Determination of the total antioxidant and oxidant status of some galactagogue and herbal teas

D. A?gagündüz

Gazi University, Faculty of Health Sciences, Department of Nutrition and Dietetics, Emniyet Mahallesi, Muammer Yas? ar Bostanc? Caddesi, Bes? evler, Ankara 06560, Turkey

ABSTRACT

This research was aimed to evaluate the total antioxidant status (TAS) and the total oxidant status (TOS)of galactagogues and herbal teas. Galactagogues and herbal teas used for other purposes were sold in the market for breastfeeding mothers and babies. Tea infusions were prepared by following brewing recipe on the package. TAS (mmol/L) and TOS (μmol/L) were measured and oxidative stress indices (OSI) were calculated. TAS values of the mixed-herbal teas in granule form that sold as still tea were found to be higher ((1.5 ± 0.00)–(1.7 ± 0.14) mmol/L) compared to other galactagogue tea types (P < 0.05). TAS value of the mixed-herbal tea in classic tea bag was (1.0 ± 0.06) mmol/L while the TAS value of the vitamin added mixed-herbal tea was (3.0 ± 0.00) mmol/L (P < 0.05). The TAS and TOS values of the night-teas were simultaneously found to be higher compared to herbal teas (P < 0.05). Besides, the highest OSI values among herbal teas was chamomile tea (6.96). In conclusion, antioxidant/oxidant status of galactagogues and other herbal teas might vary according to their form (powder or granule), type, variety of herbs in the composition, and the brand. Moreover, some galactagogues and other herbal teas have high levels of oxidant activity as well as antioxidant activity. Also, it seems that vitamin addition is important for balancing antioxidant/oxidant status of all tea types.

Keywords:

Galactagogue tea

Herbal tea

Antioxidant

Oxidant

1. Introduction

Breast milk is a unique and perfect foods in infant nutrition with its nutritional composition, immunoglobulins, important bioactive compounds, and many more components [1,2]. The World Health Organization (WHO) and the United Nations Children’s Fund(UNICEF) recommend that each baby be fed exclusively with breast milk for the first 6 months after birth, and breastfeeding should continue until at least the age of 2 with complementary feeding after the 6th month [3]. However, according to the data of WHO, it is observed that almost 2 in 3 infants are not exclusively breastfed for the first 6 months and that positive developments have not been reported on the breastfeeding rate in the last 20 years [4]. Moreover,it is reported that mothers often start to give complementary foods to infants earlier than recommended, the main factor of which is the belief in mothers suggesting that breast milk is not sufficient,and babies do not feel full [5].

Insufficient production of breast milk often leads to failures during the breastfeeding period. A decrease in breast milk may be developed due to reasons such as preterm birth, some diseases in mothers and babies and the fact that the mother and the baby are separated from each other because of these diseases while psychological reasons also constitute an important inhibitor of lactation[6]. Psychologically, most mothers may even prefer ablactation believing that their production of milk is Insufficient. In this regard,mothers thinking that their breast milk is Insufficient have opted for herbal and nutrient-based traditional practices in order to support the production of breast milk from past to present in all societies[7].

Galactagogues are defined as pharmaceutical agents, nutrients and herbal supplements used for the secretion, continuity, and increasing of the breast milk [8]. It is suggested that galactagogues increase the secretion of prolactin as well as providing psychological relief and a marginal contribution to the production of the breast milk [9]. Although there is not sufficient evidence in the literature regarding the safety and efficacy of galactagogues, they are often used by mothers and can often be recommended by health providers across the world [5,10]. In a study, it was reported that 60% of breastfeeding mothers had tried herbal medicine at least once, and 24.3% of them even said that they had tried it in order to increase the breast milk without any related problems [11]. For this purpose, the most used herbs were found to be fenugreek (18.4%),ginger (11.8%), dong quai (7.9%), chamomile (7.2%), garlic (6.6%)and blessed thistle (5.9%) [11]. In another study, it was concluded that 70% of health providers recommended galactagogues and that the most recommended galactagogue was fenugreek. It was also found that more than 80% of them believed galactagogues were beneficial and only one third of them said they might have possible side effects [10]. In addition to herbal supplements that increase breast milk, some herbal teas may also be used for purposes such as baby burping during the breastfeeding period, increasing the duration and quality of the sleep, supporting/relaxing the mother psychologically and increasing the fluid intake [12].

