scholarly journals Screening of in vitro antiviral activity of purified terpenoid extracts of selected sea weeds against chikungunya virus

Author(s):  
Sabira Siraj Sumayya ◽  
Abdulhadeef Shereefa Lubaina ◽  
Kumaraswamy Murugan

Currently, the search of novel phytochemicals with unique biological potentialities is a pre-requisite for the designing ideal drugs for the human kind. Sea weeds are bioresources with a broad spectrum of medicinal properties with minimal side effects. Kerala, the Southern state of India reported high incidence of Chikungunya virus (CHIKV) infections in the last several tears. No specific virucidal therapy or effective vaccines are available. This emphasizes the need of searching for phytochemicals as drugs with less cost and more effective. Therefore, an attempt was made in screening purified terpenoid extracts of selected sea weeds as anti-CHIKV potential. In this study the terpenoids composition from the red algae Hypnea musciformis, Kappaphycus alvarezii and Gracillaria dura were identified and analyzed by thin layer chromatography and Gas chromatography- Mass spectrum. The methanolic extract of seaweeds was purified by column chromatography and each fraction was eluted by using petroleum ether and ethyl acetate as solvent combination. The analysis of the purified fraction of H. musciformis and K. alvarezii revealed the presence of 8 terpenoid fractions, and G. dura showed only 4 major components respectively. Vero cell lines were employed in the antiviral assays, infected to CHIKV, and treated with varied doses of purified terpenoid extracts. In the antiviral activity, terpenoid extracts of G. dura showed remarkable and promising EC50 inhibitory effect at 1.25 μg/ml. Further, the terpenoid extracts displayed efficient virucidal activity against CHIKV (inhibit around 90%) with 5 μg/ml dosage. As the last phase, terpenoid extracts added at time intervals of 0, 1, 2, 3 post-infection periods still maintained a significant inhibitory potential against CHIKV viral replication. Thus, the overall study suggests that the terpenoid extracts of G. dura may be effectively used in the prevention and treatment of CHIKV infections. Clinical studies may be warranted for designing a promising new anti-CHIKV drug.

2020 ◽  
Vol 5 (2) ◽  
pp. 13-23
Author(s):  
Adeniran Lateef Ariyo ◽  
Ashafa Anofi Omotayo Tom

AbstractHermannia geniculata is a herb that plays an important role in the treatment of an array of diseases including diabetes, ulcer, and colitis in the South African traditional medicine. The bioactive constituent and medicinal properties in phenols of Hermannia geniculata (PoHG) roots were investigated using high pressure thin layer chromatography (HPTLC). The α-amylase inhibitory potentials of PoHG was determined by reacting different concentration of the plant extract with 1% starch solution containing α-amylase. The inhibitory effect of the extract on α-glucosidase was evaluated by pre-incubating α-glucosidase with varying extract concentrations followed by the addition of ρ -nitrophenylglucopyranoside.. The reactive oxygen and free radical scavenging potentials of the extract were also analyzed. The result showed the presence of phenolic compounds in the extract with retention factor (Rf) values ranging from 0.14 to 095. The extract scavenged DPPH, ABTS+, hydroxyl, and superoxide anion radicals. The extract was able to chelate metallic ions with a lower IC50 value which differs significantly (p≤0.05) from silymarin. Moreover, PoHG extract inhibited the key enzymes (α-glucosidase and α-amylase) involved in carbohydrate catabolism with IC50 values of 1.76 ±0.14 and 7.52 ±0.23 mg/mL respectively while IC50 value reported for acarbose were 7.62 ±0.12 and 4.38 ±0.25 mg/mL for glucosidase and α-amylase, respectively. The α-glucosidase exhibited non-competitive inhibition by PoHG extract while α-amylase showed uncompetitive inhibition. This study confirmed the presence of phenol in PoHG extract and also showed an appreciable antioxidant and antidiabetic activities in vitro. Therefore, PoHG extract may be of nutraceutical importance.


2020 ◽  
Author(s):  
Sean Ekins ◽  
Peter Madrid

Tilorone demonstrates in vitro antiviral activity against Chikungunya virus (CHIK) and Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV).


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0246319
Author(s):  
Raphael J. Eberle ◽  
Danilo S. Olivier ◽  
Carolina C. Pacca ◽  
Clarita M. S. Avilla ◽  
Mauricio L. Nogueira ◽  
...  

The potential outcome of flavivirus and alphavirus co-infections is worrisome due to the development of severe diseases. Hundreds of millions of people worldwide live under the risk of infections caused by viruses like chikungunya virus (CHIKV, genus Alphavirus), dengue virus (DENV, genus Flavivirus), and zika virus (ZIKV, genus Flavivirus). So far, neither any drug exists against the infection by a single virus, nor against co-infection. The results described in our study demonstrate the inhibitory potential of two flavonoids derived from citrus plants: Hesperetin (HST) against NS2B/NS3pro of ZIKV and nsP2pro of CHIKV and, Hesperidin (HSD) against nsP2pro of CHIKV. The flavonoids are noncompetitive inhibitors and the determined IC50 values are in low µM range for HST against ZIKV NS2B/NS3pro (12.6 ± 1.3 µM) and against CHIKV nsP2pro (2.5 ± 0.4 µM). The IC50 for HSD against CHIKV nsP2pro was 7.1 ± 1.1 µM. The calculated ligand efficiencies for HST were > 0.3, which reflect its potential to be used as a lead compound. Docking and molecular dynamics simulations display the effect of HST and HSD on the protease 3D models of CHIKV and ZIKV. Conformational changes after ligand binding and their effect on the substrate-binding pocket of the proteases were investigated. Additionally, MTT assays demonstrated a very low cytotoxicity of both the molecules. Based on our results, we assume that HST comprise a chemical structure that serves as a starting point molecule to develop a potent inhibitor to combat CHIKV and ZIKV co-infections by inhibiting the virus proteases.


