divided into five groups. Group 1 consisted of the negative control with a standard diet. Group 2 consisted of

the positive control with HFFD-induced obesity for 20 weeks, while groups 3, 4, and 5 were the treatment

groups with HFFD-induced obesity for 12 weeks, which were intervened with different dosages of brown rice

diet from week 13 to week 20. At week 21, the rats were sacrificed. Fasting blood glucose levels were tested

using a glucometer. Fasting serum insulin levels were tested using ELISA. HOMA-IR was calculated using

fasting glucose and insulin levels. Serum magnesium levels were tested using Atomic Absorption

Spectrophotometry. A non-parametric test of Kruskal-Wallis was used to analyze differences in mean dietary

intake, Lee index, fasting blood glucose, and HOMA-IR. As a result, there were significant differences between

groups (p<0.05). Spearman correlation test was used to analyze the relationship between the Lee index, fasting

blood glucose levels, and HOMA-IR with serum magnesium levels. As a result, there were negative

Received: August 29, 2021. Revised: October 22, 2022. Accepted: November 19, 2022. Published: December 20, 2022.

1 Introduction

Obesity is an accumulation of excessive fat in the

body that can impair health, [1]. Body mass index

(BMI) is used for clinical obesity screening, [2]. A

BMI same as or more than 30 kg/m2 is considered

obese, [1]. In Indonesia, the prevalence of obesity in

artery disease, pulmonary embolism, and

cerebrovascular accident, [7]. Type II diabetes

mellitus is the most common type of diabetes today

and is characterized by a series of malfunctions such

as insulin resistance, the inadequate secretion of

treatment, and education may control type 2

diabetes, [15]. Dietary regulation can stabilize blood

glucose and lipid levels within the normal range,

[16]. Brown rice is a highly nutritious food obtained

through a milling process by removing the husk

from the paddy to obtain rice grain that contains a

brown outer layer of bran, [17]. 'Sintanur' is one of

the brown rice variants in Indonesia. A 100 grams of

local ‘Sintanur’ brown rice contains 386.67 calories

i.e., magnesium content is seven times higher, [18].

Local brown rice also has a higher fiber content than

local white rice. Therefore, brown rice has a longer

digestion time and lower glycemic index, [19], [20].

magnesium source, [18]. Magnesium contributes to

the insulin-mediated regulation of glucose

absorption and increases insulin sensitivity, [20].

Numerous enzymes in the metabolic cycles need

Mg2+ or MgATP as a cofactor throughout the

reabsorption of magnesium in the kidneys. Serum

magnesium levels were found to be inversely

correlated with blood glucose levels. Renal tubular

reabsorption of magnesium decreases in the

presence of severe hyperglycemia, [22].

shows significant evidence that oral magnesium

supplementation (365 mg/day) for six months

improves insulin sensitivity, [23]. A Japanese study

reports that the consumption of brown rice may be

brown rice can reduce blood glucose and fasting

insulin responses, [25]. Research in Malaysia

suggests that consumption of brown rice on female

conversion factor, [28]. In humans, brown rice

needed per day was 125 grams for one meal, 250

grams for two meals, and 375 grams for three meals.

Conversion to rat feed per day was 2.25 grams, 4.5

grams, and 6.75 grams. In making 1000 grams of

feed, 112.5 grams of brown rice were added for

dose I (group 3), 225 grams of brown rice was

added for dose II (group 4), and 337.5 grams of

brown rice were added for dose III (group 5) to

substitute cornstarch, dextrinized cornstarch,

2.4 Parameters Test

The blood glucose levels were examined using

Nesco’s glucometer. The fasting serum insulin

levels were examined using Bioassay Technology

Laboratory’s ELISA kit, [29]. The HOMA-IR

values were calculated by multiplying fasting blood

glucose (mg/dL) and fasting serum insulin (μU/mL)

levels, divided by 405. The Lee index was obtained

by calculating the cube root of body weight (grams),

divided by the length of the nasal-anal (cm), and

rice (groups 3, 4, and 5) were lower than in group 2.

Lee index was observed throughout the intervention;

most significant decrease in the Lee index.

