
==== Front
ScientificWorldJournal
ScientificWorldJournal
tswj
The Scientific World Journal
2356-6140
1537-744X
Wiley

10.1155/2024/5515855
Research Article
In Vitro α-Amylase and α-Glucosidase Inhibitory Potential of Green Banana Powder Extracts
Klomsakul Pongsathorn 1
https://orcid.org/0000-0002-5568-9365
Chalopagorn Pornchanok pornchanok.pnru@gmail.com
2
1 Department of Biology Faculty of Science and Technology Phranakhon Rajabhat University, Bangkok 10220, Thailand
2 Department of Chemistry Faculty of Science and Technology Phranakhon Rajabhat University, Bangkok 10220, Thailand
Academic Editor: Nath Biswajit

2024
7 9 2024
2024 551585510 8 2023
28 3 2024
16 8 2024
Copyright © 2024 Pongsathorn Klomsakul and Pornchanok Chalopagorn.
2024
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This study investigated the proximate composition and inhibitory potential of hot water and ethanolic extracts of the pulp, peel and whole fruit of green banana (Musa sapientum) on α-amylase and α-glucosidase. Bioactive compounds were identified using GC-MS analysis. In addition, the cytotoxic effect on human gingival fibroblast (hGF) was evaluated using the sulphorhodamine B (SRB) assay. The results showed that the peel of green banana had the highest amount of ash (10.05%), fat (2.83%), protein (3.64%) and total dietary fibre (36.62%). The carbohydrate content of the whole fruit (81.79%) and pulp (81.50%) was higher than that of the peel (71.90%). The moisture content of the pulp (13.08%) was higher than that of the peel (11.58%) and whole fruit (11.30%). The ethanolic green banana peel extract showed a good inhibitory effect of α-amylase and α-glucosidase with the concentration necessary for 50% inhibition (IC50) of 0.512 and 0.100 mg·mL−1, respectively. The α-glucosidase inhibitory effect of the ethanolic green banana peel extract and the hot water green banana peel extract was not significantly different from that of acarbose (IC50 0.108 mg·mL−1). GC-MS analysis of the ethanolic green banana peel extract revealed fatty acids and fatty acid ester (9-octadecenamide (Z), octadecanamide and other compounds). The ethanolic peel extract exhibits a significant noncytotoxicity effect on hGF cells at concentrations ranging from 0.0001 to 1.0 mg·mL−1.

Phranakhon Rajabhat University02.04/65
==== Body
pmc1. Introduction

According to the International Diabetes Federation (IDF), there are more than 530 million diabetic patients globally. This number is increasing rapidly since diabetes mellitus (DM) is one of the most prevalent metabolic disorders worldwide. The condition is closely linked to chronic hyperglycaemia, and it is anticipated that the number of cases will exceed 640 million by 2030, a number that could be more than 780 million by 2045 [1]. DM usually involves inadequate secretion of insulin caused by damage to the β cells that produce insulin in the pancreas. Hyperglycaemia follows, which in turn can cause severe problems in the long term, including organ failure in some cases, typically affecting the nerves, kidneys, eyes and heart [2]. The condition has been linked to lifestyle factors such as obesity and a lack of exercise, as well as oxidative stress. DM can be addressed initially through exercise programmes and a healthy eating plan, while subsequent treatments include insulin or drugs designed to reduce the blood sugar levels of patients [3].

One of the therapeutic approaches in diabetes treatment is based on the inhibition of α-amylase and α-glucosidase activity, since these enzymes are responsible for digesting and absorbing carbohydrates. Type 2 diabetes can be treated by the use of miglitol, acarbose and voglibose, which are α-glucosidase inhibitors. The problem, however, is that hypoglycaemic drugs can lead to adverse side effects such as diarrhoea, flatulence, liver disorders and abdominal cramping [4]. As a consequence, natural sources of hypoglycaemic agents have become an important area of research; the aim is to avoid the undesirable side effects of the drugs currently used to treat diabetes as well as to reduce the costs involved.

One of the most widely grown fruits in the world is the banana, which can be found in more than a thousand different varieties. While production is high, more than 30% of the total crop yield typically goes to waste because people have a strong preference for only fully ripened bananas [5, 6]. Consequently, the commercial processing of bananas has been developed and adjusted to minimise this waste, and further research into this issue is ongoing. Waste can be utilised in the form of green banana powder (GBP), which can be obtained from bananas in Stages 1 and 2 on the Von Loesecke maturation scale [7]. These bananas are green, or green with a hint of yellow. GBP is becoming increasingly popular for human consumption since it offers notable benefits in terms of nutritional value and physiological support. It is an excellent source of vitamin C, vitamin B6 and provitamin A and is also high in minerals such as zinc, magnesium, potassium and phosphorus [5, 8]. In addition, it contains resistant starch, commonly used in the food sector since it offers health benefits through the promotion of microbiota in the human gut [9]. As a result, it is used as an ingredient in gluten- and wheat-free food products [10].