The effects of herbal galactagogues and herbal teas often used for various purposes, though the information on their efficacy and reliability is rather limited, on mothers, babies, and breast milk are mostly unknown. Only in one study, it was concluded that breast milk of the mothers who consumed galactagogue tea with fenugreek for 7–10 days (3 cups/day) did not change in terms of the total antioxidant and oxidant capacities and that the change in the oxidative stress index (OSI) value was not correlated with the consumption of galactagogues [13]. No information was found in the literature on the antioxidant and oxidant capacities of the galactagogues and herbal teas used for other purposes. This study aims to evaluate the total antioxidant and the total oxidant capacities of galactagogues and herbal teas that are sold in the market for both mothers and babies in the breastfeeding period, and to develop a new perspective on possible health effects and reliability of these types of tea.

2. Materials and method

2.1. Sample selection and acquisition

In this study, teas are classified and supplied into two categories:i) galactagogues as herbal teas which may increase lactation and/or ii) herbal teas for other purposes such as used for burping, relaxing,and sleeping purposes with or without effects on increasing breast milk.

Galactagogues and/or herbal teas used for other purposes for breastfeeding mothers and babies, which were sold in the markets in Ankara (Turkey) between November 2019 and January 2020,were included in the study (Table 1). In this context, tea types, in the form of ready-to-consume tea bags and sticks, sugar cube, powder,and granule, were procured in packaged form from five different supermarkets.

Table 1General characteristics and brewing instructions of each brand of tea samples included in the study.

2.1.1. Galactagogues

Eight-herb mixed tea of a brand as well as 8-vitamin added mixed herbal tea of another brand were included in the study in the tea bag form among the types of tea used for galactagogues by breastfeeding mothers. In addition, a type of mixed herbal tea sold as a ready-to-consume stick of a brand was included in the study.Herbal mixed tea (classic and with nutmeg) and still tea (classic and with vitamin C) types of five different brands accessed in the market were procured as types of powder and granule tea.

2.1.2. Herbal teas for other purposes

Among herbal teas that sold in the market and used for burping, relaxing, and sleeping purposes as well as for their effects on increasing breast milk, chamomile, and fennel (classic and with cumin), teas from three brands, and two types of night tea from two brands were procured.

In order to ensure the homogenization of tea samples, information on labels were checked, and only tea samples harvested in the same season in 2019 and whose production dates were within ±1 month from one another were cautiously selected for the study. In addition, the homogenization was ensured by purchasing each tea sample/brand from the three different markets.

2.2. Brewing procedure of samples

Tea samples with different sizes and in the form of tea bags,stick, and sugar cube were brewed for 4–5 min in 200 mL water(100°C) according to the instructions written on the outer packages regarding how to brew tea. While brewing these tea samples, a“l(fā)idded herbal tea brewing glass cup” was used, and tea samples were immersed in water 5–6 times. Cube-shaped tea mixtures were brewed using glass baguette and homogeneously distributed.

Samples of tea powders and granule tea were brewed in the“l(fā)idded herbal tea brewing glass cup” with water (100 or 200 mL)according to instructions written on the outer packages related to how to brew tea. All samples of tea powders and granule teas were mixed using the glass baguette and then infused. The temperature of the water used for brewing tea was determined according to the instructions (37 and 100°C). When it was recommended to use chilled water, water was chilled to 60°C and the chilled water was used for brewing the tea. When there were no brewing instructions on tea samples, tea samples were brewed according to the instructions on the closest tea type in terms of purpose and form.

2.3. Sample analyses

Tea infusions, specific to mothers and babies that were brewed according to instructions were strained, and supernatant parts were analyzed. All analyses were carried out in duplicate.

2.3.1. Temperature measurement

Water used for brewing tea samples was heated/boiled using a heat adjustable kettle with glass chamber (RossmanTM), and brewing temperatures were measured using a probe thermometer(Arcone TP101TM).

