Abstract:Phoenix dactylifera or date palm fruits are reported to contain natural compounds that exhibit antioxidant and antibacterial properties. This research aimed to study the effect of fruit chilling at 4˝C for 8 weeks, extract storage at´20˝C for 5 weeks, and extraction solvents (methanol or acetone) on total phenolic content (TPC), antioxidant activity and antibacterial properties of Saudi Arabian P. dactylifera cv Mabroom, Safawi and Ajwa, as well as Iranian P. dactylifera cv Mariami. The storage stability of total anthocyanin content (TAC) was also evaluated, before and after storing the extracts at´20˝C and 4˝C respectively, for 5 weeks. Mariami had the highest TAC (3.18˘1.40 mg cyd 3-glu/100 g DW) while Mabroom had the lowest TAC (0.54˘0.15 mg cyd 3-glu/100 g DW). The TAC of all extracts increased after storage. The chilling of date palm fruits for 8 weeks prior to solvent extraction elevated the TPC of all date fruit extracts, except for methanolic extracts of Mabroom and Mariami. All IC 50 values of all cultivars decreased after the fruit chilling treatment. Methanol was a better solvent compared to acetone for the extraction of phenolic compounds in dates. The TPC of all cultivars extracts decreased after 5 weeks of extract storage. IC 50 values of all cultivars extracts increased after extract storage except for the methanolic extracts of Safawi and Ajwa. Different cultivars exhibited different antibacterial properties. Only the methanolic extract of Ajwa exhibited antibacterial activity against all four bacteria tested: Staphylococcus aureus, Bacillus cereus, Serratia marcescens and Escherichia coli. These results could be useful to the nutraceutical and pharmaceutical industries in the development of natural compound-based products.

Vermicompost is the product of composting or breaking down organic matter through the use of earthworms. It is rich in essential plant nutrients, and has the ability to enhance the condition and increase the quality of the soil. In the present study, a field trial was conducted from January 2015 until March 2016 to elucidate the effects of vermicompost application (compared to supplementation with chemical fertilizer and no fertilizer) on the sandy loam soil and plant nutrients of pineapple (Ananas comosus var. MD2). The morphophysiology and yield performance of MD2 pineapple grown with vermicompost in the field were also evaluated. In this study, vermicompost was applied onto the sandy loam soils during transplanting, followed by a second application at seven MAP (months after planting) at the rate of 10 t ha−1. On the other hand, the chemical fertilizer was applied based on the normal conventional cultivation practice. The soil and D-leaf samples at six MAP (S1) and during the red bud stage (S2; 10 MAP) were used to determine the soil and plant nutrient contents. The morphology of the plants was evaluated every month, and the fruits that were produced were subjected to quality analysis. Data analysis revealed that soil pH was increased after a second supplementation of vermicompost and contained significantly higher total N (0.15%) in the soils compared to the control (0.07%). There was no significant difference between plants supplied with chemical fertilizer and vermicompost in terms of plant height, number of leaves, or the length and width of D-leaves. However, different fertilization treatments were found to affect the yield and physical characteristics of the resulting fruits. Plants supplied with chemical fertilizer produced the highest fruit yield (136.97 t ha−1) with the largest fruit size, followed by vermicompost (121.39 t ha−1) and the control (94.93 t ha−1). However, fruits supplied with vermicompost were observed to have the smallest crowns. Taken together, these results indicated that the use of vermicompost produced pineapple plants with excellent growth performance, comparable to that obtained when chemical fertilizer was used. Also, based on the cost analysis conducted, it was shown that the total cost (fertilizer and labor) for plants grown with vermicompost was lower than plants grown with chemical fertilizer. However, the usage of vermicompost as the single source of nutrients is not suggested for this type of soil and field conditions, but can be used as a supplement to maintain the soil quality and ensure agricultural sustainability.

