Micheline M. Mathews-Roth

Beta-Carotene Therapy for Erythropoietic Protoporphyria and Other Photosensitivity Diseases

This paper describes the development of the use of carotenoid pigments in the treatment of light-sensitive skin diseases. It also discusses the animal and human studies involved in determining whether carotenoids have any anti-cancer activity. The possible mechanisms of carotenoid photoprotective and anti-cancer actions are briefly discussed.

Erythropoietic protoporphyria 10 years experience

The clinical and laboratory findings in 32 patients with erythropoietic protoporphyria as well as a review of the pertinent literature on this relatively recently described form of porphyria are presented. The disease is thought to be transmitted in an autosomal dominant fashion with variable penetrance and was characterized in these 32 patients by the onset in childhood of burning (97 per cent) and itching (88 per cent) of the skin on exposure to sunlight. This was accompanied by edema (49 per cent) and erythema (69 per cent) of the exposed areas. Vesicles, petechiae and residual scarring occurred less frequently. Associated abnormalities included cholelithiasis (12 per cent), anemia (27 per cent) and abnormal liver function studies (4 per cent). Reports of associated liver disease including nine cases of fatal hepatic failure, are reviewed. Current methods of diagnosis as well as theories of pathophysiology of the disease are presented. Nineteen of 23 of these patients recently treated with beta-carotene responded with significant increase in their tolerance to sun exposure.

Preferential light absorption in atheromas in vitro. Implications for laser angioplasty.

Laser angioplasty, the in situ ablation of arterial obstructions with laser radiation, has been demonstrated in animal models and early clinical trials. A problem with this technique, however, is the possibility of thermal damage to adjacent or underlying normal tissues that also absorb the radiation. Using a spectrophotometer with an integrating sphere and a specially constructed tunable-dye laser-based spectrophotometer, we evaluated the transmittance and remittance of human cadaveric atheromas and adjacent normal aorta from 250 to 1,300 nm to identify wavebands where there is preferential light absorption by atheromas. Data were analyzed by both the Kubelka-Munk formalism and a Beers law model. Both methods indicate that atheromas absorb more than normal aorta between 420 and 530 nm. At 470 nm the average Kubelka-Munk absorption coefficient of atheromas from 10 cadavers was 54 +/- 9 cm-1 compared with 26 +/- 6 cm-1 for normal aortic specimens from seven cadavers. Yellow chromophores responsible for the atheroma absorbance were extractable with xylenes. Thin-layer chromatography and absorption spectra identified the extracted chromophores as predominantly consisting of a mix of carotenoids, which are known constituents of atheromatous lesions. Preferential absorption of blue light by carotenoids in atheromas may permit selective ablation of atheromatous obstructions with appropriate pulses of laser radiation.

CAROTENOID CHROMOPHORE LENGTH AND PROTECTION AGAINST PHOTOSENSITIZATION

Abstract— Carotenoid pigments were extracted and purified from wild‐type and mutants 7 and 93a of Sarcina lutea, and tested for their ability to quench 1O2. The wild‐type pigment (P‐438, 9 conjugated double bonds) is as active in quenching 1O2 as is β‐carotene. On the other hand, the pigment P‐422 (8 conjugated double bonds) from mutant 7 is 2 or 3 times less efficient, whereas phytofluene and phytoene from S. lutea are 100 and 1000 times less efficient, respectively, than is β‐carotene at quenching 1O2. It was also found that the broad EPR signal, induced by light in benzene solutions of chlorophyll a and hydroquinone, and related to chlorophyll oxidation, is efficiently quenched by P‐438 and to a much smaller extent also by Sarcina phytoene.

Beta-carotene therapy for erythropoietic protoporphyria and other photosensitivity diseases

We treated with high doses of oral beta carotene (Solatene) (15 to 180 mg/day) 133 patients suffering from erythropoietic protoporphyria (EPP), 27 patients with polymorphous light eruption, six patients with solar urticaria, three patients with hydroa aestivale, one patient with porphyria cutanea tarda, and two patients with actinic reticuloid to relieve the photosensitivity associated with these diseases. Eighty-four percent of the patients with erythropoietic protoporphyria increased by a factor of 3 or more their ability to tolerate sunlight. On the other hand, only nine of the patients with polymorphous light eruption, and one fifth of the patients with all of the other forms of photosensitivity treated showed similar improvement. We conclude that beta carotene is an effective treatment for EPP, but that other forms of photosensitivity will need empirical therapeutic study with beta carotene to determine the range of effectiveness, if any, of this compound in conditions other than EPP.

