Chemical Composition and Antifungal, Anti-Inflammatory, Antiviral, and Larvicidal Activities of the Essential Oils of Zanthoxylum acanthopodium DC. from China and Myanmar

Round 1

Reviewer 1 Report

The manuscript with the title "Essential Oils and Their Derivatives: Fundamental and Applied Studies towards the Development of the Circular Bioeconomy" addresses a current topic.

Over time, it has been demonstrated that chemical antifungals destroy the entire population of fungi. It is right to find natural alternatives for classic antifungals. Essential oils are a sustainable option, but require more relevant studies.

The current study presents studies, but not enough. This manuscript provides an overview. I would also recommend cellular studies.

For Antifungal activity, on what basis did you choose Candida albicans, Epidermophyton floccosum, Trichophyton rubrum, Microsporum gypseum?

For example, Candida albicans is the most widespread, but it is not the only one. If you have the opportunity, please also analyze for Candida Krusei, Candida tropicalis, Candida parapsilosis, especially since the study is at an early stage. This recommendation is also for the rest of the types of fungi.

In Table 2 there is no statistical analysis. The standard deviation is not enough

The discussion part is missing, or where it exists, it is very superficial.

I recommend improving this manuscript. The basic idea and purpose are interesting, but the Manuscript is superficial. It does not approach the topic in depth, it analyzes only a part of the fungi, and the discussions are superficial

Author Response

Response to Reviewer 1’ s comments and suggestions

 

Point 1:

The manuscript with the title "Essential Oils and Their Derivatives: Fundamental and

Applied Studies towards the Development of the Circular Bioeconomy" addresses a

current topic.

Over time, it has been demonstrated that chemical antifungals destroy the entire

population of fungi. It is right to find natural alternatives for classic antifungals. Essential

oils are a sustainable option, but require more relevant studies.

Response 1:

These two comments are generally nice and we also agree with that.

 

Point 2:

The current study presents studies, but not enough. This manuscript provides an overview. I would also recommend cellular studies.

Response 2:

This is a good suggestion. We have already tested the anti-inflammatory activity in RAW 264.7 cell and the antiviral activity for Zika and dengue viruses in BHK cells.

 

Point 3:

For Antifungal activity, on what basis did you choose Candida albicans, Epidermophyton floccosum, Trichophyton rubrum, Microsporum gypseum?

For example, Candida albicans is the most widespread, but it is not the only one. If you

have the opportunity, please also analyze for Candida Krusei, Candida tropicalis, Candida

parapsilosis, especially since the study is at an early stage. This recommendation is also

for the rest of the types of fungi.

Response 3:

This recommendation is reasonable. We also wanted to test more fungi, but we had limited fungi strains and resources.

The reason why we choose Candida albicans, Epidermophyton floccosum, Trichophyton rubrum, and Microsporum gypseum as the tested fungi is they are the representative fungi that might cause skin itch or infection.

Local people in Chin State, Myanmar like to boil the fruits and leaves of Zanthoxylum acanthopodium DC and then apply them as warm baths. Our results showed that essential oils had sound inhibitory effects on the four tested fungi, which could cause skin infections and itching, and may partly explain why local people like to boil the fruit of Z. acanthopodium for bathing.

 

Point 4:

In Table 2 there is no statistical analysis. The standard deviation is not enough

Response 4:

According to standard statistical analysis, all experiments were performed at least three times and expressed as the mean values ± standard deviation (SD). We addressed this at the part of statistical analysis (3.8) in our manuscript.

Point 5:

The discussion part is missing, or where it exists, it is very superficial.

I recommend improving this manuscript. The basic idea and purpose are interesting, but the Manuscript is superficial. It does not approach the topic in depth, it analyzes only a part of the fungi, and the discussions are superficial.

Response 5:

We jointly presented the results and discussion in one section. The discussion parts were carefully and clearly showed following the results.

In this study, we investigated not only the antifungi activity but also several other biological activities of the essential oils of Zanthoxylum acanthopodium fruits from China and Myanmar, respectively. Both essential oils showed good anti-inflammatory, antifungal, antiviral and larvicidal activities. Our study validated the traditional medicinal value of Z. acanthopodium, and for the first time, revealed that Z. acanthopodium can not only eliminate Aedes albopictus larvae but also inhibit dengue virus at low concentrations. The new-found antiviral and larvicidal activity of Z. acanthopodium could control and prevent the transmission of dengue virus in China and Southeast Asia, where outbreaks of Aedes albopictus and dengue fever have occurred.

We believe that our manuscript is significantly meaningful and could provide a scientific basis for the sustainable use and commercial development of Z. acanthopodium in the pharmaceutical field.

