Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells
, Mayra Colardo 1, William Sergio 1, Michele Petraroia 1, Michela Varone 1, Daniele Pensabene 2, Miriam Russo 1, Sabrina Di Bartolomeo 1, Giancarlo Ranalli 1, Gabriella Saviano 1,* and Marco Segatto 1,*
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
Dear Authors, the manuscript is interesting and shows the evaluation of the ability of LEO to regulate the protein network controlling cholesterol metabolism in the HepG2 cell line, demonstrating that LEO modulates cholesterol metabolism in hepatic cells; you have to make some modifications:
- The work is well designed and written; a grammatical revision is required throughout the text; for example, some articles are missing and adding commas, adverbs, etc.
- Throughout the text, check the conjugation of the verbs.
- The paper needs to be checked carefully for typos and grammatical error.
- The scientific names should be written in italics.
- Keep the same font style and size throughout the manuscript.
L14. …lipid that guarantees several instead and “lipid which guarantees several.”
L16. … such as essential oils (EOs) instead such essential oils
L24. It appears that Taken together may be unnecessary in this sentence. Consider remove it… I suggest: These results demonstrate…
L31. .. fluidity activity instead “the fluidity”
L33. ..vitamin D, and bile acids.
L34-L35. Should be is often associated with several.
L36-L38. The phrase “In addition, defects in cholesterol metabolism are involved in a plethora of other pathological conditions, including cardiovascular diseases (CVD), cancer and neurodegeneration [1,5,6].” I suggest: “In addition, cholesterol metabolism defects are involved in many other pathological conditions, including cardiovascular diseases (CVD), cancer, and neurodegeneration [1,5,6].
L40-L42. The phrase: “Notably, the protein machinery controlling cholesterol levels is particularly lively in the liver, where a significant part of cholesterol metabolism takes place [5]”. I suggest: “Notably, the protein machinery controlling cholesterol levels is particularly lively in the liver, where a significant portion of cholesterol metabolism occurs [5]”.
L43. … activity of the mevalonate …
L47 … belonging to the MVA pathway …
L52-L53. The phrase “LDL binding to LDLr and LRP1 is ensured by the presence of apolipoproteins such as apoE and apoB”. I suggest: “The presence of apolipoproteins such as apoE and apoB ensures LDL binding to LDLr and LRP1”.
L55. leaves instead leave.
L67. Correct to: As mentioned above… and “are frequently associated with different…”
L73. …the dietary extract of Lavandula angustifolia…
L75 … demonstrating that linalool, a significant component of LEO, …
L79-L80. To reach this objective, we used the HepG2 cell line as an experimental model.
L85 –L86. Lavandula angustifolia flowers were harvested in central Italy (Rosciano, PE). They were hydrodistillated to obtain …
L87. … the initial weight of the sample used.
L93-L94. … a set of analytical standards
L105. …component represents the most abundant…
L109. … we first investigated the putative…
L119. …proving that total intracellular cholesterol was higher upon LEO.
L122. When evaluated as a whole, the data collected indicate. It appears that as a whole, may be unnecessary in this sentence. Consider remove it.
L134-L135. Data represent means ± SD. Statistical analysis was assessed by using an unpaired Student’s t-test. * p < 0.05; ** p < 0.01; *** p < 0.001.
L137-L138. Once assessed, the impact of LEO administration on neutral lipids and cholesterol content, proteins, and enzymes…
L141. … whereas SQLE did not show any statistically significant change (Figure 2C). The reduction in HMGCR and SQLS suggests a decrease in cholesterol biosynthesis upon LEO stimulation.
L196. I suggest: Given the profound alterations in cholesterol metabolism, we evaluated whether LEO could affect SREBP-2, one of the most important transcription factors regulating cholesterol homeostasis. Immunofluorescence analysis revealed that SREBP-2 immunoreactivity in control HepG2 cells is principally confined in the cytoplasm, with higher intensity mainly seen at the perinuclear level, suggesting subcellular localization to the endoplasmic reticulum and nuclear envelope.
L202. … immunoreactivity and enhanced its localization at a nuclear level. This data led us to speculate that LEO favors SREBP-2 expression and the production of its active nuclear fragment (Figure 5).
L234. I suggest: Conversely, terpinen-4-ol treatment similarly increased LDLr abundance to what was previously observed following LEO administration (Figure 7F).
L236. I suggest: Our results indicate that terpinen-4-ol partially mimics the effects induced by LEO when evaluated as a whole.
L275. I suggest, Cholesterol is essential to all eukaryotic cells and exerts crucial biological functions, ranging from structural roles to signal transduction activities.