2.3.2. Evaluation of water-soluble dry matter content

A portable ATC Brix refractometerTMwas used in determining the amount of dry matter seeped into the brewed tea infusions. For the measurement, the zero calibration using distilled water was performed at 20°C. Then, cover plate was opened and a few drops of the sample were placed on the measurement prism to take a sample reading. The cover plate was closed for spreading the liquid across the entire surface of the prism without air bubbles or dry spots. The sample was allowed to remain on the prism for approximately 30 s.While holding the instrument under a light source, the Brix concentration (°) was determined by the intersection of the boundary of the light and dark fields on the scale. After reading process, the instrument was cleaned with distilled water immediately.

2.3.3. Total antioxidant status (TAS)

In order to determine TAS and total oxidant status (TOS), all brewed tea samples were centrifuged for 2 min at 3000 r/min and 4°C.

TAS levels were measured using commercially available kits (Relassay, Turkey) and Mindray BS300 Auto Biochemistry AnalyzerTM. The novel automated method is based on the bleaching of characteristic color of a more stable ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical cation by antioxidants. The assay has excellent precision values, which arelower than 3%. The change of absorbance at 660 nm is related with total antioxidant level of the sample. The results were expressed as mmol Trolox equivalent/L [14].

2.3.4. Total oxidant status (TOS)

TOS levels were measured using commercially available kits (Relassay, Turkey) and Mindray BS300 Auto Biochemistry AnalyzerTM. In the new method, oxidants present in the sample oxidized the ferrous ion-o-dianisidine complex to ferric ion. The oxidation reaction was enhanced by glycerol molecules abundantly present in the reaction medium. The ferric ion produced a colored complex with xylenol orange in an acidic medium. The color intensity, which could be measured spectrophotometrically in 530 nm,was related to the total amount of oxidant molecules present in the sample. The assay was calibrated with hydrogen peroxide and the results were expressed in terms of micromolar hydrogen peroxide equivalent per liter (μmol H2O2equivalent/L) [15].

2.3.5. Oxidative stress index (OSI)

The ratio of TOS to TAS was accepted as the oxidative stress index(OSI). For calculation, the resulting unit of TAS was converted to μmol/L, and the OSI value was calculated according to the following Formula [16]:

2.3.6. Statistical analysis

The data were analyzed using SPSS 22.0. Arithmetic mean ± standard deviation (x ± SD) values are given as descriptive statistics for variables. Mann-Whitney U test or Kruskal-Wallis Test were used in comparing the temperature, the amount of water-soluble dry matter (Brix°), TAS, TOS and OSI values of tea samples used for the same purpose in the similar form. P < 0.05 was determined as the level of significance for all of the analyses.

3. Results

The temperatures, water-soluble dry matter content, and TAS,TOS, OSI values of tea samples brewed according to brewing instructions of each brand were compared in Table 2.

The difference between the temperature and water-soluble dry content values of the galactagogues and other herbal tea samples in the same form brewed according to the instructions was not found to be statistically significant (P > 0.05) (Table 2).

When TAS values of galactagogue herbal tea samples brewed according to the instructions were evaluated, it was found that the TAS value of the mixed herbal tea in classic strained tea bag was(1.0 ± 0.06) mmol/L while the TAS value of the mixed herbal tea with vitamin addition was (3.0 ± 0.00) mmol/L (P < 0.05). The TAS value of the herbal tea in ready-to-consume stick form was (0.1± 0.00) mmol/L. The TAS value of the mixed herbal tea sold in the market in sugar cube form was found to be (0.2 ± 0.00) mmol/L. The TAS values of the herbal mixed teas in granule form that were soldin the market as still tea were found to be higher ((1.5 ± 0.00)–(1.7± 0.14) mmol/L) compared to other galactagogue tea types (P <0.05). The difference between the TAS values (mmol/L) of the herbal teas used for other purposes, which were brewed according to the instructions, is not statistically different (P > 0.05). The TAS values(mmol/L) of the night teas were found to be higher compared to herbal teas (P < 0.05) (Table 2).

Table 2Comparison of temperatures, water-soluble dry matter content, and TAS, TOS and OSI values of tea samples brewed according to brewing instructions of each brandφ.

