Identification of cyprinol and cyprinol sulfate from grass carp bile and their toxic effects in rats

Epidermal oxysterols function as alarm substances in zebrafish

Alarm substances signal imminent predation thread and enable anti-predation strategies. In shoaling fish, alarm cues diffuse from injured skins that induce intense fear and anti-predation behaviors in other members. While these "fear substances" are shown to be present in numerous fishes and thought to exist in roughly 8,000 Ostariophysan species, their chemical nature remains largely unknown. We posited that fish alarm cues comprise small compounds and induce specific behaviors characteristic of fish exposed to skin extracts. Using the behaviors as bioassays, we tracked the alarm function of zebrafish skin extract to two compounds, 24-methyl-5α-cholestane-3α,7α,12α,24,28-pentahydroxy 28-sulfate, an oxysterol sulfate, and 5α-cyprinol sulfate. At concentrations of less than one nanomolar, each compound induced anti-predator behaviors and increased cortisol levels in zebrafish. Their mixture, at the natural ratio, replicated the skin extract in eliciting the full suite of anti-predator behavior patterns. Our findings reveal a molecular mechanism whereby fish escape predation danger.

Acute Kidney Injury Following Ingestion of Raw Fish Gallbladder of Indian Crap (Labeo Rohita): Thirty Case Series During 1975-2018

Introduction

Ayurveda describes using desiccated and well-processed gallbladder of Indian carp (Labeorohita) as a traditional remedy for some diseases. People consume it irrationally following the hearsay advice for all types of chronic diseases.

Methods

Here we report 30 sporadic cases of acute kidney injury (AKI) following ingestion of raw gallbladder of Indian carp during 1975-2018 (44 years).

Results

Most of the victims were males (83.3%) with an average age of 37.7 years. The mean onset of symptoms was 2 to 12 hours after ingestion. All patients presented as acute gastroenteritis and AKI. Among them, 22 (73.33%) needed urgent dialysis, and 18 (81.81%) of them recovered with four (18.18%) deaths. Eight patients (26.6%) were managed conservatively, of which seven (87.5%) recovered with one (12.5%) death. Septicemia, myocarditis, and acute respiratory distress syndrome were the causes of death.

Conclusions

This longest four-decade case series highlights that indiscriminate ingestion of raw fish gallbladder by unqualified prescription results in toxic AKI with multiple organ dysfunction and death.

Acute kidney injury with consumption of raw gall bladder of Indian carp fish (Labeo rohita): A single center study from India

AIM

This retrospective study examined the clinical presentation and outcome of all patients who presented with acute kidney injury (AKI) following consumption of uncooked fish gallbladder as folk medicine.

METHODS

We reviewed all cases admitted at our institute between 1 January 1997 and 31 December 2016 following ingestion of fish gallbladder (Indian carp/Labeo rohita).

RESULTS

A total 32 of patients were included, with a male: female ratio of 3:1 and mean age 44.34 ± 13.33 years. The mean number of gall bladder consumed was 4.59 ± 4.75. All 32 patients presented with hepatic and renal failure. The mean duration of onset of symptoms following ingestion was 6.47 ± 2.84 h. At the time of admission, urine output was 187.9 ± 141 mL/24 h, serum creatinine 11.66 ± 2.50 mg/dL, serum bilirubin 6.14 ± 3.91 mg/dL, serum glutamate-pyruvate transaminase (SGPT) 687 ± 458 IU/L and serum glutamic oxaloacetic transaminase (SGOT) 188 ± 181 IU/L. All but one patient required haemodialysis. Twenty-seven patients were discharged with recovering acute kidney injury while five patients died. Mean duration of hospital stay was 12.94 ± 8.31 days. Mean number of haemodialysis sessions received by patients was 4.59 ± 3.12. Interval between consumption and onset of symptoms, serum bilirubin and SGPT were found to be significantly different between those who survived and died.

CONCLUSION

Acute kidney injury associated with ingestion of raw fish gallbladder is associated with significant morbidity and mortality.

