Fish Poisoning Research Articles

Exposure assessment and semi-quantitative risk analysis of histamine in tuna and tuna-like fish from Indonesia

This study aimed to investigate histamine exposure associated with consumption of fresh tuna and tuna-like species in West Java, and to estimate risk of Scombroid Fish Poisoning (SFP) in Indonesia. A range of species, including tuna (Thunnus spp.), bullet tuna ( Auxis sp.), and skipjack ( Katsuwonus pelamis ) were collected from local markets and fish landing sites. Subsequently, histamine concentrations were determined using NMR analysis and exposure was calculated in mg/day for toddlers, children, and adults. The results showed that skipjack had the highest histamine exposure for all age groups, followed by bullet and regular tuna. The highest EDI for histamine was from skipjack consumption, accounting for 38.67; 37.77 and 20.74 percentage of exposure for toddlers, children and adults, respectively. These values are below the defined thresholds levels (ARfD), indicating no potential risk of acute health effect. Cooked bullet tuna and skipjack were estimated to cause similar illnesses, accounting for 6–7 cases per 100,000 individuals, which was higher than cooked tuna at 1–2 cases per 100,000 individuals. Considering the preparation of raw tuna in restaurants following Good Hygienic Practices (GHP), the predicted annual cases decreased significantly to 4–5 cases per million individuals. This risk estimation only considered histamine levels in fresh fish, without including data from fish preparation. Therefore, further studies were recommended to estimate the risk level in raw/fresh tuna and similar species before consumption.

Morphological, Toxicological, and Biochemical Characterization of Two Species of Gambierdiscus from Bahía de La Paz, Gulf of California.

We describe five new isolates of two Gambierdiscus species from Bahía de La Paz in the southern Gulf of California. Batch cultures of Gambierdiscus were established for morphological characterization using light microscopy (LM) and scanning electron microscopy (SEM). Pigment and amino acid profiles were also analyzed using high-performance liquid chromatography (HPLC-UV and HPLC-DAD). Finally, toxicity (CTX-like and MTX-like activity) was evaluated using the Artemia salina assay (ARTOX), mouse assay (MBA), marine fish assay (MFA), and fluorescent receptor binding assay (fRBA). These strains were identified as Gambierdiscus cf. caribaeus and Gambierdiscus cf. carpenteri. Toxicity for CTX-like and MTX-like activity was confirmed in all evaluated clones. Seven pigments were detected, with chlorophyll a, pyridine, Chl2, and diadinoxanthin being particularly noteworthy. For the first time, a screening of the amino acid profile of Gambierdiscus from the Pacific Ocean was conducted, which showed 14 amino acids for all strains except histidine, which was only present in G. cf. caribeaus. We report the presence of Gambierdiscus and Fukuyoa species in the Mexican Pacific, where ciguatera fish poisoning (CFP) cases have occurred.

High Salinity Intensive Seaweed Growth Rate in Aquaponic Systems

Aquaponics is a closed recirculating aquaculture method combined with hydroponics. This method is very alternative for raising fish while growing plants in specially designed media. The mechanism obtained is very effective and efficient, plants can utilize fish waste as nutrients for plant growth. Poisonous fish waste in ponds can be reduced by plants as nutrients for organic substances. This can enhance profitable bio-integrated food production systems. Plants will serve as vegetation filters. This study aimed to determine the effectiveness of aquaponic treatment in high-salinity water by observing the growth in three species of seaweed namely Gracilaria sp., Sargassum sp., and Kappaphycus alvarezii. The research design used the LSD method and was carried out for 63 days. Data analysis using Analysis of Variance (ANOVA) then continued with the test Duncan's Multiple Range Test. The research method involved making aquaponic media including preparing containers for seaweed cultivation and fish and shrimp farming, observing seaweed growth rates, and measuring water quality. Aquaponic treatment can increase the growth rate of intensively cultivated seaweed. The results showed the best weight growth rate in the aquaponic treatment of Gracilaria sp. with a value of 12.33 grams than Kappaphycus alvarezii 11.33 grams and Sargassum sp. 10.83 grams.

