the present invention concerns methods for lowering serum cholesterol , triglycerides and glucose levels in subjects with obesity and diabetic conditions or prophylactically holding in check the symptoms of such a disease state . in particular , the applicants , during their study , have observed that the pregnadienone , 3β - hydroxypregna - 5 , 16 - dien - 20 - one represented by the structural formula ( ii ) shown hereinbelow and in the accompanying drawings is useful for the treatment of hypolipidemic and hypoglycemic conditions . accordingly , the invention provides a method of using compounds represented by the structural formula ( i ) as shown in the accompanying drawings , containing at least one olefinic bond in or on their d - ring for the treatment of hypolipidemic and hypoglycemic conditions in mammals , said method comprising administering an effective amount of the said compounds to recipient mammals . in one embodiment , the compounds of formula ( i ) are administered in the form of tablets , capsules or injectibles . in another embodiment , the compounds of formula ( i ) are characterised as pregnadienones and pregnadienols . in yet another embodiment , the most preferred compound belonging to the family of preganienones and pregnadienols represented by formula ( i ) is 3β - hydroxy - pregna - 5 , 16 - dien - 20 - one , which is represented by the structural formula ( ii ) as shown in the accompanying drawings . in a further embodiment , the compounds of formula ( i ) are optionally administered to the recipient mammal as an admixture with conventional anti - platelet , anti artherosclerotic , hypolipoproteinic and antidiabetic drugs . in still another embodiment , the compounds of formula ( i ) are essentially free of side effects associated with conventional hypolipidemic and hypoglycemic drugs . in an embodiment , the compounds of formula ( i ) exhibit cardioprotective , anti - diabetic , anti - artherosclerotic and anti - oxidant properties . further , the invention provides a method of treatment of hypolipidemic and hypoglycemic conditions in mammals , which comprises administration to a recipient , a therapeutic composition comprising an effective amount of compound of formula ( i ) with conventional carriers . in an embodiment , the recipient mammals are selected from the group comprising rats , human beings , rhesus monkeys and rabbits . in another embodiment , the conventional carriers are selected from anti - platelet , anti - artherosclerotic , hypolipoproteinic and anti - diabetic drugs . in yet another embodiment , the said compounds of formula ( i ) essentially contain an olefinic bond in or on their d - ring . in a further embodiment , the compounds of formula ( i ) are essentially free of androgenic , progestinal and side effects . in still another embodiment , the therapeutic composition is administered in the form of tablets , capsules and injectibles . in another embodiment , the said preganadienones and preganadienols exhibit cardio protective , antidiabetic , antialtheroselerotic and antioxidant properties . in yet another embodiment , the said preganadienones and pregnadienols of formula i essentially contain olefinic bond in one of the d - rings . the methods of synthesis are essentially known in the literature , can be obtained from diosgenin by chemical degradation [ g . rosenleranz “ history of steroids ”, steroids , 57 , 409 ( 1992 )]. although , it was later isolated from veratrum grandiflorum [ kanko , k . et al ; phytochemistry , 12 , 1509 ( 1973 )] but yield is too low to be of any practical value . oppenauer oxidation of 2 with aluminium - isopropoxide and cyclohexanone in toluene produces 4 , 16 - dienpregna - 3 , 20 - dione [ 16 - dehydroprogesterone , ( 3 )]. the c - 16 ( 17 ) olefinic bond in 1 is selectively reduced with pd - c in diethylether at very low hydrogen gas pressure . the resultant product 4 on basic hydrolysis furnishes 5 . the procedure of benn and dodson [ j . org . chem . 29 , 1142 ( 1964 )] was followed for the preparation of gugulsterone ( 9 ). the reduction of 16 - dpa ( 1 ) with lithium aluminium hydride produces diol 6 which after sigmatropic rearrangement in presence of p - toluenesulphonic acid , acetic acid and acetic anhydride produces the diacetate 7 . basic hydrolysis of the diacetate 7 , followed by oppenauer oxidation furnishes an 80 : 20 mixture of e & amp ; z - gugulsterone ( 9 ). the primary hypolipidemic effect of these compounds were established in triton induced hyperlipidemia in charles foster rats . the compounds which exhibited significant lipid lowering effect in this model were then evaluated for their hypolipidemic effect in normal , and diet induced