Oral delivery of bioencapsulated exendin-4 expressed in chloroplasts lowers blood glucose level in mice and stimulates insulin secretion in beta-TC6 cells.

Kwon KC, Nityanandam R, New JS, Daniell H

Plant biotechnology journal18 Oct 2012Cited by 81 (Europe PMC)

PMID23078126PMCIDPMC3535676DOI10.1111/pbi.12008PepBankPUB-23078126

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study10

2 results from studies that gave the peptide. No result from this study comes from people.

01AnimalAnimal study (in vivo)Efficacy outcome
In mice, intraperitoneal commercial EX4 stimulated insulin secretion similarly to oral CTB-EX4.
In plain wordsIn mice, injected commercial EX4 stimulated insulin secretion similarly to oral CTB-EX4.
Peptide
Exenatide (exendin-4)
Outcome
No significant changeCommercial EX4 insulin secretion in mice
Study
mousen: not reported in source
Mice receiving commercial EX4
Comparator
Oral CTB-EX4
Outcome group
Glycemic control · Metabolic and weight
Studied dose
Dose not stated · intraperitonealAs given in this study (mouse).
Source sentences
Summary
Even when 5000-fold excess dose of CTB-EX4 was orally delivered, it stimulated insulin secretion similar to the intraperitoneal injection of commercial EX4 but did not cause hypoglycaemia in mice.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
Report a problemFND-2307812609
02LabIn vitro (cells)Activity measurement
In beta-TC6 cells, commercial EX4 increased insulin secretion similarly to chloroplast-derived CTB-EX4.
In plain wordsIn cells, commercial EX4 increased insulin secretion similarly to CTB-EX4.
Peptide
Exenatide (exendin-4)
Outcome
No significant changeCommercial EX4 insulin secretion
Study
mousen: not reported in source
beta-TC6 pancreatic cells
Comparator
CTB-EX4
Outcome group
Glycemic control · Metabolic and weight
Studied dose
Dose not stated
Source sentences
Summary
Chloroplast-derived CTB-EX4 showed increased insulin secretion similar to the commercial EX4 in beta-TC6, a mouse pancreatic cell line.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
Report a problemFND-2307812607

Studies that did not test the peptide alone8

In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Exenatide (exendin-4).