Ciguatera fish poisoning: origins, pathophysiology and management

Ciguatera fish poisoning: origins, pathophysiology and management

Identification of Fish Species Involved with Ciguatera Food Poisoning in Okinawan Waters by Using PCR-RFLP analysis

Ciguatera fish poisoning (CFP), known as a seafood-borne disease, is caused by consumption of fish contaminated with ciguatoxins in tropical and subtropical sea. The ciguatera fishes, Variola louti, Lutjanus monostigma and L. bohar have an absolute majority in the Ryukyu Archipelago, southwestern Japan. We developed the cluster analysis of phylogenetic tree by using mitochondrial (mt) DNA 16S rRNA sequences of V. louti, L. monostigma and L. bohar and differentiate them from morphologically similar species (L. fulviflamma, L. russellii, L. argentimaculatus, Plectropomus leopardus and V. albimarginata) in our previous study. The fish were acquired from the coastal waters of the Ryukyu Archipelago, and a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) marker of the mtDNA 16S rRNA region was used, employing the restriction enzymes BmgT120 I, Dde I, and SnaB I, to identify the fish species responsible for CFP. These results showed that a PCR-RFLP marker can be obtained more easily than a nucleotide sequence.

Anesthetic concerns in ciguatera poisoning

Ciguatoxin, a potent neurotoxin from tropical and subtropical fish, causes ciguatera fish poisoning, presenting with a spectrum of gastrointestinal, neurological, and cardiovascular symptoms. Ciguatoxin affects the voltage-gated sodium channels in the body, so there is a need for additional considerations for administering anesthesia in patients with ciguatera poisoning. Understanding the long-term implications of ciguatoxin exposure is essential for optimizing anesthesia management in these patients.

Triazophos toxicity induced histological abnormalities in Heteropneustes fossilis Bloch 1794 (Siluriformes: Heteropneustidae) organs and assessment of recovery response

BackgroundAgricultural pesticides have toxic effects in the aquatic ecosystem, and their persistence poses a hazard to aquatic life, as seen by fish poisoning, both acute and chronic. Triazophos, a broad-spectrum organophosphate insecticide, is used to control agricultural crops from insect pests. For a period of 10 days, Heteropneustes fossilis, a fish of great economic and therapeutic value, was exposed to various levels of triazophos toxicity (5, 10 and 15 ppm), after which they were sacrificed. For recovery tests, the treated fish were switched to clean tap water after 10 days of exposure to the toxicant, examined for another 10 days, and then sacrificed. The histological changes in the tissues of the sacrificed fishes' gill, liver, intestine, kidney, brain, and muscle (treatment and recovery) were investigated.ResultsThe histology investigations revealed that the toxicant was hazardous, with histopathological changes increasing as the concentration of the toxicant increased. The gills had the most damage, with fusion of secondary lamella and epithelial hyperplasia; liver had vacuolization, pyknotic nuclei, and focal necrosis; intestine had degenerated, necrotic villi, degeneration of epithelial cells, and atropy; kidney had narrowing of the tubular lumen, pyknotic nuclei, hypertrophy, degeneration; swelling, haemorrhage, larger neuronal cells, and karyolysis were observed in the brain, whereas infiltration of leucocytes, loss of striated muscles, and an increase in intra fibril area were observed in the muscle. When compared to the treated fishes, the 10-day recovery research demonstrated tissue damage and a slower recovery pattern.ConclusionsTriazophos caused histological changes in the gill, liver, intestine, kidney, brain and muscle of the test fish Heteropneustes fossilis. With reference to recovery response, a slow recovery was observed. Furthermore, this is the first investigation into the effects of triazophos on the recovery response in Heteropneustes fossilis.

