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Sagna A, Nair RVR, Hulyalkar N, Rajasekharan S, Nair VTG, Sivakumar KC, Suja SR, Baby S, Sreekumar E. Ethyl palmitate, an anti-chikungunya virus principle from Sauropus androgynus, a medicinal plant used to alleviate fever in ethnomedicine. J Ethnopharmacol 2023; 309:116366. [PMID: 36914036 DOI: 10.1016/j.jep.2023.116366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/21/2023] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Sauropus androgynus is a medicinal shrub used for the treatment of fever in ethnomedical traditions in various Southeast Asian countries. AIM OF THE STUDY This study was aimed to identify antiviral principles from S. androgynus against Chikungunya virus (CHIKV), a major mosquito-borne pathogen that re-emerged in the last decade, and to unravel their mechanism of action. MATERIALS AND METHODS Hydroalcoholic extract of S. androgynus leaves was screened for anti-CHIKV activity using cytopathic effect (CPE) reduction assay. The extract was subjected to activity guided isolation and the resultant pure molecule was characterized by GC-MS, Co-GC and Co-HPTLC. The isolated molecule was further evaluated for its effect by plaque reduction assay, Western blot and immunofluorescence assays. In silico docking with CHIKV envelope proteins and molecular dynamics simulation (MD) analyses were used to elucidate its possible mechanism of action. RESULTS S. androgynus hydroalcoholic extract showed promising anti-CHIKV activity and its active component, obtained by activity guided isolation, was identified as ethyl palmitate (EP), a fatty acid ester. At 1 μg/mL, EP led to 100% inhibition of CPE and a significant 3 log10 reduction in CHIKV replication in Vero cells at 48 h post-infection. EP was highly potent with an EC50 of 0.0019 μg/mL (0.0068 μM) and a very high selectivity index. EP treatment significantly reduced viral protein expression, and time of addition studies revealed that it acts at the stage of viral entry. A strong binding to the viral envelope protein E1 homotrimer during entry, thus preventing viral fusion, was identified as a possible mechanism by which EP imparts its antiviral effect. CONCLUSIONS S. androgynus contains EP as a potent antiviral principle against CHIKV. This justifies the use of the plant against febrile infections, possibly caused by viruses, in various ethnomedical systems. Our results also prompt more studies on fatty acids and their derivatives against viral diseases.
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Affiliation(s)
- A Sagna
- Ethnomedicine and Ethnopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram, 695562, Kerala, India.
| | - Reshma V R Nair
- Phytochemistry and Phytopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram, 695562, Kerala, India.
| | - Neha Hulyalkar
- Molecular Virology Laboratory, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud P.O., Thiruvananthapuram, 695014, Kerala, India.
| | - S Rajasekharan
- Ethnomedicine and Ethnopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram, 695562, Kerala, India.
| | - Vinodkumar T G Nair
- Ethnomedicine and Ethnopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram, 695562, Kerala, India.
| | - K C Sivakumar
- Molecular Virology Laboratory, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud P.O., Thiruvananthapuram, 695014, Kerala, India.
| | - S R Suja
- Ethnomedicine and Ethnopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram, 695562, Kerala, India.
| | - Sabulal Baby
- Phytochemistry and Phytopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram, 695562, Kerala, India.
| | - Easwaran Sreekumar
- Molecular Virology Laboratory, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud P.O., Thiruvananthapuram, 695014, Kerala, India; Institute of Advanced Virology (IAV), Bio360 Life Sciences Park, Thonnakkal P.O, Thiruvananthapuram, 695317, Kerala, India.
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Nair RVR, Jayasree DV, Biju PG, Baby S. Anti-inflammatory and anticancer activities of erythrodiol-3-acetate and 2,4-di-tert-butylphenol isolated from Humboldtia unijuga. Nat Prod Res 2018; 34:2319-2322. [PMID: 30475646 DOI: 10.1080/14786419.2018.1531406] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Humboldtia unijuga Bedd., endemic to Agasthyamala in Western Ghats in India, is traditionally used by local Kani tribes for chicken pox, head ache and snake bite. This study reports the isolation of erythrodiol-3-acetate (HU-1) and 2,4-di-tert-butylphenol (HU-2) from H. unijuga roots and their anti-inflammatory and anticancer activities in macrophage, skin and breast cancer cell lines. Effects of HU-1 and HU-2 treatments (50, 100 µg/mL) on gene expression profiles of pro-inflammatory cytokines TNFα, IL-6 and IL-1β, and apoptosis genes p53 and caspase 7 were studied. HU-2 exerted a significantly superior anti-inflammatory effect compared to HU-1 in all three pro-inflammatory genes. HU-2 showed a superior dose dependent anticancer effect through activation of p53 gene over HU-1 in MCF-7 cells. HU-1 exhibited a dose dependent effect on caspase 7 gene in both cell lines while HU-2 was more effective in A431. HU-2 has potential for development as a novel anti-inflammatory and anticancer agent.
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Affiliation(s)
- Reshma V R Nair
- Phytochemistry and Phytopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Thiruvananthapuram, Kerala, India.,University of Kerala, Thiruvananthapuram, Kerala, India
| | | | | | - Sabulal Baby
- Phytochemistry and Phytopharmacology Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Thiruvananthapuram, Kerala, India
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