hyperlipidemic rats , rabbits and rhesus monkeys . the cholesterol lowering effect of some representative compounds of pregrenadieniols and pregrenadienones as compared to clofibrate and gugulsterone in triton treated charles foster rats is described in table - 2 . the results showed that of the compounds tested , the highest effect was exhibited by 16 - dpa ( 1 ) and its 3 - des - acetyl analog 2 comparable to gugulsterone ( 9 ), and that the removal of double bond in ring d of 1 or 2 almost abolished the effect . in normal rats , 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ), at 50 mg / kg produced a significant lowering of serum cholesterol and triglycerides as describe in table - 3 below . the animals did not develop any tolerance to the compound even after administering for 30 days . twenty three normal male rats average weight 110 - 120 g were taken for study and were divided into four groups . group i : animals received special diet and 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) 50 mg / kg p . o . in 1 % gum acacia . group ii : animals received 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ). 100 mg / k p . o . in 1 % gum acacia and special diet . group iii : animals received special fat diet and 1 % gum acacia and served as control . group iv : aniniials were fed with stock diet and served as normal control . all animals were sacrificed at the end of 36 days blood was drawn from the tail at 10 days and from the aorta at the time of sacrifice for estimation of serum cholesterol , triglycerides and hdl - cholesterol . ldl - cholesterol was calculated as described . [ roschlau , p . in : methods of enzymatic analysis 4th ed . h . u . bergmeyer ., ed ( academic press , new york ) 1975 p 1890 ; wahlefield , w . a . in : methods of enzymatic analysis ., 4th ed . ; h . u . bergmeyer , ed . ( academic press , new york ) 1974 p 1831 .] animals treated with 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ), at 50 and 100 mg / kg showed a significant lowering in serum cholesterol by 31 and 59 %, triglycerides by 55 and 62 %, ldl - cholesterol by 27 and 74 % respectively ( table - 4 & amp ; 5 ). effect of 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) was studied on hypercholesterolemic albino rabbits . twelve male albino rabbits ( approx 1 . 5 - 2 kg ) on a stock diet were made hyperlipidemic by feeding daily cholesterol 0 . 5 g / kg in 2 ml of groundnut oil for 45 days and then blood was drawn from the marginal vein in the ear of rabbits for serum cholesterol and triglycerides estimation . two controlled experiments were carried out for a period of three months . in one set of experiments , the control group received 0 . 5 g / kg of cholesterol for 90 days and 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) in dose of 100 mg / kg and 50 mg / kg while in the control group ( given only cholesterol ) a massive rise of serum cholesterol and triglycerides were seen after 90 days , the addition of 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) at 50 and 100 mg / kg doses kept the rise well under control . the percentage decrease at 100 mg dose was 28 % at 30 days to 52 % at 90 days for cholesterol and 45 to 81 % for triglycerides . in the 50 mg / kg dose group the decrease percentage ranged from 40 % at 30 days to 50 % at 90 days for cholesterol and 45 % at 30 days to 75 % at 90 days for triglyceride ( table - 6 ) in rhesus monkeys : 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) was administered orally daily for 90 days in doses of 62 . 5 , 125 or 650 mg / kg to different group of animals . significant decrease in serum cholesterol was observed ( 45 - 52 %). at 90 days , percentage decrease in triglycerides varied from 14 to 36 %. compound 2 caused a marked decrease in low density lipoprotein ( 75 - 90 %) whereas changes in hdl - cholesterol were not significant ( table - 8 & amp ; 9 ) the compounds were tested for their hypoglycemic effects in normal , glucose loaded and streptozotocin induced diabetic rats . the experimental details of the testing of one such compound 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) is described below which possessed marked hypoglycemic effect in two models . ( tables 10 and 11 ) the experiments were carried out with albino rats ( charles foster strain ) of either sex weighing 150 - 160 g . they were fed on laboratory diet prepared by m / s lipton india ltd . and maintained under 12 hr . light / dark cycle at 25 ± 2 ° c . the animals were divided into eight groups , each of six rats ; group i was given 1 % gum acacia ( 0 . 