Myanmar has a rich pool of, but less known, medicinal plants with traditional knowledge. In this study, we aimed to investigate the inhibitory activity of traditional Myanmar medicinal plants against the type III secretion system (T3SS) of
Globally, the search for antimicrobials has encountered serious challenge of resistance from pathogenic microorganisms to antibiotics. Conventional antibiotics developed to inhibit the growth of pathogenic microbes are generally no more effective over three years of clinical applications. Though the cost to treat infectious diseases and to find new antibiotics has been largely increased during the past decades, little breakthrough has been made [
Gram-negative bacteria, such as
As a major cause of death to global population [
In contrary to its high risk of gastrointestinal infection to the population, Myanmar is endowed with rich plant resources and traditional knowledge that has been used for generations for treating various ailments. The
Since December of 2015, we implement continuous market surveys on documenting the medicinal plants sold and recording their traditional knowledge at Zay Cho Market in Mandalay, Myanmar. We acquired 93 dried medicinal plant samples belonging to 51 families (Unpublished Data) with good traditional knowledge for evidence-based scientific explorations in the direction of antibacterial, antioxidant, and antidiabetes properties. In this study, we focus on validation of these medicinal plants on antibacteria properties on (1) antibacterial activity against
The 93 samples of medicinal plants were purchased from Zay Cho Market in April 2016 after a preliminary ethnobotanical survey in December 2015. The samples were requested through Myanmar name recorded in the Medicinal Plant List of Myanmar [
Each plant material was extracted three times with EtOH. The supernatant of each extract was filtered through Whatman No. 2 filter paper and evaporated under reduced pressure at 60°C to afford corresponding crude extracts, respectively. All the 93 EtOH extracts were dissolved in DMSO at the concentration of 20 mg/mL, respectively.
The antibacterial activities of 93 extracts against
The potential anti-T3SS activities of 93 Myanmar medicinal plant extracts were screened for their effects on the secretion of the SPI-1 effector proteins of
To concretely detect SipC or FliC (flagellar protein),
The ethnobotanical inventory of medicinal plants in Myanmar enlisted more than 100 plant materials that are widely traded at Zay Cho Market (Unpublished Data). For the 93 species tested in this study, 71 were noted with traditional uses related to anti-infectious functions such as diarrhea, dysentery, digestion, flatulence, fever, and cough. Taking into consideration the screening of more potential agent for anti-T3SS, we included all the materials for the bioactivity tests in this research. Eighteen (Figure
Ethnobotanical information and antibacterial and anti-T3SS activities of the 18 traditional medicinal plants.
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My3 | | Malvaceae | Bustard sandalwood | | Karamat | woods | 3.76 | Urein, melena, purgative, skin diseases, hemafecia, paralysis, laxative, fever | Sa | 13 (4) | Antifungal, antioxidant and larvicidal, effective compounds includes mansonone C, E, N, and mansorin A, B [ |
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My4 | | Lauraceae | Caraway (Karaway) | | Karaway | fruits | 21.00 | Digestion, gynecological, regulating menstruation, confectionary flavouring liqueurs | SPI-1 | 131 (21) | The essential oil of fruits have moderate antibacterial properties [ |
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My7 | | Rutaceae | Lavang lata | | Kakawli | seeds | 12.17 | Gall-bladder disease, insecticidal, flatulence, phlegmy in throat, hypotension, fever, haematemesis, scorpion poison, insecticidal, anti-itching | SPI-1 | 6 (0) | Essential oil have been reported to be antifungal activity against Keratinophilic fungi [ |
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My10 | | Calophyllaceae | Ironwood tree | | Gangaw | flowers | 24.20 | Mixed with thana-ka good for skin, insomnia palpitation, dizziness, breathlessness | Pv | 156 (13) | 4-Alkyl- and 4-phenylcoumarins from |
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My11 | | Pentaphylacaceae | Box myrtle | | Kat-pho | barks | 33.26 | Hypertension, coughing, gall-bladder diseases ( | SPI-1 | 18 (1) | |
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My21 | | Combretaceae | Citrina tree | | Kyasu (Phan-kha-nge) | fruits | 45.18 | Asthma, flatulence, burn, toothache | SPI-1 | 8 (1) | Tanins are responsible for antimicrobial activity [ |
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My44 | | Apiaceae | Fennel | | Samon-saba (Awa) | seeds | 12.48 | Cough, fevers, indigestion, stomachache, apophlegmatisant | SPI-1 | 933 (128) | Antibacterial property [ |
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My45 | | Apiaceae | Anise (Sweet fennel) | | Sameik-si-mwe | seeds | 13.05 | Spice, medicine to emit unhealthy vapour | SPI-1 | 410 (60) | Antibacterial property [ |