As it is rich in numerous bioactive components, GBP is a promising and attractive target for antidiabetes studies. GBP exhibits multifaceted potential by preventing oxidative damage to the liver and kidneys, enhancing the biochemical parameters in type 1 diabetic rats [11], reducing body weight and improving insulin sensitivity in obese type 2 diabetics [12]. Furthermore, it shows promise in ameliorating type 2 diabetes and associated cardiovascular risks [13]. However, the nutritional composition of GBP depends on the soil, climate, banana variety, mutation stage, local production and other factors [5]. The study of various parts of plants has contributed significantly to the discovery of numerous biologically active drugs [14]. Various components of bananas, including the peel, pulp and whole fruit, exhibit dissimilar percentages of phenolic compounds and flavour components [15]. It is widely recognised that various solvents have the capacity to extract distinct phytochemical groups depending on their polarity, consequently leading to variations in the biological activity of the extracts [16]. Hence, the objective of the present study was to investigate the proximate composition and inhibitory potential of hot water and ethanolic extracts of the pulp, peel and whole fruit of green banana (Musa sapientum) on α-amylase and α-glucosidase. In addition, the bioactive compounds can be identified using gas chromatograph interfaced with a mass spectrometer (GC-MS) analysis.

2. Materials and Methods

2.1. Plant Material

Green bananas (Musa sapientum; Musa ABB cv. Kluai “Namwa”) at Maturation Stage 1 were collected in May 2022 from the Chu-Jit banana cultivating farm, Nong Yai To Subarea, Chai Badan Area, Lopburi Province, Thailand. Bananas were identified by the Forest Herbarium, Department of National Park, Wildlife and Plant Conservation, Bangkok, Thailand.

2.2. Preparation of GBP

Green bananas were washed with water and then separated into three portions, including the pulp, peel and whole fruit. The samples were cut into small pieces and dried immediately at 50°C for 24 h using a hot-air oven. Subsequently, the dried samples were ground to a fine powder using a mechanical blender.

2.3. Proximate Composition

The proximate parameters (ash, moisture, carbohydrate, fats, protein and fibre contents) of GBP were determined using the method suggested by the Association of Official Analytical Chemists (AOAC) (2019) [17]. The food energy values [18] were expressed as(1) food energy kcal=% protein×4+% fat×9+% carbohydrate×4.

2.4. Extraction of GBP

2.4.1. Hot Water Extraction

Ten grams of each sample (pulp, peel and whole fruit) was extracted in 200 mL of hot water at 80°C for 10 min on a hot plate, followed by maceration with an ultrasonicator for 1 h. The extract was then filtered with a Whatman filter paper (110 mm) and centrifuged at 3500 × g for 15 min (Centrifuge 5810 R, Eppendorf AG, Hamburg, Germany). The extract was dried by evaporation under vacuum and stored at 4°C.

2.4.2. Ethanol Extraction

Ten grams of each sample (pulp, peel and whole fruit) was extracted in 200 mL of 80% ethanol by maceration with an ultrasonicator for 1 h. The extract was then filtered with a Whatman filter paper (110 mm) and centrifuged at 3500 × g for 15 min (Centrifuge 5810 R, Eppendorf AG, Hamburg, Germany). The extract was dried by evaporation under vacuum and stored at 4°C.

2.5. Determination of α-Amylase Inhibition

The α-amylase inhibition was determined by assay, as previously reported [19]. Porcine pancreatic α-amylase was prepared using 0.5 mg·mL−1 in a 20 mM sodium phosphate buffer (pH 6.9). The preincubation mixture consisted of 50 μL of α-amylase and 50 μL of GBP extract. The mixture was incubated at 25°C for 10 min. Thereafter, 50 μL of 0.5% starch solution in 20 mM sodium phosphate buffer (pH 6.9) was added and incubated at 25°C for 10 min. The reaction was stopped by adding 50 μL of 96 mM 3,5-dinitrosalicylic acid and incubating it in a boiling water bath for 10 min. The absorbance of the solution was then measured spectrophotometrically at 540 nm (VICTOR Nivo, PerkinElmer, Massachusetts, USA). Subsequently, a control was prepared using the same procedure except that the extract was replaced with a buffer. Acarbose was used as a positive control. The extent of inhibition by the addition of samples was expressed as the concentration necessary for 50% inhibition (IC50). The percentages of α-amylase inhibition were expressed as(2) % inhibition=Acontrol−AsampleAcontrol×100.

2.6. Determination of α-Glucosidase Inhibition

The α-glucosidase inhibition was determined by assay, as previously reported [19, 20]. α-Glucosidase from a Saccharomyces cerevisiae solution was prepared using 1 U·mL−1 in a 20 mM sodium phosphate buffer (pH 6.9). The preincubation mixture consisted of 50 μL of α-glucosidase and 25 μL of GBP extract. The mixture was incubated at 25°C for 10 min. Thereafter, 25 μL of 5 mM p-nitrophenyl-α-D-glucopyranoside solution in 20 mM sodium phosphate buffer (pH 6.9) was added and incubated at 25°C for 5 min. The absorbance was measured at 405 nm using a spectrophotometer (VICTOR Nivo, PerkinElmer, Massachusetts, USA). Subsequently, a control was prepared using the same procedure except that the extract was replaced with a buffer. Acarbose was used as a positive control. The extent of inhibition by the addition of samples was expressed as the concentration necessary for IC50. The percentages of α-glucosidase inhibition were expressed as(3) % inhibition=Acontrol−AsampleAcontrol×100.