L281. I suggest, Over the last decades, several naturally-occurring compounds have been investigated for their prospective influence on cholesterol metabolism, particularly in the context of CVD and liver dysmetabolism [13].
L289. I suggest, Our results demonstrate that LEO elicits profound alterations in lipid homeostasis, as it promotes the accumulation of neutral lipids and total, free and esterified cholesterol.
L393. The reference for the Oil Red O Staining and Quantification is missing.
In some parts of the text, the reference is missing.
There are some significant points that should be addressed before the manuscript can be considered for publication.
Author Response
Dear Editor,
Thank you very much for your message of December 23, 2022, concerning our manuscript "Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells" (Manuscript ID cimb-2127975) by N. Martella and colleagues.
We were very pleased to read the positive comments of the reviewers, and we would like to thank them for the thoughtful and constructive comments, which have helped us to significantly improve the submitted work.
We have carefully revised the manuscript, taking the received comments into account. We hereby would like to submit our revised paper for publication in Current Issues in Molecular Biology. Please find a detailed response to the comments below. Changes in the manuscript have been highlighted in red.
Yours faithfully,
Gabriella Saviano
Marco Segatto
Specific comments:
Reviewer 1
- “Dear Authors, the manuscript is interesting and shows the evaluation of the ability of LEO to regulate the protein network controlling cholesterol metabolism in the HepG2 cell line, demonstrating that LEO modulates cholesterol metabolism in hepatic cells; you have to make some modifications:
- The work is well designed and written; a grammatical revision is required throughout the text; for example, some articles are missing and adding commas, adverbs, etc.
- Throughout the text, check the conjugation of the verbs.
- The paper needs to be checked carefully for typos and grammatical error.
- The scientific names should be written in italics.
- Keep the same font style and size throughout the manuscript.
- L14. …lipid that guarantees several instead and “lipid which guarantees several.”
- L16. … such as essential oils (EOs) instead such essential oils
- L24. It appears that Taken together may be unnecessary in this sentence. Consider remove it… I suggest: These results demonstrate…
- L31. .. fluidity activity instead “the fluidity”
- L33. ..vitamin D, and bile acids.
- L34-L35. Should be is often associated with several.
- L36-L38. The phrase “In addition, defects in cholesterol metabolism are involved in a plethora of other pathological conditions, including cardiovascular diseases (CVD), cancer and neurodegeneration [1,5,6].” I suggest: “In addition, cholesterol metabolism defects are involved in many other pathological conditions, including cardiovascular diseases (CVD), cancer, and neurodegeneration [1,5,6].
- L40-L42. The phrase: “Notably, the protein machinery controlling cholesterol levels is particularly lively in the liver, where a significant part of cholesterol metabolism takes place [5]”. I suggest: “Notably, the protein machinery controlling cholesterol levels is particularly lively in the liver, where a significant portion of cholesterol metabolism occurs [5]”.
- L43. … activity of the mevalonate …
- L47 … belonging to the MVA pathway …
- L52-L53. The phrase “LDL binding to LDLr and LRP1 is ensured by the presence of apolipoproteins such as apoE and apoB”. I suggest: “The presence of apolipoproteins such as apoE and apoB ensures LDL binding to LDLr and LRP1”.
- L55. leaves instead leave.
- L67. Correct to: As mentioned above… and “are frequently associated with different…”
- L73. …the dietary extract of Lavandula angustifolia…
- L75 … demonstrating that linalool, a significant component of LEO, …
- L79-L80. To reach this objective, we used the HepG2 cell line as an experimental model.
- L85 –L86. Lavandula angustifolia flowers were harvested in central Italy (Rosciano, PE). They were hydrodistillated to obtain …
- L87. … the initial weight of the sample used.
- L93-L94. … a set of analytical standards
- L105. …component represents the most abundant…
- L109. … we first investigated the putative…
- L119. …proving that total intracellular cholesterol was higher upon LEO.
- L122. When evaluated as a whole, the data collected indicate. It appears that as a whole, may be unnecessary in this sentence. Consider remove it.
- L134-L135. Data represent means ± SD. Statistical analysis was assessed by using an unpaired Student’s t-test. * p < 0.05; ** p < 0.01; *** p < 0.001.
- L137-L138. Once assessed, the impact of LEO administration on neutral lipids and cholesterol content, proteins, and enzymes…
- L141. … whereas SQLE did not show any statistically significant change (Figure 2C). The reduction in HMGCR and SQLS suggests a decrease in cholesterol biosynthesis upon LEO stimulation.
