Microplastic (MP) occurrence is a major global issue, though data on MP occurrence in the Philippines is limited and the potential effects of MPs on biota are still poorly studied. MP occurrence in fishes remains a concern, especially in economically and ecologically important species such as Siganus spp. This study determined MP occurrence in the gastrointestinal tract of wild rabbit fishes from Tañon Strait, the largest marine protected area in the Philippines. Siganus canaliculatus (n = 65), S. spinus (n = 17), S. guttatus (n = 5), S. virgatus (n = 8) and S. punctatus (n = 1) were sampled from the north and south of the strait. All MPs isolated from the gut of the rabbit fishes except for fibers were chemically analyzed by ATR-FTIR spectroscopy; an established library was used to determine the polymeric identities. Five particles were confirmed as polyester, polyamide, polyethylene or phenoxy resin MPs. The average MP abundance was 0.05 items/individual (S. virgatus > S. guttatus > S. canaliculatus > S. spinus = S. punctatus), which is comparable to studies conducted in other locations using similar methods. Fibers were counted (1556 in total), but not chemically analyzed. The low MP abundance in the samples may be attributed to the capability of rabbit fishes to discriminate food preferences. However, the risks associated with MPs should not be underestimated, especially as all parts of the fishes—including the gut—are utilized as human foods in the Philippines and many other Asian countries.

Excessive nitrogen input in natural ecosystems is a major threat to biodiversity. A coastal dune area near Amsterdam in the Netherlands suffers from high atmospheric nitrogen deposition affecting sensitive habitats such as fixed coastal dunes with herbaceous vegetation (‘grey dunes’). To mitigate its effect year round grazing was applied from 2007 until 2012. In winter, when natural food supply is low, the cattle received supplementary hay that caused additional inputs of nitrogen. Estimates based on nitrogen contents of hay, as well as of manure, showed the input through winter feeding (c. 3–14 kg N ha-1.y-1) is in the same order of magnitude as both the actual deposition (c. 17 kg N ha-1.y-1) and the critical load for a number of herbaceous habitat types (10–15 kg N ha-1.y-1). Locally, the effect of winter feeding adds to the effect of nitrogen redistribution within the area caused by the cattle's terrain usage. We conclude that winter feeding may aggravate effects of atmospheric nitrogen deposition. Keywords: Vegetation management; Manure; Nitrogen; Eutrophication; Natura 2000; Grey dune

A mixture of common Southern Piedmont (USA) grassland species (Lolium arundinacea, Paspalum dilatatum, Cynodon dactylon and Trifolium repens) was exposed to O₃ [ambient (non-filtered; NF) and twice-ambient (2X) concentrations] and fed to individually caged New Zealand white rabbits (Oryctolagus cuniculus) in a digestibility experiment. Forages and feed refusals were analyzed for concentrations of total cell wall constituents, lignin, crude protein, and soluble and hydrolyzable phenolic fractions. Neutral detergent fiber and acid detergent fiber digestibility by rabbits were significantly lower for 2X than NF forage. Decreased digestibility could not be attributed to lignin concentrations, but was associated with increased concentrations of acid-hydrolyzable and saponifiable phenolics. Exposure of forage to elevated O₃ resulted in decreased digestible dry matter intake by rabbits. Elevated O₃ concentrations could be expected to have a negative impact on forage quality, resulting in decreased nutrient utilization by mammalian herbivores in Southern Piedmont grasslands under projected future climate scenarios.

Carbendazim (CBZ), a broad-spectrum pesticide frequently detected in fruits and vegetables, could trigger potential toxic risks to mammals. To facilitate the assessment of health risks, this study aimed to characterize the cytochrome P450 (CYPs)-mediated metabolism profiles of CBZ by a combined experimental and computational study. Our results demonstrated that CYPs-mediated region-selective hydroxylation was a major metabolism pathway for CBZ in liver microsomes from various species including rat, mouse, minipig, dog, rabbit, guinea pig, monkey, cow and human, and the metabolite was biosynthesized and well-characterized as 6-OH-CBZ. CYP1A displayed a predominant role in the region-selective hydroxylation of CBZ that could attenuate its toxicity through converting it into a less toxic metabolite. Meanwhile, five other common pesticides including chlorpyrifos-methyl, prochloraz, chlorfenapyr, chlorpyrifos, and chlorothalonil could significantly inhibit the region-selective hydroxylation of CBZ, and consequently remarkably increased CBZ exposure in vivo. Furthermore, computational study clarified the important contribution of the key amino acid residues Ser122, and Asp313 in CYP1A1, as well as Asp320 in CYP1A2 to the hydroxylation of CBZ through hydrogen bonds. These results would provide some useful information for the metabolic profiles of CBZ by mammalian CYPs, and shed new insights into CYP1A-mediated metabolic detoxification of CBZ and its health risk assessment.