Fish gall bladder consumption presenting as acute renal failure

A forty two year old male was admitted with history of anuria and breathlessness following consumption of raw rohu fish gall bladder. He had azotemia and required hemodialysis. His renal failure improved over a period of about four weeks. Incidences have been reported from South East Asian countries associating consumption of raw rohu fish gall bladder with acute renal failure.

Food poisonings by ingestion of cyprinid fish

Raw or dried gallbladders of cyprinid fish have long been ingested as a traditional medicine in the Asian countries, particularly in China, for ameliorating visual acuity, rheumatism, and general health; however, sporadic poisoning incidences have occurred after their ingestion. The poisoning causes complex symptoms in patients, including acute renal failure, liver dysfunction, paralysis, and convulsions of limbs. The causative substance for the poisoning was isolated, and its basic properties were examined. The purified toxin revealed a minimum lethal dose of 2.6 mg/20 g in mouse, when injected intraperitoneally. The main symptoms were paralysis and convulsions of the hind legs, along with other neurological signs. Liver biopsy of the euthanized mice clearly exhibited hepatocytes necrosis and infiltration of neutrophils and lymphocytes, suggesting the acute dysfunction of the liver. Blood tests disclosed the characteristics of acute renal failure and liver injury. Infrared (IR) spectrometry, fast atom bombardment (FAB) mass spectrometry, and 1H- and 13C-nuclear magnetic resonance (NMR) analysis indicated, a molecular formula of C27H48O8S, containing a sulfate ester group for the toxin. Thus, we concluded that the structure of carp toxin to be 5α-cyprinol sulfate (5α-cholestane-3α, 7α, 12α, 26, 27-pentol 26-sulfate). This indicated that carp toxin is a nephro- and hepato- toxin, which could be the responsible toxin for carp bile poisoning in humans.

Indian carp (Labeo rohita) gall bladder poisoning-report of four cases in a single family

The ingestion of Indian carp gallbladder may result in transient hepatitis with subsequent acute renal failure. This case series also illustrates the importance of understanding the use and potential serious complications of alternative medicines. So fish gallbladder poisoning should be considered in unexplained acute renal failure in Chinese and Asian patients. We report four family members who developed acute renal failure and toxic hepatitis at the same time following ingestion of raw Indian carp (Labeo rohita) gall bladder.

Synthesis and olfactory activity of unnatural, sulfated 5β-bile acid derivatives in the sea lamprey (Petromyzon marinus)

A variety of unnatural bile acid derivatives (9a-9f) was synthesized and used to examine the specificity with which the sea lamprey (Petromyzon marinus) olfactory system detects these compounds. These compounds are analogs of petromyzonol sulfate (PS, 1), a component of the sea lamprey migratory pheromone. Both the stereochemical configuration at C5 (i.e., 5α vs. 5β) and the extent and sites of oxygenation (hydroxylation or ketonization) of the bile acid derived steroid skeleton were evaluated by screening the compounds for olfactory activity using electro-olfactogram recording. 5β-Petromyzonol sulfate (9a) elicited a considerable olfactory response at sub-nanomolar concentration. In addition, less oxygenated systems (i.e., 9b-9e) elicited olfactory responses, albeit with less potency. The sea lamprey sex pheromone mimic 9f (5β-3-ketopetromyzonol sulfate) was also examined and found to produce a much lower olfactory response. Mixture studies conducted with 9a and PS (1) suggest that stimulation is occurring via similar modes of activation, demonstrating a relative lack of specificity for recognition of the allo-configuration (i.e., 5α) in sea lamprey olfaction. This attribute could facilitate design of pheromone analogs to control this invasive species.

Petromyzonol sulfate and its derivatives: the chemoattractants of the sea lamprey

Petromyzonol sulfate (PZS) and 3 keto-PZS are bile alocohol derivatives that serve as chemoattractants during the life cycle of sea lamprey (Petromyzon marinus). The sulfonate moiety is crucial perhaps conferring the required solubility for the pheromone that is released into the streams and for the specificity to bind to its receptor. During the life cycle of lamprey, larvae produce copious amounts of 5 alpha-cholan-PZS, and trace amounts of allocholic acid (ACA), which attracts adults to the same breeding ground. Later the spermeating males produce 3keto-PZS, and trace amounts of 3-keto-ACA, which attracts the ovulating females, signaling both its reproductive status and its nesting location for successful reproduction. In both stages, a mixture of components serves as pheromone plume, similar to insects. The receptors for the migratory and the reproductive pheromones need to be molecularly cloned and characterized in order to understand the molecular biology of olfaction in the sea lamprey.

