Endemic and indigenous plants from Mascarene Islands with antiviral propensities

Background: Antiviral resistance and inefficiency of available antiviral drugs to effectively treat viral infections have prompted many researchers worldwide to explore medicinal plants and their isolated compounds as alternative antivirals. The rich flora from the Mascarene Islands has also been thoroughly studied for their wide therapeutic activities, including their antiviral properties. Objective: The aim of this paper is to highlight the antiviral propensities of Mascarene endemic and indigenous medicinal plants. Methodology: A review of the literature was conducted via major databases and other primary sources of information. The inhibitory concentration/effective dose causing 50% viral inhibition (IC50/ED50), cytotoxic concentration causing 50% reduction in cell viability (CC50), and selectivity index (SI) were reported, and mechanisms of antiviral action were also discussed. Results: Stillingia lineata was the most effective against chikungunya virus (SI: 10.9), and among its isolated compounds, 12-O-acetylphorbol-13(2″-methyl)- butyrate and 12-deoxyphorbol-13(2″-methyl)butyrate were the most potent and selective inhibitors of chikungunya virus replication (SI= 41 and >240, respectively). 12-O-acetylphorbol-13(2″-methyl)- butyrate, 12β-O-[nona-2Z,4E,6E-trienoyl]-4α-deoxyphorbol-13-butyrate, 12-deoxyphorbol-13(2″-methyl)butyrate, and 12-deoxyphorbol-13-[8′-oxohexadeca-2E,4E,6E-trienoate showed strong selective antiviral effect on human immunodeficiency virus-I (SI 36-899) and II (SI 33-2056). Obetia ficifolia and Erythroxylon laurifolium were most active against the herpes virus (SI: 16 and 18.5, respectively). Labourdonnaisia glauca showed potent anti-poliovirus activity (SI: 40), while Badula insularis Labourdonnaisia glauca and Myonima violacea were active against Rhinovirus (SI: 1.3-2.5). The most effective against the Zika virus were Aphloia theiformis and Psiloxylon mauritianum. Both anti-zika and anti-dengue virus activity were reported for Doratoxylon apetalum. Conclusion: Promising spectrum of antiviral properties notably against Zika, dengue, chikungunya, polio, rhino, herpes, and human immunodeficiency viruses were presented by the Mascarene plants suggesting them as viable candidates for the potential development of effective natural antiviral drugs.

A New Species of Ophioglossolambis Dekkers, 2012 from the Mascarene Islands (Mollusca: Gastropoda: Strombidae)

This paper describes a new species of Ophioglossolambis Dekkers, 2012 from the Mascarene Islands (Mauritius, Rodrigues, and Réunion) and Saint Brandon (also known as Cargados Carajos) Shoals in the western Indian Ocean as Ophioglossolambis itsumiae. It is separated from Ophioglossolambis digitata (Perry, 1811), its closest congener from the coastal waters of Madagascar and East Africa, by its typically larger and broader build, longer spines, lighter coloration, a more flared labral flange, and, most especially, very compact and short spire.

New intertidal crickets from Comoros and Mascarene islands (Orthoptera: Trigonidiidae: Nemobiinae: Burcini)

Nemobiinae crickets of the tribe Burcini Gorochov, 1986 are described for the first time from the shores of South Western Indian Ocean islands. The new genus Makalapobius n. gen. is proposed to include M. aigrettensis n. gen. n. sp. from Mauritius and M. masihu n. gen. n. sp. from Grande Comore, and the new genus Gabusibius n. gen. to include G. ndzilu n. gen. n. sp. from Anjouan, G. mosi n. gen. n. sp., from Mohéli, and G. dzindzanu n. gen. n. sp. from Mayotte. The species Speonemobius littoreus Vannini & Chelazzi, 1978 from Somalia coast is tentatively placed in the genus Gabusibius n. gen. as G. ? litoreus (Vannini & Chelazzi, 1978) n. gen. n. comb. The songs of G. mosi n. gen. n. sp. and M. aigrettensis n. gen. n. sp. are described. The threats to SWIO Burcini and endemism of Orthoptera from SWIO coastal areas are discussed.

