Determination of the Compatibility, UV Resistance of Extracted Plant Pigments in Emulsion Paints and the Effects of Inhalation on Haematological Parameters of Wistar Rats

Abstract

The present study was designed to determine the effect of extracted plant pigments of Curcuma longa rhizome, Hibiscus sabdariffa flower and inorganic colourants in emulsion paint as it relates to the haematological activities in Wistar rats. The 24-hours acute toxicity test (LD50) of the different mixtures of the colourants in emulsion paint exposed to Wistar rats was determined using Lorke’s method. Wistar rats weighing between 120g to 150g were randomized into eight groups (A – H) of five rats each. Different group of rats (groups A to H) were exposed to different mixtures of organic and inorganic colourants in emulsion paint for six months. Group A was exposed to white emulsion paint only, Group B was exposed to 20mls of Curcuma longa paste in white emulsion paint. Group C was exposed to 20mls of Hibiscus sabdariffa pigment in white emulsion paint. Group D was exposed to 20mls (1:1) combination of C. longa and H. sabdariffa. Group E was exposed to 20mls of C. longa paste and inorganic yellow oxide paste in white emulsion paint, Group F was exposed to 20mls (1:1) combination of H. sabdariffa paste and inorganic red oxide paste in white emulsion paint. Group G was exposed to 20mls (1:1) combination of yellow oxide paste and red oxide paste in white emulsion paint. Group H was the Normal Control which was not exposed to paint. All animals were allowed free access to commercial rat mash and distilled water throughout the six months of exposure. The results revealed that the 24-hour acute toxicity test did not record any mortality. The Curcuma longa paste and Hibiscus sabdariffa paste were completely miscible and compatible with other components of the paint although they degraded or faded in colour faster on exterior application than interior application. The fading of the colours exposed externally compared to the ones exposed internally can be attributed to the effect of sunlight, rain and intense temperature from the ultra-violet rays. the exposure of the rats to the different paint samples reveal a non- significant increase or decrease in the haemoglobin concentrations compared to normal control group H from 2nd to 6th month apart from group D which showed a significant decrease (p<0.05) in haemoglobin concentration within the first month of the experiment compared to normal control. Group C and D also showed a significant decrease (p<0.05) in the packed cell volume concentration at 5th month and 1st month of exposure respectively compared to the normal control (group H). There was a significant decrease (p<0.05) in the red blood cells of group D compared to the control group H at the first month. Also, a significant increase (p<0.05) in the concentration of the white blood cell was noticed on first month of exposure compared to the control group H. However, it was also interesting to note the compatibility of the plant extracts with conventional paint components but the alterations in the red blood cells and white blood cells could be attributed to the level of toxicity of the different paint samples and prolonged inhalation of the paint fumes by the wistar rats.