Ramlah Mohamad Ibrahim1, Nurul Syima Hamdan1, Maznah Ismail1,2, Suraini Mohd Saini3, Saiful Nizam Abd Rashid3, Latiffah Abd Latiff4, Rozi Mahmud3*
1 Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.
2 Nutrigenomic Programme, Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.
3 Department of Imaging, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.
4 Department of Community Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.
A B S T R A C T
Purpose: This study was conducted in menopausal women to determine the metabolic impact of Nigella sativa.
Methods: Thirty subjects who were menopausal women within the age limit of 45-60 were participated in this study and randomly allotted into two experimental groups. The treatment group was orally administered with N. sativa seeds powder in the form of capsules at a dose of 1g per day after breakfast for period of two months and compared to control group given placebo. Anthropometric and biochemical parameters were measured at baseline, 1st month, 2nd month and a month after treatment completed to determine their body weight, serum lipid profile and fasting blood glucose (FBG).
Results: The treatment group showed slight reduction with no significant difference in body weight changes of the respondents. However, significant (p<0.05) improvement was observed in total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and blood glucose (p<0.05).
Conclusion: These results suggested that treatment with N. sativa exert a protective effect by improving lipid profile and blood glucose which are in higher risk to be elevated during menopausal period.
Keywords: Nigella sativa Menopause
Metabolic syndrome Hyperlipidemic Hyperglycemia
Introduction
Menopause is an important physiological event, with the cessation of menstruation indicating the end of a woman’s reproductive lifespan.1 Menopause is associated with a fall in estrogen levels which accompanied with many health changes. Changes in the hormone levels at menopause, in particular estrogen deficiency are associated with an increase in body fat.2 Additionally, it sounds an alarm for women’s health since it leads to elevated blood pressure, insulin resistance and dyslipidemia.3 These changes may contribute to increased risks of metabolic syndrome (MetS) in menopause women. The features of the metabolic syndrome include the accumulation of visceral (abdominal) adiposity, insulin resistance, hypertension, and dyslipidemia (hypertriglyceridemia, reduced high density lipoprotein (HDL), and small dense LDL particles based on a set of diagnostic criteria suggested by National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III).4 To date, several previous studies found significant difference in prevalence of MetS among pre- and postmenopausal women.5-8 The prevalence of MetS in menopausal women was found to be 36.7% in one of the states, Kelantan in Malaysia.9
Nowadays there is an increased demand for using plants in therapy instead of using synthetic drugs which may have adverse effects. Traditional medicinal plants are often cheaper, locally available, and easily consumable (raw or as simple medicinal preparations). The seeds of Nigella sativa (N. sativa) plant have been used to promote health and fight disease for centuries especially in the Middle East and Southeast Asia.10
Locally, it is called Habattus Sauda and referred as Black cumin in English. This plant has been a great focus of research and has several traditional uses and consequently has been extensively studied for its chemical constituents and biological activities. A lot of studies have been done to determine the various activities of N. sativa on different components of the metabolic syndrome for example blood sugar, lipid profile, hypertension and etc.11,12 In spite of large number of pharmacological studies carried out worldwide on N. sativa seeds, only few experimental studies have been done in menopausal women especially in Malaysia. Moreover, many Malaysian women were consuming N. sativa in the form of coffee mix, oil products as a source of supplement which they believe can help to boost energy level. However, not many aware neither the actual benefits nor toxicity effect of those N. sativa products. Previous studies on the various effect of N. sativa in individuals have been performed on a heterogeneous population and only limited data are available for the effect of N. sativa on metabolic syndrome in menopausal women. Thus, this study was undertaken with the aim to know the adjuvant effect of N. sativa on clinical and biochemical parameters of the metabolic syndrome in menopausal women in Klang Valley, Malaysia.
Materials and Methods
Plant materials
N. sativa seeds samples imported from three different countries like Iran, India and Yemen were purchased through a local company named Sari Tani Desa SDN. BHD located in Shah Alam, Malaysia which has health accreditation from Ministry of Health, Malaysia. The seeds were identified and authenticated by Professor Dr. Maznah Ismail, Head of the Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia and the voucher specimens of the seeds were kept there. The identified seeds were analyzed for its thymoquinone (active compound) content and among the seeds that contained high thymoquinone were sent back to the company for cleaning and capsulation process according to Good Manufacturing Practices (GMP). The N. sativa seeds were crushed into fine powder and capsulated at a dose of 500mg per capsule and further bottled with an amount of 60 capsules per bottle. The bottles then were sealed and kept under room temperature until further use.
