Table 4.

Aim, chemicals/compounds and results of findings reported on the selected studies

Reference	Aim	Chemicals/Compounds	Results
Rothan et al, 2014	To identify anti-dengue activities of medicinal plants extracts that are used in traditional medicine.	General ME	The highest inhibitory activities against dengue NS2B-NS3pro was observed in ethanolic extract of SA leaves, ME of VC leaves and ethanol extract of TP stems. These findings were further verified by in vitro viral inhibition assay. ME of VC leaves, ethanol extract of TP stems and at less extent ethanolic extract of SA leaves were able to maintain the normal morphology of DENV-2-infected Vero cells without causing much CPE. The percentage of viral inhibition of VC and TP extracts were higher than SA extract as measured by plaque formation assay and RT-qPCR.
Lee et al., 2013	To evaluate the possibility of developing a local medicinal plant, Phyllanthus as an anti-dengue agent.	Active compounds including gallic acid, galloylglucopyronside, corilagen, geraniin, rutin, quercetin glucoside, syringing, syringing diamer, digalloylglucopyronside, trigalloylglucopyronside, apigenin rhamnoside, and quercetin rhamnoside have been identified.	The MNTD of both aqueous and ME on Vero cells were 250.0 and 15.63μg/ml respectively. Phyllanthus showed strongest inhibitory activity against DENV-2 with more than 90% of virus reduction in simultaneous treatment. Two-dimensional analysis revealed altered levels of thirteen proteins, which were identified by tandem MS (MS/MS). The altered proteins were involved in biological processes, as viral entry, viral transcription and translation regulations, cytoskeletal assembly, and cellular metabolism.
Tang et al., 2012	To investigate the antiviral effects of standardized ME of AP, CL, CC, MC, OS and PC on DENV-1.	OS contained 88.6% of total flavonoids content, an amount that was the highest among all the six plants tested while the least was detected in MC.	The MNTD of the 6 medicinal plants was determined with ME against Vero E6 cells in vitro. The MNTD was in the decreasing order of MC > CL > PC, OS > AP > CC. Antiviral assay based on CPE denoted by degree of inhibition upon treating DENV-1-infected Vero E6 cells with MNTD of 6 medicinal plants showed that AP has the most antiviral inhibitory effects followed by MC. These results were verified with an in vitro inhibition assay using MTT, in which 113.0% and 98.0% of cell viability were recorded as opposed to 44.6% in DENV-1 infected cells. Although ME of OS and CC showed slight inhibition effect based on CPE, an inhibition was not reflected in MTT assay. ME of CL and PC did not prevent CPE or cell death from DENV-1.
Garcia et al., 2010	To screen for cytotoxicity and in vitro inhibitory activity against HSV-1, DENV-2 and JUNV.	LF (1,8-Cineole, guaiol, β-caryophyllene, camphor, camphene, borneol and aromadendrene). CA (Cadinol-epi-alpha, germacrene-D, spathulenol δ-cadinene, presilphiperfolan-1-ol, α-muurolene, bicyclogermacrene and β–caryophyllene). LG (bicyclogermacrene, germecrene-D, spathulenol, β-caryophyllene, piperitenone, α–copaene). LC (spathulenol, bicyclogermacrene, β-caryophyllene, α-humulene, humulene-epoxide II and phytol). EC (limonene, piperitenone, trans-dihydrocarvone, camphor, cis-dihydrocarvone, β-caryophyllene and bicyclogermacrene). EA (spathulenol, β-caryophyllene, germacrene-D bicyclogermacrene α-humulene, γ-muurolene, α-cadinol, cis-Cadin-4-en-7-ol, and caryophyllene oxide). Trixis divaricata (β–caryophyllene, spathulenol, β-elemene and caryophyllene oxide).	The oils showed a variable virucidal action according to the virus. JUNV was the least susceptible virus in comparison with HSV-1 and DENV-2. The better relationship between cytotoxicity and inhibitory activity was observed for the essential oil of LG against DENV-2 and HSV-1 with IC50 values of 21.1 and 26.1 ppm, respectively. This effect was specific since the selectivity indices (ratio cytotoxicity/virucidal activity) were > 23.7 and > 19.1 for DENV-2 and HSV-1, respectively. The oil from LG was also an effective inhibitor of HSV-2 and acyclovir resistant variants of HSV.
Garcia et al., 2003	To screen for virucidal activity against HSV-1, JUNV and DEN-2.	AG: caryophyllene oxide; cadinol; chrysanthenyl acetate; limonene oxide;β-caryophyllene. AD: α-thujone; β-thujone; borneol; p-cymene; 1.8-cineole; isocaryophylene-epoxide. EP: D-germacrene; β-caryophyllene; bicyclogermacrene;α-pinene; caryophyllene oxide. HL: borneol; camphor; limonene; β-pinene. HM: β-caryophyllene; germacrene D; curzerene; bicyclogermacrene. LJ: piperitenone oxide; limonene; camphor; spathulenol. LT: limonene; piperitenone oxide; β-caryophyllene. TA: caryophyllene oxide; (E)-β-damacenone; γ-eudesmol; α-gurjunene; terpinen-4ol.	The most potent inhibition was observed with the essential oil of LJ and LT against JUNV with VC50 values in the range 14–20 ppm, whereas AG, HL and TA inhibited JUNV in the range 52–90 ppm. Virucidal activity was time-and-temperature-dependent. Essential oils of AG, AD, EP and TA inactivated HSV-1 at 65–125 ppm. Only AD and EP had any discernible effect on DENV-2 infectivity with VC50 values of 60 and 150 ppm, respectively.
Gabrielsen et al., 1992	To evaluate the effect of 23 Amaryllidaceae isoquinoline alkaloids and related synthetic analogues isolated or synthesized and subsequently in cell culture against the RNA-containing flaviviruses.	Amaryllidaceae isoquinoline alkaloids and related synthetic analogues isolated or synthesized	Activity against SF virus was only observed with 7deoxy analogues. In most cases, selectivity of the active compounds was low, with toxicity in uninfected cells (TC50) within 10- fold that of the viral IC50. No activity was observed against HIV-1, VEEV, or vaccinia viruses. PN and its 7deoxy analogue were evaluated in JE mouse models (differing in viral dose challenge, among other factors). In experiments (low LD, viral challenge, variant I), prophylactic administration of PN at 4 and 6 mg/kg/ day (2% EtOH/saline, sc, once daily for 7 days) increased survival of JE-virus-infected mice. Prophylactic administration of 5 at 40 mg/kg/day in hydroxypropylcellulose (sc, once daily for 7 days) increased survival of JE-virus-infected mice. With high LD, viral challenge, administration of 4 at 6 mg/kg/day (ip, twice daily for 9 days) resulted in a 50% survival rate. PN and 7deoxy-PN demonstrated activity in mice infected with JE virus at near toxic concentrations.