Cadmium (Cd) is a harmful heavy metal that can cause many health problems, while selenium (Se) is an essential nutrient for organisms that can protect them from heavy metal-induced damage. To explore the effects of Se on Cd-induced mitophagy in the liver, forty 3-month-old New Zealand white rabbits (2–2.5 kg), half male and half female, were randomly divided into four groups: the Control group, the Se (0.5 mg/kg body weight (BW)) group, the Cd (1 mg/kg BW) group and the Se+Cd group. After 30 days, the toxicity from Cd in the liver was assessed in terms of the nuclear xenobiotic receptor (NXR) response, oxidative stress and mitophagy. It was found that Cd decreased the activities of CYP450 enzymes and antioxidant enzymes and increased the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) and also increased the consumption of reduced glutathione (GSH). Moreover, the mRNA levels of NXRs (CAR, PXR, AHR and Nrf2), some mitochondrial function factors (PGC-1α, Sirt1, Sirt3, Nrf1 and TFAM) and mitochondrial fusion factors (Mfn1, Mfn2 and OPA1) were downregulated, but the mRNA levels of other mitochondrial function factors (VDAC1, Cyt C and PRDX3), mitochondrial fission factors (Fis1 and MFF) and those in the PINK1/Parkin-mediated mitophagy pathway (p62, Bnip3 and LC3) were upregulated under Cd exposure. The protein expression levels of Nrf2, SOD2, PGC-1α, PINK1 and Parkin were consistent with the mRNA expression levels in the Cd group. Se alleviated the changes in the abovementioned factors induced by Cd. In conclusion, the results indicate that Cd can cause oxidative stress in rabbit livers by inhibiting NXRs and the antioxidation response leading to mitophagy, and these harmful changes caused by Cd can be alleviated by Se.

Mining is responsible of releasing trace elements to the environment with potential negative effects on wildlife. Traditionally, wildlife exposure assessment has been developed by analyzing mainly environmental compartments or internal tissues. Nowadays, the use of non-destructive matrices such as hair or feathers has increased. Nevertheless, its use in free-living terrestrial mammals or in birds other than raptors or passerines is less frequent. The main objective of our study was to determine the potential for hair and feathers in a rabbit and bird species to be used as non-invasive proxy tissues for assessing internal metal concentrations at polluted sites from mining. We tested whether hair of European rabbit (Oryctolagus cuniculus) and feathers of red-legged partridge (Alectoris rufa) can be used as non-destructive biological monitoring tools of both essential (Cu, Zn) and non-essential (Pb, Cd, As) trace elements in a currently active copper mining site. We found significant different concentrations, particularly in non-essential elements, between reference area and mining site. Non-essential elements Pb and Cd showed higher correlations between tissues and hair/feathers, while few significant patterns were observed for essential elements such as Cu and Zn. Although feathers showed lower levels of correlation with internal tissues than hair, both could be useful as non-destructive biological monitoring tools. Further tissues, and more importantly, hair and feathers allowed discrimination between polluted and reference sites to indicate bioavailability and pollution status. In addition, hair and feathers can be used in monitoring pollution of an active mining site, being specially interesting for biomonitoring a certain period of time in the event of a particular episode of pollution, in addition to the chronic exposure. As occurred with hair in rabbits, feathers seem to be a good compartment to detect differences between a potential polluted area, such the surrounding of an active mine site, and a non-polluted area.

Excessive nitrogen input in natural ecosystems is a major threat to biodiversity. A coastal dune area near Amsterdam in the Netherlands suffers from high atmospheric nitrogen deposition affecting sensitive habitats such as fixed coastal dunes with herbaceous vegetation (‘grey dunes’). To mitigate its effect year round grazing was applied from 2007 until 2012. In winter, when natural food supply is low, the cattle received supplementary hay that caused additional inputs of nitrogen. Estimates based on nitrogen contents of hay, as well as of manure, showed the input through winter feeding (c. 3–14 kg N ha-1.y-1) is in the same order of magnitude as both the actual deposition (c. 17 kg N ha-1.y-1) and the critical load for a number of herbaceous habitat types (10–15 kg N ha-1.y-1). Locally, the effect of winter feeding adds to the effect of nitrogen redistribution within the area caused by the cattle's terrain usage. We conclude that winter feeding may aggravate effects of atmospheric nitrogen deposition. Keywords: Vegetation management; Manure; Nitrogen; Eutrophication; Natura 2000; Grey dune

