Improving Alzheimer’s Disease and Parkinson’s Disease
in Rats with Nanoemulsion and Byproducts Prepared from
Cinnamon Leaves
Bing-Huei Chen 1,*, Chen-Te Jen 2, Chia-Chuan Wang 3 and Min-Hsiung Pan 2,*
1 Department of Food Science, Fu Jen Catholic University, New Taipei City 242062, Taiwan
2 Graduate Institute of Food Science, National Taiwan University, Taipei City 106319, Taiwan;
d11641002@ntu.edu.tw
3 School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City 242062, Taiwan;
050814@mail.fju.edu.tw
* Correspondence: 002622@mail.fju.edu.tw (B.-H.C.); mhpan@ntu.edu.tw (M.-H.P.)
Abstract
Background/Objectives: Cinnamon leaves, an important source of the functional com-
pound cinnamaldehyde (CA), have been shown to be effective in improving type II dia-
betes and Parkinson’s disease (PD) in rats following the incorporation of cinnamon leaf
extract into a nanoemulsion. However, the effect of a cinnamon leaf extract nanoemulsion
(CLEN) on improving Alzheimer’s disease (AD), the most prevalent type of dementia,
remains unexplored. The objectives of this study were to determine functional com-
pounds in cinnamon leaves by UPLC-MS/MS, followed by the preparation of a nanoemul-
sion and its byproducts to study their effects on AD and PD in rats. Methods: Oven-dried
(60°C for 2 h) cinnamon leaf powder and hydrosol, obtained by steam distillation of cin-
namon leaf powder, were stored at 4°C. After determination of basic composition (crude
protein, crude fat, carbohydrate, moisture and ash) of cinnamon leaf powder, it was ex-
tracted with 80% ethanol with sonication at 60°C for 2 h and analyzed for bioactive com-
pounds by UPLC-MS/MS. Then, the CLEN was prepared by mixing cinnamon leaf extract
rich in CA with lecithin, soybean oil, tween 80 and ethanol in an optimal ratio, followed
by evaporation to form thin-film and redissolving in deionized water. For characteriza-
tion, mean particle size, polydispersity index (PDI), zeta potential, encapsulation effi-
ciency, and surface morphology were determined. Animal experiments were done by di-
viding 90 male rats into 10 groups (n=9), with group 2-8 being subjected to mini-osmotic
pump implantation surgery in brain to infuse Amyloid-beta 40 (Aβ40) solution in groups
2-8 for induction of AD, while groups 9 and 10 were pre-fed respectively with cinnamon
powder in water (0.5 g/10 mL) and in hydrosol for 4 weeks, followed by induction of AD
as shown above. Different treatments for a period of 4 weeks included groups 1-9, with
group 1 (control) and group 2 feeding with sterilized water, while groups 3, 4 and 5 were
fed respectively with high (90 mg/kg), medium (60 mg/kg) and low (30 mg/kg) doses of
cinnamon leaf extracts, groups 6, 7 and 8 fed respectively with high (90 mg/kg),
medium (60 mg/kg) and low (30 mg/kg) doses of nanoemulsions, groups 9 and 10 fed
respectively with 10 mL/kg of cinnamon powder in water and hydrosol (0.5 g/10 mL).
Morris water maze test was conducted to determine short-term memory, long-term
memory and space probing of rats. After sacrificing of rats, brain and liver tissues were
collected for determination of Aβ40, BACE1 and 8-oxodG in hippocampi, and AchE and
malondialdehyde (MDA) in cortices, antioxidant enzymes (SOD, CAT, GSH-Px) and
MDA in both cortices and livers, and dopamine in brain striata by using commercial kits.
教授表示：「此篇論文為我學術生涯最具挑戰性的一篇，從論文完成經過審查修正到接受已經過了8個月。」
https://www.mdpi.com/1999-4923/17/9/1200
