HPLC-DAD and UHPLC/QTOF-MS Analysis of Polyphenols in Extracts of the African Species Combretum padoides, C. zeyheri and C. psidioides Related to Their Antimycobacterial Activity

Combretum padoides Engl. & Diels, C. psidioides Welv. and C. zeyheri Sond. are used for the treatment of infections and tuberculosis related symptoms in African traditional medicine. In order to verify these uses, extracts were screened for their growth inhibitory effects against M. smegmatis ATCC 14468. Ultra-high pressure liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS) and GC-MS were used to investigate the polyphenolic composition in the active extracts. The lowest minimum inhibitory concentration (MIC), 625 µg/mL, was shown by a methanol extract of the stem bark of C. psidioides. A butanol extract of C. psidioides gave large inhibition zone diameters (IZD 21 mm) and inhibited 84% of the mycobacterial growth at 312 µg/mL. Combretastatin B-2 and dihydrostilbene derivatives were present in the methanol extract of C. psidioides, whereas the butanol extract of this species contained punicalagin, corilagin, and sanguiin H-4. Methanol and butanol extracts of the stem bark of C. padoides gave large inhibition zone diameters (IZD 26.5 mm) and MIC values of 1250 and 2500 µg/mL, respectively. C. padoides contained an ellagitannin with a mass identical to punicalagin ([M-H]⁻ 1083.0587) and a corilagin like derivative ([M-H]⁻ 633.0750) as well as ellagic acid arabinoside and methyl ellagic acid xyloside. A butanol extract of the roots of C. zeyheri showed mild antimycobacterial activity and contained a gallotannin at m/z [M-H]⁻ 647.0894 as the main compound along with punicalagin and three unknown ellagitannins at m/z [M-H]⁻ 763.0788, 765.0566, and 817.4212. Our results indicate that the studied species of Combretum contain phenolic and polyphenolic compounds with possible potential as leads for antimycobacterial drugs or as adjuvants for conventional anti-TB drugs.

In Vivo Antiplasmodial Activity of Terminalia mantaly Stem Bark Aqueous Extract in Mice Infected by Plasmodium berghei

Background

Terminalia mantaly is used in Cameroon traditional medicine to treat malaria and related symptoms. However, its antiplasmodial efficacy is still to be established.

Objectives

The present study is aimed at evaluating the in vitro and in vivo antiplasmodial activity and the oral acute toxicity of the Terminalia mantaly extracts.

Materials and Methods

Extracts were prepared from leaves and stem bark of T. mantaly, by maceration in distilled water, methanol, ethanol, dichloromethane (DCM), and hexane. All extracts were initially screened in vitro against the chloroquine-resistant strain W2 of P. falciparum to confirm its in vitro activity, and the most potent one was assessed in malaria mouse model at three concentrations (100, 200, and 400 mg/kg/bw). Biochemical, hematological, and histological parameters were also determined.

Results

Overall, 7 extracts showed in vitro antiplasmodial activity with IC₅₀ ranging from 0.809 μg/mL to 5.886 μg/mL. The aqueous extract from the stem bark of T. mantaly (Tmsb^w) was the most potent (IC₅₀ = 0.809 μg/mL) and was further assessed for acute toxicity and efficacy in Plasmodium berghei-infected mice. Tmsb^w was safe in mice with a median lethal dose (LD₅₀) higher than 2000 mg/kg of body weight. It also exerted a good antimalarial efficacy in vivo with ED₅₀ of 69.50 mg/kg and had no significant effect on biochemical, hematological, and histological parameters.

Conclusion

The results suggest that the stem bark extract of T. mantaly possesses antimalarial activity.

In Vivo Antimalarial Activity of 80% Methanol and Aqueous Bark Extracts of Terminalia brownii Fresen. (Combretaceae) against Plasmodium berghei in Mice

Background

Despite a substantial scientific progress over the past two decades, malaria continues to be a worldwide burden. Evergrowing resistance towards the currently available antimalarial drugs is a challenge to combat malaria. Medicinal plants are a promising source of new drugs to tackle this problem. Thus, the present study aimed at evaluating the antiplasmodial activity of Terminalia brownii in Plasmodium berghei infected mice.