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My49 | | Lamiaceae | Thyme | | Samon-byu | seeds | 13.84 | Dysentery, stomach pain, vomiting and diarrhoea used to happen in children ( | SPI-1 | 1613 (379) | Essential oil of |
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My61 | | Myristicaceae | Nutmeg | | Zadeik-po | seeds | 11.39 | Tonic, stomachache, piles, nourish blood, arthralgia | SPI-1 | 380 (33) | 3′,4′,7-trihydroxyflavone was major component for treating bactetiial infctiions including mutidrug resistant phenotypes [ |
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my67 | | Zingiberaceae | Bitter turmeric | | Nawin-kha | roots | 17.06 | Stomachache, anti-diabetic with honey | Sa | 93 (1) | Five diphenylhepranoids were found to be as ematocidal agents [ |
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My86 | | Clusiaceae | Boabab | | Metlin-chin | fruits | 33.20 | Constipation and stomachache | SPI-1 | 29 (1) | The hexane and chloroform extracts of |
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My89 | | Apiaceae | Asiatic pennywort | | Myin-hkwa-pin | whole plants | 12.12 | Lungs disease, dysentery, oliguria, hematuria, antidote, influenza, skin disease, hematochezia, wound inflammation ( | SPI-1 | 960 (35) | Anti-mycobacterial effect against |
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My90 | | Simaroubaceae | Java fruit | | Yar-tan-sae | seeds | 8.82 | Skin disease, leprosy, scabies, dysentery | SPI-1 | 224 (1) | A novel antibacterial peptide specific to |
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My104 | | Lauraceae | Cinnamon | | Thit-kyabo | barks | 2.28 | Digestion, gynecological disease, apoplexy, arthralgia, arthrodynia | SPI-1 | 14 (3) | The essential oil of |
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My105 | | Menispermaceae | Tree turmeric | | Thit-nan-nwin (Nanwin-nwe) | stems | 5.30 | Fevers, diabetes, celiac disease, snake bite | SPI-1 | 65 (2) | Antibacterial activity of |
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My108 | | Apocynaceae | Country ipecac | | Upa-tha-ka | stems | 13.60 | Prevent to perspiration, inflammation, asthma | SPI-1 | 113 (5) | The extracts of |
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My109 | | Ranunculaceae | Golden thread | | Khandauk | rhizomes | 22.50 | Mix with | Sa | 25 (3) | Anti-microbial potential [ |
Note: ① unsolved name based on The Plant List (
The antibacterial activities of 93 extracts were carried out against
The screening of the antibacterial activity of crude extract of MTMs. (A) My3 and My10 inhibited the growth of
Among the 93 tested samples, the extracts of
(a) The inhibitory activities of My7, My11, My21, My49, and My104 (80
Pictures of 18 crude drugs of traditional medicinal plants with antibacterial and anti-T3SS properties.
The results of this study confirmed that the crude extracts of four medicinal plants, i.e.
The crude extract from
As a Myanmar folk medicine,
Upon the acknowledgment of the alarming fast biological evolution of resistance to antibiotics, the shift from killing and/or inhibiting pathogenic bacteria to inhibit virulence factors provide a new solution for the treatment of microbial infectious diseases [
For the 15 medicinal plants with T3SS inhibitory potential, seven of them (
In total, 18 out of 93 traditional Myanmar medicinal plants showed evident antibacterial activities including antivirulence, suggesting a great potential of Myanmar medicinal plant resources and the accompanied knowledge systems on combating infectious diseases. The positive results of
The data used to support the findings of this study are included in the paper and within the supplementary information file.
Tianhong Li and Dongdong Zhang contributed equally to this study and are co-first authors.
The authors declare that they have no conflicts of interest.
Yang XF and Lu CH conceived and designed the experiments. Li TH and Zhang DD performed the experiments. Yang XF, Zhang DD, and Wang YH contributed plant materials/extract. Thaung Naing Oo, Myint Myint San, Aye Mya Mon, and Pyae Phyo Hein worked on the traditional knowledge and specimen collection. Yang XF and Lu CH wrote the manuscript. All the authors have read and approved the final manuscript.
This work was supported by the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (2015CASEABRIRG001), and the Program for Changjiang Scholars and Innovative Research Team in University (IRT_17R68).
We thanks to all the anonymous informants at Zay Cho Market for providing valuable information. We are grateful to the great help from Professor Shengji Pei, Dr. Yao Fu, Dr. Jie Cai, Ms. Jun Yang and Mr. Yu Zhang from Kunming Institute of Botany, Daw Mu Mu Aung and U Aung Zaw Moe from Forest Research Institute, and Professor Shude Yang from Yunnan University of TMC for taxonomic identification.
Fig S1 and Table S1 are provided as the supplementary materials. Fig S1 presents the screening of 93 medicinal Myanmar plants for their effects on the secretion of the