OBJECTIVES:Bronchitis is a common respiratory tract infection of humans mainly caused by influenza virus, rhinovirus, adenovirus, coronavirus and respiratory syncytial virus. The aim of this review was to gather fragmented literature on ethnomedicinal plants used against bronchitis in the Himalayan region and their in-vitro validation against bronchitis causing viral pathogens.

KEY FINDINGS:Present review contains ethnomedicines of total 55 plants from different countries of the Himalayas. Most of the literature reported was from India followed by Pakistan, China and Nepal. Familiarly used plant families for bronchitis treatment in the Himalayan region were Leguminosae (six plants) and Lamiaceae (five plants). Leaves and roots were the most common parts used in ethnomedicines against bronchitis. Of these 55 plants, only six plants have been studied in vitro against viral pathogens causing bronchitis. Different compounds like monoterpenoids, flavonoids, triterpenoids, iridoid glycosides, sesquiterpenes, benzoic and phenolic compounds were reportedly isolated from these plant extracts having strong antiviral potential.

SUMMARY:The Himalayan regions possess variety of ethnomedicinal plants used against respiratory diseases, but still there are only few studies related with their in-vitro validation. We invite the attention of researchers for detailed ethnopharmacological and phytochemical studies on unexplored plants used to treat bronchitis for the development of novel antiviral drugs.

OBJECTIVES:Bronchitis is a common respiratory tract infection of humans mainly caused by influenza virus, rhinovirus, adenovirus, coronavirus and respiratory syncytial virus. The aim of this review was to gather fragmented literature on ethnomedicinal plants used against bronchitis in the Himalayan region and their in-vitro validation against bronchitis causing viral pathogens.

KEY FINDINGS:Present review contains ethnomedicines of total 55 plants from different countries of the Himalayas. Most of the literature reported was from India followed by Pakistan, China and Nepal. Familiarly used plant families for bronchitis treatment in the Himalayan region were Leguminosae (six plants) and Lamiaceae (five plants). Leaves and roots were the most common parts used in ethnomedicines against bronchitis. Of these 55 plants, only six plants have been studied in vitro against viral pathogens causing bronchitis. Different compounds like monoterpenoids, flavonoids, triterpenoids, iridoid glycosides, sesquiterpenes, benzoic and phenolic compounds were reportedly isolated from these plant extracts having strong antiviral potential.

SUMMARY:The Himalayan regions possess variety of ethnomedicinal plants used against respiratory diseases, but still there are only few studies related with their in-vitro validation. We invite the attention of researchers for detailed ethnopharmacological and phytochemical studies on unexplored plants used to treat bronchitis for the development of novel antiviral drugs.

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One hundred methanolic plant extracts were screened for antiviral activity against seven viruses. Twelve extracts were found to have antiviral activity at the non-cytotoxic concentrations tested. The extracts of Rosa nutkana and Amelanchier alnifolia, both members of the Rosaceae, were very active against an enteric coronavirus. A root extract of another member of the Rosaceae, Potentilla arguta, completely inhibited respiratory syncytial virus. A Sambucus racemosa branch tip extract was also very active against respiratory syncytial virus while the inner bark extract of Oplopanax horridus partially inhibited this virus. An extract of Ipomopsis aggregata demonstrated very good activity against parainfluenza virus type 3. A Lomatium dissectum root extract completely inhibited the cytopathic effects of rotavirus. In addition to these, extracts prepared from the following plants exhibited antiviral activity against herpesvirus type 1: Cardamine angulata, Conocephalum conicum, Lysichiton americanum, Polypodium glycyrrhiza and Verbascum thapsus.

