361
Research studies shown that polysaccharide present in the plant protects β-cells of
islets of langerhans from oxidative damage by alloxan monohydrate and also
enhance the insulin levels showing hypoglycaemic effect (Das et al. 2011). The
major plant derived phytosterols like 24-methylene cycloartanol, lophenol, cycloartanol, 24-methyl-lophenol, and 24-methyl-lophenol were reported to show beneficial effects in obesity and diabetes (Misawa et al. 2012). In another study a
phytoconstituent (aloe-emodin-8-O-glycoside) isolated from A. vera gel were
reported to enhance transport of glucose through proximal and distal marker modulation concerned with better uptake of glucose and its transformation into glycogen
(Anand et al. 2010). Aloe species shows positive effect in the treatment of diabetes
over short intervention periods. Through pilot study, improvements were observed
in serum insulin, end-point glucose, TC:HDL-C and HDL-C using leaf gel extracts
of A. greatheadii var. davyana, in a STZ-induced diabetic rodent model. Another
Aloe species A. ferox intervention showed similar positive effects but to a lesser
extent (Loots et al. 2011).
Jain et al. (2010) reported that A. vera gel shows significant cardioprotective and
antidiabetic effects, as it significantly enhance antioxidant status and reduce oxidative stress in streptozotocin-induced diabetic rats.
18.5.9.1 Leaf Extract
The leaf of genus Aloe is different from the normal leaves, which contains a latex
and gel. In most of the literatures, the latex is referred to as leaves and gel as a separate entity from the plant (Bozzi et al. 2007). In an experiment, Aloe vera juice was
prepared with the aloe gel, sorbitol as sweeting agent and certain preservatives are
given to 50- and 22-women diabetic subjects for 42 days. The result of the study
revealed that the Aloe vera gel has antidiabetic activity by reducing total cholesterol, post-prandial and fasting blood sugar, total lipids, triglycerides and increase
high density lipoproteins (Yongchaiyudha et al. 1996). Similarly, alcoholic extract
of Aloe vera leaf gel was orally administered to diabetic rats to evaluate their antidiabetic effect. The result confirmed that the phytochemicals present in alcoholic
extract decrease blood glucose level, glycosylated hemoglobin and increases the
hemoglobin level. Further, the extract brings down the level of lipid peroxidation
and hydroperoxides in diabetes rat tissues, and increases superoxide dismutase,
catalase, reduced glutathione, glutathione peroxidase and glutathione-S-transferase
in diabetic kidney and liver of rats (Noor et al. 2008). Also, the leaf pulp and gel
extract of A. vera was subjected to non-diabetic, type 1 and type 2 diabetic rats to
evaluate their antidiabetic activity. The result emphasized that the extracts do not
reduce blood sugar level in non-diabetic subjects, whereas the pulp extract reduces
glucose levels in type 1 and 2 diabetes rats, compared to glibenclamide diabetic
drug. However, the gel extract enhances hyperglycemic activity in type 2 diabetic
rats, which showed that the pulp extracts of A. vera leaves are highly beneficial in
the treatment of non-insulin dependent diabetes patients (Okyar et al. 2001).
18 Aloe Species as Valuable Sources of Functional Bioactives
Research studies shown that polysaccharide present in the plant protects β-cells of
islets of langerhans from oxidative damage by alloxan monohydrate and also
enhance the insulin levels showing hypoglycaemic effect (Das et al. 2011). The
major plant derived phytosterols like 24-methylene cycloartanol, lophenol, cycloartanol, 24-methyl-lophenol, and 24-methyl-lophenol were reported to show beneficial effects in obesity and diabetes (Misawa et al. 2012). In another study a
phytoconstituent (aloe-emodin-8-O-glycoside) isolated from A. vera gel were
reported to enhance transport of glucose through proximal and distal marker modulation concerned with better uptake of glucose and its transformation into glycogen
(Anand et al. 2010). Aloe species shows positive effect in the treatment of diabetes
over short intervention periods. Through pilot study, improvements were observed
in serum insulin, end-point glucose, TC:HDL-C and HDL-C using leaf gel extracts
of A. greatheadii var. davyana, in a STZ-induced diabetic rodent model. Another
Aloe species A. ferox intervention showed similar positive effects but to a lesser
extent (Loots et al. 2011).
Jain et al. (2010) reported that A. vera gel shows significant cardioprotective and
antidiabetic effects, as it significantly enhance antioxidant status and reduce oxidative stress in streptozotocin-induced diabetic rats.
18.5.9.1 Leaf Extract
The leaf of genus Aloe is different from the normal leaves, which contains a latex
and gel. In most of the literatures, the latex is referred to as leaves and gel as a separate entity from the plant (Bozzi et al. 2007). In an experiment, Aloe vera juice was
prepared with the aloe gel, sorbitol as sweeting agent and certain preservatives are
given to 50- and 22-women diabetic subjects for 42 days. The result of the study
revealed that the Aloe vera gel has antidiabetic activity by reducing total cholesterol, post-prandial and fasting blood sugar, total lipids, triglycerides and increase
high density lipoproteins (Yongchaiyudha et al. 1996). Similarly, alcoholic extract
of Aloe vera leaf gel was orally administered to diabetic rats to evaluate their antidiabetic effect. The result confirmed that the phytochemicals present in alcoholic
extract decrease blood glucose level, glycosylated hemoglobin and increases the
hemoglobin level. Further, the extract brings down the level of lipid peroxidation
and hydroperoxides in diabetes rat tissues, and increases superoxide dismutase,
catalase, reduced glutathione, glutathione peroxidase and glutathione-S-transferase
in diabetic kidney and liver of rats (Noor et al. 2008). Also, the leaf pulp and gel
extract of A. vera was subjected to non-diabetic, type 1 and type 2 diabetic rats to
evaluate their antidiabetic activity. The result emphasized that the extracts do not
reduce blood sugar level in non-diabetic subjects, whereas the pulp extract reduces
glucose levels in type 1 and 2 diabetes rats, compared to glibenclamide diabetic
drug. However, the gel extract enhances hyperglycemic activity in type 2 diabetic
rats, which showed that the pulp extracts of A. vera leaves are highly beneficial in
the treatment of non-insulin dependent diabetes patients (Okyar et al. 2001).
18 Aloe Species as Valuable Sources of Functional Bioactives