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Deaths Due to Asphyxiant Gases
Published in Sudhir K. Gupta, Forensic Pathology of Asphyxial Deaths, 2022
Naturally, cyanides are found in bitter almonds; and fruits like apricot, peach, plum, and cherry. These contain cyanogenic glycoside (amygdalin), which is hydrolyzed during digestion to release hydrocyanic acid.1 Laetrile (another name for amygdalin derived from apricot kernels), which was formerly used as an anticancer agent, releases cyanide upon metabolism.2
The Non-Prescription Products – Market-Profits and Public Health in Conflict
Published in Mickey C. Smith, E.M. (Mick) Kolassa, Walter Steven Pray, Government, Big Pharma, and the People, 2020
The APhA (now known as the American Pharmacists Association) has several publications which reveal the organization’s attitude toward quackery. As previously stated, the organization’s attitude against quackery in 1963 was sufficiently negative to result in an anti-quackery-themed issue of the Journal of the American Pharmaceutical Association. In 1975, an editorial in the same journal bemoaned the New York Times’ acceptance of laetrile for cancer (668). The newspaper apparently stated that laetrile may be ineffective, but at least it would be harmless. The editorial forcibly disagreed with the sale of ineffective remedies, even though they might be harmless.
Cancer Ward
Published in Borys Surawicz, Beverly Jacobson, Doctors in Fiction, 2018
The patients are stirred by the widely circulating rumor about the discovery of a cancer cure in an extract from a fungus named chaga growing on birch trees. A researcher, Maslennikov, had observed that the peasants in his district brewed chaga as a substitute for real tea and had no cancer, connecting the two observations in his mind. But even in the absence of proof that chaga cures cancer for all patients with advanced malignancy, this treatment becomes a ray of hope to which the patients cling while awaiting scientific confirmation and the release of the alternative treatment. This is similar to the hopes of cancer patients in the United States expecting to be cured by laetrile, who remained undeterred by publications reporting the complete ineffectiveness of this compound.
Molecular mechanism of amygdalin action in vitro: review of the latest research
Published in Immunopharmacology and Immunotoxicology, 2018
Przemysław Liczbiński, Bożena Bukowska
The first theories on anticancer properties of amygdalin and laetrile concerned the role of β-glucosidase in cancer cells5. This enzyme is responsible for conversion of amygdalin, it hydrolyzes glycosidic bonds, and thus mediates generation of HCN. Krebs Jr. based this thesis on the fact that β-glucosidase content is significantly higher in cancer tissues than in physiologically unchanged tissues, which leads to a greater HCN release. In addition, in physiologically unchanged cells, such as hepatocytes and nephrocytes, the rhodanese enzyme responsible for the removal of HCN from the organism is present. Cancer cells also contain the rhodanese enzyme and its amount is comparable to that found in normal cells in the liver and kidneys, making it hard to be attacked by cyanide6. The mechanism proposed Dr. Krebs and Krebs Jr. suggesting that glucosidase activity concerns only cancer cells has also occurred to be wrong because this enzyme has been found (but in lower amounts) in physiologically unchanged tissues7,8. Naming the vitamin B-17 in 1970 created a new concept, which aimed to circumvent the ban on the use of medicines. The ban did not include the use of vitamins, including vitamin B-179. To date, in 1977, The U.S. Food and Drug Administration (FDA) banned shipping amygdalin and laetrile in 23 states of the USA10.
Rebound metabolic acidosis following intentional amygdalin supplement overdose
Published in Clinical Toxicology, 2020
Rachel M. Shively, Stephen A. Harding, Robert S. Hoffman, Adam D. Hill, Alfredo J. Astua, Alex F. Manini
Amygdalin is a cyanogenic glycoside found in seeds of the genus Prunus. As a supplement, it has been marketed as “Amygdalin,” “Vitamin B-17,” and “Laetrile.” Amygdalin is hydrolyzed by the enzyme beta-glucosidase into hydrogen cyanide (HCN), benzaldehyde, and glucose. Cyanide then exerts toxicity via inhibition of oxidative phosphorylation [1]. Mammalian cells contain trace amounts of beta-glucosidase, mostly in the liver [2]. However, gastrointestinal (GI) bacteria have large amounts, allowing for substantial cyanide production with amygdalin ingestion [3]. As toxicity does not occur until amygdalin is metabolized to cyanide, toxic amygdalin ingestions present in a delayed fashion.
Antitumor Action of Amygdalin on Human Breast Cancer Cells by Selective Sensitization to Oxidative Stress
Published in Nutrition and Cancer, 2019
Muayad Mehdi Abboud, Wajdy Al Awaida, Hakam Hasan Alkhateeb, Asia Numan Abu-Ayyad
Amygdalin C20H27NO11 is a cyanogenic glycoside compound derived from the aromatic amino acid phenylalanine (1). This natural product is mainly present in the seeds of apricot, peach, bitter almond, plum, and apple (2). Laetrile is simpler semisynthetic form produced by a chemical modification of amygdalin. Both amygdalin and laetrile can be hydrolyzed to yield common components of D-glucuronic acid and L-mandelonitrile (3,4). The latter is further broken down to produce benzaldehyde and hydrocyanic acid. The generation of hydrocyanic acid from amygdalin is performed by the enzyme β-glucosidase, which shows 1,000 – 3,000 times higher activity in tumor cells than in normal cells (5). This difference in enzyme activity permits tumor cells to accumulate excessive amounts of liberated hydrocyanic acid with antineoplastic activity. A further detoxification of hydrocyanic acid to thiocyanate requires another enzyme called rhodanese (6), which is more active in normal tissues but has almost negligible activity in cancer cells (7). Thus, it was proposed that a combination of abundant cyanide-liberating β-glucosidase activity together with a deficiency of the cyanide-detoxifying rhodanese activity, could provide a selective advantage for the killing of cancer cells by amygdalin without having substantial harmful effects on normal cells (5). By taking advantage of this interesting cell-killing approach, many attempts have been made to use amygdalin as an anticancer agent against human tumors. The earliest human trial was dated back to 1845 in Russia, when positive results were reported on the first treatment of cancer patient with amygdalin (8). In 1920, a similar attempt to treat cancer patients with amygdalin was conducted in the USA; but the drug was considered too toxic and its use to treat human cancer was abandoned. Later on, a more soluble and less toxic form of amygdalin was developed in 1950, which was commercially referred to as laetrile (9). However, at high doses even the laetrile itself could have adverse effects due to possible development of liver injury, damaged nerves, fever, and coma (10). These side effects appear to depend on the route of laetrile administration, with oral uptake showing much higher toxicity than the intravenous, intraperitoneal, or intramuscular injection (10). Furthermore, recent epidemiological studies on animal experiments found little antitumor activity of laetrile, which was supported by the failure of this compound to show effective anticancer therapy during human trials (11). These disappointing clinical data together with the potential of developing toxicity have discouraged the Food and Drug Administration (FDA) in the USA from approving laetrile as an anticancer agent in human therapy (11).