Antiviral properties of a crude extract from a green alga Caulerpa taxifolia (Vahl) C. Agardh

The Ethyl Acetate Extract of Caulerpa microphysa Promotes Collagen Homeostasis and Inhibits Inflammation in the Skin

Inflammation and collagen-degrading enzymes' overexpression promote collagen decomposition, which affects the structural integrity of the extracellular matrix. The polysaccharide and peptide extracts of the green alga Caulerpa microphysa (C. microphysa) have been proven to have anti-inflammatory, wound healing, and antioxidant effects in vivo and in vitro. However, the biological properties of the non-water-soluble components of C. microphysa are still unknown. In the present study, we demonstrated the higher effective anti-inflammatory functions of C. microphysa ethyl acetate (EA) extract than water extract up to 16-30% in LPS-induced HaCaT cells, including reducing the production of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α (TNF-α). Furthermore, the excellent collagen homeostasis effects from C. microphysa were proven by suppressing the matrix metalloproteinase-1 (MMP-1) secretion, enhancing type 1 procollagen and collagen expressions dose-dependently in WS1 cells. Moreover, using UHPLC-QTOF-MS analysis, four terpenoids, siphonaxanthin, caulerpenyne, caulerpal A, and caulerpal B, were identified and may be involved in the superior collagen homeostasis and anti-inflammatory effects of the C. microphysa EA extract.

Advances in algal drug research with emphasis on enzyme inhibitors

Enzyme inhibitors are now included in all kinds of drugs essential to treat most of the human diseases including communicable, metabolic, cardiovascular, neurological diseases and cancer. Numerous marine algae have been reported to be a potential source of novel enzyme inhibitors with various pharmaceutical values. Thus, the purpose of this review is to brief the enzyme inhibitors from marine algae of therapeutic potential to treat common diseases. As per our knowledge this is the first review for the potential enzyme inhibitors from marine origin. This review contains 86 algal enzyme inhibitors reported during 1989-2013 and commercial enzyme inhibitors available in the market. Compounds in the review are grouped according to the disease conditions in which they are involved; diabetes, obesity, dementia, inflammation, melanogenesis, AIDS, hypertension and other viral diseases. The structure-activity relationship of most of the compounds are also discussed. In addition, the drug likeness properties of algal inhibitors were evaluated using Lipinski's 'Rule of Five'.

The sesquiterpene caulerpenyne from Caulerpa spp. is a lipoxygenase inhibitor

Many algae contain secondary metabolites with the potential to gain importance as pharmaceutically active secretions. Caulerpa racemosa var. cylindracea and Caulerpa prolifera are very abundant on the Mediterranean coastlines. The methanolic extracts of C. racemosa and C. prolifera were tested for inhibitory effects on soybean lipoxygenase. The extract of C. prolifera showed potent inhibitory effect in a lipoxygenase enzyme activity assay. HPLC comparison revealed that C. racemosa extract contained less caulerpenyne, the major secondary metabolite of both algae. In accordance with these findings, purified caulerpenyne inhibited lipoxygenase with an IC(50) of 5.1 μM. The enzyme kinetic studies indicated that both K (M) and V (max) decreased from 0.041 to 0.019 mM and 312.5 to 151.5 U mL(-1) in the presence of 5 µM caulerpenyne, revealing an un-competitive type of inhibition kinetics. The major secondary metabolite of Caulerpa species, caulerpenyne, is thus a novel lipoxygenase inhibitor that can be easily obtained in high quantities from the abundant algae.

Effects of irradiance and temperature on the photosynthesis and vegetative propagation of Caulerpa serrulata

The photosynthetic oxygen evolution of Caulerpa serrulata was determined with oxygen electrodes. The effects of light and temperature on the growth and regeneration of fragmented C. serrulata thalli were analyzed. The regenerating rate and establishment of different sizes and portions of C. serrulata were studied. The results showed that the light saturation point of C. serrulata was 200 micromol photons/m(2) per s and the optimum growth temperature was 25-30 degrees C. Under these conditions, the maximum photosynthetic oxygen evolution rate was 15.1 +/- 0.29 mg O(2)/mg Chl a/h, the growth rate and elongation rate reached the highest values, 4.67 +/- 0.09 mg FW/d and 0.78 +/- 0.01 mm/d, respectively. The fragmented C. serrulata thalli was regenerated at 20-35 degrees C and survived at 15 degrees C and 200 micromol photons/m(2) per s. A different survival rate was detected according to fragment size. All of these results indicated that C. serrulata was a candidate to become an invasive species if introduced into a new place. Therefore, we should pay more attention to C. serrulata for its potential threat to marine ecosystem when it is sold for aquarium use.