Selenium-enriched Lactobacillus plantarum alleviate of high alkalinity-induced microbiota-gut-blood systems affect by improving the gut microbiota

High alkalinity is the most important limiting factor in carbonate-type saline–alkali water aquaculture, and fish growth is slow and survival is low in highly alkaline environments. Selenium-enriched (Se-enriched) Lactobacillus plantarum (L. plantarum) has antioxidant and anti-inflammatory properties and can regulate the balance of the gut flora. However, the physiological regulatory mechanism of Se-enriched L. plantarum on common carp under high alkalinity stress is still unclear. In the present study, 360 common carp were randomly divided into a control group, a high alkalinity group, and a Se-enriched L. plantarum and high alkalinity group and fed for 56 days. High alkalinity stress induced growth inhibition in common carp. Histopathology revealed atrophy of the intestinal villi and damage to the intestinal microvilli and tight junction complexes. Serological parameters showed that the serum ammonia and LPS contents were significantly increased. Gut microbial disruption under high alkalinity stress increased the abundance of Bacteroidota (LPS-producing bacteria), Providencia sp. (ammonia-producing bacteria) and Vibrio (pathogenic bacteria) and significantly decreased the expression of the tight junction proteins Zonula occludens-1 (ZO-1) and Occludin, disrupting the gut barrier. However, Se-enriched L. plantarum decreased the abundance of Bacteroidota Providencia sp. and Vibrio, increased the expression of the tight junction proteins ZO-1 and Occludin, and alleviated intestinal damage caused by high alkalinity while reducing the content of lipopolysaccharides (LPS) and ammonia in the serum. In addition, metabolomic analysis of serum revealed that high alkalinity stress activated autophagy, glucocorticoids and mineralocorticoid receptor agonists/antagonists, ABC transporters, the phosphatidylinositol signalling system, and the Mammalian Target of Rapamycin (mTOR) signalling pathway and significantly increased creatine content and riboflavin. Se-enriched L. plantarum treatment significantly decreased the creatine and D-alanine contents. In summary, this study revealed that Se-enriched L. plantarum can alleviate the harmful effects of high alkalinity on common carp by regulating the balance of the intestinal microbiota, improving intestinal barrier function, reducing the amount of harmful substances entering the bloodstream, and regulating blood metabolites. This study demonstrates the physiological regulatory mechanism of Se-enriched L. plantarum in alleviating high alkalinity stress and provides ideas and a theoretical basis for the protection against high alkalinity poisoning of fish in saline–alkali waters.

A Review on the Poisonous Plant Cleistanthus collinus

Cleistanthus collinus is a toxic plant belonging to the Euphorbiaceae family, and all parts of the plant are poisonous. It is used as suicidal, homicidal, cattle and fish poison and for inducing criminal abortion. The leaves and plant parts are consumed in various forms for homicidal and suicidal and it results in symptoms such as chest pain, dyspnea, central nervous system symptoms, and vision disturbances. There is no specific antidote for the C. collinus poisoning. The percentage of mortality with C. collinus poisoning varies from 20% to 50%, and the mortality depends on the amount and mode of consumption of the leaves. The major phytoconstituents of the plant include ellagic acid, diphyllin, collinusin, cleistanthin A, and cleistanthin B. The two major compounds cleistanthin A and cleistanthin B were evaluated for pharmacological activities such as antineoplastic activity, antiviral activity, diuretic activity, neuromuscular blocking property, alpha receptor blocking property, and antioxidant effect. The current review focuses on the toxicological and pharmacological properties of this plant and its phytoconstituents.

The Ethnobotany of Amazon Indians: a Rapidly Disappearing Source of botanical Knowledge for Human Welfare

The Amazon Indians are a rich source of botanical information. Some 200 tribes each have their own unique botany with many different plant recipes for their common needs e.g. arrow poisons, narcotics, food and fibers. Examples from several tribes are given of the variety of arrow poisons, fish poisons and hallucinogenic drugs which arc used in Amazonia. The Indians have had thousands of years of management of the Amazon ecosystem. However, the rate of acculturation and extinction of tribes is accelerating-even faster than the 90 tribes which have gone extinct in the 20th Century. Information of great potential use to human welfare about unexploited plants and management of the forest ecosystem is rapidly becoming lost. A review is given of this destruction of the Indians and their forest and habitat and it is suggested that there is an urgent need to study these people and for biologists to be active in the efforts which are being made to protect the Amazon Indians.

