This seventy-ninth volume of IARC Monographs contains evaluations of the carcinogenic risk to humans of 19 chemicals that have produced thyroid tumours in rodents. Unless otherwise stated, the term ‘thyroid tumour’, as used in this volume, refers to neoplasms of thyroid follicular cell origin. These substances have diverse uses. A number are used as drugs, including socalled ‘anti-thyroid’ agen...

The objective of this study was to quantitatively evaluate mycotoxins in samples of maize and poultry feed produced in Brazil. A multimycotoxin method based on HPLC-MS/MS was applied to investigate the occurrence of toxical fungal metabolites in 119 samples collected from poultry feed factory integrated poultry farms: maize grain (74), poultry feed (36), and feed factory residue (9). Twenty of ...

Objective: Kojic Acid (KA) is a natural substance which inhibits skin melanin production and, when used alone or in combination with other compounds, is effective in reducing pigmentation in melasma patients. KA was classified by IARC as presenting limited evidence of carcinogenicity based largely on a single study showing thyroid neoplasms. More recently KA has been shown to be carcinogenic in...

Skin-lightening agents such as kojic acid, arbutin, ellagic acid, lucinol and 5,5′-dipropylbiphenyl-2,2′-diol are used in ‘anti-ageing’ cosmetics. Cases of allergic contact dermatitis caused by these skin-lightening agents have been reported (1, 2). Vitamin C and its derivatives have also been used in cosmetics as skin-lightening agents for a long time. Vitamin C in topical agents is poorly abs...

The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin...

melanin protects the skin from the harmful effects of sunlight, but unwanted hyperpigmentation can also produce significant psychological stress. Melanin is synthesized in the melanosomes in melanocytes, which produce melanin by a process that involves the transformation of tyrosine into 3,4dihydroxyphenylalanine (L-DOPA) by the enzyme tyrosinase and the subsequent transformation of L-DOPA into...

In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, and N,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a-5f) showed the most potent mushroom tyrosinase inhibition (IC₅₀ values in the range of 4.39 ± 0.76-1.71 ± 0.49 µM), compara...

PURPOSE The aim of this study was to investigate acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and antityrosinase activities of extracts from ten Piper species namely; P. caninum, P. lanatum, P. abbreviatum, P. aborescens, P. porphyrophyllum, P. erecticaule, P. ribesioides, P. miniatum, P. stylosum, and P. majusculum. METHODS Anticholinesterase and antityrosinase activities were e...