2.7. GC-MS Analysis

In this study, gas chromatography and mass spectrometry were used to identify the phytochemical compounds present in the ethanol extract of green banana peel. GC-MS analysis was carried out on a GC Shimadzu QP2020 and GC-MS equipped with a SH-Rxi-5Sil MS capillary column (30 m × 0.25 mm ID × 0.25 μm film thickness, Shimadzu, Japan). Helium (99.99%) was the carrier gas at a constant flow rate of 3 mL·min−1. The oven temperature programme was 50°C (isothermal for 2 min), with an increase of 10°C·min−1 to 280°C for 3 min. The total GC-MS running time was 28 min. The relative percentage of each component was evaluated by comparing its average peak area to the total area.

2.8. Determination of Cytotoxic Activity

For the sulphorhodamine B (SRB) assay, human gingival fibroblast (hGF) cells were seeded onto 96-well plates and treated with different concentrations of the GBP peel extract at 0.0001, 0.001, 0.01, 0.1 and 1.0 mg·mL−1 for 48 h. Cells were fixed by adding 100 μL of cold 10% trichloroacetic acid for 1 h at 4°C. Thereafter, the supernatant was removed, and cells were rinsed four times with slow-running tap water. The plate was allowed to air-dry and stained with 100 μL of 0.057% SRB solution at room temperature for 30 min. Subsequently, the wells were washed four times with 1% (v/v) acetic acid to remove unbound dye. The bound SRB was dissolved by 100 μL of 10 μM Tris, pH 10.5, for 10 min. The absorbance was measured at 510 nm (VICTOR Nivo, PerkinElmer, Massachusetts, USA). Cells treated with a culture medium served as the negative control, while those treated with sodium lauryl sulphate (SLS) were the positive control [21].

2.9. Statistical Analysis

Comparison of the means of three replicates was carried out for mean ± standard deviation to establish whether there were differences between the activities of samples, and the variance analysis was applied to the result. Values of p ≤ 0.05 were considered significantly different (α = 0.05).

3. Results and Discussion

3.1. Proximate Composition

The ash, moisture, carbohydrate, fat, protein and fibre contents in different parts of GBP in g/100 g dry weight are shown in Table 1. GBP peel had the highest amount of ash (10.05%), fat (2.83%), protein (3.64%) and total dietary fibre (36.62%). The carbohydrate content of GBP pulp (81.50%) and whole fruit (81.79%) did not reveal a significant difference, though it was higher than that in the peel (71.90%) with a significant difference. The moisture content of the peel (11.58%) and whole fruit (11.30%) was less than that of the pulp (13.08%) with a statistically significant difference. The results revealed that GBP is a good source of healthy minerals, nutrients and dietary fibre. Ash content in foods refers to the amount of minerals in food [18]. This indicates that GBP peel is rich in minerals. Fat, protein and carbohydrate contents provide energy for the body. The energy value of GBP was ranked in the order of whole fruit (345.01 kcal) > pulp (339.12 kcal) > peel (327.63 kcal). Variances in protein and fat contents may be due to geographical location and varietal differences [5, 18]. Total dietary fibre has various health benefits, including the prevention of heart disease, hypertension, diabetes, obesity and gastrointestinal diseases [22]. The total dietary fibre content in GBP peel was found to be approximately three times higher than that in the pulp and whole fruit. Moisture content in food products influences their shelf life. The moisture in flour should be at an acceptable limit of not more than 10% for long-term storage [23]. The moisture content of GBP pulp, peel and whole fruit was found to be from 11.30 to 13.08%, which is not suitable for storage stability and longer shelf life.

3.2. Inhibition of α-Amylase

The percentage of α-amylase inhibition of hot water or ethanolic extracts of different parts of GBP is presented in Table 2. The results revealed that the α-amylase inhibition of GBP extracts increases slightly as the concentration increases. Acarbose had the highest inhibitory α-amylase activity at all concentrations. At 2.0 mg·mL−1, the pulp, peel and whole fruit of hot water extract did not show a significant difference in the α-amylase inhibition (Table 2). However, there were significant differences in the inhibition rates of ethanol extracts (Table 3). The α-amylase activity of the GBP extracts is summarised in Table 4. All GBP extracts had a higher value of IC50 than acarbose as the positive control. IC50 values of extracts for α-amylase activity ranged from 0.512 to 1.615 mg·mL−1, while the IC50 value of acarbose was 0.219 mg·mL−1. Previous reports have shown that severe inhibition of pancreatic α-amylase may lead to aberrant bacterial fermentation of undigested starch in the colon. Thus, modest α-amylase inhibitory action appears beneficial [24].

