C O l l P h R h T I \ - E IKFLUESCE OF SUSLIGHT, I R O S PREPARAT I O S S AXD YITXlIISS Ih’ T H E l l h I S T E X . \ S C E O F HEALTH BY C. C. PALIT, R . K . KACL A S D S . R . DHAR
It is well known that substances like sugar, starch, fats and proteins do not osidise in air at the ordinary temperature but they are readily oxidised at the body temperature inside the animal body. I n previous communications’ from these laboratories, we have tried to explain the mechanism of the oxidation in the animal body and we have imitated these oxidation reactions. IVe have proved that the food materials can be oxidised by passing air at the ordinary temperature when they are mixed with reducing agents like sodium sulphite, ferrous hydroxide, cerous hydroxide, manganous hydroxide etc. It is well known that there are certain reducing agents in the animal body and these reducing agents when oxidised by atmospheric osygen inside the body, are likely to induce the oxidation of food materials. Moreover, these food materials have been oxidised by us by passing air at the ordinary temperature in presence of sunlight. Also all these substances have been osidised by hydrogen peroxide in presence of ferrous or ferric salts at a temperature of about 4o°C. Having induced the oxidation of food materials by passing air in presence of sunlight, we have carried on experiments on the metabolism in animals in presence and in absence of sunlight. We have also compared the influence of sunlight with that of substances containing vitamins and iron preparations on animal metabolism. We have carried on experiments with pigeons and white rats. We divided the pigeons and rats among six compartments, each containing four pigeons and four rats respectively. The first compartment had sufficient amount of sunlight for about six hours, the second, fourth, fifth and the sixth ones had diffused light, while the third one was quite dark. The arrangements were the same jn the case of the rats. All the six sets-pigeons and rats-were given polished (Rangoon) rice-which is known as being entirely devoid of vitamins-as food. The first and the third sets were given only rice, the second set was given z j grms of ‘palak’ (spinacia oleracea) juice and I O grms of ‘palak’ leaf, the fifth set was given 2 s grms of ‘bathua’ (chenopodiuni album) juice and I O grms of ‘bathua’ leaf and the sixth set was given 2 j grms of tomato together with the same amount of rice in each case. The fourth set was given 2 j C.C.of colloidal ferric hydroxide ( 2 5 C.C.= 0.002 gnn. of Fe per 3 pigeons or 4 rats) or z j C.C.of very dilute solution of ferric chloride ( 2 j C.C. = 0.00086 grm. Fe per 4 pigeons or 1 rats) together with the same amount of rice. This diet was continued for three weeks. For the first week, they were found to be quite well, though there were very slight decrease in their weights. During the second week, no remarkable change but decrease Palit and Dhsr: J. Phys. Chem., 29, 799 (1925);3 0 , 939 (1926).