PN-Pancratistatin, ME-methanolic extracts, SA-Senna angustifolia, VC-Vernonia cinerea, TP-Tridax procumbers, AP-Andrographis paniculata, CL- Citrus limon, CC-Cymbopogon citrates, MC - Momordica charantia, OS- Ocimum sanctum, PC- Pelargonium citrosum, LF-Lepechinia floribunda, CA-Cleome aculeata, LG-Lantana grisebachii, LC-Lantana camara, EC-Eupatorium catarium, EA-Eupatorium arnottianum, AG-Aloysia gratissima, AD-Artemisia douglasiana, EP-Eupatorium patens, HL-Heterotheca latifolia, HM-Hyptis mutabilis, LJ-Lippia junelliana, LT-Lippia turbinate, TA-Tessaria absinthioides DENV – dengue virus; CPE - cytopathic effects, RTq-PCR - real time quantitative PCR, MNTD - maximum non-toxic dose, VC50 - virucidal concentration 50%, JUNV – junin virus; HSV – herpes simplex virus, MS- mass spectrometry, IC50 - inhibitory concentration 50%, HIV- human immunodeficiency virus, JE - japanese encephalitis, LD –letal dose, YF - yellow fever; PT - punta toro; SF - sandfly fever-Sicilian; RVF - rift valley fever, VEEV - Venezuelan equine encephalomyelitis virus