3.3. Inhibition of α-Glucosidase

The results of α-glucosidase inhibition for hot water and ethanolic extracts of different parts of GBP showed that 0.05 to 0.5 mg·mL−1 concentrations of pulp, peel and whole fruit extracts were significantly different among the α-glucosidase inhibition values for all extracts (Tables 5 and 6). All extracts showed the concentration-dependent inhibition of enzyme activity. At 1 mg·mL−1 of peel with hot water (81.84 mg·mL−1) and ethanolic (87.48 mg·mL−1) extracts, there was no significant difference in the α-glucosidase inhibition when compared to acarbose (83.94 mg·mL−1). All peel extracts showed the most increasing rate of inhibition ranging from 29.50 to 87.48 mg·mL−1 with significant differences. Meanwhile, the hot water extract of whole fruit showed the highest inhibition than others but was not significantly different from acarbose at a concentration of 0.05 mg·mL−1. However, pulp with hot water and ethanolic extracts showed the lowest α-glucosidase inhibition with a significant difference. When increasing the concentration of extracts, the results revealed that the percentage of α-glucosidase inhibition increased in all extracts. Inhibition of α-glucosidase activity was calculated with the IC50 values (Table 4). Most extracts had a higher value of IC50 than acarbose. In addition, the IC50 values of GBP peel with hot water and ethanolic extracts were determined to be 0.164 and 0.100 mg·mL−1, respectively. The inhibitory effect of the ethanolic peel extract was not significantly different from that of acarbose (IC50 0.108 mg·mL−1). From these results, the ethanolic peel extract exhibited the potential inhibition of α-glucosidase activity. Moreover, the α-glucosidase inhibition of the hot water peel extract (0.164 mg·mL−1) suggested that there were no significant differences between ethanolic peel, hot water peel extracts and acarbose. Natural inhibitors derived from dietary plants are beneficial because they have a reduced inhibitory activity against α-amylase and a higher inhibitory activity against α-glucosidase [25]. Moreover, they can be utilised for the safe and efficient treatment of postprandial hyperglycaemia.

3.4. GC-MS Analysis

The ethanol extract of peel was subjected to GC-MS analysis to identify its phytochemical constituents. GC-MS analysis showed the presence of fourteen compounds in the extract (Table 7). The chromatographic analysis indicated the presence of numerous components in the ethanol peel extract that might be involved in biological processes. The maximum peak was shown by 9-octadecenamide (Z), followed by octadecanamide, hexadecanamide and 2,4-di-tert-butylphenol. Several of the compounds contained in the peel extract have already been demonstrated to possess antioxidant, antibacterial, hypocholesterolemic and antidiabetic characteristics [26, 27]. The compound 1-undecanol has previously been researched for its bactericidal and membrane-damaging properties [28]. Several publications have underlined the antioxidant and anti-inflammatory properties of 2,4-di-tert-butylphenol. Most significantly, the phenol displayed a wide range of toxicity in all tested species, including the producers, comprising cytotoxicity in human cells and animals, insecticidal and nematicidal activity, antibacterial activity and phytotoxicity [29]. 1-Hexadecanol is a 16-C fatty alcohol that can protect the skin against irritations triggered by insect bites, rashes and stings. It has been found that 1-hexadecanol inhibits the development of Mycoplasma gallisepticum and Mycoplasma pneumoniae [30], while 1-nonadecene has antitubercular, anticancer, antioxidant and antibacterial properties [28, 31]. n-Hexadecanoic acid demonstrates potential pharmacological activities including antioxidant, anti-inflammatory, anticancer, antitumour, hypocholesterolemic, nematicide and pesticide [32–35]. Decanoic acid has been demonstrated to possess substantial antibacterial and antifungal properties, and its esters have been employed in the medicinal, nutritional and dietetic fields [36]. Butyrate and its derivatives have the potential to serve as effective antibacterial and immunomodulatory therapeutics in the treatment of bacterial infections [37]. Hexadecanamide is a saturated fatty acid amide produced from palmitic acid. It has been investigated for potential therapeutic applications, such as its capacity to modulate inflammation, decrease oxidative stress and enhance cognitive performance [38]. Moreover, 9-octadecenamide (Z) is abundant in natural volatile oil with strong antioxidant, antibacterial, anti-inflammatory, antifungal and hypolipidaemic properties [39, 40].

3.5. Cytotoxic Activity

hGFs are accountable for a substantial portion of the extracellular matrix production in connective tissue and significantly impact wound healing [21]. GBP could be considered a functional food and has fewer side effects in comparison with conventional drugs, offering a safer alternative for the management of diabetes [5, 22]. Therefore, it is essential to verify the safety and effectiveness of GBP before their utilisation. In this respect, the cytotoxic potential of the GBP peel extract was assessed on hGF cells in comparison with SLS as a positive control. The results are presented in Table 8. hGF cells were treated with different concentrations of ethanolic peel extract (0.0001 to 1 mg·mL−1) to determine cell survival. The results showed that cell survival was 50% at 0.086 mg·mL−1 when cells were treated with SLS. However, when increasing the concentration of the peel extract to 1.0 mg/mL, hGF cells survived (87.62 mg·mL−1). The results indicated that the ethanolic GBP peel extract exerts cytotoxic effects on hGF cells with lower potency compared to SLS.