PHYTOENE AS A PROTECTIVE AGENT AGAINST SUNBURN (>280nm) RADIATION IN GUINEA PIGS

Abstract— Phytoene, the colorless triene precursor of β‐carotene (17 mg/g body weight) or a placebo was given to guinea pigs by daily intraperitoneal injection for 14 days, after which the animals were exposed to radiation (> 280 nm). It was found that the animals receiving phytoene developed significantly less erythema to the radiation than did the animals receiving placebo.

STUDIES ON THE PROTECTIVE FUNCTION OF THE CAROTENOID PIGMENTS OF SARCINA LUTEA

Abstract— An investigation was made of both the composition of and mechanism of photo‐protection by the carotenoid pigments of Sarcina lutea ATCC 9341a and three induced mutants.

[42] Erythropoietic protoporphyria: Treatment with antioxidants and potential cure with gene therapy

Publisher Summary Erythropoietic protoporphyria (EPP) is a rare genetic disease in which singlet oxygen is involved in the production of its clinical manifestations and singlet oxygen quenchers are utilized in its treatment. In EPP, the enzyme ferrochelatase, which inserts iron into protoporphyrin to form heme, is defective. This defect allows protoporphyrin to accumulate in the blood, from which it makes its way to the skin, as well as to other organs. Protoporphyrin is known to be a powerful photosensitizer, which in the presence of light and oxygen will form free radicals and singlet oxygen. These excited species will attack cellular components, which will eventually lead, via a series of reactions that are unelucidated at this time, to the symptoms of pain, burning, or itching of the light-exposed skin experienced by patients suffering from EPP. This chapter describes a method that can be used to determine the involvement of singlet oxygen in photosensitized skin and also discuss the present treatment for EPP and the possibilities for curing this disease by means of gene therapy.

Erythropoietic Protoporphyria — Diagnosis and Treatment

Erythropoietic protoporphyria is a disease of porphyrin metabolism characterized by abnormally elevated levels of protoporphyrin IX in erythrocytes, feces and plasma, and by sensitivity to visible ...

FAILURE OF CONJUGATED OCTAENE CAROTENOIDS TO PROTECT A MUTANT OF SARCINA LUTEA AGAINST LETHAL PHOTOSENSITIZATION

MUCH evidence has been obtained to show that the carotenoid pigments of nonphotosynthetic bacteria are capable of protecting these cells against lethal photosensitization mediated by endogenous or exogenous photosensitizers [ I]. It has also been shown by Stanier[2] and Crounse et al.[3] that this photoprotection by carotenoids is related to the length of the conjugated double-bond chain of the pigment. Pigments with 7 conjugated double bonds in the molecule were unable to confer photoprotection, whereas pigments containing 9 conjugated double bonds were protective. Earlier reports studied only pigments with odd numbers of conjugated double bonds in the molecule. We wish to report the isolation of a mutant of Sarcina lutea whose major carotenoid pigments contain, as deduced from their spectral characteristics, 8 conjugated double bonds in the molecule. The pigments of this new mutant confer no photoprotection on the organism. The mutant strain, mutant 7, used in this study was obtained by treating S. lutea ATCC 9341a with the mutagen ethyl methanesulfonate, as described previously [4]. The methods of growing and exposing the bacteria to light, and of extracting the pigments were those used in previous studies [4,5]. The pigments of mutant 7 were separated into four distinct fractions by thin-layer chromatography on silica gel sheets using 10% ethanol-90% petroleum ether (b.p. 30-60°C) as developing solvents. The first fraction contained a small quantity of precursor pigments. The three additional pigment fractions, fractions 2, 3 and 4, had identical absorption maxima at 398, 422 and 448 nm. In our study of WT S . lutea, we found that the carotenoid pigments also consisted of a precursor fraction and three main fractions of pigments with identical absorption maxima at 414, 438 and 469 nm indicative of a carotenoid chromophore composed of 9 acyclic conjugated double bonds[4]. The spectra of the fraction 2 pigment of mutant 7 and the corresponding fraction 2 pigment of WT [data from (4)] are presented in Fig. 1. The spectrum of fraction 2 pigment of mutant 7 is similar to that of WT fraction 2 pigment, but the absorption maxima are shifted I6 nm towards the ultraviolet; this hyposchromic shift indicates that the fraction 2 pigment of mutant 7 (and also fractions 3 and 4, since they have identical spectra) are conjugated octaenes, containing one less double bond than do the fraction 2,3 and 4 pigments of WT (6). The spectral characteristics