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R. DHAR
in their weights was noticed, but a t the end of this period, most of the pigeons in the third set had stomachic troubles. During the third week, the third set which was kept in the dark, and the fourth set which was given colloidal ferric hydroxide, were found to be ill which turned serious day by day, Moreover it was found that all those that were ill had stomachic troubles and had their eyes greatly affected. All of them practically lost their moving power and showed symptoms of polyneuritis and beri-beri. At the end of the third week, the pigeons fed with ‘palak,’ (spinacia oleracea) ‘bathua’ (Chenopodium album) and tomato were affected one after the other and became ill. The third set which was kept in the dark was found to be most affected. The order in which they were affected was the following:Set No. I11 > set No. I\‘ > set No. I1 > set No. V > set No. VI, while the set KO.I was not ill a t all, though there was a considerable decrease in their weights. The diet was a t once changed and the rice was discontinued. Those that were seriously affected and practically lost their eye-sight and moving power, were given milk, tomato juice, whole wheat and other substances rich in vitamins for the first two days, after which when they improved a little, were given a small quantity of “bajra,” (Pennisetum typhoideum) and gram along with other substances. All the rest were given ‘‘bajra”, (Pennisetum typhoideum) and gram. Those that were seriously affected and could not take their food, were separated from the rest and exposed to sunlight daily for three to four hours and were fed artificially with milk and tomato juice. Within a week the symptoms of beri-beri and polyneuritis disappeared and had their stomachic troubles removed. All of them were found to gain in weight and ultimately recovered perfectly. The first set which had sufficient amount of sunlight, though rendered weak, did not show any sign of beri-beri or polyneuritis at all. The second, fifth and sixth sets which were given ‘palak’, ‘bathua’ and tomato, were not as much affected as the third and the fourth sets, though they were not exposed to sunlight. I t was also found that iron preparations given in very small doses (Fe = 0.00086 p.for 4 pigeons per day) is beneficial whereas in larger doses (Fe = 0.002 grm. for 4 pigeons per day) become harmful. These iron preparations appeared to have more favourable action on rats than on pigeons. All these experiments were repeated and the same results were obtained showing that the results are reproducible. With the rats exactly similar results were obtained as in the case of the pigeons. When these birds and rats are fed on polished rice and kept in diffused daylight, they also develop the same troubles as described before. Our results show that the animals receiving sunlight and no substances containing vitamin A, B or C and fed on polished (Rangoon) rice, kept good health for about three weeks whilst the same number of animals-pigeons and rats-getting the same food but no sunlight, developed stomachic troubles after a fortnight and acute form of polyneuritis and paralysis and their eyes were highly affected. Our experiments show that the addition of leafy vegetables like ‘palak’ (spinacia oleracea), ‘bathua’ (chenopidium album) etc. to polished rice have beneficial effect but their influence is less than that
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of sunlight. Tomatoes and small doses of ferric chloride ( 2 j C.C. = 0.00086 grm of Fe for 4 pigeons or 4 rats per day) are also beneficial. In slightly larger doses (25 C.C. = 0.002 grm of Fe for 4 pigeons or 4 rats per day) is not helpful as is quite evident from our experiments. From our results we conclude that sunlight is more efficacious than leafy vegetables and tomatoes, when the animals are fed with polished (Rangoon) rice. In previous papers,’ we have suggested that vitamin A acts as promoters in the oxidation of fatty food materials and \+tamin B as promoter in that oxidation of carbohydrates. From our experiments it seems likely that sunlight acts as an accelerator of all kinds of food materials and can replace at least for a limited period vitamin A and B. It is, therefore, evident that in poor tropical countries like India and China, where the quality of food materials is unsatisfactory and also insufficient from the vitamin point of view, deficiency diseases would have been more prevalent, had not the compensating agent, the sunlight, been present. We are convinced that in tropical countries, the metabolism in the animal body is helped by sunlight and hence several diseases are avoided. McCollum and Simmonds (The Sewer Knowledge of Kutrition-3rd Edition 192j page 5 1 2 ) have advanced the view that leafy vegetables (sdk) have been the protective food of the Indians, because they contain vitamin A. We are of opinion that the beneficial effect of the leafy vegetables is not due mainly to the vitamin content but is also due to their iron content. We have repeatedly shown that iron is a marked accelerator in the oxidation of the food materials. We have carried on systematic analysis of the iron content of many leafy and other vegetables and the results are as follows:Name of substance taken for analysis
Amount of ash taken in gm.
Palak (Spinacia oleracea)
I
Bathua (Cenopodium album) Methi (Trigonella Foenum-Graecum) Tomato
0,7754
,1256
Percentage amount of iron found I
.69
1.13
I . 5278
I .92
0.5480
1.45
From our researches, it will be seen that polyneuritis and beri-beri can be avoided by sunlight and hence the following statement of Maye? is
erroneous :“Deficiency diseases which may be counteracted by vitamins ere specially prevalent in the tropics and seem not affected by ultra-violet light, e.g. beri-beri and scurvy. Experiments with vitamins other than antirachitic and deficiency diseases other than rickets seem to have met with no success”. ‘Chemie der Zelle und Gewebe, 12, 217,225, 317 (1925); 13, zog (1926). “Clinical Application of Sunlight and Artificial Radiation,” 70 (1926).
