Objective:

2

To assess the effects of

Thunbergia laurifolia

L. extract (TLE) on gestational diabetes mellitus (GDM) in a rat model.

Methods:

2

Thunbergia laurifolin

L. leaves were subjected to ethanolic extraction.

In vivo

study

50 pregnant rats were randomly divided into 5 groups (10 for each): non-GDM group

GDM induced by streptozotocin (STZ

60 mg/kg i.p.)

metformin (MET) 100 mg/kg

TLE 50

and 500 mg/kg groups. Administration was performed on gestation day 7 until term (day 21). The effects of TLE on blood glucose

insulin levels

lipid profiles

liver enzymes

and maternal performances were assessed. In

in vitro

study

the effect of TLE was examined using the organ bath for uterine force measurement.

Results:

2

In

in vivo

study

TLE significantly reduced blood glucose as compared to GDM (

P

<

0.05) with gradually increased insulin level. This effect was consistent with islets of Langerhans restoration. Histologically

the uterine muscular layer displayed a marked increase in fibe

r area in response to both doses as compared to GDM (

P

<

0.05). Additionally

TLE significantly reduced total cholesterol

triglyceride

and alanine transaminase levels (

P

<

0.05). Intriguingly

TLE also led to a notable augmentation in gravid uterus size

live fetuses count

and implantation numbers

while significantly reducing the post-implantation loss rate associated with fetal classification (

P

<

0.05). Thus

GDM improvements were close to those produced by MET. In

in vitro

study

TLE exerted a concentration-dependent inhibition of spontaneous uterine contractility (half-maximal inhibition concentration=1.2 mg/L). This inhibitory effect extended to potassium chloride depolarization and oxytocin-mediated contractions. When combined with its major constituent

rosmarinic acid

TLE produced an enhanced inhibitory effect (

P

<

0.05).

Conclusions:

2

TLE ameliorated blood glucose levels

enhanced uterine muscular structure

and improved maternal and fetal performance in GDM. TLE also displayed tocolytic properties. These findings underscore the need for further exploration of TLE as a potential tocolytic agent to mitigate GDM-associated complications.