One hundred methanolic plant extracts were screened for antiviral activity against seven viruses. Twelve extracts were found to have antiviral activity at the non-cytotoxic concentrations tested. The extracts of Rosa nutkana and Amelanchier alnifolia, both members of the Rosaceae, were very active against an enteric coronavirus. A root extract of another member of the Rosaceae, Potentilla arguta, completely inhibited respiratory syncytial virus. A Sambucus racemosa branch tip extract was also very active against respiratory syncytial virus while the inner bark extract of Oplopanax horridus partially inhibited this virus. An extract of Ipomopsis aggregata demonstrated very good activity against parainfluenza virus type 3. A Lomatium dissectum root extract completely inhibited the cytopathic effects of rotavirus. In addition to these, extracts prepared from the following plants exhibited antiviral activity against herpesvirus type 1: Cardamine angulata, Conocephalum conicum, Lysichiton americanum, Polypodium glycyrrhiza and Verbascum thapsus.

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BACKGROUND:A search for new anti-coronaviral drugs to treat coronaviral infections was motivated by an outbreak of severe acute respiratory syndrome (SARS).

OBJECTIVES:In order to find drugs that treat coronavirus infections, including SARS, we screened traditional medicinal herbal extracts and evaluated their antiviral activities on coronavirus replication.

STUDY DESIGN:We employed a plaque assay to evaluate the effect of 22 medicinal herbal extracts on virus replication. We determined the 50% effective concentration (EC50) of each extract that was necessary to inhibit the replication of mouse hepatitis virus A59 (MHV-A59); we also determined 50% cytotoxic concentrations (CC50) for each extract. Northern and Western blot analyzes were performed to investigate antiviral activity in MHV-infected DBT cells, including virus entry, viral RNA and protein expression, and virus release. Coronavirus specific inhibition was also demonstrated using porcine epidemic diarrhea virus (PEDV).

RESULTS:Cimicifuga rhizoma, Meliae cortex, Coptidis rhizoma, Phellodendron cortex and Sophora subprostrata radix decreased the MHV production and the intracellular viral RNA and protein expression with EC50 values ranging from 2.0 to 27.5 microg/ml. These extracts also significantly decreased PEDV production and less dramatically decreased vesicular stomatitis virus (VSV) production in vitro.

CONCLUSIONS:The extracts selected strongly inhibited MHV replication and could be potential candidates for new anti-coronavirus drugs.

BACKGROUND:A search for new anti-coronaviral drugs to treat coronaviral infections was motivated by an outbreak of severe acute respiratory syndrome (SARS).

OBJECTIVES:In order to find drugs that treat coronavirus infections, including SARS, we screened traditional medicinal herbal extracts and evaluated their antiviral activities on coronavirus replication.

STUDY DESIGN:We employed a plaque assay to evaluate the effect of 22 medicinal herbal extracts on virus replication. We determined the 50% effective concentration (EC50) of each extract that was necessary to inhibit the replication of mouse hepatitis virus A59 (MHV-A59); we also determined 50% cytotoxic concentrations (CC50) for each extract. Northern and Western blot analyzes were performed to investigate antiviral activity in MHV-infected DBT cells, including virus entry, viral RNA and protein expression, and virus release. Coronavirus specific inhibition was also demonstrated using porcine epidemic diarrhea virus (PEDV).

RESULTS:Cimicifuga rhizoma, Meliae cortex, Coptidis rhizoma, Phellodendron cortex and Sophora subprostrata radix decreased the MHV production and the intracellular viral RNA and protein expression with EC50 values ranging from 2.0 to 27.5 microg/ml. These extracts also significantly decreased PEDV production and less dramatically decreased vesicular stomatitis virus (VSV) production in vitro.

CONCLUSIONS:The extracts selected strongly inhibited MHV replication and could be potential candidates for new anti-coronavirus drugs.

BACKGROUND:Cimicifuga rhizome, Meliae cortex, Coptidis rhizome and Phellodendron cortex have been previously shown to exhibit anti-coronavirus activity. Here, an additional 19 traditional medicinal herbal extracts were evaluated for antiviral activities in vitro.