Author Response File: Author Response.docx

Reviewer 2 Report

O terceiro parágrafo da introdução se perde no texto, não segue uma sequência lógica de pensamento. Sugiro que o autor reformule esta passagem.

Nos resultados, o autor deve explicar melhor o motivo das variações e como elas podem afetar as atividades biológicas

Esclarecer a que itens 1 e 2 se referem no rodapé da tabela 2

Coloque o nome em itálico no título da tabela 3

Na metodologia, corrija o nome do método de extração para "extração e destilação simultâneas"

 

 

Author Response

Response to Reviewer 2’ s comments and suggestions

 

Point 1:

O terceiro parágrafo da introdução se perde no texto, não segue uma sequência lógica de pensamento. Sugiro que o autor reformule esta passagem.

 

Response 1:

This is a very sound point. We read the third paragraph in introduction section again and again. To connecting this paragraph logically with the second and last paragraph, we revised it and presented it as: “Recent studies found that essential oils demonstrated anti-mosquito and mosquito repellent effects [30-33]. Essential oil is a mixture of several compounds collected from aromatic plants and has been frequently used in pharmaceuticals, preservatives, households, and cosmetic products since ancient times [34]. Compared with synthetic insecticides, essential oils are likely to cause less pollution to the environment and less toxic to humans [35]. The mechanism by which essential oil is lethal to mosquitoes is complicated. Thus, it is difficult for mosquitoes to develop resistance to essential oils [36, 37]. Without an effective vaccine, the best way to control dengue fever is to limit the population of mosquitoes [28, 38, 39]. Therefore, it is of great significance to develop eco-friendly insecticides from essential oils to eliminate mosquitoes.”

 

Point 2:

Nos resultados, o autor deve explicar melhor o motivo das variações e como elas podem

afetar as atividades biológicas

Response 2:

This is a constructive comments. We checked the cited references and added more description about their biological activities. We revised it and showed as below:

The steam distillation extracted essential oils of Z. acanthopodium fruits from Medan, Indonesia, had 29 chemical compositions with geranyl acetate (23.18%), citronella (11.23%), and β-citronelol (10.64%) as the main chemical components and had different influence to locomotor activity depended given doses on mice [40]. The n-hexane extracted essential oils of Z. acanthopodium fruits from Sumatra Island, Indonesia, had 32 chemical compositions, with carveol (47.70%) and myrtenyl acetate (12.55%) as the dominant components and expressed antidiabetic activity [41]. Steam distillation extracted essential oils of Z. acanthopodium fruits from Meghalaya state, India, had 21 chemical compositions, with eucalyptol (36.56%), limonene (16.90%) and δ-3-carene (13.53%) as the primary components and showed promising antibacterial activity against Staphylococcus aureus [42]. Thus, we found that the essential oils of Z. acanthopodium fruits, collected from different geographical sites and extracted by different methods, had significant differences in their major components and biological activities, indicating that the exploration of the essential oil composition of the same species collected from different regions was very improtant and enlightening.

 

Point 3:

Esclarecer a que itens 1 e 2 se referem no rodapé da tabela 2

 

Response 3:

Thanks to reviewer 2, we marked the missing number1 and 2 in table 2.

Point 4:

Coloque o nome em itálico no título da tabela 3

 

Response 4:

Thanks to reviewer 2, we had changed Z. acanthopodium into italic version in the title of table 3.

 

Point 5:

Na metodologia, corrija o nome do método de extração para "extração e destilação

simultâneas"

Response 5:

Jointly following the comments from reviewer 2 and reviewer 3, we revised the extraction method sentences to make it clearer and presented as below:

Following the described procedure with minor modification, the samples (100 g), which were dried in shade and ground with a laboratory mill, were subjected to simultaneous distillation extraction at 180°C for 3 h to produce the essential oils (34).

Author Response File: Author Response.docx

Reviewer 3 Report

Instead of "traditional medicine" another term must be used, like "traditional medicinal product"

The distillation method is not well described.  Which distillation method was applied?

Author Response

Response to Reviewer 3’ s comments and suggestions

 

Point 1:

Instead of "traditional medicine" another term must be used, like "traditional medicinal

product"

Response 1:

This comment is constructive. We revised it as “traditional medicinal plant”.

 

Point 2:

The distillation method is not well described. Which distillation method was applied?

Response 2:

Jointly following the comments from reviewer 2 and reviewer 3, we revised the extraction method sentences to make it clearer and presented as below:

Following the described procedure with minor modification, the samples (100 g), which were dried in shade and ground with a laboratory mill, were subjected to simultaneous distillation extraction at 180°C for 3 h to produce the essential oils (34).

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors responded to all my comments

Author Response

We are so grateful for reviewer 1. Thanks a lot for helping us to figure out a better manuscript.