When the TOS values (μmol/L) of galactagogue herbal tea types brewed according to the instructions were evaluated, it was found that the TOS value of strained tea bag with vitamin addition was lower compared to that of the classic strained bag ((4.3 ± 0.44)μmol/L vs. (24.7 ± 0.41) μmol/L) (P < 0.05). It was also found that the TOS value of the galactagogue tea sold as ready-to-consume stick in the market was (6.2 ± 0.02) μmol/L while the TOS value of the mixed herbal tea in the sugar cube form was (1.3 ± 0.09)μmol/L, and the same value was (2.0 ± 0.00) μmol/L for the herbal tea with nutmeg. The TOS values of the mixed herbal tea types in the granule form sold as still tea in the market with vitamin addition were found to be lower compared to those of the classic tea types ((5.1 ± 0.21)–(12.6 ± 0.26) μmol/L vs. (49.8 ± 0.60) μmol/L)(P < 0.05). When the TOS values (μmol/L) of other mixed herbal tea types were evaluated, it was found that the tea type with the highest TOS value was chamomile tea ((29.6 ± 0.23) μmol/L). While the TOS value of the fennel tea was (17.0 ± 0.02) μmol/L, TOS values of the fennel tea types with cumin were (6.8 ± 0.07) and (8.1 ± 0.63)μmol/L (P < 0.05). It was found that the TOS values of the herbal teas sold in the market as night teas were higher ((63.4 ± 0.31) and(67.8 ± 0.04) μmol/L) compared to other mixed herbal tea types(P < 0.05) (Table 2).

When OSI values of these tea types were evaluated, galactagogue mixed herbal teas were respectively found in terms of OSI values as follows: mixed herbal tea sold as sticks (3.56), classic strained tea bag (2.42), mixed herbal tea with nutmeg (0.97), and strained mixed herbal tea bag with vitamin addition (0.14). The OSI values of still tea types with vitamin addition in the granule form(0.21–0.79) were found to be lower than the classic still tea (3.16)(P < 0.05). The tea types with highest OSI values among herbal teas used for other purposes were chamomile (6.96) and fennel tea(5.42), respectively. The OSI values of fennel tea with cumin were found to be 1.68 and 1.84. The OSI values of the night teas were found to be higher (3.63 and 4.32) (Table 2).

4. Discussion

The reliability and efficacy of herbal teas often used as galactagogues and other purposes during the breastfeeding period and sold in the market for both mothers and babies is an important topic often discussed, and the antioxidant and oxidant capacities of these tea types and their health effects related to the antioxidant/oxidant system are not clear currently. The first step of forming this causality relationship can only be possible by determining the antioxidant/oxidant values, and this study is of the utmost importance in this regard.

Many herbs and foods can be used for galactagogue purposes.Galactagogues that are reported to be used mostly in the literature are fennel, blessed thistle, fenugreek, chaste tree fruit, milk thistle,and goat’s rue [17]. Although there is contradictory information on their efficacy and safety, they are widely used [18,19]. In this study,it was found that some of the galactagogue teas, each was composed of different herbs, especially those with vitamin, had remarkably high antioxidant capacities. It was also found that some teas had high oxidative capacities simultaneously with or independent of their antioxidant capacities. Oxidative stress occurs as a result of the imbalance between reactive oxygen species (ROS) and intraand extracellular antioxidant system, which is a protective system[20]. Reactive oxygen species (ROS) is an umbrella term encompassing oxygen radicals such as superoxide [O2] and hydroxyl radicals[OH], and compounds without oxygen radicals such as hydrogen peroxide [H2O2] [21]. ROS may damage biological macromolecules such as lipids, proteins, polysaccharides, and Deoxyribonucleic acid(DNA), and may lead to some oxidative diseases [20]. Metabolic changes in the uterus during labor and in the postpartum ablactation period seems to be quite important for the mother’s and baby’s health [22,23]. The transition from fetal life to neonatal life causes acute and complex physiological changes. The fetus passes from a hypoxic environment called intrauterine, whose partial oxy-gen pressure (PO2) is 20–25 mm Hg, into a normoxic environment called extrauterine with PO2100 mm Hg, and this transition stimulates ROS production [24,25]. It is reported that the damage caused by free radicals due to oxidative stress derived from metabolic changes in newborns, especially preterm/premature babies, plays a role in the pathogenesis of various diseases such as respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia, necrotizing enterocolitis, patent ductus arteriosus,and retinopathy of prematurity [26]. Given the diseases in newborns caused by oxidative stress, it is recommended that tea types with high levels of oxidative capacity/OSI not be consumed if there is persistence in the use of galactagogues and other tea types. Considering especially the fact that these tea types have a tendency to be used in case of preterm/premature birth and oxidative stress increases in preterm/premature cases, it is predicted that tea types with high OSI values will not contribute positively to the oxidative stress.

