AUTHOR=Kama-Kama Francisca , Omosa Leonidah K. , Nganga Joseph , Maina Naomi , Osanjo Georges , Yaouba Souaibou , Ilias Muhammad , Midiwo Jacob , Naessens Jan 

TITLE=Antimycoplasmal Activities of Compounds from Solanum aculeastrum and Piliostigma thonningii against Strains from the Mycoplasma mycoides Cluster

JOURNAL=Frontiers in Pharmacology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2017.00920

DOI=10.3389/fphar.2017.00920

ISSN=1663-9812

ABSTRACT=<p>Infections caused by <italic>Mycoplasma</italic> species belonging to the <italic>‘mycoides</italic> cluster’ negatively affect the agricultural sector through losses in livestock productivity. These <italic>Mycoplasma</italic> strains are resistant to many conventional antibiotics due to the total lack of cell wall. Therefore, there is an urgent need to develop new antimicrobial agents from alternative sources such as medicinal plants to curb the resistance threat. Recent studies on extracts from <italic>Solanum aculeastrum</italic> and <italic>Piliostigma thonningii</italic> revealed interesting antimycoplasmal activities hence the motivation to investigate the antimycoplasmal activities of constituent compounds. The CH<sub>2</sub>Cl<sub>2</sub>/MeOH extracts from the berries of <italic>S. aculeastrum</italic> yielded a new β-sitosterol derivative (<bold>1</bold>) along with six known ones including; lupeol (<bold>2</bold>), two long-chain fatty alcohols namely undecyl alcohol (<bold>3</bold>) and lauryl alcohol (<bold>4</bold>); two long-chain fatty acids namely; myristic acid (<bold>5</bold>) and nervonic acid (<bold>6</bold>) as well as a glycosidic steroidal alkaloid; (25R)-3β-<italic>O</italic>-α-<sc>L</sc>-rhamnopyranosyl-(1→2)-<italic>O</italic>-[α-<sc>L</sc>-rhamnopyranosyl-(1→4)]-β-<sc>D</sc>-glucopyranosyloxy-22α-N-spirosol-5-ene (<bold>7</bold>) from the MeOH extracts. A new furan diglycoside, (2,5-<sc>D</sc>-diglucopyranosyloxy-furan) (<bold>8</bold>) was also characterized from the CH<sub>2</sub>Cl<sub>2</sub>/MeOH extract of stem bark of <italic>P. thonningii</italic>. The structures of the compounds were determined on the basis of spectroscopic evidence and comparison with literature data. Compounds <bold>1, 3, 4, 7</bold>, and <bold>8</bold> isolated in sufficient yields were tested against the growth of two <italic>Mycoplasma mycoides</italic> subsp. <italic>mycoides</italic> (<italic>Mmm</italic>), two <italic>M. mycoides. capri</italic> (<italic>Mmc</italic>), and one <italic>M. capricolum capricolum</italic> (<italic>Mcc</italic>) using broth dilution methods, while the minimum inhibitory concentration (MIC) was determined by serial dilution. The inhibition of <italic>Mycoplasma in vitro</italic> growth was determined by the use of both flow cytometry (FCM) and color change units (CCU) methods. Compounds <bold>4</bold> and <bold>7</bold> showed moderate activity against the growth of <italic>Mmm</italic> and <italic>Mmc</italic> but were inactive against the growth of <italic>Mcc</italic>. The lowest MIC value was 50 μg/ml for compound <bold>7</bold> against <italic>Mmm</italic>. The rest of the compounds showed minimal or no activity against the strains of <italic>Mycoplasma mycoides</italic> tested. This is the first report on the use of combined FCM and CCU to determine inhibition of <italic>in vitro</italic> growth of <italic>Mycoplasma mycoides</italic>. The activity of these compounds against other bacterial strains should be tested and their safety profiles determined.</p>