4. Conclusion

GBP has the potential to serve as a significant component in health food products. GBP peel is a good source of minerals and fibre. Further, it effectively inhibits carbohydrate-hydrolysing enzymes. The ethanolic peel extract displayed the highest potency in inhibiting both α-amylase and α-glucosidase activities, suggesting that the solvent has the capability to extract the active constituents present in GBP. GC-MS analysis indicated the presence of numerous components in the ethanolic peel extract that might be involved in biological processes. GBP peel appears to be a promising candidate that might be beneficial for various applications in plant-based superfoods, nutraceuticals and alternative medicine.

Acknowledgments

This research was supported by Thailand Science Research and Innovation, Phranakhon Rajabhat University, Grant number 02.04/65 (project number 169924). The authors are grateful to Miss Sukanda Phokpinit and Miss Rattanapon Kongkokfak for technical assistance. The authors feel deeply indebted to Mr. Tee at Chu-Jit banana cultivating farm and Mrs. Em, Nong Yai To Subarea, Chai Badan Area, Lopburi Province, for kindly providing information on the local wisdom in organic green banana powder production.

Data Availability Statement

The data used to support the findings of this study are included within the article.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Funding

This research was supported by Thailand Science Research and Innovation, Phranakhon Rajabhat University, Grant number 02.04/65 (project number 169924).

Table 1 Proximate composition of GBP.

Parts of GBP	Proximate composition	
Ash (%)	Moisture (%)	Carbohydrate (%)	Fat (%)	Protein (%)	Total dietary fibre (%)	
Pulp	3.03 ± 0.21c	13.08 ± 0.42a	81.50 ± 0.22a	0.72 ± 0.06c	1.66 ± 0.07b	10.58 ± 0.56c	
Peel	10.05 ± 0.52a	11.58 ± 0.38b	71.90 ± 0.04b	2.83 ± 0.11a	3.64 ± 0.29a	36.62 ± 1.41a	
Whole fruit	3.80 ± 0.12b	11.30 ± 0.67b	81.79 ± 0.55a	1.09 ± 0.14b	2.01 ± 0.16b	13.49 ± 0.53b	
Note: Each value is presented as mean ± SD (n = 3). Mean with different letters (a–c) shows statistically significant differences (p ≤ 0.05).

Table 2 α-Amylase inhibition effect from hot water GBP extracts at different concentrations (0.25–2.0 mg·mL−1).

GBP extract concentration (mg·mL−1)	α-Amylase inhibition (%)	
0.25	0.5	1.0	2.0	
Acarbose	48.50 ± 3.10Ac	52.97 ± 1.81Ab	59.54 ± 1.54Aa	63.07 ± 0.81Aa	
Pulp	38.54 ± 3.69Bb	41.01 ± 3.97Bb	44.18 ± 2.81Cb	53.72 ± 1.39Ba	
Peel	35.92 ± 2.06Bb	38.13 ± 8.92Bb	44.44 ± 3.78Cb	54.02 ± 1.00Ba	
Whole fruit	41.78 ± 3.35Bb	44.13 ± 4.62ABb	50.74 ± 0.49Ba	53.08 ± 2.27Ba	
Note: Each value is presented as mean ± SD (n = 3). Mean within columns with different letters (A–C) shows statistically significant differences (p ≤ 0.05). Mean within rows with different letters (a–c) shows statistically significant differences (p ≤ 0.05).

Table 3 α-Amylase inhibition effect from ethanolic GBP extracts at different concentrations (0.25–2.0 mg·mL−1).

GBP extract concentration (mg·mL−1)	α-Amylase inhibition (%)	
0.25	0.5	1.0	2.0	
Acarbose	48.50 ± 3.10Ac	52.97 ± 1.81Ab	59.54 ± 1.54Aa	63.07 ± 0.81Aa	
Pulp	39.49 ± 1.59Bc	45.67 ± 3.60Bb	46.28 ± 1.39Cb	62.04 ± 1.22ABa	
Peel	47.76 ± 0.95Ac	49.22 ± 2.28ABbc	53.08 ± 2.98Bb	58.69 ± 3.39BCa	
Whole fruit	44.79  ±  1.13Ac	48.33 ± 2.57ABbc	51.33 ± 1.74Bb	55.76 ± 2.23Ca	
Note: Each value is presented as mean ± SD (n = 3). Mean within columns with different letters (A–C) shows statistically significant differences (p ≤ 0.05). Mean within rows with different letters (a–c) shows statistically significant differences (p ≤ 0.05).

Table 4 IC50 (mg·mL−1) value from GBP with hot water and ethanolic extracts for α-amylase and α-glucosidase inhibition.

Parts of GBP	IC50 (mg·mL−1)	
α-Amylase inhibition	α-Glucosidase inhibition	
Acarbose	0.219 ± 0.08e	0.108 ± 0.025d	
	
Hot water extraction	
Pulp	1.615 ± 0.173a	0.939 ± 0.023b	
Peel	1.574 ± 0.128a	0.164 ± 0.006cd	
Whole fruit	1.302 ± 0.359ab	0.403 ± 0.162c	
	
Ethanol extraction	
Pulp	1.069 ± 0.07bc	1.294 ± 0.297a	
Peel	0.512 ± 0.182de	0.100 ± 0.008d	
Whole fruit	0.741 ± 0.240cd	0.219 ± 0.070cd	
Note: Each value is presented as mean ± SD (n = 3). Mean with different letters (a–e) shows statistically significant differences (p ≤ 0.05).