Antiviral activity in vitro of Urtica dioica L., Parietaria diffusa M. et K. and Sambucus nigra L

Parietaria diffusa M. et K., Urtica dioica L. (Urticaceae) and Sambucus nigra L. (Caprifoliaceae) are plants usually used in popular medicine of central Italy for treating numerous diseases, first of all Herpes zoster. Several plant products have been described as potential antiviral agents, with special attention being devoted to those having retroviruses as etiological agents, including acquired immunodeficiency syndrome (AIDS), in which a retrovirus, the designated human immunodeficiency virus HIV, has been clearly identified as the primary cause of this disease. The present study proposes a preliminary screening of the antiviral activity of Parietaria diffusa, Sambucus nigra and Urtica dioica preparation against the feline immunodeficiency virus (FIV) infection. The feline immunodeficiency virus is a widespread lentivirus of domestic cats sharing numerous biological and pathogenic features with the human immunodeficiency virus (HIV). FIV infection in cats has therefore been proposed as an animal model for AIDS studies with respect to pathogenesis, chemotherapy, and vaccine development [Pedersen, N.C., 1993. Feline immunodeficiency virus infection. In: Levy, J.A. (Ed.), The Retroviridae. Plenum Press, New York; Bendinelli, M., Pistello, M., Lombardi, S., Poli, A., Garzelli, C., Matteucci, D., Ceccherini-Nelli, L., Malvaldi, G., Tozzini, F., 1995. Feline immunodeficiency virus: an interesting model for AIDS studies and an important cat pathogen. Clinical Microbiology Revue 8, 87-112; North, T.W., LaCasse, R.A., 1995. Testing anti-HIV drugs in the FIV model. Nature Medicine 1, 410-411; Matteucci, D., Pistello, M., Mazzetti, P., Giannechini, S., Isola, P., Merico, A., Zaccaro, L., Rizzati, A., Bendinelli, M., 2000. AIDS vaccination studies using feline immunodeficiency virus as a model: immunisation with inactivated whole virus suppresses viraemia levels following intravaginal challenge with infected cells but non-following intravenous challenge with cell-free virus. Vaccine 18, 119-130]. Early studies showed that some of them presented antiviral activity against infection of FIV as assayed by syncytia formation using feline kidney Crandell cells (CrFK).

Novel antiviral agents: a medicinal plant perspective

Several hundred plant and herb species that have potential as novel antiviral agents have been studied, with surprisingly little overlap. A wide variety of active phytochemicals, including the flavonoids, terpenoids, lignans, sulphides, polyphenolics, coumarins, saponins, furyl compounds, alkaloids, polyines, thiophenes, proteins and peptides have been identified. Some volatile essential oils of commonly used culinary herbs, spices and herbal teas have also exhibited a high level of antiviral activity. However, given the few classes of compounds investigated, most of the pharmacopoeia of compounds in medicinal plants with antiviral activity is still not known. Several of these phytochemicals have complementary and overlapping mechanisms of action, including antiviral effects by either inhibiting the formation of viral DNA or RNA or inhibiting the activity of viral reproduction. Assay methods to determine antiviral activity include multiple-arm trials, randomized crossover studies, and more compromised designs such as nonrandomized crossovers and pre- and post-treatment analyses. Methods are needed to link antiviral efficacy/potency- and laboratory-based research. Nevertheless, the relative success achieved recently using medicinal plant/herb extracts of various species that are capable of acting therapeutically in various viral infections has raised optimism about the future of phyto-antiviral agents. As this review illustrates, there are innumerable potentially useful medicinal plants and herbs waiting to be evaluated and exploited for therapeutic applications against genetically and functionally diverse viruses families such as Retroviridae, Hepadnaviridae and Herpesviridae