Isolation, partial purification, and characterization of a novel petromyzonol sulfotransferase from Petromyzon marinus (lamprey) larval liver

We have isolated, partially purified, and characterized the 5 alpha-petromyzonol (5 alpha-PZ), (5 alpha-cholan- 3 alpha, 7 alpha, 12 alpha, 24-tetrahydroxy-) sulfotransferase (PZ-SULT) from larval lamprey liver. Crude liver extracts exhibited a PZ-SULT activity of 0.9120 pmol/min/mg in juvenile and 12.62 pmol/min/mg in larvae. Using crude larval liver extracts and various 5 beta-cholan substrates and allocholic acid there was negligible activity, however, with 5 alpha-PZ and 3-keto-5 alpha-PZ the SULT activity was 231.5 pmol/min/mg and 180.8 pmol/min/mg respectively. This established that the sulfotransferase of lamprey larval liver extracts prefers (5 alpha) substrates and it is selective for hydroxyl at C-24. PZ-SULT was purified through various chromatography procedures. Partially purified PZ-SULT exhibited a pH optimum of 8.0, a temperature optimum of 22 degrees C, and activity was linear for 1h. PZ-SULT exhibited a K(m) of 2.5 microM for PAPS and a K(m) of 8 microM for PZ. The affinity purified peak PZ-SULT exhibited a specific activity of 2,038 pmol/min/mg. The peak protein upon SDS-PAGE, correlated to an Mw 47 kDa. Photoaffinity labeling with PAP(35)S, specifically crosslinked the 47 kDa protein, further confirming the identity of PZ-SULT. Partial amino acid sequencing of the putative 47 kDa PZ-SULT protein yielded a peptide sequence (M)SISQAVDAAFXEI, which possessed an overall (approximately 35-40%) homology with mammalian SULT2B1a.

Bile acid composition in snake bile juice and toxicity of snake bile acids to rats

We determined the bile acid profiles in bile juice of snake gallbladders by HPLC on a silica gel RP-18 reversed-phase column. Cholic acid and chenodeoxycholic acid were predominant components in three of four snake species. To elucidate the toxic effect of snake bile acids on rats, a synthetic bile acid mixture was prepared mimicking the bile acid composition of a snake Naja naja atra bile juice. Twenty-four male Wistar rats were divided into four groups and treated orally at 3-day intervals with saline (control group) and different doses (1-3x doses) of the bile acid mixture. After treatment, the following parameters increased: the relative ratios of liver and kidney mass to body mass, the concentrations of red blood cell, hemoglobin and hematocrit in the blood, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, plasma urea nitrogen and creatinine in the plasma, and the levels of urine urea nitrogen and creatinine in the urine. Body mass of rats and the levels of Na+, K+, Ca++ in the urine of rats were significantly decreased, especially for groups treated with 2x and 3x doses of the bile acid mixture. Examination of liver and kidney pathology also showed cell enlargement and lesion in cell integrity in treated groups, especially for groups treated with 2x and 3x bile acid mixture, indicating that short-term toxicity of snake N. naja atra bile acids was significant in rats.

Ichthyotoxic ARF after fish gallbladder ingestion: a large case series from Vietnam

