Nutritional significance of rice bran oil.

India is the second largest producer of rice in the world and has the high potential to produce rice bran oil (RBO), a by-product of the rice milling industry. Since RBO is, an unconventional oil, the chemical composition, nutrient evaluation and toxicological safety were assessed. The fatty acid composition RBO is very close to that of groundnut oil (GNO). Though RBO has high unsaponifiable matter (4.2%), it is rich In minor constituents such as phytosterols, triterpene alcohols, tocopherols and tocotrienols. Experimental as well as human studies have demonstrated the hypolipidaemic effects of RBO. Further, It was established that minor constituents present in unsaponifiable fraction of RBO were responsible for its hypolipidaemic effects. Nutritional evaluation studies, carried out with 10 per cent RBO and 20 per cent protein, indicated that growth, feed efficiency and mineral balance were comparable to GNO-fed animals. Toxicological studies had shown that there were no abnormalities In animals fed either RBO or GNO. The reproductive performance was also found to be normal as compared with that of GNO-fed animals in all three generations. In addition, neither RBO nor the foods deepfried in it showed any mutagenicity as judged by Ames test. In view of its safety and hypolipidaemic activity, RBO could be considered as an alternative source of edible oil.

Basic concepts of clinical pharmacokinetics.

Clinical pharmacology is now a well established discipline. Unlike the yester years when dosage schedules were determined by trial and error, in the present day selection of dose, dosage interval and route of administration are based on pharmacokinetic and pharmacodynamic principles. The primary utility of pharmacokinetics is to study the process of absorption, distribution, metabolism and elimination of drugs, fundamental for drug action. Individuals show a wide variation in kinetic parameters due to internal and external factors. Sometimes change in one variable may be compensated by change in another variable so that dose need not be altered e.g. metabolism of some drugs is increased in thyrotoxicosis but due to increased protein binding overall dose adjustment may not be required. On the other hand sometimes variations in these parameters can markedly affect the plasma concentrations of and the pharmacological response to drugs e.g. anticonvulsant treatment in oral contraceptive users, phenylbutazone addition in warfarin therapy. Drug concentrations can be measured in plasma, urine or saliva. Equipped with this knowledge the modern physician will be able to make a wiser use of drugs under altered physiological conditions like pregnancy, lactation, infancy, old age and pathological states like renal and liver failure and shock.