Study Subjects
Ethical clearance for this study was reviewed and approved by the Faculty of Medicine and Health Sciences Medical Research Ethics Committee, Universiti Putra Malaysia. Respondents for the study were selected based on the inclusion and exclusion criteria to ensure the accurately associated factors of metabolic syndrome. The inclusion criteria were women aged 45-60, menopause for a period>12 months since the last regular menstruation, presenting one or more features of the MetS based on the NCEP-ATP III definition. The exclusion criteria were women having endocrine or other chronic diseases, taking medication for chronic diseases, herbal or supplementation.
Experimental design
The respondents were randomly allotted into two experimental groups. A co-investigator was selected to create subject identification numbers to assign respondents into the groups. A total of 18 respondents were assigned to N. sativa group and 17 respondents to placebo group. After a 2-two week’s washout period, the respondents received the alternative treatment for 2 months. Capsules of N. sativa powder were orally administered at a dose of 1g after breakfast every day for period of two months. A follow- up assessment a month later has been done after the subjects completed the two months treatment. The physical and pathological histories of these subjects were recorded. All subjects requested to maintain their regular lifestyles including their dietary intake and physical activity during the intervention period. Venous blood was drawn from the subjects before and after treatment for further analysis on the effects of N. sativa.
Biochemical analysis
Whole blood was collected in plain tube and further centrifuged at 2500rpm for 15min under 25 °C. Serum was collected in order to run the analysis of TC, TG, HDL-C and LDL-C levels, and FBG using commercial diagnostic kits (Randox Laboratories Limited, UK) on Selectra XL chemical analyzer (Vital Scientific, Netherlands)
Statistical analysis
All experimental values are presented as means ± standard deviation (SD). Statistical analysis was performed using SPSS windows program version 18 (SPSS Institute, Inc., Chicago, IL, USA). The One-way Analysis of Variance (ANOVA) with Bonferroni correction was used for analysis of data. Difference was considered to be significant if the probability value was less than 0.05 (p<0.05).
Results
Body weight
Over the period of treatment, the body weight of N. sativa group reduced slightly 0.32% compare to baseline (Figure 1). The body weight of placebo group had no changes. Supplementation with N. sativa for eight weeks tended to reduce the body weight of N. sativa groups as compared to control group, however no significant reduction was noticed, (p>0.05). To be noted, a month after treatment ends body weight of N. sativa group showed significant increase (p<0.05).
Fasting blood glucose
Supplementation of N. sativa for eight weeks was able to reduce fasting blood glucose significantly (p<0.05) by 9.271% at the end of treatment. In contrast, placebo groups showed an elevation in blood glucose, where it increased significantly by 3.796% (p<0.05) over the period of treatment (Figure 2).
Figure 1. Treatment effect of N. sativa and placebo on body weight (kg). Values are expressed as mean + SD. Same and different lower case letters indicates significant and no significant difference within group, respectively. A.T= one month after treatment ends
Figure 2. Treatment effect of N. sativa and placebo on FBG level (mmol/L). Values are expressed as mean + SD. Same and different lower case letters indicates significant and no significant difference within group, respectively. A.T= one month after treatment ends about the high prevalence of MetS in menopause women.13 In this study, body weight of the respondents in N. sativa group showed slight reduction compared to placebo group throughout the two months of treatment however, not significant reduction was noticed (p>0.05). In the same way from another study, body weight was observed to reduce more in N. sativa group as compared to the standard group but the difference was not significant.14 The metabolic pathway of the effect of N. sativa on weight reduction is yet to be explored and further studies are needed.
Table 1. Treatment effect of N. sativa and placebo on lipid profile changes. Values are expressed as mean + SD. Same and different lower case letters (abcd) indicates significant and no significant difference within group, respectively. Same and different uppercase letters (AB) indicate significant difference between the groups by weeks, p<0.05.