The surf flies of the Mascarene Islands (Diptera: Canacidae: Canacinae), with the description of a new species

A survey of the surf flies (Canacinae) of the main Mascarene Islands of La Réunion, Mauritius, and Rodrigues was undertaken between 2015 and 2018. It encompassed intertidal material from 38 sampling stations on the islands and included records supplied by Martin J. Ebejer from La Réunion. No specimens of surf flies were collected on Rodrigues Is., which lacks suitable rocky shore habitats. A new species of Isocanace Mathis, 1982, that is deemed closely related to I. briani Mathis, 1982 described from Aldabra Is. and Madagascar, is described and figured from Mauritius (I. mauritiana Munari sp. nov.). Nocticanace mahensis (Lamb, 1912) is also reported from La Réunion and Mauritius and Procanace pninae Mathis & Freidberg, 1991 from Mauritius (all representing first records for the islands concerned). The Procanace grisescens species-group is also reported from Mauritius for the first time, representing a first record of this species-group from the Mascarenes. An identification key to Afrotropical species of Isocanace is provided and the distributions of all species are mapped.

Taxonomic Studies of Diospyros (Ebenaceae) from the Malagasy Region. VII. Revision of Diospyros sect. Forbesia in Madagascar and the Comoro Islands

A recent molecular phylogenetic study revealed that Diospyros L. sect. Forbesia F. White, originally circumscribed to encompass two species from Africa and several from the Mascarene Islands (White, 1980), also includes a group of species endemic to Madagascar. The taxonomy of the Malagasy members of the section has not been examined since Perrier de la Bâthie’s 1952 treatment in the Flore de Madagascar et des Comores, and in the intervening seven decades, numerous specimens have been collected that cannot be identified based on the key provided. This revision presents a significantly updated taxonomy of Diospyros sect. Forbesia in the Malagasy region in which 18 species are recognized, 14 of which are newly described and illustrated, including one new species restricted to Mayotte Island in the Comoro archipelago. An identification key is provided as well as IUCN risk of extinction assessments, which indicate that two species are Critically Endangered, four are Endangered, and seven are Vulnerable, while one is Near Threatened and four are Least Concern. A full description is provided for each species, along with color photos; each of the new species is also illustrated with a line drawing.

Characterization of the Complete Chloroplast Genome Sequences of Four Zanthoxylum L. Species (Sapindales: Rutaceae) from the Caribbean, Madagascar, the Mascarene Islands, and the South Pacific

Zanthoxylum is a genus of woody plants in the Citrus family (Rutaceae) distributed pantropically, with some species extending to temperate regions in East Asia and North America. Here, we present the complete chloroplast genome sequences of four species, two of them critically endangered, endemic to tropical islands.

New Mixaderus species from the Mascarene Islands (Coleoptera: Aderidae)

Following a previous revision of species of the genus Mixaderus Collado & Alonso-Zarazaga, 1996 (Coleoptera: Aderidae) from Madagascar and the Mascarene islands, I describe here six new species from the same genus from La Réunion and Mauritius: Mixaderus reunionensis n. sp.; Mixaderus chassaini n. sp.; Mixaderus lemagneni n. sp.; Mixaderus tamisieri n. sp.; Mixaderus voisini n. sp.; Mixaderus mauritiensis n. sp. I also provide an updated key to the Mixaderus species from the Mascarene archipelago.

Macrothelypteris torresiana (swordfern).

Macrothelypteris torresiana is a perennial fern native to Asia, Madagascar, the Mascarene Islands and Oceania. It has been widely introduced across the Americas as an ornamental plant. It grows in disturbed areas including roadsides and forest edges and behaves as a weed. It spreads via spores in wind and water but can also spread via stolons and rhizomes in garden waste. Currently, M. torresiana is listed as invasive in Cuba and Brazil and may also be invasive in Hawaii where it is spreading. The impact of this species where it is invasive is largely unknown, but it is possible that its weedy and opportunistic nature results in competition with native species and alteration of successional patterns.