Bacteriological Analyses of Fish Mucus from Fish Market with Reference to Consumer’s Health

A study was conducted to evaluate the bacteria load present in fish mucus collected from Nanpura wholesale fish market during the period from 30th December 2022 to 20th February 2023. Total 20 fish mucus samples were determined by Total Plate Count (TPC) and identification of bacteria. High bacterial load with pathogens such as Escherichia coli (Gram negative bacteria) and Staphylococcus aureus (Gram positive bacteria) were found in all fresh and marine fish samples from study area. These pathogens can survive and multiply in fish, transferred into consumer by way of food and main source of fish poisoning, diarrhoea, meningitis and septicemia which cause health risk to consumer. The fishes were contaminated with pathogenic bacteria indicated poor handling of fishes, lack of preservation facility and unhygienic condition of study area. Thus, it is strongly recommended to improve the quality control and quality assurance systems of the study area to minimize the prevalence of pathogenic bacteria.

الآثار البيئية والاقتصادية والاجتماعية لظاهرة المد الأحمر على مجتمع الصيادين في ولاية بركاء بسلطنة عمان

Red tide is not a recent phenomenon. Rather, it is linked to the development and bloom of plankton and phytoplankton that accompanied ancient geological times and climate changes. Japan is the first country that was able to monitor this phenomenon more than 300 years ago, while its appearance in the countries of the Arabian Peninsula was in 1976 in the Sultanate of Oman. Natural and human factors contribute to the growth of harmful algae, which is the main cause of red tide, especially Dinotlagellates, which represents 78% of the samples analyzed in the Sultanate of Oman. Red tides damage ecosystems and coastal communities. This study mainly aims to highlight the economic, social and environmental impacts of the red tide phenomenon on the fishing community in the Wilayat of Barka in the Sultanate of Oman, and to develop appropriate solutions for fishing communities to mitigate the negative effects of this phenomenon. The study relied in its methodology on a review of previous studies, a field study, and direct interviews with fishermen in Barka State, in addition to questionnaires distributed to 120 fishermen using a random sampling method. One of the most prominent findings of this study is that red tide directly causes air pollution through the spread of unpleasant odors in the region, according to 99% of the sample population. However, what should be noted is that fishermen are completely unaware of the effects of red tide on public health related to the possibility of fish poisoning. As to the economic impacts, 94% of the study population pointed out to cost of cleaning equipment used in the fishing process. The problem was compounded by expatriate workers exploitation of situation by raising the costs of cleaning. Among the most prominent recommendations that came out of the study: conducting further studies and research, raising awareness on negative impacts of red tide and establishing fishermen associations to mitigate the effects of red tide.

Molecular mechanism of apoptosis induced by 4-tBP in common carp (Cyprinus carpio L.) head kidneys was explored from various angles: Hippo pathway, miR-203a, oxidative stress, ER stress, and mitochondrial pathway