Colorectal cancer (CRC) is the most common cancer among males and females, which is associated with the increment of telomerase level and activity. Some plant-derived compounds are telomerase inhibitors that have the potential to decrease telomerase activity and/or level in various cancer cell lines. Unfortunately, a deeper understanding of the effects of telomerase inhibitor compound(s) on CRC cells is still lacking. Therefore, in this study, the aspects of telomerase inhibitors on a CRC cell line (HCT 116) were investigated. Screening on HCT 116 at 48 h showed that berberine (10.30 ± 0.89 µg/mL) is the most effective (lowest IC50 value) telomerase inhibitor compared to boldine (37.87 ± 3.12 µg/mL) and silymarin (>200 µg/mL). Further analyses exhibited that berberine treatment caused G0/G1 phase arrest at 48 h due to high cyclin D1 (CCND1) and low cyclin-dependent kinase 4 (CDK4) protein and mRNA levels, simultaneous downregulation of human telomerase reverse transcriptase (TERT) mRNA and human telomerase RNA component (TERC) levels, as well as a decrease in the TERT protein level and telomerase activity. The effect of berberine treatment on the cell cycle was time dependent as it resulted in a delayed cell cycle and doubling time by 2.18-fold. Telomerase activity and level was significantly decreased, and telomere erosion followed suit. In summary, our findings suggested that berberine could decrease telomerase activity and level of HCT 116, which in turn inhibits the proliferative ability of the cells.

This project studied the effect of vermicompost application on the composition of bioactive anthocyanin and phenolic compounds, and the antioxidant activity of Clinacanthus nutans. The correlation between the bioactive constituents and antioxidant capacity was also evaluated. In this project, a field study was conducted using a randomized complete block design (RCBD) with four treatment groups, including control plants (CC), plants supplied with chemical fertilizer (CF), plants supplied with vermicompost (VC), and plants supplied with mixed fertilizer (MF). The leaves of C. nutans from all treatment groups were harvested, subjected to solvent extraction, and used for quantification of total anthocyanin content (TAC), total phenolic content (TPC), and total flavonoid content (TFC). The initial antioxidant activity of the extracts was evaluated using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, as well as after two and four weeks of storage at −20 °C and 4 °C. Data analysis showed that CC plants contained the highest TAC (2180.14 ± 338.43 µg/g dry weight) and TFC (276.25 ± 3.09 mg QE/g dry weight). On the other hand, CF plants showed the highest TPC (181.53 ± 35.58 mg GAE/g dry weight). Moreover, we found that CC plants had the highest antioxidant potential against DPPH radicals whereas MF plants showed the lowest antioxidant potential. After four weeks of extract storage at −20 °C and 4 °C, the TPC, TFC, TAC, and antioxidant potential of the extracts decreased. Extracts from VC showed the lowest percentage of total phenolic and total flavonoid loss after extract storage at −20 °C and 4 °C compared with other plant extracts. At this juncture, it could be deduced that the application of vermicompost had little effect on the expression of phenolics, flavonoids, or anthocyanin in C. nutans. However, the extract from plants treated with vermicompost (VC and MF) showed better stability compared with CC and CF after extract storage at different temperatures.

Vermicompost is a nutrient-rich organic waste produced from earthworms that is beneficial in enhancing the soil condition and has been reported to aid in improving the crop yield and quality. In the present study, a field trial was conducted using a randomized complete block design with four replicates to elucidate the effects of vermicompost application (compared to supplementation with chemical fertilizer and no fertilizer) on the productivity of ex vitro MD2 pineapple plants. Vermicompost was applied on the sandy loam soils at transplanting followed by a second application at 7 months after planting (MAP) at the rate of 10 t·ha−1, while chemical fertilizer was applied based on the recommended cultivation practice. Data analysis revealed that there was no significant difference between the plants treated with vermicompost and chemical fertilizer in terms of the plant height, number of leaves, length and width of D-leaves, stomatal density and stomatal size. However, the fruits produced with vermicompost amendment were smaller in size but contained higher total soluble solids, titratable acidity, total solids, ascorbic acid and total chlorophyll content compared to the fruits produced from plants supplied with chemical fertilizer. Based on the DPPH, ABTS and FRAP assays, the methanolic fruit extracts from the control plants showed the highest antioxidant potential, followed by those of plants treated with vermicompost and chemical fertilizer. On the other hand, the application of vermicompost reduced soil acidity and produced macro- and micronutrient contents (N, P, K, Mg, Ca, S, Fe, Zn, B and Al) in the soil and plants that were comparable to or higher than those produced by the chemical fertilizer treatment. However, some of the nutrient contents observed in all treatments were lower than the recommended range for pineapple plant growth, suggesting that vermicompost or chemical fertilizer should not be used alone as a source of nutrients for ex vitro MD2 pineapple plants under these soil and field conditions. However, vermicompost can be used as a supplement to increase the fruit chemical quality and maintain the soil quality for agricultural sustainability.