Surface water, sediment, and biota: The first multi-compartment analysis of microplastics in the Karnafully river, Bangladesh.

The Karnafullly River, which flows through Chattogram and falls into the Bay of Bengal, Bangladesh, is vulnerable to microplastic contamination. In this study, we looked at microplastics in the Karnafully River's surface water (5 sites), sediment (9 sites), and biota (4 species). Microplastic concentrations ranged from 0.57 ± 0.07 to 6.63 ± 0.52 items/L in surface water, 143.33 ± 3.33 to 1240 ± 5.77 items/kg dry weight in sediment, and 5.93 ± 0.62 to 13.17 ± 0.76 items/species in biota. A significant difference (P < 0.05) was found in the concentration of MPs in the Karnafully River's sediment, biota, and surface water. High percentage of fiber-shaped and small-sized MPs (<1 mm) were detected throughout the samples. Water and sediment MPs were often transparent/white and blue, whereas biota MPs were mostly black and red, indicating a color preference during biological uptake. The Bay of Bengal received 61.3 × 109 microplastic items per day. The feeding zone of biota influenced the level of microplastics, with a trend of pelagic > demersal > benthic > benthopelagic. Polyethylene and polyethylene terephthalate were the most abundant polymer. Using the average fish intake rate in Bangladesh, we computed a possible consumption of 4015-7665 items of MPs/person/year.

Analgesic, anti-inflammatory, and anti-oxidant activities of Phlogacanthus thyrsiflorus leaves.

BACKGROUND: Our present study was carried out to explore the potential role of the methanol extract from the leavesof Phlogocanthus thyrsiflorus (PT) Nees. in central and peripheral analgesic activities using hot plate and acetic acid-induced writhing methods. We also tested the antiinflammatory effects and anti-oxidant activity using carrageenan-induced paw edema and the DPPH method, respectively. METHODS: Methanol extracts of PT leaves were prepared using 500 g powder in 1.8 L methanol by percolation method, followed by evaporation in a rotary evaporator under controlled temperature and pressure. The crude methanol extract was dried by freeze drier and preserved at 4 °C. RESULTS: Oral administration of PT significantly (p < 0.05)increased the reaction time at 55.73% (250 mg/kg) and 72.81% (500 mg/kg) inhibition (p < 0.05) in the hot plate test at 3 h. PT significantly (p < 0.05) inhibited 42.17% (250 mg/kg) and 56.63% (500 mg/kg) acetic acid-induced writhing. PT leaves (250 and 500 mg/kg) also significantly (p < 0.05) inhibited paw edema 6 h after carrageenan injection. Furthermore, this plant showed significant (p < 0.05) free radical-scavenging activity at a dose range of 25­800 µg/mL. CONCLUSIONS: Based on the findings, we can conclude that PT leaf possesses analgesic, anti-inflammatory, and antioxidant activities. Preliminary phytochemical study of PT leaves revealed the presence of flavonoids, tannins and triterpens in methanol extract which could be correlated with its observed biological activities.