4-tert butylphenol (4-tBP), a toxic environmental pollutant estrogen, received widespread attention due to its widespread presence, environmental persistence, and toxic effect. Common carp (Cyprinus carpio L.) is the most important freshwater economic animal in China and is also a model animal for the study on molecular mechanisms of poisoning. Head kidney is a target organ attacked by environmental pollutants. Here, we established a common carp 4-tBP poisoning model. The results showed that exposure to 4-tBP resulted in mitochondrial damage, endoplasmic reticulum damage, and apoptotic damage in head kidneys of common carps using microstructure and ultrastructure observations, as well as TUNEL kit methods. Furthermore, we found at transcriptional level from three perspectives that 4-tBP induced apoptosis in common carp head kidney cells: Hippo pathway, mitochondrial pathway, and ER stress. Hippo pathway formed a complex network, in which LATS1 was a core gene. It's noteworthy that Hippo pathway triggered mitochondrial pathway through YAP/NR4A1/Bcl-2 and YAP/BIRC5/Caspase-9 pathways under 4-tBP-induced apoptosis. PERK-eIF2α-ATF4-Caspase-3 pathway was involved in 4-tBP-induced apoptosis via ER stress. Moreover, miR-203a mediated 4-tBP-induced apoptosis through targeting MST1, MAP4K4, and NR4A1. In addition, 4-tBP disrupted balance between oxidants and antioxidants, and caused oxidative stress, and oxidative stress mediated ER stress under 4-tBP-caused apoptosis via via H2O2-PERK-eIF2α-ATF4-Caspase-3 pathway. miR-203a and oxidative stress participated in 4-tBP-induced apoptosis in common carp head kidney cells. For the first time, we found that Hippo pathway took part in molecular mechanism of fish poisoning, which needs to be investigated in the future. Our research provided foundational knowledge for exploring toxic effects of estrogen on fish and provided new insights into a theoretical basis for safety risk assessment for humans and fish, which deserves further profound exploration in the future. Moreover, the insights we generated help inform new strategies for preventing toxic injury in fish.

Expansion of Toxic Algal Blooms in Coastal and Marine Areas in the Philippines and Malaysia: Is It Climate Change Related?

This paper provides a review of toxic algal blooms in the Philippine and Malaysian coastal and marine systems, considering relevant available knowledge, including climate change dimension/s in the assessment of their recorded recent expansion. The first record of human toxicity in the Philippines associated with HABs/toxic algal blooms specifically was during the bloom of Pyrodinium bahamense in the Sorsogon, Samar, and Leyte waters in 1983. Since then, the species has been identified to occur and cause blooms in about 44 sites/areas in the country. Recent government reports, i.e., 2021, 2022, and 2023, have also identified other paralytic shellfish poisoning (PSP) causative organisms (Gymnodinium catenatum, Alexandrium spp.) in the country. New records indicate that the presence of PSP causative species has been reported almost year-round in the Philippines. In Malaysia, PSP caused by P. bahamense was initially confined in 1981 to the state of Sabah, Malaysia Borneo, but since then, blooms of this species have been reported almost annually at different scales across the coastal waters of Sabah. P. bahamense and other cyst-forming dinoflagellates could be transported naturally or through human activities. Other eco-physiological and environment factors from the field and the laboratory have been used to study the bloom dynamics and transport of PSP causative species in several areas in the Philippines and Malaysia. More recently, plastics and other marine litter have been considered potential vectors of invasion/transport or expansion of dinoflagellates with other microorganisms. ENSO events have been observed to be stronger since 1950 compared with those recorded from 1850 to 1950. The extreme phases of the ENSO phenomenon have a strong modulating effect based on seasonal rainfall in the Philippines, with extreme ENSO warm events (El Niño) often associated with drought and stresses on water resources and agriculture/aquaculture. In contrast, cold events (La Niña) often result in excessive rainfall. The La Nina Advisories from 2021 to 2023 (18 advisories) showed the persistence of this part of ENSO, particularly in regions with recurrent and new records of HABs/toxic algal blooms. More studies and monitoring of another type of toxic algal bloom, Ciguatera Fish Poisoning (CFP), are recommended in tropical countries such as the Philippines and Malaysia, which have extensive reef areas that harvest and culture marine fish for local and export purposes, as accelerating reports of this type of poisoning have apparently increased and causative organisms have been identified in several areas. There is an urgent need to enhance HAB/toxic algal bloom research and monitoring, particularly those related to climate change, which has apparently impacted these blooms/occurrences directly or indirectly. Local researchers and managers should be made aware of the knowledge and tools already available for their utilization and enhancement to meet local conditions and challenges for potential recurrence and expansion of HABs/toxic algal blooms. Regional and international HAB research and collaboration should be further advanced for the protection of public health and marine resources.