Fig. 1: Average Lee Index at the End of Intervention

Note:

The data are mean ± standard deviation

Data accompanied by different notations show significant

differences

Group 1: Negative control

Group 2: Positive control

Group 3: HFFD + brown rice dose I (11.25%)

Group 4: HFFD + brown rice dose II (22.5%)

Fig. 2: The Spearman Correlation Test between the

Lee Index and Serum Magnesium Levels

Fig. 4: The Spearman Correlation Test between

Fasting Blood Glucose Levels and Serum

Magnesium Levels

The fasting blood glucose levels negatively

Kruskal-Wallis and Post Hoc Mann-Whitney tests

were used to see the relationship between variables.

The average HOMA-IR values significantly differed

between groups (p=0.003) (Figure 5), but group 5

had no significant difference from group 1 (negative

control). Group 2 had the highest average HOMA-

IR, and group 1 had the lowest average HOMA-IR.

Group 5 had the lowest average HOMA-IR among

the brown rice intervention groups.

differences were found in dietary intake data

(average daily feed intake, brown rice, fructose

intake, fiber, and total energy).

the highest average intake of brown rice and fiber

but had the lowest average daily feed intake and

total energy. Local brown rice 'Sintanur' contains

more fiber and energy than local white rice of the

same variety. One hundred grams of local brown

rice, 'Sintanur', contains 386.67 calories of energy

more prolonged feeling of fullness, thus preventing

from consuming more food, [19].

significant difference in Lee index values at the end

of the intervention, especially between the controls

and the intervention groups. The results showed that

all rats administered with Sintanur rice (groups 3, 4,

and 5) had a lower Lee index than the positive

control (group 2). Group 5 had the most significant

change in the Lee index among the treatment

[36]. Consumption of brown rice has been reported

to reduce hunger and increase satiety, leading to

lower energy intake, [24]. This study’s result is

consistent with a previous study in Malaysia, which

showed that consumption of brown rice (30

kcal/100 grams body weight/day) in female Sprague

Dawley rats for eight weeks reduced body weight

and Lee index compared to white rice, [26].

ability to induce insulin resistance. Insulin

fasting insulin levels in the calculations, [13].

Individuals with obesity have higher HOMA-IR

can directly affect glucokinase by acting as a

cofactor for adenine nucleotides. G6P, the enzyme

reaction's product, is processed to form ATP. The

KATP channel's opening depends on the binding of

MgATP and SUR1 subunits. Meanwhile, the KATP

channel’s closure depends on the binding of ATP

and Kir6.2 subunits, which causes depolarization of

release of insulin vesicles, [21].

formation, and ATP accumulation in the pancreatic

β-cells. It can interfere with the closure of KATP

channels and delay the initial and late phases of

insulin responses to glucose. In magnesium

deficiency, MgATP intracellular levels decrease. It

can interfere with the opening of KATP channels

and prolong the depolarization of the β-cells plasma

membrane, which causes more insulin release. Thus,

magnesium deficiency can lead to β-cells

dysfunction in type 2 diabetes, [44].

kinase/protein kinase B (PI3K/Akt). It manages

most insulin metabolic activities and significant

functions in insulin signaling. Its activation leads to

the phosphorylation of many substrates that play

essential roles in biological processes, such as

stimulation of glucose transport, synthesis of

glycogen and protein, and lipogenesis. Akt has a

crucial role in insulin metabolic actions, including

glucose uptake in muscle and adipose tissue through

glucose transporter type 4 (GLUT4) translocation

changes in the metabolic level, [44].

relevant associations between magnesium and

index, fasting blood glucose levels, and HOMA-IR

values in HFFD-induced obesity Sprague Dawley

rats. The study’s results using Indonesian local

brown rice, 'Sintanur', shows a tremendous

advantage in reducing the risk of insulin resistance,

especially in group 5. Furthermore, it is necessary to

carry out further research and its implementation in

humans using local brown rice 'Sintanur' to test the

benefits of local rice against obesity and insulin

resistance it causes in humans. It is also necessary to

this study.

References

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[2] C. Arroyo-Johnson and K. D. Mincey,

[4] K. D. Hall et al., “Quantification of the effect

[5] L. V. Campbell, “Genetics of obesity,”

[15] S. Soelistijo et al., Konsesus Pengelolaan

[17] A. S. M. Saleh, P. Wang, N. Wang, L. Yang,

[18] E. Sulistyowati, A. Rudijanto, S. Soeharto,

[19] S. Pirasath, K. Thayaananthan, S.

[20] A. Fardet, “New hypotheses for the health-