1 ml / 100 g body weight ) intragastrically ( p . o .) and the group ii were given 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) in 1 % gum acacia , animals of groups iii were given the standard antidiabetic drug , tolbutamide in the similar fashion . 2 . 0 g / kg glucose was given p . o . to all the rats along with the vehicle / compound / standard antidiabetic drug . blood samples were taken from retroorbital plexus at periodic intervals . glucose levels in the blood samples were measured by glucose oxidase method [ bergmeyer and benut , 1963 cited in “ methods of enzymatic analysis ” ed . h bergmeyer , verlag chemie , gmbh , weinheim , beroster , pp123 , academic press , new york ]. hyperglycemia in rats was produced by streptozotocin treatment . the animals showing blood glucose levels between 250 - 350 mg / dl were selected . blood samples were collected after treatment at intervals and blood glucose levels were estimated immediately . the results showed lowering in blood glucose level within 1 hr and the maximum fall was observed at 12 hrs . the free radical oxidative stress has been implicated in the pathogenesis of a variety of human disease conditions including atherosclerosis . polyunsaturated fatty acids within cell membranes and lipoproteins are oxidized and resulting active specie modify macrophages and bystander cells monocytes which then move to subendothelial space , engorge cholesteryl esters and are transformed into what are known as foam cells . group of these foam cells form atherosclerotic plaques in the intima . the antioxidant potential of compound 2 was evaluated against metal induced oxidation of ldl as well as generation of hydroxy ( oh ) radical . in vivo experiment with cholesterol fed animals caused marked formation of lipid peroxides in serum lipoproteins . simultaneous treatment with compound 2 caused significant reversal of the lipid peroxide levels in serum vldl , ldl and liver in cholesterol fed animals . however gemfibrozil failed to protect the phenomenon of lipid peroxidation ( table 12 ). human serum ldl was oxidized with cu + 2 in different concentrations of test compound in 0 . 05 mole pbs , ph 7 . 4 for 16 hr at 37 ° c . thiobarbituric acid reactive lipid peroxides are measured by standard procedure . compound 2 and α - tocopherol inhibit the generation of ldl lipid peroxide in concentration dependent manner . however the gemfibrozil at tested concentrations did not inhibit the oxidative modification ( table 13 ). cu + 2 induced oxidation in ldl lipids are mainly due to the free oh radical during incubation . therefore the effect tested for generation of oh radical in vitro in nonenzymatic system of fe + 2 , sodium ascorbate , hydrogenperoxide and deoxyribose oxidative attack of oxy radical oil deoxyribose caused fragmentation and formation of dialdehyde which are spectrophotometrically measured after their reaction with thiobarbituric acid . as observed in case of oxidation of ldl by metal ion , the compound 2 inhibits the generation of oh radical in concentration dependent manner . however , the activity of 2 is of low order to that of mannitol , a selective inhibitor of oh radical ( table 14 ) the underlying cause of myocardial infarction is believed to be the progressive deposition of lipids and fibrotic material into the arterial wall . these pregnadienols and pregnadienous also provided cardiac protection as assessed in isoproterneol induced myocardial necrosis in rat model , which produces myocardial infarction due to an increased blood pressure and heart rate . the protection was comparable with that of gemfibrozil as described in table 15 . the relative affinity of a few selected compounds in the series for cytoplasmic androgenic receptors present in human breast tumour cells mcf - 7 ( michigan cancer foundation , mcf , usa ) was estimated and compared with 4 , 5 - dihydrotestosterone ( dht ). the results showed that the compounds 2 , 3 and 5 have no or only negligible binding affinity which therefore would be a reflection of their low androgenic effect . the relative affinity of compounds for cytoplasmic progesterone receptors present in human breast tumour cells ( mcf - 7 ) were estimated and compared with 16 - ethyl - 21 - hydroxy - 19 - norpregna - 4 - ene - 3 , 20 - dione ( org 2058 ). the experiments conducted revealed that the compounds 2 , 3 and 5 have no or only negligible binding affinity . the progestational activity was also tested in vivo by clauberg assay method . the degree of endometrial proliferation was estimated on the mcphail scale where 3 ′ or 4 ′ was considered as a full progestational effect . 3β - hydroxypregna - 5 , 16 - dien - 20 - one ( 2 ) did not exhibit any activity even at 200 mg / kg dose , whereas progesterone showed , as expected marked progestational activity even at 50 mg / kg .