Table 5 α-Glucosidase inhibition effect from hot water GBP extracts at different concentrations (0.05–1.0 mg·mL−1).

GBP extract concentration (mg·mL−1)	α-Glucosidase inhibition (%)	
0.05	0.25	0.5	1	
Acarbose	38.23 ± 3.85Ac	60.54 ± 3.90Ab	79.75 ± 2.48Aa	83.94 ± 5.04Aa	
Pulp	14.75 ± 1.26Cc	16.05 ± 0.35Cc	25.44 ± 5.62Cb	55.62 ± 0.77Ba	
Peel	29.50 ± 1.42Bd	53.50 ± 2.13Bc	74.05 ± 3.82Ab	81.84 ± 1.28Aa	
Whole fruit	41.10 ± 5.37Ac	47.58 ± 5.49Bbc	52.08 ± 2.45Bb	62.50 ± 5.54Ba	
Note: Each value is presented as mean ± SD (n = 3). Mean within columns with different letters (A–C) shows statistically significant differences (p ≤ 0.05). Mean within rows with different letters (a–d) shows statistically significant differences (p ≤ 0.05).

Table 6 α-Glucosidase inhibition effect from ethanolic GBP extracts at different concentrations (0.05–1.0 mg·mL−1).

GBP extract concentration (mg·mL−1)	α-Glucosidase inhibition (%)	
0.05	0.25	0.5	1	
Acarbose	38.23 ± 3.85Ac	60.54 ± 3.90Ab	79.75 ± 2.48Aa	83.94 ± 5.04Aa	
Pulp	5.62 ± 2.14Cd	13.20 ± 2.19Cc	29.45 ± 2.61Cb	57.21 ± 5.63Ca	
Peel	36.96 ± 1.10Ad	65.08 ± 1.11Ac	75.84 ± 2.33Ab	87.48 ± 1.50Aa	
Whole fruit	29.14 ± 4.96Bc	53.72 ± 2.27Bb	60.09 ± 9.30Bb	74.08 ± 4.64Ba	
Note: Each value is presented as mean ± SD (n = 3). Mean within columns with different letters (A–C) shows statistically significant differences (p ≤ 0.05). Mean within rows with different letters (a–d) shows statistically significant differences (p ≤ 0.05).

Table 7 Chemical profile of the ethanolic GBP peel extract by GC-MS.

Peak	Retention time (min)	Compounds	Molecular weight	Chemical formula	
1	3.275	Ethane	118	C6H14O2	
2	7.185	Tetraethyl silicate	208	C8H20O4Si	
3	9.323	2-Azacyclooctanone	127	C7H13NO	
4	13.486	1-Undecanol	172	C11H24O	
5	14.988	2,4-Di-tert-butylphenol	206	C14H22O	
6	15.986	1-Hexadecanol	242	C16H34O	
7	18.229	1-Nonadecene	266	C19H38	
8	19.928	n-Hexadecanoic acid	256	C16H32O2	
9	20.230	Decanoic acid, ethyl ester	200	C12H24O2	
10	20.286	Butanoic acid	320	C20H32O3	
11	21.815	9,9-Dimethoxybicyclo[3.3.1]nona-2,4-dione	212	C11H16O4	
12	21.990	Hexadecanamide	255	C16H33NO	
13	23.570	9-Octadecenamide (Z)	281	C18H35NO	
14	23.772	Octadecanamide	283	C18H37NO	

Table 8 Percentage of survival of human gingival fibroblast cells treated with sulphorhodamine B (SRB).