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Recently Campbell’ has found no effect of radiation from a mercury vapour lamp on the metabolism of men, rats and mice. Our results are not in agreement with Campbell’s observations. We have proved that food materials can be oxidised in presence of sunlight by passing air at the ordinary temperature. R e have also been able to oxidise cholestrol in presence of light at, the ordinary t,emperature. These results are interesting in view of the recent observations of different, workers who have stated that inert food materials irradiated with the quartz mercury vapour lamp may be endowed with antirachitic qualities. It seems likely that these food materials when exposed to light take up oxygen from air and form a compound of the peroxide type Xvhich can oxidise any other food materials when mixed with it. Consequently the addition of the exposed substances to ordinary food materials facilitates the proper assimilation of ingested food stuff and hence we observe the efficacious results. The number of food materials that can be made antirachitic by simply exposing them to light is far from being limited. Steenbock and Daniels state that, it is a property quite common to food of both plant and vegetable origin. We are of opinion that these substances on exposure t o light take up oxygen directly and become converted into peroxides which can oxidise the foods taken into the system. We have found that when a stream of oxygen is passed through a solution of olive oil in benzene or cholesterol in alcohol in presence of sunlight for two hours, an appreciable amount of the substance of the peroxide type is formed in both the cases, but the peroxide compound formed in the case of olive oil is much greater than that formed with cholesterol. These substancesperoxide type-when acidified with dilute sulphuric acid, decolourise potassium permanganate very quickly and then the pink colour of the permanganate slowly disappears and takes up more permanganate little by little. This very phenomenon was also observed in the case of the oxidation of potassium oxalate and sodium nitrite and has already been mentioned in one of our previous publications.2 They also liberate iodine from potassium iodide and when compared colorimetrically, it was observed that the amount of iodine liberated from olive oil was much greater than that liberated from cholesterol. We have further observed that olive oil can be retained in that activated or excited state for a sufficient length of time if kept in the dark, but this phenomenon was not observed in a marked degree in the case of cholesterol, as it was found to have lost its active state in the course of a few days. Hence t,hese facts corroborate our previous statements regarding the oxidation of food materials in the animal body. I n this connection, it will be interesting to note that E. Baur and C. Neuweiler3 obtained hydrogen peroxide in aqueous suspensions of zinc oxide exposed to sunlight. 1
3
Proc. Roy. Soc., 99B,451 (1926) J. Phys. Chem., 3A, 939 (1926). Helv. Chim. Acta, 10, 90 (1927).
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summary
Experiments on pigeons and rats show that they do not get polyneuritis when fed on Rangoon rice alone provided they get some sunshine. 2). Leafy vegetables like Palak, Bathua, etc. and tomatoes when mixed with polished rice appear less effective than sunlight in the prevention of polyneuritis and eye troubles. Colloidal ferric hydroxide and ferric chloride in very small doses are as effective as the above vegetables. 3). Analysis shows that common leafy vegetables contain iron and hence the usefulness of leafy vegetables in the prevention of deficiency diseases is not only due to the presence of vitamins in them but is also due to their iron contents. 4). In tropical countries many deficiency diseases are avoided due to sunlight. 5 ) . When substances like cholesterol, olive oil etc. are exposed to light in presence of air, peroxides are formed and these induce the oxidation of food materials mixed with them. Hence the antirachitic and beneficial properties of substances when exposed to light and not containing the necessary vitamins, are due to the presence of peroxides, which help the oxidation of food materials in the animal body. The substances can acquire antirachitic properties when exposed to light only in presence of air or oxygen. I).
Chemical Laboratory, University of Allahabad, India. July 2, 1968.