03AnimalNot a test of Exenatide (exendin-4) aloneAnimal study (in vivo)Efficacy outcome
In mice, oral CTB-EX4 stimulated insulin secretion similarly to intraperitoneal commercial EX4 despite a 5000-fold excess dose.
In plain wordsIn mice, oral CTB-EX4 stimulated insulin secretion similarly to injected commercial EX4.
Peptide
Exenatide (exendin-4)
Outcome
No significant changeCTB-EX4 insulin secretion in mice
Study
mousen: not reported in source
Mice receiving oral CTB-EX4
Comparator
Intraperitoneal commercial EX4
Outcome group
Glycemic control · Metabolic and weight
Source sentences
Summary
Even when 5000-fold excess dose of CTB-EX4 was orally delivered, it stimulated insulin secretion similar to the intraperitoneal injection of commercial EX4 but did not cause hypoglycaemia in mice.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812608
04AnimalNot a test of Exenatide (exendin-4) aloneAnimal study (in vivo)Safety outcome
In mice, oral CTB-EX4 did not cause hypoglycaemia even at a 5000-fold excess dose.
In plain wordsIn mice, oral CTB-EX4 did not cause low blood sugar even at the reported excess dose.
Peptide
Exenatide (exendin-4)
Outcome
Not applicableHypoglycaemia with CTB-EX4
Study
mousen: not reported in source
Mice receiving oral CTB-EX4
Outcome group
Adverse events · Metabolic and weight
Source sentences
Summary
Even when 5000-fold excess dose of CTB-EX4 was orally delivered, it stimulated insulin secretion similar to the intraperitoneal injection of commercial EX4 but did not cause hypoglycaemia in mice.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812610
05LabNot a test of Exenatide (exendin-4) aloneIn vitro (cells)Other
In tobacco chloroplasts, CTB-EX4 expression reached up to 14.3% of total leaf protein.
In plain wordsIn lab tests, CTB-EX4 expression reached up to 14.3% of total leaf protein.
Peptide
Exenatide (exendin-4)
Outcome
Not applicableFusion protein expression
Study
tobaccon: not reported in source
Tobacco chloroplasts expressing CTB-EX4
Outcome group
Formulation, delivery and stability · Pharmacology
Measurements
Expression level
≤ 14.3%
total leaf protein
Source sentences
Summary
Expression level of CTB-EX4 reached up to 14.3% of total leaf protein (TLP).
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812601
06LabNot a test of Exenatide (exendin-4) aloneIn vitro (cells)Activity measurement
In beta-TC6 cells, chloroplast-derived CTB-EX4 increased insulin secretion similarly to commercial EX4.
In plain wordsIn cells, CTB-EX4 increased insulin secretion similarly to commercial EX4.
Peptide
Exenatide (exendin-4)
Outcome
No significant changeCTB-EX4 insulin secretion
Study
mousen: not reported in source
beta-TC6 pancreatic cells
Comparator
Commercial EX4
Outcome group
Glycemic control · Metabolic and weight
Source sentences
Summary
Chloroplast-derived CTB-EX4 showed increased insulin secretion similar to the commercial EX4 in beta-TC6, a mouse pancreatic cell line.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812606
07LabNot a test of Exenatide (exendin-4) aloneIn vitro (cell-free)Other
In plant material, lyophilization increased CTB-EX4 protein concentration by 12- to 24-fold.
In plain wordsIn lab tests, freeze-drying increased CTB-EX4 protein concentration by 12- to 24-fold.
Peptide
Exenatide (exendin-4)
Outcome
IncreaseConcentration after lyophilization
Study
n: not reported in source
Chloroplast-derived CTB-EX4
Outcome group
Formulation, delivery and stability · Pharmacology
Source sentences
Summary
Lyophilization of leaf material increased therapeutic protein concentration by 12- to 24-fold
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812602
08LabNot a test of Exenatide (exendin-4) aloneIn vitro (cell-free)Other
In plant material, lyophilization extended CTB-EX4 shelf life up to 15 months at room temperature.
In plain wordsIn lab tests, freeze-drying extended CTB-EX4 shelf life up to 15 months at room temperature.
Peptide
Exenatide (exendin-4)
Outcome
IncreaseShelf life
Study
n: not reported in source
Chloroplast-derived CTB-EX4
Outcome group
Formulation, delivery and stability · Pharmacology
Source sentences
Summary
Lyophilization of leaf material increased therapeutic protein concentration by 12- to 24-fold, extended their shelf life up to 15 months when stored at room temperature and eliminated microbes present in fresh leaves.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812603
09LabNot a test of Exenatide (exendin-4) aloneIn vitro (cell-free)Other
In plant material, lyophilization eliminated microbes present in fresh leaves containing CTB-EX4.
In plain wordsIn lab tests, freeze-drying eliminated microbes present in fresh leaves containing CTB-EX4.
Peptide
Exenatide (exendin-4)
Outcome
DecreaseMicrobial elimination
Study
n: not reported in source
Chloroplast-derived CTB-EX4
Outcome group
Formulation, delivery and stability · Pharmacology
Source sentences
Summary
Lyophilization of leaf material increased therapeutic protein concentration by 12- to 24-fold, extended their shelf life up to 15 months when stored at room temperature and eliminated microbes present in fresh leaves.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812604
10LabNot a test of Exenatide (exendin-4) aloneIn vitro (cell-free)Other
In lyophilized material, CTB-EX4 retained pentameric structure, disulphide bonds and functionality.
In plain wordsIn lab tests, freeze-dried CTB-EX4 retained its reported structural and functional properties.
Peptide
Exenatide (exendin-4)
Outcome
Not applicablePreservation of fusion protein properties
Study
n: not reported in source
Chloroplast-derived CTB-EX4
Outcome group
Formulation, delivery and stability · Pharmacology
Source sentences
Summary
The pentameric structure, disulphide bonds and functionality of CTB-EX4 were well preserved in lyophilized materials.
1 context sentence(design, population, supporting numbers)
Summary · context
Therefore, exendin-4 (EX4) was expressed as a cholera toxin B subunit (CTB)-fusion protein in tobacco chloroplasts to facilitate bioencapsulation within plant cells and transmucosal delivery in the gut via GM1 receptors present in the intestinal epithelium.
In this study, Exenatide (exendin-4) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Exenatide (exendin-4).
Report a problemFND-2307812605

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
22 Oct 2026, 02:26 UTC
Study results updated
Version 1
21 Oct 2026, 18:59 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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