Samples	hGF cell survival (%)	
Concentration (mg·mL−1)	0.0001	0.001	0.01	0.1	1.0	
GBP peel extract	98.82 ± 1.39a	95.46 ± 1.83a	92.89 ± 2.46a	89.97 ± 6.35a	87.62 ± 3.85a	
Sodium lauryl sulphate	95.82 ± 4.39a	92.15 ± 6.29a	84.30 ± 2.42b	43.17 ± 4.73b	17.21 ± 1.44b	
Note: Each value is presented as mean ± SD (n = 4). Mean within column with different letters (a-b) shows statistically significant differences (p ≤ 0.05).
==== Refs
1 International Diabetes Federation IDF Diabetes Atlas 2021 Brussels Belgium: International Diabetes Federation
2 Jadalla B. M. I. S. Moser J. J. Sharma R. In Vitro Alpha-Glucosidase and Alpha-Amylase Inhibitory Activities and Antioxidant Capacity of Helichrysum cymosum and Helichrysum pandurifolium Schrank Constituents Separations 2022 9 8 p. 190 10.3390/separations9080190
3 Riaz S. Diabetes Mellitus Scientific Research and Essays 2009 4 367 373
4 Madar Z. The Effect of Acarbose and Miglitol (BAY-M-1099) on Postprandial Glucose Levels Following Ingestion of Various Sources of Starch by Nondiabetic and Streptozotocin-Induced Diabetic Rats The Journal of Nutrition 1989 119 12 2023 2029 10.1093/jn/119.12.2023 2-s2.0-0024850796 2695605
5 Falcomer A. L. Riquette R. F. R. de Lima B. R. Ginani V. C. Zandonadi R. P. Health Benefits of Green Banana Consumption: A Systematic Review Nutrients 2019 11 6 p. 1222 10.3390/nu11061222 2-s2.0-85067308493
6 FAO Banana Market Review February 2020 Snapshot 2019 Rome Italy: FAO Food Outlook
7 Von Loesecke H. W. Bananas-Harry W. Von Loesecke-Google Livros 1950 New York, NY USA: Interscience Publishers
8 Lii C. Y. Chang S. M. Young Y. L. Investigation of the Physical and Chemical Properties of Banana Starches Journal of Food Science 1982 47 5 1493 1497 10.1111/j.1365-2621.1982.tb04968.x 2-s2.0-84986500354
9 Li P. Li M. Song Y. Green Banana Flour Contributes to Gut Microbiota Recovery and Improves Colonic Barrier Integrity in Mice Following Antibiotic Perturbation Frontiers in Nutrition 2022 9 p. 832848 10.3389/fnut.2022.832848
10 De Gouveia P. F. Zandonadi R. P. Green Banana: New Alternative for Gluten-Free Products Agro Food Industry Hi-Tech 2013 24 49 52
11 Silva A. R. d. Cerdeira C. D. Brito A. R. Green Banana Pasta Diet Prevents Oxidative Damage in Liver and Kidney and Improves Biochemical Parameters in Type 1 Diabetic Rats Archives of Endocrinology and Metabolism 2016 60 4 355 366 10.1590/2359-3997000000152 2-s2.0-84989225658 26910629
12 Ble-Castillo J. L. Aparicio Trápala M. A. Francisco Luria M. U. Effects of Native Banana Starch Supplementation on Body Weight and Insulin Sensitivity in Obese Type 2 Diabetics International Journal of Environmental Research and Public Health 2010 7 5 1953 1962 10.3390/ijerph7051953 2-s2.0-77954767683 20623003
13 Arun K. B. Thomas S. Reshmitha T. R. Akhil G. C. Nisha P. Dietary Fibre and Phenolic-Rich Extracts From Musa Paradisiaca Inflorescence Ameliorates Type 2 Diabetes and Associated Cardiovascular Risks Journal of Functional Foods 2017 31 198 207 10.1016/j.jff.2017.02.001 2-s2.0-85012077587
14 Haruna A. Yahaya S. M. Recent Advances in the Chemistry of Bioactive Compounds From Plants and Soil Microbes: A Review Chemistry Africa 2021 4 2 231 248 10.1007/s42250-020-00213-9
15 Li Z. Qin C. He X. Development of Green Banana Fruit Wines: Chemical Compositions and In Vitro Antioxidative Activities Antioxidants 2022 12 1 p. 93 10.3390/antiox12010093
16 Cieniak C. Walshe-Roussel B. Liu R. Phytochemical Comparison of the Water and Ethanol Leaf Extracts of the Cree Medicinal Plant, Sarracenia purpurea L. (Sarraceniaceae) Journal of Pharmacy and Pharmaceutical Sciences 2015 18 4 484 493 10.18433/j35w27 26626246
17 AOAC Official Methods of Analysis of the AOAC 2019 Washington DC: AOAC
18 Kassegn H. H. Determination of Proximate Composition and Bioactive Compounds of the Abyssinian Purple Wheat Cogent Food and Agriculture 2018 4 1 p. 1421415 10.1080/23311932.2017.1421415
19 Eleazu C. O. Eleazu K. C. Iroaganachi M. In Vitro Starch Digestibility, α-Amylase and α-Glucosidase Inhibitory Capacities of Raw and Processed Forms of Three Varieties of Livingstone Potato (Plectranthus esculentus) Innovative Food Science and Emerging Technologies 2016 37 37 43 10.1016/j.ifset.2016.08.007 2-s2.0-84981288441
20 Kim Y. M. Jeong Y. K. Wang M. H. Lee W. Y. Rhee H. I. Inhibitory Effect of Pine Extract on α-Glucosidase Activity and Postprandial Hyperglycemia Nutrition 2005 21 6 756 761 10.1016/j.nut.2004.10.014 2-s2.0-19544387948 15925302
