Abstract:
In tlic South Eastern part of Nigeria. the decoction of roots of Iltrn~rlltr ~ / ~ I Y I " I and
Srrrcvceph~~l~I L~I.I,I.~ O ~ Z U S i s used in the management of dlabetcs niell~tns. I lie
antihyperglycaemic potentials of acqueous and alcoholic root extracts of tlicsc plant\ werc t11~1s
evaluated in ~iornial and alloxan induced diabetic male Sprague-Dawley rats. I lit' ilir dr~cd
roots were shredded and subsequently extracted in both water and etlianol to givc
Scrrcoccpholz~l.~ ~ / ~ ~ ia)qluiezo~u,ss e xtract (SLA), Sarcocephalus/L)aniella aclucous extract (SUA)
and ,Yurcoccq7hrrlu.(. Iu/~fi)liu.est lianol extract (SLE). 'The pliytoclie~iiicala nalysis of the extracts
revealed the presence of tlavonoids, saponins, glycosides and tannins. Tannins were absent in
SI,I<. SLA and SDA (250 mglkg) significantly (P4.05) lowered fasling blood glucose lcvcls ul
diabetic rats from 31 114.26 mgldl and 261*3.02 nigldl respectively to 7312.23 mgldl and
6515.40 mgldl within 6 hours. In nor~iioglycacmic rats, the sanic dose did not produce
b
significant ( k 0 . 0 5 ) change (SLA: 55.5017.76 to 55.0018.16 and SDA: 59.0013.70 to
60.2015.56) i n fasting blood glucose levels cvcn after 12 hours of treatment Both c\lracts
increased the activities of hepatic hexokinase ( I I[<), glucokinase (GI<) and pliospl~nfY~~ctoI~~~i;~sc
(PFK). The) also induced increases in hepatic glycogcn content of' diabetic rats. 51 I dcp~c\\cd
the activities 01' GI< and PFK, but incrcascd the activity of HK. The results obtained ind~catcd
that relative to the contml, SLA and SIIA significantlj reduced the activities of supcro\~de
dihmutase and catalase. The extracts also increased The concentration 01' rcduced glutath~onc
(GSH). SDA reduced the level of lipid peroxidation products assayed as malondialdclijdc
(MIIA) in both liver and Itidnej lionioge~iatcs of diabetic rats while SLA and 51 I , \houcd no
el'fecl on MDA relative to the diabetic (C;I,A, 51 E and SDA). The eutracts \~gnilic,lnlly
decreased serum trigljceride (froni 1.8710 13 mMolIL to 0.87+0.18. 1.0610.18 and 1 10+0 36
respectively) and total cholesterol (from 2.8010.30 to 1.2710.47, 1.5410.22 arid l 95+0.2 1
~iiMol/L, respectively) of diabetic treated rats. When compared to the diabetic cont~ol. 5I)A
increased significantly (P4.05) the level of HDL cholesterol by about 50%. Both acutc and
subacute toxicity testing in mice showed that the mcdian lethal dose (LD,,,) of each ol' ~ h c
extract is greater than 5 glkg. Moreover. the extracts showed no adverse cfkct on
liacmatnlagical parameters (WBC and RHC counts, Hb, Hct. MCV and MC'I-I) as well as on
serum liver clizynie markers (AST and AI,'~')'.I -lawever, the Iiistopatliologic~~slt udic\ inclicatc
mild degeneration of the liepatocytes. 7'his investigation denionstrates that the plant extracts
especially SLA and SDA have reniarltablc antihyperglycaemic effect with accompanying
hypolipidaeniic and antioxidant properties in diabetic rats. It furtlier indicalcs clinical ~.elevancc
in reducing coniplicatio~iso f diabetes
TABLE