Methods

A 4-day suppressive test was employed to evaluate the antimalarial effect of 80% methanol and aqueous bark extracts of T. brownii against P. berghei in Swiss albino mice.

Results

The in vivo acute toxicity test indicated that both extracts of T. brownii against p < 0.001) compared to negative control. The maximum level of chemosuppression (60.2%) was exhibited at 400 mg/kg dose of 80% methanol extract. Moreover, the 80% methanol extract showed a significant (p < 0.001) compared to negative control. The maximum level of chemosuppression (60.2%) was exhibited at 400 mg/kg dose of 80% methanol extract. Moreover, the 80% methanol extract showed a significant (

Conclusion

The present study indicated that hydromethanolic and aqueous bark extracts of T. brownii possess a promising antimalarial activity, with higher effect exhibited by the hydromethanolic extract.T. brownii against

A Comprehensive Review of the Structure Elucidation of Tannins from Terminalia Linn

OBJECTIVES

Tannins with complex structures are important plant resources, which are abundant in the genus Terminalia. Various Terminalia species have been playing an important role in traditional medicine system. A systematic scoping review of Terminalia Linn. research literature for tannins was conducted to summarize the structures of tannins and analysis fragmentation pathway characteristics, which could provide references for the structural analysis of tannins from Terminalia Linn.

METHODS

After an update of the literature search up to September 2018, the terms of Terminalia in all publications were analyzed. Electronic searches were conducted in scifinder and PubMed, and the information from 197 articles in all with regard to the tannin structure study was extracted.

RESULTS

The compounds of 82 tannins from the genus Terminalia were reviewed. According to the structural differences, they can be divided into three categories, hydrolysable tannins, condensed tannins, and complex tannins, respectively. The fragmentation pathways of 46 identified tannins were analyzed, and the fragmentation rules of tannins were speculated according to different types.

CONCLUSION

This review has attracted attention to the active substances in this species such as the tannins summarized in further study. How to improve the extraction and purification technology of tannins from genus Terminalia is an urgent problem to be solved.

Compounds from Terminalli brownii Extracts with Toxicity against the Fish Pathogenic Bacterium Flavobacterium columnare

The pond-raised channel catfish (Ictalurus punctatus) industry in the United States of America can incur losses of over a $100 million annually due to bacterial diseases including columnaris disease caused by Flavobacterium columnare. One management approach available to catfish producers is the use of medicated-feed containing antibiotics. However, the negative attributes of antibiotic use in agriculture include public concerns and the potential development of antibiotic-resistant bacteria. Therefore, the discovery of environmentally-safe natural compounds for use as therapeutic agents would greatly benefit the catfish industry. In this study, a rapid bioassay was used to evaluate crude plant extracts as the first step in the discovery of natural therapeutants. Plant extracts from Terminalia brownii were found to be inhibitory towards F. columnare. The minimum inhibitory concentration (MIC) of the 5% water-methanol extract of T. brownii (stem bark) was 10 μg/mL and the 24 h 50% inhibition concentration (IC50) was 40 μg/mL. Subsequent bioassay-guided fractionation of the T. brownii ethanol extract using reverse phase C-4 chromatography revealed the highest level of activity in the aqueous methanol (50:50) fraction. HPLC analysis and subsequent purification of this fraction provided two compounds identified as ellagic acid (1) and 4- O-(3″,4″-di- O-galloyl-α-L-rhamnopyranosyl)ellagic acid (2). Compound 2 was the most active isolated compound, with a minimum inhibitory concentration (MIC) of 10±0 μg/mL and 24 h IC50 of 31±1 μg/mL. Although 1 was more active according to a MIC of 6±5 μg/mL, its 24 h IC50 was >100 μg/mL, and, therefore, it was less active overall of the two most active isolated compounds.