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SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 13 NUMBER 2 • DECEMBER 2016
61
Cardioprotective and anti-hypertensive effects of
Prosopis
glandulosa
in rat models of pre-diabetes
B HUISAMEN, C GEORGE, D DIETRICH, S GENADE
Correspondence to: B Huisamen
MRC DDP, Parow; Faculty of Health Sciences, University of Stellenbosch,
Tygerberg, South Africa
e-mail:
bh3@sun.ac.zaB Huisamen, C George, S Genade
Department of Biomedical Sciences, Division of Medical Physiology, Faculty
of Health Sciences, University of Stellenbosch, Tygerberg, South Africa
D Dietrich
Department of Medical Biosciences, University of Western Cape, Bellville,
South Africa
Previously published in
Cardiovasc J Afr
2013;
24
: 10–16
S Afr J Diabetes Vasc Dis
2016;
13
: 61–67
Abstract
Aim:
Obesity and type 2 diabetes present with two
debilitating complications, namely, hypertension and heart
disease. The dried and ground pods of
Prosopis glandulosa
(commonly known as the Honey mesquite tree) which is part
of the Fabaceae (or legume) family are currently marketed
in South Africa as a food supplement with blood glucose-
stabilising and anti-hypertensive properties. We previously
determined its hypoglycaemic effects, and in the current
study we determined the efficacy of
P glandulosa
as anti-
hypertensive agent and its myocardial protective ability.
Methods:
Male Wistar rats were rendered either pre-diabetic
(diet-induced obesity: DIO) or hypertensive (high-fat diet:
HFD). DIO animals were treated with
P glandulosa
(100 mg/
kg/day for the last eight weeks of a 16-week period) and
compared to age-matched controls. Hearts were perfused
ex vivo to determine infarct size. Biometric parameters were
determined at the time of sacrifice. Cardiac-specific insulin
receptor knock-out (CIRKO) mice were similarly treated with
P glandulosa
and infarct size was determined. HFD animals
were treated with
P glandulosa
from the onset of the diet
or from weeks 12–16, using captopril (50 mg/kg/day) as the
positive control. Blood pressure was monitored weekly.
Results:
DIO rats and CIRKO mice:
P glandulosa
ingestion
significantly reduced infarct size after ischaemia–reperfusion.
Proteins of the PI-3-kinase/PKB/Akt survival pathway were
affected in a manner supporting cardioprotection. HFD
model:
P glandulosa
treatment both prevented and corrected
the development of hypertension, which was also reflected
in alleviation of water retention.
Conclusion:
P glandulosa
was cardioprotective and infarct
sparing as well as anti-hypertensive without affecting the
body weight or the intra-peritoneal fat depots of the animals.
Changes in the PI-3-kinase/PKB/Akt pathway may be causal
to protection. Results indicated water retention, possibly
coupled to vasoconstriction in the HFD animals, while
ingestion of
P glandulosa
alleviated both. We concluded that
treatment of pre-diabetes, type 2 diabetes or hypertension
with
P glandulosa
poses possible beneficial health effects.
Keywords:
Prosopis glandulosa
, hypertension, cardioprotection,
PKB, insulin resistance
Obesity and type 2 diabetes present with two debilitating
complications, namely, hypertension and heart disease. The dried
and ground pods of
Prosopis glandulosa
(commonly known as the
Honey mesquite tree) which is part of the Fabaceae (or legume)
family are currently marketed as a food supplement with blood
glucose stabilising and anti-hypertensive properties in South Africa.
In the past, the pods of this tree were used as the primary foodstuff
for the residents of the south-western regions of the North
American deserts and these trees are still widely distributed across
a large portion of the south-western United States.
1
The pods are
composed of 80% carbohydrate, 13% protein, 25% fibre and 3%
fat, and grinding of the plant is thought to improve its use.
2
Obesity is currently classified as a pandemic and is recognized as
the leading cause in the development of the metabolic syndrome.
The metabolic syndrome is described as a cluster of pathophysiology
outlined by the National Cholesterol Education Program’s Adult
Treatment Panel III (NCEP: ATP III) and the European Group for
the Study of Insulin Resistance, to include insulin resistance or
glucose intolerance (pre-diabetes), type 2 diabetes, hypertension
and atherogenic dyslipidaemia.
3,4
In addition, all of these factors
can be considered independent risk factors for the development of
cardiovascular disease.
3
According to the World Health Organisation (WHO), non-
communicable diseases such as heart disease, stroke, cancer,
chronic respiratory diseases and diabetes are currently (updated
June 2011) the leading causes of mortality in the world.
5
This
invisible epidemic is an under-appreciated cause of poverty and
hinders economic development in many countries. The burden
is growing and the number of people, families and communities
afflicted is increasing.
The time-line for development of overt type 2 diabetes is
described as developing over many years. The cardiovascular
consequences of this so-called ‘ticking clock’ hypothesis, starting
from obesity and culminating in type 2 diabetes, is present from the
early pre-diabetic stages.
6
In view of the scarcity and cost of modern oral hypoglycaemic
agents, plant-based therapies for the treatment of diabetes are
gaining considerable prominence.
7
According to these authors
more than 400 plant species have been described as having
hypoglycaemic activity. However, not all of these substances have
been researched scientifically to validate their efficacy.
We have researched a product from one such plant species,
consisting solely of the dried and ground pods of the plant
P glandulosa
, for hypoglycaemic properties.
8
In addition, potent