Parameters | Weeks | Nigella sativa | Placebo |
TC | 0 | 6.027 + 1.045aA | 1.053 + 6.057aB |
4 | 5.613 + 0.971aA | 0.796 + 5.880bA | |
8 | 5.453 + 1.014aA | 0.702 + 5.793cA | |
12 | 5.973 + 0.830aA | 0.498 + 5.873dB | |
TG | 0 | 0.357 + 1.510aA | 0.483 + 1.497aB |
4 | 0.320 + 1.000aA | 0.369 + 1.207bB | |
8 | 0.370 + 0.980aA | 0.398 + 1.360cA | |
12 | 0.577 + 1.187bA | 0.568 + 1.393dA | |
LDL-C | 0 | 0.925 + 4.647aA | 0.597 + 4.827aB |
4 | 0.863 + 3.890bA | 0.655 + 4.553bA | |
8 | 0.784 + 3.413bA | 0.606 + 4.343bA | |
12 | 0.836 + 4.037bA | 0.284 + 4.393cB | |
HDL-C | 0 | 0.258 + 1.575aA | 0.281 +1.357aA |
4 | 0.355 + 1.620bA | 0.207 + 1.347bA | |
8 | 0.330 + 1.703bA | 0.255 + 1.327cA | |
12 | 0.253 + 1.487bA | 0.275 + 1.353dB |
Lipid profile
The sequential changes in serum TC, TG, LDL-C and HDL-C are summarized in Table 1. N. sativa supplementations for eight weeks in menopausal women significantly improved TC, TG and LDL-C which was reduced significantly by 9.52%, 35.10% and 26.60%, respectively. HDL-C levels were increased by 8.13% at the end of treatments; however no significant effect was observed (p > 0.05). Whereas, in placebo, the results development showed significant decrease in the of hyperlipidemia among menopausal groups, serum TC and LDL-C were found to decreased significantly (p<0.05) by 4.36% and 10.02%, respectively. HDL-C was reduced by 2.25% at the end of treatment with no significant difference (p<0.05). In contrast, TG was increased by 9.15% at the end of treatment without significant difference (p<0.05).
Discussion
The present study was designed to investigate the effect of N. sativa on some of the MetS parameters such as body weight, lipid profile and blood glucose level. It is well documented menopause often contribute to increase in body weight due to hormonal changes. Fat substitution in different tissues (fat accumulation in visceral tissues) with menopausal transition due to decrease in estrogen secretion is one of the theories women in N. sativa treatment group compared to placebo group. This result was comparable with a study on oral administration of N. sativa seeds powder at a dose of 500 mg/ daily along with statin for 180 days had improved lipid profile in patients who’s having stable coronary artery disease in Multan, Pakistan. That study demonstrated the TC, LDL-C and triglycerides decreased by 14.58%, 23.0% and 15.16% respectively whereas HDL-C increased 3.18% significantly when compared with control group taking statin only.15 Another study showed positive impact (p<0.05) of 2 g powdered N. sativa seeds intake daily for 4 weeks on lipid profile of hypercholesterolemic patients in Isfahan city, Iran. The study reported a significant decrease in the concentration of TC (4.78%), LDL-C (7.6%) and TG (16.65%) compared to control group receiving wheat powder.16
The possible mechanisms of hypolipidemic action of N. sativa as suggested from previous study were most probably due to an up-regulation of LDL-C molecules through receptor mediated endocytosis. The endocytosed membrane vesicles fused with lysosomes and in which the apoproteins were degraded and the cholesterol esters were hydrolyzed to yield free cholesterol. The cholesterol was then incorporated into plasma as necessary and excreted from the body.17 Indeed, lipid lowering activity of N. sativa through decreased dietary cholesterol absorption, stimulation of primary bile acid synthesis and its fecal losses were probably contributed from its dietary soluble fibers18 and sterols.19 Another mechanism involved probably through non-enzymatic lipid peroxidation by antioxidant properties of N. sativa making liver cells more efficient to remove LDL-C from blood by increasing LDL-C receptor densities in liver and binding to apolipoprotein, apo B.20
The changes on FBG observed in the present study were similar with a number of clinical studies in patients with diabetes type II. Incorporation of N. sativa as add on therapy at a dose of 2 g/day for 12 weeks improves significantly (p<0.001) the blood parameters of glycemia and diabetes control in patients with DM type II.21 Moreover, fasting blood glucose and HbA1c levels were found to decrease significantly (p = 0.006) from 102.4 + 20.8 to 91.5 + n 12.5 mg/dL in N. sativa treated subjects as compared to control group at the end of two months treatment in a randomized control trial conducted in 70 healthy subjects attending general health check up at Bagiatallah Hospital, Iran.22