Fish gallbladders are consumed in rural areas of Asia as a traditional medicine to improve symptoms of arthritis, decreased visual acuity, and impotence. Consumption of large amounts of this traditional medicine can result in systemic toxicities; in particular, acute renal failure. We reviewed records of all admissions to Cho Ray Hospital (Ho Chi Minh City, Vietnam) between January 1995 and December 2000 after this ingestion. Clinical courses and outcomes were similar in 16 of 17 patients. Within hours, patients experienced profuse vomiting (n = 16) and diarrhea (n = 15). All developed acute renal failure, with a mean serum creatinine concentration of 14.7 +/- 3.9 mg/dL (1,299.5 +/- 344.8 micromol/L). Four patients administered intravenous fluid (IVF) developed extracellular fluid volume overload, as did 1 patient not administered IVF. Time to peak creatinine concentration was 8.6 +/- 3.0 days, which was accompanied by decreased urine volume (174.7 +/- 161.6 mL/24 h). Blood pressure remained normal, with a mean arterial pressure of 91 +/- 12 mm Hg. Twelve patients required renal replacement therapy. A mean of 1.9 +/- 1.1 hemodialysis sessions was performed per patient. Sixteen patients recovered renal function; 1 patient died of fulminant hepatic failure. Kidney biopsies showed features of acute tubular injury. Acute renal failure after fish gallbladder ingestion is characterized by a failure to respond to IVF, an 8.6-day interval to peak creatinine level, frequent need for dialysis therapy, and findings on renal biopsy consistent with acute tubular necrosis. Acute renal failure after fish gallbladder ingestion has an excellent prognosis. However, death from fulminant hepatic failure can occur.

Effect of chenodeoxycholic acid on the toxicity of 5alpha-cyprinol sulfate in rats

Attempts are made to elucidate the effect of bile acid chenodeoxycholic acid on the toxicity of bile alcohol 5alpha-cyprinol in rats. Twenty-four male Wistar rats were divided into four groups and treated orally at 3-days periodic treatment with each 160 mg/kg of 5alpha-cyprinol sulfate/chenodeoxycholic acid (9:1), 5alpha-cyprinol sulfate and chenodeoxycholic acid for 19 days. After treated with 5alpha-cyprinol sulfate/chenodeoxycholic acid (9:1), 5alpha-cyprinol sulfate and chenodeoxycholic acid, the relative ratios of liver and kidney weight to body weight, the concentrations of red blood cells (RBC), hemoglobin and hematocrit in the blood, the levels of aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), blood urea nitrogen (BUN) and creatinine in the plasma, and the levels of BUN and creatinine in the urine of rats were significantly increased, but body weight of rats and the levels of Na(+), K(+), Ca(++) in the urine of rats were significantly decreased, especially for both groups of 5alpha-cyprinol sulfate/chenodeoxycholic acid (9:1) and 5alpha-cyprinol sulfate. The pathological examination of liver and kidney also showed the cell enlargement and lesion in cell integrity in these treated groups, especially for both groups with 5alpha-cyprinol sulfate/chenodeoxycholic acid (9:1) and 5alpha-cyprinol sulfate. The toxicity of 5alpha-cyprinol sulfate/chenodeoxycholic acid (9:1) and 5alpha-cyprinol sulfate was similar to each other, and the toxic effect of chenodeoxycholic acid was less.

Short-term toxicity of grass carp bile powder, 5alpha-cyprinol and 5alpha-cyprinol sulfate in rats

We compared the short-term toxicity of toxic components of grass carp bile juice (GCBJ) in rats. Twenty-four male Wistar rats were divided into four groups and treated orally every 3 days with 40 mg each of freeze-dried GCBJ powder, 5alpha-cyprinol and 5alpha-cyprinol sulfate for 19 days. After treatment, the relative ratio of liver and kidney weight to body weight, the concentrations of RBC, hemoglobin and hematocrit in the blood, the levels of aspartate amino transferase, alanine amino transferase, alkaline phosphatase, blood urea nitrogen and creatinine in the plasma, and the levels of urinary urea nitrogen and creatinine in the urine were significantly increased. Body weight of rats and the levels of Na+, K+, Ca2+ in the urine were significantly decreased, especially for groups treated with GCBJ powder and 5alpha-cyprinol sulfate. Pathological examination of liver and kidney also showed cell enlargement and lesions, especially for groups treated with GCBJ powder and 5alpha-cyprinol sulfate. The grass carp bile juice exhibited significant toxicity, and the short-term toxicity of 5alpha-cyprinol sulfate and GCBJ powder was similar to each other. Renal but not hepatic failure induced by grass carp bile juice could be prevented by pentoxifylline.