The Effects of Freshwater Clam (Corbicula fluminea) Extract on Activated Hepatic Stellate Cells

Background. The extract of freshwater clams has been used to protect the body against liver diseases in traditional folk medicine. This study aims at investigating the effects of freshwater clam extract on activated hepatic stellate cells (aHSCs), which are critical contributors to liver fibrosis. Methods. The aHSCs used in this study were derived from hepatic stellate cells that were isolated and purified from the livers of male Wistar rats and then transformed into the activated phenotype by culturing on uncoated plastic dishes. Freshwater clam extract (CE) was collected after the outflow from the live freshwater clams in a water bath at 100°C for 60 min. The effects of CE on aHSCs were analyzed by MTT assay, flow cytometry, Oil Red O (ORO) staining, western blot, and real-time RT-PCR. Results. The results indicated that CE suppressed the proliferation of aHSCs through G0/G1 cell cycle arrest by downregulating cyclin D1 and upregulating p27. The expression levels of a-SMA, collagen I, TGF-β, and TNF-α were inhibited in the CE-treated aHSCs. In addition, the CE treatment increased the lipid contents in aHSCs by promoting PPARγ expression. Furthermore, CE modulated the expression of ECM-related genes, i.e., by upregulating MMP-9 and downregulating TIMP-II. Conclusions. These data revealed that CE could induce the deactivation of aHSCs. We therefore suggest that CE has potential as an adjuvant therapeutic agent against hepatic fibrosis.

Nutrient content and physical properties of instant baby porridge substituted with freshwater clams flour (Pilsbryoconcha exilis)

Stunting is one of the nutritional problems with high frequency in Indonesia. One cause of stunted children is the improper complementary feeding practice. A good quality diet contains macronutrients (protein) and micronutrients (iron, zinc, and calcium) are linearly correlated with children’s growth. A freshwater clam was a local food enriched with highprotein and zinc that is potential to be nutritional complementary foods. However, this was substituted by full cream milk in instant baby porridge. The purpose of this study was to analyze the effect of freshwater clams flour substitution on energy, protein, fat, carbohydrate, fiber, zinc, calcium, and iron as well as physical properties (bulk density, water absorption, and solubility) in instant baby porridge. The design of this study was a single factor completely randomized design with the ratio of freshwater clams flour as substituted in the instant baby porridge as 0% (F0), 5% (F1) and 10% (F2). There was also an effect of substitution of freshwater clamss flour (Pilsbryoconcha exilis) on energy, carbohydrate, protein, fat, moisture content, ash, crude fiber, calcium, iron, and zinc (p = 0.0001) in instant baby porridge. Variation in the percentage of freshwater clamss flour substitution did not significantly influence the bulk density (p = 0.085), solubility (p = 0,05) and water absorption (p = 0.341). Instant baby porridge F0 contained protein, calcium, iron, and zinc less than the requirements. Instant baby porridge F1 had protein and zinc less than the requirements, but calcium and iron levels met the requirements. Meanwhile, the level of protein, iron, calcium and zinc on instant baby porridge F2 met the requirements. Instant baby porridge with the substitution of freshwater clams flour increased the nutrient content which includes protein, fiber, calcium, iron, and zinc but decreased carbohydrate and fat content. Both formulations had a bulk density and solubility which meet the requirement. However, water absorption did not meet the requirements.