21 Vichai V. Kirtikara K. Sulforhodamine B Colorimetric Assay for Cytotoxicity Screening Nature Protocols 2006 1 3 1112 1116 10.1038/nprot.2006.179 2-s2.0-34347230544 17406391
22 Anderson J. W. Baird P. Davis R. H. Jr. Health Benefits of Dietary Fiber Nutrition Reviews 2009 67 4 188 205 10.1111/j.1753-4887.2009.00189.x 2-s2.0-67649889132 19335713
23 Adom K. K. Sorrells M. E. Liu R. H. Phytochemicals and Antioxidant Activity of Milled Fractions of Different Wheat Varieties Journal of Agricultural and Food Chemistry 2005 53 6 2297 2306 10.1021/jf048456d 2-s2.0-15444370342 15769171
24 Oboh G. Akinyemi A. J. Ademiluyi A. O. Adefegha S. A. Inhibitory Effects of Aqueous Extract of Two Varieties of Ginger on Some Key Enzymes Linked to Type-2 Diabetes In Vitro Journal of Food and Nutrition Research 2010 49 14 20
25 Ramu R. Shirahatti P. S. Zameer F. Nagendra Prasad M. N. Investigation of Antihyperglycaemic Activity of Banana (Musa sp. var. Nanjangud rasa bale) Pseudostem in Normal and Diabetic Rats Journal of the Science of Food and Agriculture 2015 95 1 165 173 10.1002/jsfa.6698 2-s2.0-84922786337 24752944
26 Waghmare J. S. Kurhade A. H. GC-MS Analysis of Bioactive Components From Banana Peel (Musa sapientum Peel) European Journal of Experimental Biology 2014 4 10 15
27 Togashi N. Shiraishi A. Nishizaka M. Antibacterial Activity of Long-Chain Fatty Alcohols Against Staphylococcus aureus Molecules 2007 12 2 139 148 10.3390/12020139 2-s2.0-33847748197 17846563
28 Rukachaisirikul T. Siriwattanakit P. Sukcharoenphol K. Chemical Constituents and Bioactivity of Piper sarmentosum Journal of Ethnopharmacology 2004 93 2-3 173 176 10.1016/j.jep.2004.01.022 2-s2.0-3242735917 15234750
29 Zhao F. Wang P. Lucardi R. D. Su Z. Li S. Natural Sources and Bioactivities of 2,4-Di-Tert-Butylphenol and Its Analogs Toxins 2020 12 1 p. 35 10.3390/toxins12010035
30 National Center for Biotechnology Information PubChem Compound Summary for CID 2682, 1-Hexadecanol 2023 https://pubchem.ncbi.nlm.nih.gov/compound/1-Hexadecanol
31 Lee Y. S. Kang M. H. Cho S. Y. Jeong C. S. Effects of Constituents of Amomum xanthioides on Gastritis in Rats and on Growth of Gastric Cancer Cells Archives of Pharmacal Research 2007 30 4 436 443 10.1007/bf02980217 17489359
32 Sheela D. Uthayakumari F. GC-MS Analysis of Bioactive Constituents From Coastal Sand Dune Taxon-Sesuvium portulacastrum (L.) Bioscience Discovery 2013 4 47 53
33 Aparna V. Dileep K. V. Mandal P. K. Karthe P. Sadasivan C. Haridas M. Anti-Inflammatory Property of n-Hexadecanoic Acid: Structural Evidence and Kinetic Assessment Chemical Biology and Drug Design 2012 80 3 434 439 10.1111/j.1747-0285.2012.01418.x 2-s2.0-84864129053 22642495
34 Korbecki J. Bajdak-Rusinek K. The Effect of Palmitic Acid on Inflammatory Response in Macrophages: An Overview of Molecular Mechanisms Inflammation Research 2019 68 11 915 932 10.1007/s00011-019-01273-5 2-s2.0-85069941032 31363792
35 Harada H. Yamashita U. Kurihara H. Fukushi E. Kawabata J. Kamei Y. Antitumor Activity of Palmitic Acid Found as a Selective Cytotoxic Substance in a Marine Red Alga Anticancer Research 2002 22 2587 2590 12529968
36 Kumar A. Singh S. Jain S. Kumar P. Synthesis, Antimicrobial Evaluation, QSAR and in Silico ADMET Studies of Decanoic Acid Derivatives Acta Poloniae Pharmaceutica 2011 68 2 191 204 21485292
37 Du K. Bereswill S. Heimesaat M. M. A Literature Survey on Antimicrobial and Immune-Modulatory Effects of Butyrate Revealing Non-Antibiotic Approaches to Tackle Bacterial Infections European Journal of Microbiology and Immunology 2021 11 1 9 10.1556/1886.2021.00001 33735105
38 Farrell E. K. Chen Y. Barazanji M. Jeffries K. A. Cameroamortegui F. Merkler D. J. Primary Fatty Acid Amide Metabolism: Conversion of Fatty Acids and an Ethanolamine in N18TG2 and SCP Cells Journal of Lipid Research 2012 53 2 247 256 10.1194/jlr.m018606 2-s2.0-84862965840 22095832
39 Cheng M. C. Ker Y. B. Yu T. H. Lin L. Y. Peng R. Y. Peng C. H. Chemical Synthesis of 9(z)-Octadecenamide and its Hypolipidemic Effect: A Bioactive Agent Found in the Essential Oil of Mountain Celery Seeds Journal of Agricultural and Food Chemistry 2010 58 3 1502 1508 10.1021/jf903573g 2-s2.0-76449097355 20078072
40 Olaoluwa O. Moronkola D. Taiwo O. Iganboh P. Volatile Oil Composition, Antioxidant and Antimicrobial Properties of Boerhavia erecta L. and Euphorbia hirta L. Trends in Phytochemical Research 2018 2 171 178
