132 Marine Macro- and Microalgae: An Overview
screening macroalgae for antiprotozoal activity (Tempone et al. 2011). Despite the promising availability
of novel bioactive compounds, very little research has, until now, been directed towards marine algae and
their antiprotozoal potential (Moo-Puc et al. 2008; Vonthron-Sénécheau et al. 2011).
The search for novel antiprotozoal compounds from algae is reported in a few screening papers that
highlight the inhibition of protozoan parasites activity by extracts from different algae belonging to the
Chlorophyta, Ochrophyta, and Rhodophyta phyla (Nara et al. 2005; Sabina et al. 2005; Lakshmi et al.
2006; Orhan et al. 2006; Freire-Pelegrin et al. 2008; Moo-Puc et al. 2008; Chen et al. 2009; Genovese et
al. 2009; Léon-Deniz et al. 2009; Allmendinger et al. 2010; Felício et al. 2010; Spavieri et al. 2010a,b;
Süzgeç-Selçuk et al. 2010; Dos Santos et al. 2010, 2011; Fouladvand et al. 2011; Vonthron-Sénécheau et
al. 2011; Table 4).
In spite of the interest on this subject, very few published articles describe the identification of
bioactive compounds from marine algae, in contrast with the literature on terrestrial plants (Schmidt et
al. 2012a,b).
Data reported by these authors reflects the well-known phenomenon that marine organisms collected
from different environments have different chemistries, which affects their biological activities (Spavieri
et al. 2010b). For example, antileishmanial activity of three samples of either Ulva lactuca or Dictyota
dichotoma from different locations against L. donovani axenic amastigote forms, evaluated by the resazurin
method, resulted in IC 50 values between 5.9 and 12 μg/mL and 8.8 and 52 μg/mL, respectively (Orhan et
al. 2006; Spavieri et al. 2010b; Vonthron-Sénécheau et al. 2011). The observed discrepancies may stem
from several factors ranging from abiotic (e.g., salinity) and biotic (e.g., predation) components to the
use of different extraction methods and solvents resulting in extracts of diverse chemical composition.
Also different trypanosomatid parasite species have different responses and sensibilities to the same
species extracts. For example, both Orhan et al. (2006) and Spavieri et al. (2010b) evaluated antiprotozoal
activity of U. lactuca on L. donovani, T. cruzi, and T. brucei rhodesiensis by the resazurin method.
Although the Turkish sample was more potent against L. donovani (IC 50 = 5.9 μg/mL (Orhan et al. 2006),
it had weaker anti-T. brucei rhodesiense activity (IC 50 = 22.3 µg/mL) and had no activity against T. cruzi
(Spavieri et al. 2010b). Also Sabina et al. (2005) and Lakshimi (2006) reported non-concordant antileishmanial activities using Codium elongatum (Chlorophyta) and Scinaia indica (Rhodophyta) extracts
during surveys developed for the screening of extracts of Pakistani and Indian marine samples.
Different bioactivity results were also registered using the same algal species but tested in specific
forms of the parasite. Dos Santos et al. (2011) observed a higher sensibility of the promastigote forms
(IC 50 = 2.0 μg/mL) as compared with intracellular (IC 50 = 4.0 μg/mL) and especially when compared with
axenic amastigote forms (IC 50 = 12.0 μg/mL) of L. amazonensis to the (4R,9S,14S)-4α-acetoxy-9β,14αdihydroxydolast-1(15),7-diene isolated from Canistrocarpus cervicornis.
Since 2005, few bioactive compounds with antiprotozoal activity have been isolated from marine
macroalgae. Most data report the effects of crude extracts, obtained by different sequential extractions
usually using solvents (hexane, dichloromethane, ether, ethyl acetate, chloroform, water, ethanol, and
methanol) of various polarities. However, Marcolino (2010), Veiga-Santos et al. (2010), and Dos Santos
et al. (2010, 2011) studied the effect of purified compounds isolated from macroalgae from Brazil on
protozoan parasites, L. amazonensis and T. cruzi. The identified compounds are sesquiterpene elatol,
isolated from Laurencia dendroidea (Veiga-Santos et al. 2010; Dos Santos et al. 2010), 4-acetoxydolastane diterpene obtained from Canistrocarpus cervicornis (Dos Santos et al. 2011) and sulphated
polysaccharides obtained from Gayralia oxysperma, Gymnogongrus griffithsiae, and Eucheuma
denticulatum. All these compounds had already been recognized as secondary metabolites with important
roles in ecological interactions, such as anti-herbivore activity and potential defence against infection by
microorganisms (Marcolino 2010).
Regarding the type of solvents used for extraction, Freire-Pelegrin et al. (2008) mentioned that
organic extracts of tropical marine algae from Gulf of Mexico and Caribbean coast showed activity against
L. mexicana promastigote forms. On a screening study of French macroalgae, Vonthron-Sénécheau et al.
(2011) observed that the majority of the active extracts were obtained using ethyl acetate as extraction
solvent, while the hydroalcoholic extracts were mainly inactive, suggesting that, in general, the active
anti-protozoal compounds were relatively non polar (Genovese et al. 2009). However, Fouladvand et
screening macroalgae for antiprotozoal activity (Tempone et al. 2011). Despite the promising availability
of novel bioactive compounds, very little research has, until now, been directed towards marine algae and
their antiprotozoal potential (Moo-Puc et al. 2008; Vonthron-Sénécheau et al. 2011).
