Streptococcus mutans (ATCC 25,175), Streptococcus salivarius (ATCC 7073), and
Staphylococcus aureus (ATCC 6538). As positive control, antibiotics ampicillin
(10 µg/ml), amoxicillin (10 µg/ml), and penicillin (30 µg/ml) were used for bacterial strains; and the antifungal ketoconazole (2 mg/ml), for yeast. There was a
positive drug interaction of the extracts with antibiotics and ketoconazole in concentrations of 1: 2 for the extract. The extract of B. anisandra has an antimicrobial
potential and drug interaction with drugs related to oral health. Studies on the
pharmacological properties of the species in question are rare and the results are the
first reports on its antimicrobial activity in association with antibiotics and
antifungals.
The positive results found not only in these reported studies, but also in
countless other studies, with different species increasingly show the importance of
the search for new metabolites that can help and reinforce drugs that no longer play
the role of eliminating pathogenic microorganisms.
7.6 Essential Oils with Antimicrobial Activity
from Tropical Medicinal Plants
In nature, EOs play an important role in providing plant protection against pathogenic bacteria, viruses, and fungi and preventing the attack by insect pests. In
addition, EOs can attract or repel insects when present in pollen and seeds. To
protect chemical compounds’ ecological equilibrium, the use of EOs in pharmaceutical, food, bactericidal, and fungicidal is becoming more prevalent in recent
times (Swamy et al. 2016). EOs yielding medicinal and aromatic plants are normally native to warm countries, where they represent an important traditional
pharmacopeia.
Apiaceae, Lamiaceae, Myrtaceae, Poaceae, and Rutaceae families are of particular importance for medicinal applications. For example, some of the EOs, like
anise, caraway, black caraway, clove, oregano, cumin, coriander, sage, basil, dill,
lemon balm, peppermint, thyme, and tea oils, already have widespread medicinal
applications. Some of the essential oil containing plant families, like Liliaceae,
Fabaceae, Pinaceae, Piperaceae, Cupressaceae, Asteraceae and Hypericaceae, also
exhibit a considerable medicinal potential.
The Apocynaceae family is considered to be dicotyledonous characterized usually
by the presence of latex, consisting of about 155 genus and 2000 species, with
distribution in Tropical and Subtropical regions (Lorenzi 1998). This family can be
considered one of the most important plant sources of chemical constituents with
therapeutic utility in modern medicine. The most important genres in this family are
Alstonia, Aspidosperma, Vinca, Tabernaemontana, Mandevilla, Hancornia, Nerium,
Strophantus, Catharanthus, Allamanda, Thevetia, Wrightia, Plumeria, Himatanthus
and Rauvolfia. The Apocynaceae family is chemically characterized by structures
alkaloids mainly monoterpenic. Several indolic alkaloids have already been isolated
7 Antibacterial and Antifungal Plant Metabolites …
275
Staphylococcus aureus (ATCC 6538). As positive control, antibiotics ampicillin
(10 µg/ml), amoxicillin (10 µg/ml), and penicillin (30 µg/ml) were used for bacterial strains; and the antifungal ketoconazole (2 mg/ml), for yeast. There was a
positive drug interaction of the extracts with antibiotics and ketoconazole in concentrations of 1: 2 for the extract. The extract of B. anisandra has an antimicrobial
potential and drug interaction with drugs related to oral health. Studies on the
pharmacological properties of the species in question are rare and the results are the
first reports on its antimicrobial activity in association with antibiotics and
antifungals.
The positive results found not only in these reported studies, but also in
countless other studies, with different species increasingly show the importance of
the search for new metabolites that can help and reinforce drugs that no longer play
the role of eliminating pathogenic microorganisms.
7.6 Essential Oils with Antimicrobial Activity
from Tropical Medicinal Plants
In nature, EOs play an important role in providing plant protection against pathogenic bacteria, viruses, and fungi and preventing the attack by insect pests. In
addition, EOs can attract or repel insects when present in pollen and seeds. To
protect chemical compounds’ ecological equilibrium, the use of EOs in pharmaceutical, food, bactericidal, and fungicidal is becoming more prevalent in recent
times (Swamy et al. 2016). EOs yielding medicinal and aromatic plants are normally native to warm countries, where they represent an important traditional
pharmacopeia.
Apiaceae, Lamiaceae, Myrtaceae, Poaceae, and Rutaceae families are of particular importance for medicinal applications. For example, some of the EOs, like
anise, caraway, black caraway, clove, oregano, cumin, coriander, sage, basil, dill,
lemon balm, peppermint, thyme, and tea oils, already have widespread medicinal
applications. Some of the essential oil containing plant families, like Liliaceae,
Fabaceae, Pinaceae, Piperaceae, Cupressaceae, Asteraceae and Hypericaceae, also
exhibit a considerable medicinal potential.
The Apocynaceae family is considered to be dicotyledonous characterized usually
by the presence of latex, consisting of about 155 genus and 2000 species, with
distribution in Tropical and Subtropical regions (Lorenzi 1998). This family can be
considered one of the most important plant sources of chemical constituents with
therapeutic utility in modern medicine. The most important genres in this family are
Alstonia, Aspidosperma, Vinca, Tabernaemontana, Mandevilla, Hancornia, Nerium,
Strophantus, Catharanthus, Allamanda, Thevetia, Wrightia, Plumeria, Himatanthus
and Rauvolfia. The Apocynaceae family is chemically characterized by structures
alkaloids mainly monoterpenic. Several indolic alkaloids have already been isolated
7 Antibacterial and Antifungal Plant Metabolites …
275