The hypoglycemic effect of N. sativa was mediated through multiple pharmacological actions. Study by Al- saif, 2008 and El- Dakhakkhny et al., 2002 reported that glucose lowering effects of N. sativa was due to improved insulin insensitivity and extra pancreatic actions of insulin in diabetic rats, respectively.23,24 Fararh et al., 2005 demonstrated that hepatic glucose production from gluconeogenic precursors (alanine, glycerol and lactate) was significantly lowered in N. sativa treated hamsters indicating the hypoglycemic effect of N. sativa somehow partly mediated through decreased liver gluconeogenesis in menopausal women.25 Kaleem et al., 2006 confirmed this anti- diabetic activity of N. sativa linking to its antioxidant effects. Thymoquinone, the active constituent of N. sativa has been demonstrated to attenuate oxidative stress in streptozotocin-induced diabetic rats through preserving pancreatic β- cell integrity leading to increased insulin levels.26 Nigella sativa was also able to reduce glucose absorption from intestine as evidenced by aqueous extract of N. sativa (0.1 pg/ml to 100 ng/ ml) which exerted dose-dependent inhibition of sodium dependent glucose transport across isolated rat jejunum and controlled the activity of SGLT1, a major transporter of glucose in intestine.27
As suggested in the previous studies, the effect of N. sativa powder on metabolic parameters seem to be on multiple components and the synergistic action of its different constituents including thymoquinone and nigellamine, soluble fiber, sterols, flavanoids and high content of poly-unsaturated fatty acids.28,29 A study evident the presence of phyto-sterols in amounts of 0.33 to 0.36% which further strengthens the protective effect of N. sativa interact with several metabolic pathways of human body.30
Conclusion
Nigella sativa has beneficial effects on fasting blood sugar and lipid profile in menopause women suggesting it as one such remedy that may prove beneficial in the future for the prevention and treatment of Mets. Even though there is positive correlation with the intakes of N. sativa on MetS but this finding is not enough to consider N. sativa as an alternative to drugs. However, it can be taken as complementary supplement in patients having mild or elevated risk of MetS which eventually leads to reduce dependency towards drugs.
Acknowledgements
This study was financially supported by the Research University Grant Scheme, RUGS (Vote No.: 91600), University Putra Malaysia. We also would like to thank Sari Tani Desa SDN. BHD, Shah Alam for their contribution in sample capsulation. We also thank the administration and staffs of Pusat Kesihatan University (PKU) and Institute Bioscience (IBS), University Putra Malaysia for their assistance in respondent recruitment and sample analyses.
Conflict of Interest
The authors report no conflicts of interest.
References
Atsma F, Bartelink ML, Grobbee DE, Van Der Schouw YT. Postmenopausal status and early menopause as independent risk factors for cardiovascular disease: a meta-analysis. Menopause 2006;13(2):265-79.
Schneider JG, Tompkins C, Blumenthal RS, Mora S. The metabolic syndrome in women. Cardiol Rev 2006;14(6):286-91.
Wellons M, Ouyang P, Schreiner PJ, Herrington DM, Vaidya D. Early menopause predicts future coronary heart disease and stroke: the Multi-Ethnic Study of Atherosclerosis. Menopause 2012;19(10):1081-7.
Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III). JAMA 2001;285(19):2486-97.
Goyal S, Baruah M, Devi R, Jain K. Study on Relation of Metabolic Syndrome with Menopause. Ind J Clin Biochem 2013;28(1):55-60.
Janssen I, Powell LH, Crawford S, Lasley B, Sutton- Tyrrell K. Menopause and the metabolic syndrome: the Study of Women's Health Across the Nation. Arch Intern Med 2008;168(14):1568-75.
Lin WY, Yang WS, Lee LT, Chen CY, Liu CS, Lin CC, et al. Insulin resistance, obesity, and metabolic syndrome among non-diabetic pre- and post- menopausal women in North Taiwan. Int J Obes (Lond) 2006;30(6):912-7.
Ainy E, Mirmiran P, Zahedi Asl S, Azizi F. Prevalence of metabolic syndrome during menopausal transition Tehranian women: Tehran Lipid and Glucose Study (TLGS). Maturitas 2007;58(2):150-5.
Kadir AA, Hamid HA, Hussain NHN. Metabolic syndrome among postmenopausal women: Prevalence of metabolic syndrome and its associated factors among postmenopausal women at Hospital Universiti Sains Malaysia. Int J Coll Res Intern Med Public Health 2012;4(6):1286-96.
Khoddami A, Ghazali HM, Yassoralipour A, Ramakrishnan Y, Ganjloo A. Physicochemical characteristics of Nigella Seed (Nigella sativa L.) oil as affected by different extraction Methods. J Am Oil Chem Soc 2011;88(4):533-40.