The search for novel antiprotozoal compounds from algae is reported in a few screening papers that
highlight the inhibition of protozoan parasites activity by extracts from different algae belonging to the
Chlorophyta, Ochrophyta, and Rhodophyta phyla (Nara et al. 2005; Sabina et al. 2005; Lakshmi et al.
2006; Orhan et al. 2006; Freire-Pelegrin et al. 2008; Moo-Puc et al. 2008; Chen et al. 2009; Genovese et
al. 2009; Léon-Deniz et al. 2009; Allmendinger et al. 2010; Felício et al. 2010; Spavieri et al. 2010a,b;
Süzgeç-Selçuk et al. 2010; Dos Santos et al. 2010, 2011; Fouladvand et al. 2011; Vonthron-Sénécheau et
al. 2011; Table 4).
In spite of the interest on this subject, very few published articles describe the identification of
bioactive compounds from marine algae, in contrast with the literature on terrestrial plants (Schmidt et
al. 2012a,b).
Data reported by these authors reflects the well-known phenomenon that marine organisms collected
from different environments have different chemistries, which affects their biological activities (Spavieri
et al. 2010b). For example, antileishmanial activity of three samples of either Ulva lactuca or Dictyota
dichotoma from different locations against L. donovani axenic amastigote forms, evaluated by the resazurin
method, resulted in IC 50 values between 5.9 and 12 μg/mL and 8.8 and 52 μg/mL, respectively (Orhan et
al. 2006; Spavieri et al. 2010b; Vonthron-Sénécheau et al. 2011). The observed discrepancies may stem
from several factors ranging from abiotic (e.g., salinity) and biotic (e.g., predation) components to the
use of different extraction methods and solvents resulting in extracts of diverse chemical composition.
Also different trypanosomatid parasite species have different responses and sensibilities to the same
species extracts. For example, both Orhan et al. (2006) and Spavieri et al. (2010b) evaluated antiprotozoal
activity of U. lactuca on L. donovani, T. cruzi, and T. brucei rhodesiensis by the resazurin method.
Although the Turkish sample was more potent against L. donovani (IC 50 = 5.9 μg/mL (Orhan et al. 2006),
it had weaker anti-T. brucei rhodesiense activity (IC 50 = 22.3 µg/mL) and had no activity against T. cruzi
(Spavieri et al. 2010b). Also Sabina et al. (2005) and Lakshimi (2006) reported non-concordant antileishmanial activities using Codium elongatum (Chlorophyta) and Scinaia indica (Rhodophyta) extracts
during surveys developed for the screening of extracts of Pakistani and Indian marine samples.
Different bioactivity results were also registered using the same algal species but tested in specific
forms of the parasite. Dos Santos et al. (2011) observed a higher sensibility of the promastigote forms
(IC 50 = 2.0 μg/mL) as compared with intracellular (IC 50 = 4.0 μg/mL) and especially when compared with
axenic amastigote forms (IC 50 = 12.0 μg/mL) of L. amazonensis to the (4R,9S,14S)-4α-acetoxy-9β,14αdihydroxydolast-1(15),7-diene isolated from Canistrocarpus cervicornis.
Since 2005, few bioactive compounds with antiprotozoal activity have been isolated from marine
macroalgae. Most data report the effects of crude extracts, obtained by different sequential extractions
usually using solvents (hexane, dichloromethane, ether, ethyl acetate, chloroform, water, ethanol, and
methanol) of various polarities. However, Marcolino (2010), Veiga-Santos et al. (2010), and Dos Santos
et al. (2010, 2011) studied the effect of purified compounds isolated from macroalgae from Brazil on
protozoan parasites, L. amazonensis and T. cruzi. The identified compounds are sesquiterpene elatol,
isolated from Laurencia dendroidea (Veiga-Santos et al. 2010; Dos Santos et al. 2010), 4-acetoxydolastane diterpene obtained from Canistrocarpus cervicornis (Dos Santos et al. 2011) and sulphated
polysaccharides obtained from Gayralia oxysperma, Gymnogongrus griffithsiae, and Eucheuma
denticulatum. All these compounds had already been recognized as secondary metabolites with important
roles in ecological interactions, such as anti-herbivore activity and potential defence against infection by
microorganisms (Marcolino 2010).
Regarding the type of solvents used for extraction, Freire-Pelegrin et al. (2008) mentioned that
organic extracts of tropical marine algae from Gulf of Mexico and Caribbean coast showed activity against
L. mexicana promastigote forms. On a screening study of French macroalgae, Vonthron-Sénécheau et al.
(2011) observed that the majority of the active extracts were obtained using ethyl acetate as extraction
solvent, while the hydroalcoholic extracts were mainly inactive, suggesting that, in general, the active
anti-protozoal compounds were relatively non polar (Genovese et al. 2009). However, Fouladvand et