Author(s):  
Adewunmi Rofiat Funmilola ◽  
Gidado Abubakar ◽  
Zanna Hassan

Solanum dasyphyllum belongs to the family of plants called Solanaceae, it is commonly called "Africa eggplant" and one of the medicinal plants used in the treatment of snake envenomation in the southwestern part of Nigeria, but investigation concerning its anti-venom activity has not been established. The present study evaluates the in-vitroenzyme inhibition potential of S.dasyphyllum leaf and fruit extracts against Naja nigricollis (Black-necked spitting cobra) venom. The inhibitory potential of S. dasyphyllum leaf and fruit on proteases, acetylcholinesterase, phospholipase A2 and hyaluronidase enzymes present in the snake venom was evaluated. The methanolic leaf and fruit extracts of S. dasyphyllum inhibited the activity of all enzymes evaluated, however, the leaf extract exhibited better enzyme inhibitory effect on N. nigricollis venom when compared with the fruit. This could be due to the presence of various phytochemicals in leaf and fruit extract.  This result substantiates the ethnomedicinal usage of S. dasyphyllum and would help to develop potent antidote therapy against N. nigricollis envenomation.


2019 ◽  
Vol 14 (10) ◽  
pp. 1934578X1988372
Author(s):  
Hiroaki Shimada ◽  
Chiaki Kuma ◽  
Taichi Iseri ◽  
Shin-ichi Matsumura ◽  
Atsushi Kawase ◽  
...  

The tea of Ocimum gratissimum (OG) leaves has been commonly consumed by people living in Ishigaki Island, Okinawa prefecture, Japan, and is considered to be effective for improving diabetes mellitus. In this study, we aimed to clarify the inhibitory potential of OG leaves extract (OG-ext) on gastrointestinal glucose absorption and to provide theoretical evidence for the anti-hyperglycemic effect of OG-ext. The increase of blood glucose after oral administration of α-starch and glucose in mice was suppressed by co-administration of OG-ext. An in vitro enzymatic assay suggested that amylase and maltase were inhibited weakly by the addition of OG-ext. In Caco-2 cells, a human intestinal epithelial model, the sodium-dependent glucose transporter (SGLT) 1-mediated uptake of fluorescence glucose analog was inhibited significantly by the addition of OG-ext in a concentration-dependent manner. These results indicate that the inhibitory effect on SGLT1 is one of the mechanisms of the anti-hyperglycemic effect of the tea of OG leaves.


Author(s):  
Kumari Smita

Objective: The present investigation was designed to study the inhibitory effects of methanolic leaf extract of Ocimum canum (O. canum) on α-glucosidase using in vitro model followed by an assessment of bioactive compounds.Methods: The methanolic leaf extract was prepared by Soxhlet extraction method and partially purified by thin layer chromatography (TLC). Each band was subjected to α-glucosidase inhibition study. The positive bands were further characterized by high-performance liquid chromatography (HPLC) and quadrupole time of flight (Q-TOF) micro mass spectrometer.Results: Out of the several combinations of solvent systems, toluene, ethyl acetate and formic acid combination in the ratio of 7:2:1 revealed 5 bands on the TLC sheet. Among all the TLC bands, 2 bands (band A and B) showed the significant inhibitory effect on α-glucosidase activity. HPLC analysis of band A and B revealed the presence of two important polyphenolic compounds, namely rosmarinic acid (RA) and ursolic acid (UA). Q-TOF micromass spectrometer analysis revealed the percentage availability of RA, caffeic acid, tartaric acid, quercetin and other polyphenolic components in the bioactive bands.Conclusion: The study revealed that methanolic leaf extract of O. canum exhibits potent inhibition of α-glucosidase activity. Inhibition of α-glucosidase activity might be attributed to the presence of the polyphenolic compounds like RA and UA. Therefore, this finding can lead to the development of natural α-glucosidase inhibitors by the O. canum leaf extract.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shu-Jen Chang ◽  
Yi-Chih Chang ◽  
Kai-Zen Lu ◽  
Yi-Yun Tsou ◽  
Cheng-Wen Lin

Isatis indigoticais widely used in Chinese Traditional Medicine for clinical treatment of virus infection, tumor, and inflammation, yet its antiviral activities remain unclear. This study probed antiviral activity ofI. indigoticaextract and its marker compounds against Japanese encephalitis virus (JEV).I. indigoticamethanol extract, indigo, and indirubin proved less cytotoxic than other components, showing inhibitory effect (concentration-dependent) on JEV replicationin vitro. Time-of-addition experiments proved the extract, indigo, and indirubin with potent antiviral effect by pretreatment (before infection) or simultaneous treatment (during infection), but not posttreatment (after entry). Antiviral action of these agents showed correlation with blocking virus attachment and exhibited potent virucidal activity. In particular, indirubin had strong protective ability in a mouse model with lethal JEV challenge. The study could yield anti-JEV agents.


1996 ◽  
Vol 51 (7-8) ◽  
pp. 558-562 ◽  
Author(s):  
Angel S. Galabov ◽  
Tanya Iosifova ◽  
Elka Vassileva ◽  
Ivanka Kostova

Abstract Esculetin (6,7-dihydroxycoumarin) and its diacetate exhibited a marked inhibitory effect on Newcastle disease virus replication in cell cultures at concentrations of 36 jam and 62 jam, respectively. These compounds were selected from ten hydroxycoumarin derivatives through an in vitro antiviral screen involving viruses of the picorna-, orthomyxo-, paramyxo-, and herpes virus families.


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