Desain Kearifan Lokal Gorontalo sebagai Bahan Kajian dalam Pembelajaran Sains

The development of science and technology has a spirit that does not necessarily need to be translated, indicating that science can be related to academic studies associated with physics, chemistry, biology, as well as other natural sciences such as geology and astronomy. Science also means looking closely at social, economic, psychological, humanities and even educational phenomena. Lokal wisdom which has the value of indigenous science is a traditional custom passed down from generation to generation in Indonesia which needs to be supported by educational experts to be researched so that it is hoped that it will become scientific science. In Gorontalo there are several studies regarding indigenous science becoming scientific knowledge, such as discussions about panggoba related to astronomy and agrotechnology; payango (in the field of house building engineering/architecture), yinthu tuluhe plant for the health sector (medicine for skin diseases). Other research has been carried out on the benefits of tubile (tuba roots) for fish poison (piscisida), mongubingo which has religious, cultural and health value. However, it is realized that the design of Gorontalo lokal wisdom as study material in science learning is still very poorly studied. Referring to these phenomena and real facts, it is deemed necessary to carry out research using the literature study method (library) with the topic "Gorontalo Lokal Wisdom Design as Study Material in Science Learning."

Structural Assignment of the Product Ion Generated from a Natural Ciguatoxin-3C Congener, 51-Hydroxyciguatoxin-3C, and Discovery of Distinguishable Signals in Congeners Bearing the 51-Hydroxy Group.

Ciguatoxins (CTXs) stand as the primary toxins causing ciguatera fish poisoning (CFP) and are essential compounds distinguished by their characteristic polycyclic ether structure. In a previous report, we identified the structures of product ions generated via homolytic fragmentation by assuming three charge sites in the mass spectrometry (MS)/MS spectrum of ciguatoxin-3C (CTX3C) using LC-MS. This study aims to elucidate the homolytic fragmentation of a ciguatoxin-3C congener. We assigned detailed structures of the product ions in the MS/MS spectrum of a naturally occurring ciguatoxin-3C congener, 51-hydroxyciguatoxin-3C (51-hydoxyCTX3C), employing liquid chromatography/quadrupole time-of-flight mass spectrometry with an atmospheric pressure chemical ionization (APCI) source. The introduction of a hydroxy substituent on C51 induced different fragmentation pathways, including a novel cleavage mechanism of the M ring involving the elimination of 51-OH and the formation of enol ether. Consequently, new cleavage patterns generated product ions at m/z 979 (C55H79O15), 439 (C24H39O7), 149 (C10H13O), 135 (C9H11O), and 115 (C6H11O2). Additionally, characteristic product ions were observed at m/z 509 (C28H45O8), 491 (C28H43O7), 481 (C26H41O8), 463 (C26H39O7), 439 (C24H39O7), 421 (C24H37O6), 171 (C9H15O3), 153 (C9H13O2), 141 (C8H13O2), and 123 (C8H11O).

Molecular level interaction, HOMO-LUMO, MEP, UV–Vis, Hirshfeld, topological analysis, and in-vitro of isoflavones from Eremostachys Vicaryi Benth. Ex Hook. f.

