Potential human health risk assessment associated with Hg, Cd, Pb, and As in sardines and shrimp from four Egyptian coastal governorates.

Heavy metal contamination in seafood is a developing concern due to the potential negative consequences on human health. Egypt's coastal regions are important for seafood production and consumption, making it critical to assess the safety of these aquatic resources. The current study examined toxic metal levels (Hg, Pb, Cd, and AS) in 96 samples of sardine and shrimp from four Egyptian coastal governorates (Alexandria, Kafr El-Sheikh, Damietta, and Port Said) from 2019 to 2021. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was used to investigate the four hazardous metals. The recovery percentages of the determined metals ranged between 97 % and 99 %. Limits of detection (LOD) and limit of quantification (LOQ) for the determined metals ranged from 0.001 to 0.0077 mg/l and from 0.0035 to 0.026 mg/l, respectively. Mercury (Hg) was not found in any of the samples tested. The concentrations of Pb and Cd in the sardines and shrimp samples were higher in the winter seasons than in the summer seasons. Meanwhile, the difference in seasons had no effect on the concentration of As in the sardines and shrimp samples. The highest concentrations of the other three metals in the sardine and shrimp samples were used to calculate the Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Hazard Index (HI). The obtained THQ as well as the HI of Pb, Cd, and As were all less than 1.0 (with the exception of sardine samples from Kafr El-Sheikh Governorate, which recorded 1.262), indicating that there is no significant health risk to the consumer from consuming such sardines and shrimp from these governorates. The effect of different seasons on the concentrations of the metals under study does not have a specific behavior, but varies according to the governorate, the type of sample, and the type of contaminated metal. Due to the high level of contamination with heavy metals in sardine samples collected from Kafr El-Sheikh governorate (TTHQ = 1.26), an environmental study is required to determine the causes of contamination and control them.

CYTOTOXIC EFFECTS OF THE RED SEA SOFT CORAL SARCOPHYTON TROCHELIOPHORUM.

The present study describes the in vitro cytotoxic effects of soft coral (Sarcophyton tiocheliophorum). Soft corals of genus Sarcophyton were reported to contain compounds that are active against brine shrimp and promote paclitaxel cytotoxicity in the human colon cancer Caco-2 cell line. The n-hexane extract of the soft coral Sarcophyton tiocheliophorum induced significant dose-dependent toxicity (LC50 96.7 ppm) compared with ethyl acetate (LC50. 120 ppm). We reported the most active cytotoxic level to be correspondence to LC50 values of 20.2, 59.2 ppm and 18.9 and 26 ppm. Accordingly, bio-assay guided fractionation was conducted to identi- fy the bioactive compounds. Arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid were characterized based on GC-MS analyses. Our results demonstrate the value of marine products as a natural source of medicinally interesting cytotoxic compounds.

Antibacterial effect of the red sea soft coral Sarcophyton trocheliophorum.

The marine soft corals Sarcophyton trocheliophorum crude extracts possessed antimicrobial activity towards pathogenic bacterial strains, i.e. Bacillus cereus, Salmonella typhi, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Bioassay-guided fractionation indicated that the antimicrobial effect was due to the presence of terpenoid bioactive derivatives. Further biological assays of the n-hexane fractions were carried out using turbidity assay, inhibition zone assay and minimum inhibitory concentration for investigating the growth-inhibition effect towards the Gram-positive and Gram-negative bacteria. The fractions were screened and the structure of the isolated compound was justified by interpretation of the spectroscopic data, mainly mass spectrometry (GC-MS). The structure was assigned as (5S)-3-[(3E,5S)-5-hydroxy-3-hepten-6-yn-1-yl]-5-methyl-2(5H)-furanone and was effective at concentrations as low as 0.20 mg/mL. The above findings, in the course of our ongoing research on marine products, may implicate that the profound anti-microbial activity of the S. trocheliophorum soft corals, inhabiting the red sea reefs, is attributed to the presence of growth-inhibiting secondary metabolites mainly terpenoids.