METHODS:A plaque assay was used to evaluate the effects of 19 extracts, and the concentration of extract required to inhibit 50% of the replication (EC(50)) of mouse hepatitis virus (MHV) A59 strain (MHV-A59) was determined. The 50% cytotoxic concentration (CC(50)) of each extract was also determined. Northern and western blot analyses were conducted to evaluate antiviral activity on viral entry, viral RNA and protein expression, and release in MHV-infected DBT cells.

RESULTS:Sophorae radix, Acanthopanacis cortex and Torilis fructus reduced intracellular viral RNA levels with comparable reductions in viral proteins and MHV-A59 production. The extracts also reduced the replication of the John Howard Mueller strain of MHV, porcine epidemic diarrhoea virus and vesicular stomatitis virus in vitro. Sanguisorbae radix reduced coronavirus production, partly as a result of decreased protein synthesis, but without a significant reduction in intracellular viral RNA levels. The EC(50) values of the four extracts ranged from 0.8 to 3.7 microg/ml, whereas the CC(50) values ranged from 156.5 to 556.8 microg/ml. Acanthopanacis cortex and Torilis fructus might exert their antiviral activities in MHV-A59-infected cells by inducing cyclooxygenase-2 expression via the activation of extracellular signal-related kinase (ERK) and p38 or ERK alone, respectively.

CONCLUSIONS:Sophorae radix, Acanthopanacis cortex, Sanguisorbae radix and Torilis fructus might be considered as promising novel anti-coronavirus drug candidates.

BACKGROUND:Cimicifuga rhizome, Meliae cortex, Coptidis rhizome and Phellodendron cortex have been previously shown to exhibit anti-coronavirus activity. Here, an additional 19 traditional medicinal herbal extracts were evaluated for antiviral activities in vitro.

METHODS:A plaque assay was used to evaluate the effects of 19 extracts, and the concentration of extract required to inhibit 50% of the replication (EC(50)) of mouse hepatitis virus (MHV) A59 strain (MHV-A59) was determined. The 50% cytotoxic concentration (CC(50)) of each extract was also determined. Northern and western blot analyses were conducted to evaluate antiviral activity on viral entry, viral RNA and protein expression, and release in MHV-infected DBT cells.

RESULTS:Sophorae radix, Acanthopanacis cortex and Torilis fructus reduced intracellular viral RNA levels with comparable reductions in viral proteins and MHV-A59 production. The extracts also reduced the replication of the John Howard Mueller strain of MHV, porcine epidemic diarrhoea virus and vesicular stomatitis virus in vitro. Sanguisorbae radix reduced coronavirus production, partly as a result of decreased protein synthesis, but without a significant reduction in intracellular viral RNA levels. The EC(50) values of the four extracts ranged from 0.8 to 3.7 microg/ml, whereas the CC(50) values ranged from 156.5 to 556.8 microg/ml. Acanthopanacis cortex and Torilis fructus might exert their antiviral activities in MHV-A59-infected cells by inducing cyclooxygenase-2 expression via the activation of extracellular signal-related kinase (ERK) and p38 or ERK alone, respectively.

CONCLUSIONS:Sophorae radix, Acanthopanacis cortex, Sanguisorbae radix and Torilis fructus might be considered as promising novel anti-coronavirus drug candidates.

A novel human coronavirus has been reported to be the causative agent of severe acute respiratory syndrome (SARS). Since replication of HcoVs depends on extensive proteolytic processing, the main proteinase, 3CLpro, is an attractive drug target for anti-SARS agents. We have employed molecular docking of a chemical database into the active site of 3CLpro to search for non-peptidyl inhibitors. One compound was identified to be the natural product sabadinine, isolated from a historical herbal remedy.

A novel human coronavirus has been reported to be the causative agent of severe acute respiratory syndrome (SARS). Since replication of HcoVs depends on extensive proteolytic processing, the main proteinase, 3CLpro, is an attractive drug target for anti-SARS agents. We have employed molecular docking of a chemical database into the active site of 3CLpro to search for non-peptidyl inhibitors. One compound was identified to be the natural product sabadinine, isolated from a historical herbal remedy.