Eremostachys vicaryi Benth. Ex Hook. f. (Labiatae), a Pakistani (Baluchistan) herbal medicinal plant commonly known as “Stagh,” which has a sharp taste and smell. It acts as an antiseptic and antimicrobial agent and is used for fish poisoning, treating skin diseases, and holding a cooling effect. Following the assessment of the plant extract's cytotoxic and phytotoxic assays using phytochemical screening, the antioxidant and anti-inflammatory properties of the pure ingredients that were separated from the ethyl acetate soluble fractions have been evaluated. The bioassay-guided fractionation and purification of E. vicaryi B. crude methanol extract yielded two isoflavones (1–2) that showed promising antioxidative activities with DPPH and cytochrome-c-reduction assays. Compounds 1 and 2 have shown considerable anti-inflammatory efficacy, 1 being a good inhibitor of the superoxide within the living system. Initial assumptions on the one-electron transfer process indicated that Compound 1 has a smaller ionization potential value compared to Compound 2 and so has greater antioxidant potential than its predecessor, isoflavone. Moreover, the anti-inflammatory and antioxidant activity of isoflavones was also probed by first-principles calculations. Based on the findings, it has been concluded that the crude extract of E. vicaryi B. and its organic components exhibit noteworthy phytotoxic and cytotoxic properties. The isolated pure isoflavones 1 and 2 showed significant antioxidant and anti-inflammatory activities. Solute-solvent interactions were studied and reported for both compounds. An analysis was conducted on the UV–Vis electronic transition for different solvents. Using a Multiwave function analyzer the topological findings such as ELF, LOL, and RDG were done to comprehend the surface electron density, delocalization, localized orbital, and weak interaction in the compounds. The antioxidant activity is evaluated by radical methods using DPPH, and cytochrome-c-reduction assays using ascorbic acid as a standard. Through cell-based respiratory burst testing, the anti-inflammatory activity of standard indomethacin was examined. The ground state geometries of isoflavones and reference compounds were optimized by Density Functional Theory- (DFT) by computing various electronic properties. In-vitro bioassay results were validated by first-principles calculations.

Biocultural Diversity of the Ryukyu Archipelago based on the Plant Diversity used as Fish Poison

Biocultural Diversity of the Ryukyu Archipelago based on the Plant Diversity used as Fish Poison

A pilot study on the isolation and identification of histamine-producing bacteria from narrow barred Spanish mackerel and Japanese thread fin bream from Ukkadam fish market, Coimbatore, India

Consumption of marine fishes with high histamine levels due to improper storing leads to cause scombroid or histamine fish poisoning. In spoiled fishes, bacteria begin to break down the histidine into histamine by decarboxylation activity. Previous studies reported that black muscle fishes usually produce large amounts of histamine-producing bacteria (HPB). In this study, two white muscle fishes such as Scomberomorus commerson (Narrow-barred Spanish mackerel) and Nemipterus japonicus (Japanese threadfin bream) were chosen to detect the presence of histamine-producing bacteria (HPB). The fish samples were purchased from Ukkadam fish market in Coimbatore and examined for the occurrence of HPB on Niven agar. The isolated HPB on media were analyzed for identification based on their morphological characteristics, primary test, and biochemical test. Finally, 8 colonies were confirmed as the cause for histamine production of both fishes and among them, 5 belong to the family Enterobacteriaceae and others belong to the family Aeromonadaceae, Morganellaceae, and Enterococcaceae. Our study showed that the histamine-producing bacteria highly reported in dark-muscle fishes were also isolated from the chosen white-muscle fishes. Hence the presence of HPB indicates the improper maintenance of fish in retail fish markets. This considerable incidence of histamine-producing bacteria which on proliferation under suitable conditions may contribute to toxic histamine accumulation in the flesh of fishes.

IDENTIFICATION AND DETERMINATION OF SAPONIN CONTENT FROM EXTRACT OF Embelia borneensis BARK

Abstract Embelia borneensis known sekilang used by the Dayak Kenyah tribe of Long Temuyat Village, Malinau, North Kalimantan as a fish poison and leech repellent. Sekilang bark extract contains alkaloids, tannins, saponins and flavonoids compounds. The purpose of this study was to determine the type and content of saponins in the methanol extract based on different maceration, reflux, and Soxhlet extraction methods. Saponin content was determined by the gravimetric method. The results showed that the type of saponin contained in sekilang bark extract was triterpenoid saponin. The average saponin content with maceration method was 24.87%, reflux method was 28.97 and soxhlation method was 29.99%. The results of data analysis with one-way anova statistical test showed that there was a significant difference between extraction methods on saponin content of sekilang stem bark with sig value of 0.009 with a significant level of 0.05 (5%).