures decreased when exposed to high-dose UVA+B radiation. UV irradiation downregulated the expression of phosphorylated p38 (pp38) in HaCaT cells irrespective of the UV dose and type. In Colo16 cells, UV radiation induced pp38 expression in the cells following exposure, with the highest increase in cells exposed to high-dose UVA. The expression of furin in UV-irradiated HaCaT cells was similar to that seen for pp38 expression. In Colo16 cells, UV radiation induced furin expression, with the highest increase seen in cells 24 h after exposure to both high-dose UVB and UVA+B radiation. CONCLUSION: The results show that there are differences between the effect of UV types and doses on cell function in the keratinocyte-derived cell lines examined in this study. The level of furin expression in Colo16 cells correlated to changes in pp38 levels in the cells following exposure to UV radiation, but not in HaCaT cells. From an improved understanding of the signalling pathways and their downstream events and how these may differ as a result of tumorigenesis, it may enable the development of inhibitors, which may have therapeutic applications.