Breast milk contains many enzymatic and non-enzymatic compounds while it is also thought to contain many more undefined antioxidant compounds. Normally, compounds in breast milk such as superoxide dismutase, glutathione peroxidase, catalase, vitamin E, vitamin C, and beta-carotene protect the newborn against ROS in the first stage of life [13]. However, the effect of foods/herbs, other than breast milk, on maternal antioxidant status and therefore on breast milk, and on the antioxidant status of infants is controversial.In a study, it was found that coffee and tea ranked in the top places among the drinks contributing the most to the total antioxidant intake in women through dietary habits [27]. However, in another study, it was found that consumption of black tea during pregnancy did not affect the antioxidant/oxidant status of the breast milk [28].Another study was concluded that the total antioxidant and oxidant capacities of the breast milk in mothers, who had consumed a galactagogue tea containing fenugreek for 7–10 days (3 cups/day),did not change [13]. This study is not a study in which the effect of tea consumption on the antioxidant/oxidant capacity of milk is evaluated; however, it is a study aiming to provide necessary data on the antioxidant/oxidant capacity of tea types for the studies that will analyze this effect.

One of the most important findings of this study is the fact that some types of galactagogues and other herbal teas have high levels of oxidant activity as well as antioxidant activity. Based on OSI, which allows the evaluation of both antioxidant and oxidant activity together, it was found that the tea type with the highest OSI was chamomile tea. Similarly, in another studies, it was found that the polyphenol content and antioxidant activity was lower in chamomile tea compared to other tea types [29,30]. Actually, while it was difficult to make a generalization in this study, it was found that the antioxidant/oxidant capacity of galactagogues and other herbal teas, and therefore their OSIs might vary according to their form (powder/granule), type (teabag/stick/powder or granule), variety of herbs in the composition, and the brand.However, as expected, vitamin content in all tea types increased their antioxidant capacities while decreasing their oxidant capacities/OSI values.

In the light of this study, when there is a cumulative evidencebased data on the efficacy and reliability of galactagogues and other herbal teas, it is thought that they may increase the antioxidant capacity alone or by increasing the amount of breast milk produced. On the contrary, a paradox may also come into question about causing also negative changes in the antioxidant capacity of the breast milk due to the oxidant capacity values. In this regard,it is also thought that consumption of tea types with high levels of antioxidant capacity and low levels of oxidant capacity con firmed in this study may support the antioxidant capacity if consumption of herbal tea types is persistent for any kind of reasons. However, it should be emphasized that the present study could not give precise recommendations about consuming these tea products in terms of oxidant and antioxidant capacity. Because the current study has no evidence on the level of OSI have a real impact on mothers or their babies. Hence, it is important to determine the antioxidant/oxidant capacity effects of these tea types and the mechanisms they will use to affect while studying their efficacy and safety.

5. Conclusion

In conclusion, antioxidant/oxidant status of galactagogues and other herbal teas might vary according to their form (powder/granule), type, variety of herbs in the composition, and the brand. Moreover, some types of galactagogues and other herbal teas have high levels of oxidant activity as well as antioxidant activity and antioxidant. Also, it seems that vitamin addition is important for balancing antioxidant/oxidant status of all tea types.

There are some limitations in this study. The first of these limitations is that characterization of bioactive substances which may have an effect on the antioxidant/oxidant capacity of tea types but was not conducted in this study. Secondly, antioxidant/oxidant capacity values found in this study could not be compared since there was not any similar study in the literature. Thirdly, this study only reflects the results of the tea types that sold in market in our country in a specific time period. Therefore, it is thought that results obtained in this study may be partially limited in the generalization of the tea types in the market in other countries. It is recommended to consider these conditions in future studies to be conducted.

Declaration of Competing Interest

The Author(s) declare(s) that there is no conflict of interest.