The keratin-degrading bacterium Actinomadura viridilutea DZ50 secretes a keratinase (KERDZ) with potential industrial interest. Here, the kerDZ gene was extracellularly expressed in Escherichia coli BL21(DE3)pLysS using pTrc99A vector. The recombinant enzyme (rKERDZ) was purified and biochemically characterized. Results showed that the native and recombinant keratinases have similar biochemical characteristics. The conventional dehairing with lime and sodium sulfide degrades the hair to the extent that it cannot be recovered. Thus, these chemical processes become a major contributor to wastewater problem and create a lot of environmental concern. The complete dehairing was achieved with 2000 U/mL rKERDZ for 10 h at 40 °C. In fact, keratinase assisted dehairing entirely degraded chicken feather (45 mg) and removed wool/hair from rabbit, sheep, goat, or bovine’ hides (1.6 kg) while preserving the collagen structure. The enzymatic process is the eco-friendly option that reduces biological (BOD) (50%) and chemical (COD) oxygen demands (60%) in leather processing. Consequently, the enzymatic hair removal process could solve the problem of post-treatments encountering the traditional leather processing. The enzymatic (rKERDZ) dehaired leather was analyzed by scanning electron microscopic (SEM) studies, which revealed similar fiber orientation and compactness compared with control sample. Those properties support that the rKERDZ enzyme–mediated process is greener to some extent than the traditional one.

Cadmium and mercury are non-biodegradable toxic metals that may cause many detrimental effects to the thyroid gland and blood. Vitamin C has been found to be a significant chain-breaking antioxidant and enzyme co-factor against metal toxicity and thus make them less available for animals. The current study was performed to find the effect of individual metals (cadmium and mercury), their co-administration, and the ameliorative effects of vitamin C on some of the parameters that indicate oxidative stress and thyroid dysfunction. Cadmium chloride (1.5 mg/kg), mercuric chloride (1.2 mg/kg), and vitamin C (150 mg/kg of body weight) were orally administered to eight treatment groups of the rabbits (1. control; 2. Vit C; 3. CdCl₂; 4. HgCl₂; 5. Vit C + CdCl₂; 6. Vit C + HgCl₂; 7. CdCl₂ + HgCl₂, and 8. Vit C + CdCl₂ + HgCl₂). After the biometric measurements of all experimental rabbits, biochemical parameters viz. triidothyronine (T₃), thyroxine (T₄), thyroid-stimulating hormone (TSH), and triglycerides were measured using commercially available kits. The results exhibited significant decline (p < 0.05) in mean hemoglobin, corpuscular hemoglobin, packed cell volume, T₃ (0.4 ± 0.0 ng/ml), and T₄ (26.3 ± 1.6 ng/ml) concentration. While, TSH (0.23 ± 0.01 nmol/l) and triglyceride (4.42 ± 0.18 nmol/l) were significantly (p < 0.05) increased but chemo-treatment with Vit C reduces the effects of Cd, Hg, and their co-administration but not regained the values similar to those of controls. This indicates that Vit C had a shielding effect on the possible metal toxicity. The Cd and Hg also found to accumulate in vital organs when measured by atomic absorption spectrophotometer. The metal concentration trend was observed as follows: kidney > liver > heart > lungs. It was concluded that Cd and Hg are toxic and tended to bioaccumulate in different organs and their toxic action can be subdued by vitamin C in biological systems.

This study aimed to evaluate the removal of polychlorinated biphenyls, with a vermicomposting system, using the following as components: the earthworm Eisenia fetida, peat moss and rabbit excrement and a compound called decachlorobiphenyl, for a period of 91 days under non-sterile conditions. The results obtained were a removal of decachlorobiphenyl 79.6 % with an initial concentration of 100 mg L⁻¹, 89.7 % with 150 mg L⁻¹and 95.38 % with 200 mg L⁻¹; the earthworms bioaccumulated less than 5 mg L⁻¹in all concentrations of decachlorobiphenyl analysed without apparent toxic effect. Weight gain was observed in earthworms that assimilated contaminant during vermicomposting, as the number of cocoons produced in contrast to the control in which both the weight and the number of cocoons were lower. To our knowledge, this is the first study which suggests that vermicomposting may be a suitable mechanism for removal of decachlorobiphenyl with high recalcitrance from contaminated sediment or soils.