This study aimed to explore the changes in morphological, physiological and biochemical characteristics of lettuce (Lactuca sativa L.) in response to salt stress when grown using hydroponic techniques. The seedlings were subjected to five different concentrations (0 mM, 50 mM, 100 mM, 150 mM, and 200 mM) of NaCl for three weeks. During the salt stress, morphological properties (shoot length, root length, total plant weight, leaf number) were measured in every week. After 21 days of salt stress, physiological properties (water content and relative water content) and biochemical properties (proline, protein, phenol, reducing and non-reducing sugar content) were measured. Morphological and physiological properties were found decreased gradually with increasing salt concentrations. Biochemical properties such as proline and protein content increased remarkably, and total phenol content decreased gradually with increasing salt concentrations. Reducing sugar accumulation was higher in all treatments except 50 mM in comparison to control. Non-reducing sugar accumulation was decreased in 100 mM and 200 mM treatment, similar in 150 mM treatment, and increased in 50 mM treatment when compared to control. These findings render lettuce a salt-sensitive plant at higher salt concentration. However, changes in characteristics were realistic up to 50 mM salt concentration.

No abstract

Background Bixa orellana L. is a plant native to Brazil but grows in other parts of the world including Bangladesh. This plant has been used for many years by indigenous people around the globe for a variety of applications. In Bangladesh, it is known as Doigota and the plant is underutilized and reported endangered. The present study aimed to perform comparative profiling where aqueous, ethanolic, and methanolic extracts of the seed, branch, and leaf of B. orellana plants were investigated for in vitro phytochemicals, antioxidant, and antibacterial activities. Results Phytochemical screening indicated the presence of nine different phytochemicals in varying degrees, which suggests the chemical diversity of this plant. Quantification of phenolics, flavonoids, and tannins was performed where leaf extracts contained significantly higher quantities of these phytochemicals than extracts from seed and branch. The highest phenolics (186.02 mg/g) were found in the methanolic extract of the leaf, whereas the highest flavonoids (61.01 mg/g) and tannins (36.74 mg/g) were found in aqueous extract of the leaf. Antioxidant activity has been evaluated by DPPH scavenging assay where the aqueous extract of leaf showed 93.62% scavenging activity at 800 μg/mL extract concentration. Although the extracts prevented the growth of both Gram-positive and Gram-negative bacteria, the antibacterial activity (zone of inhibition) of aqueous and methanolic extracts of the leaves were higher than those of the seed and branch extracts against Gram-negative (Escherichia coli) and Gram-positive (Bacillus subtilis) bacteria, respectively. Conclusions We found that B. orellana leaf extracts possess the highest antibacterial activities. The extracts had significant antioxidant and free radical-scavenging activities. The antioxidant and antibacterial activities could be attributed to high flavonoid and phenolic contents. These results suggest that the extracts of B. orellana possess bioactive compounds that could be used for different purposes such as source of new antibiotics or alternative natural preservatives in food matrices due to mainly their antioxidant and antibacterial activities.

Tomato (Solanum lycopersicum L.) is a widely cultivated vegetable crop worldwide and its consumption is increasing day by day. The only edible part of tomato plant is its fruit. Therefore, the residual tomato plant parts are considered as waste after fruit collection despite some portion of it is used as livestock feed and in the production of fertilizer. Moreover, due to the consumption issue, much of the research is focused on tomato fruit rather than other plant parts. Bioactive compounds can be present in any part of the plant and can be isolated and recovered. Therefore, tomato plant may be useful as a source of bioactive compounds. Our study focuses on the phytochemical constituents and bioactive compounds that are present in different parts of the tomato plant that were being less studied before. Qualitative phytochemical tests were performed to identify the presence of different bioactive compounds. Saponins, tannins, glycosides, phenols, alkaloids, flavonoids and resins are present in significant amount. Total phenol, total flavonoids, total tannin, and total protein content were measured quantitatively. Leaf samples showed higher concentrations of bioactive compounds than roots and stem. Highest total phenol content (66.43 mg/g), total flavonoids content (28.00 mg/g), total tannin content (7.36 mg/g) and total protein content (26.55 mg/g) was found from the leaf water extract. DPPH scavenging assay was performed to find the antioxidant potential and positive results were found. Thin layer chromatography (TLC) was also employed to check the constituents. Our study found several spots for different samples and their retention factors (Rf) were evaluated. Jahangirnagar University J. Biol. Sci. 7(2): 65-77, 2018 (December)

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third most common cause of cancer mortality worldwide. Infection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) is the most predominant cause of HCC. Concerns arise for the presence of additional risk factors, as there is still a large proportion of patients without HBV or HCV infection. Previous studies have reported that higher intake of fruits and vegetables and reduced consumption of red/processed meat might play a protective role in HCC etiology, though the nationwide proof is limited. Hence, we studied multiple risk factors including food habit, lifestyle, and clinical implications of HCC patients in Bangladeshi. Demographic, clinical, and biochemical data, as well as data on food habits, were collected in this study. Our results indicated that a high intake of rice (AOR 4.28, 95% CI 1.48 to 14.07, p = 0.011), low intake of fruits (AOR = 4.41 95% CI 1.48-15.46; p = 0.012), leafy vegetables (AOR = 2.80, 95% CI 1.32-6.08; p = 0.008), and fish (AOR = 4.64 95% CI 2.18-10.23; p<0.001) increased the HCC risk. Moreover, a high intake of eggs (AOR = 2.07 95% CI 0.98-4.43; p = 0.058) also showed an increased risk. Roti, non-leafy vegetables, red meat, and tea were found to have no association with HCC risk. This study revealed that food habit patterns and lifestyle may have a profound effect on HCC development among Bangladeshi patients in addition to well established risk factors.