Quinolone and Organophosphorus Insecticide Residues in Bivalves and Their Associated Risks in Taiwan

Bivalves, such as freshwater clams (Corbicula fluminea) and hard clams (Meretrix lusoria), are the most extensive and widely grown shellfish in land-based ponds in Taiwan. However, few studies have examined the contamination of bivalves by quinolone and organophosphorus insecticides. Thus, we adapted an established procedure to analyze 8 quinolones and 12 organophosphorus insecticides using liquid and gas chromatography–tandem mass spectrometry. Surveys in Taiwan have not noted high residual levels of these chemicals in bivalve tissues. A total of 58 samples of freshwater or hard clams were obtained from Taiwanese aquafarms. We identified 0.03 mg/kg of enrofloxacin in one freshwater clam, 0.024 mg/kg of flumequine in one freshwater clam, 0.02 mg/kg of flumequine in one hard clam, 0.05 mg/kg of chlorpyrifos in one freshwater clam, 0.03 mg/kg of chlorpyrifos in one hard clam, and 0.02 mg/kg of trichlorfon in one hard clam. The results indicated that 5.17% of the samples had quinolone insecticide residues and 5.17% had organophosphorus residues. However, the estimated daily intake (EDI)/acceptable daily intake quotient (ADI) indicated no significant risk and no immediate health risk from the consumption of bivalves. These results provide a reference for the food-safety screening of veterinary drugs and pesticides in aquatic animals. Aquatic products should be frequently screened for residues of prohibited chemicals to safeguard human health.

A contribution to the fauna of freshwater Bivalvia of waterbodies and watercourses of the Eastern slope of the Polar and Pre-Polar Urals

The article is devoted to the fauna of Bivalvia (family Sphaeriidae) of waterbodies and water-courses of the eastern slope of the Polar and Pre-Polar Urals. The fauna of freshwater clams of this region remains practically unexplored. This study aimed at identification of the species content of Bivalvia and publication of images of their shells. We analyzed both qualitative and quantitative samples of molluscs as well as fish stomach contents. The identification of the material was based on conchological features, including the hinge structure. In total, 31 sphaeriid species is reported, and the annotated check-list, brief zoogeographic characteristics of the fauna, and shell images are provided. Most species demonstrate a limited spatial distribution within the studied area. The causes of discrepancies between published lists of sphaeriid species are discussed.

Phylogenomic analyses confirm a novel invasive North American Corbicula (Bivalvia: Cyrenidae) lineage

The genus Corbicula consists of estuarine or freshwater clams native to temperate/tropical regions of Asia, Africa, and Australia that collectively encompass both sexual species and clonal (androgenetic) lineages. The latter have become globally invasive in freshwater systems and they represent some of the most successful aquatic invasive lineages. Previous studies have documented four invasive clonal lineages, Forms A, B, C, and Rlc, with varying known distributions. Form A (R in Europe) occurs globally, Form B is found solely in North America, mainly the western United States, Form C (S in Europe) occurs both in European watersheds and in South America, and Rlc is known from Europe. A putative fifth invasive morph, Form D, was recently described in the New World from the Illinois River (Great Lakes watershed), where it occurs in sympatry with Forms A and B. An initial study showed Form D to be conchologically distinct: possessing rust-colored rays and white nacre with purple teeth. However, its genetic distinctiveness using standard molecular markers (mitochondrial cytochrome c oxidase subunit I and nuclear ribosomal 28S RNA) was ambiguous. To resolve this issue, we performed a phylogenomic analysis using 1,699–30,027 nuclear genomic loci collected via the next generation double digested restriction-site associated DNA sequencing method. Our results confirmed Form D to be a distinct invasive New World lineage with a population genomic profile consistent with clonality. A majority (7/9) of the phylogenomic analyses recovered the four New World invasive Corbicula lineages (Forms A, B, C, and D) as members of a clonal clade, sister to the non-clonal Lake Biwa (Japan) endemic, Corbicula sandai. The age of the clonal clade was estimated at 1.49 million years (my; ± 0.401–2.955 my) whereas the estimated ages of the four invasive lineage crown clades ranged from 0.27 to 0.44 my. We recovered very little evidence of nuclear genomic admixture among the four invasive lineages in our study populations. In contrast, 2/6 C. sandai individuals displayed partial nuclear genomic Structure assignments with multiple invasive clonal lineages. These results provide new insights into the origin and maintenance of clonality in this complex system.