- L196. I suggest: Given the profound alterations in cholesterol metabolism, we evaluated whether LEO could affect SREBP-2, one of the most important transcription factors regulating cholesterol homeostasis. Immunofluorescence analysis revealed that SREBP-2 immunoreactivity in control HepG2 cells is principally confined in the cytoplasm, with higher intensity mainly seen at the perinuclear level, suggesting subcellular localization to the endoplasmic reticulum and nuclear envelope.
- L202. … immunoreactivity and enhanced its localization at a nuclear level. This data led us to speculate that LEO favors SREBP-2 expression and the production of its active nuclear fragment (Figure 5).
- L234. I suggest: Conversely, terpinen-4-ol treatment similarly increased LDLr abundance to what was previously observed following LEO administration (Figure 7F).
- L236. I suggest: Our results indicate that terpinen-4-ol partially mimics the effects induced by LEO when evaluated as a whole.
- L275. I suggest, Cholesterol is essential to all eukaryotic cells and exerts crucial biological functions, ranging from structural roles to signal transduction activities.
- L281. I suggest, Over the last decades, several naturally-occurring compounds have been investigated for their prospective influence on cholesterol metabolism, particularly in the context of CVD and liver dysmetabolism [13].
- L289. I suggest, Our results demonstrate that LEO elicits profound alterations in lipid homeostasis, as it promotes the accumulation of neutral lipids and total, free and esterified cholesterol.
- L393. The reference for the Oil Red O Staining and Quantification is missing.
- In some parts of the text, the reference is missing.
- There are some significant points that should be addressed before the manuscript can be considered for publication.”
Reply by the authors: We really thank the reviewer for the appreciation of our work and for the precious suggestions. We have taken into consideration all the reviewer’s concerns, and in the revised version of the manuscript, we amended the text as indicated. We also carefully checked the whole manuscript for grammar and typographical errors. Missing references (including that one related to Oil Red O staining) are now inserted in the manuscript.
All the changes are highlighted in red.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The topic of the paper „Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells” is novelty and very interesting for readers because it is known that cholesterol is an essential lipid which guarantees several biological processes in eukaryotic cells, its metabolism being regulated by a complex protein network that could be significantly influenced by numerous exogenous sources, such essential oils.
The aim of the present manuscript was to evaluate whether lavender essential oil can affect the protein network controlling cholesterol homeostasis, using HepG2 cell line as experimental model. The results showed that this liver cell line expresses a wide variety of liver-specific metabolic functions and is considered a valuable model to study cholesterol metabolism.
The manuscript is well written, and the text is easy to read.
The design research is appropriate.
The results are consistent and clearly presented.
The reference list is variously and recently.
At the reference list, some names of species are not italic.
Examples:
- reference 14: Lavandula officinalis
- reference 17: Lavandula angustifolia
- reference 22: melaleuca alternifolia
- reference 33: Plantago asiatica
Author Response
Dear Editor,
Thank you very much for your message of December 23, 2022, concerning our manuscript "Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells" (Manuscript ID cimb-2127975) by N. Martella and colleagues.
We were very pleased to read the positive comments of the reviewers, and we would like to thank them for the thoughtful and constructive comments, which have helped us to significantly improve the submitted work.
We have carefully revised the manuscript, taking the received comments into account. We hereby would like to submit our revised paper for publication in Current Issues in Molecular Biology. Please find a detailed response to the comments below. Changes in the manuscript have been highlighted in red.
Yours faithfully,
Gabriella Saviano
Marco Segatto
Specific comments:
Reviewer 2
- “The topic of the paper „Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells” is novelty and very interesting for readers because it is known that cholesterol is an essential lipid which guarantees several biological processes in eukaryotic cells, its metabolism being regulated by a complex protein network that could be significantly influenced by numerous exogenous sources, such essential oils.
The aim of the present manuscript was to evaluate whether lavender essential oil can affect the protein network controlling cholesterol homeostasis, using HepG2 cell line as experimental model. The results showed that this liver cell line expresses a wide variety of liver-specific metabolic functions and is considered a valuable model to study cholesterol metabolism.
The manuscript is well written, and the text is easy to read.
The design research is appropriate.
The results are consistent and clearly presented.
The reference list is variously and recently.
At the reference list, some names of species are not italic.
Examples:
- reference 14: Lavandula officinalis
- reference 17: Lavandula angustifolia
- reference 22: melaleuca alternifolia
- reference 33: Plantago asiatica”
Reply by the authors: We are very grateful to the reviewer for the positive consideration about our manuscript. In the revised version of the manuscript, names of plant species are now written in italic as suggested.
Author Response File: Author Response.pdf