Salehisurmaghi MH. Nigella sativa. Herbal Med Herbal Therapy 2008;2:216-9.
Parhizkar S, Latif LA, Rahman SA, Dollah MA. Preventive effect of Nigella sativa on metabolic syndrome in menopause induced rats. J Med Plants Res 2011;5(8):1478-84.
Carr MC. The emergence of the metabolic syndrome with menopause. J Clin Endocrinol Metab 2003;88(6):2404-11.
Najmi A, Haque SF, Naseeruddin M, Khan RA. Effect of Nigella Sativa oil on various clinical and biochemical parameters of metabolic syndrome. Int J Diabetes Metabolism 2008;16(2):85-7.
Tasawar Z, Siraj Z, Ahmad N, Lashari MH. The effects of Nigella sativa(Kalonji) on lipid profile in patients with stable coronary artery disease in Multan Pakistan. Pak J Nutr 2011;10(2):162-7.
Sabzghabaee AM, Dianatkhah M, Sarrafzadegan N, Asgary S, Ghannadi A. Clinical evaluation of Nigella sativa seeds for the treatment of hyperlipidemia: a randomized, placebo controlled clinical trial. Med Arh 2012;66(3):198-200.
Bhatti IU, Ur Rehman F, Khan MA, Marwat SK. Effect of prophetic medicine kalonji (Nigella sativa L.) on lipid profile of human beings. An in vivo approach. World Appl Sci J 2009;6(8):1053-7.
Talati R, Baker WL, Pabilonia MS, White CM, Coleman CI. The effects of barley-derived soluble fiber on serum lipids. Ann Fam Med 2009;7(2):157- 63.
Moruisi KG, Oosthuizen W, Opperman AM. Phytosterols/stanols lower cholesterol concentrations in familial hypercholesterolemic subjects: a systematic review with meta-analysis. J Am Coll Nutr 2006;25(1):41-8.
Al- Naqeeb G, Ismail M, Al- Zubairi AS. Fatty acid profile, α- tocopherol content and total antioxidant activity of oil extracted from N. sativa seeds. Int J Pharmacol 2009;5(4);244-50.
Bamosa AO, Kaatabi H, Lebdaa FM, Elq AM, Al- Sultanb A. Effect of Nigella sativa seeds on the glycemic control of patients with type 2 diabetes mellitus. Indian J Physiol Pharmacol 2010;54(4):344-54.
Mohtashami R, Amini M, Fallah Huseini H, Ghamarchehre M, Sadeqhi Z, Hajiagaee R, et al. Blood glucose lowering effects of Nigella Sativa L. seeds oil in healthy volunteers: A Randomized, Double-blind, placebo-controlled clinical trial. J Med Plants 2011;39(10):90-4.
Alsaif MA. Effect of Nigella sativa oil on impaired glucose tolerance and insulin insensitivity induced by high-fat-diet and turpentine-induced trauma. Pak J Biol Sci 2008;11(8):1093-9.
El-Dakhakhny M, Mady N, Lembert N, Ammon HP. The hypoglycemic effect of Nigella sativa oil is mediated by extrapancreatic actions. Planta medica 2002;68(5):465-6.
Fararh KM, Shimizu Y, Shiina T, Nikami H, Ghanem MM, Takewaki T. Thymoquinone reduces hepatic glucose production in diabetic hamsters. Res Vet Sci 2005;79(3):219-23.
Hamdy NM, Taha RA. Effects of Nigella sativa oil and thymoquinone on oxidative stress and neuropathy in streptozotocin-induced diabetic rats. Pharmacology 2009;84(3):127-34.
Meddah B, Ducroc R, El Abbes Faouzi M, Eto B, Mahraoui L, Benhaddou-Andaloussi A, et al. Nigella sativa inhibits intestinal glucose absorption and improves glucose tolerance in rats. J Ethnopharmacol 2009;121(3):419-24.
Ali BH, Blunden G. Pharmacological and toxicological properties of Nigella sativa. Phytother Res 2003;17(4):299-305.
Talati R, Baker WL, Pabilonia MS, White CM, Coleman CI. The effects of barley-derived soluble fiber on serum lipids Ann Fam Med 2009;7(2):157- 63.
Cheikh-Rouhoua S, Besbesa S, Lognayb G, Bleckerc C, Deroannec C, Attia H. Sterol composition of black cumin (Nigella sativa L.) and Aleppo pine (Pinushalepensis Mill.) seed oils. J Food Compos Anal 2008;21(2):162-8.