Phytochemical and antifungal studies on Terminalia mollis and Terminalia brachystemma

Isolation and Bioassay of a New Terminalone A from Terminalia arjuna

Terminalia arjuna possesses significant cardioprotective, antidiabetic and antioxidant properties as these properties are described in Ayurveda. In the present study, three flavonoids were isolated through the separation and chromatographic purification of the whole plant material of T. arjuna. Spectroscopic characterization identified one of them as a new flavonoid "Terminalone A (1)" and two known flavonoids i.e., 6-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-4H-chromen-4-one (2) and 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4H-chromen-4-one (3). The bioactivity studies showed considerable antibacterial and antioxidant (DPPH radical scavenging) potential for all the three compounds 1-3 where the compound 1 showed strong antibacterial and antioxidant activity.

Non-albicans Candida Species: Immune Response, Evasion Mechanisms, and New Plant-Derived Alternative Therapies

Fungal infections caused by Candida species have become a constant threat to public health, especially for immunocompromised patients, who are considered susceptible to this type of opportunistic infections. Candida albicans is known as the most common etiological agent of candidiasis; however, other species, such as Candida tropicalis, Candida parapsilosis, Nakaseomyces glabrata (previously known as Candida glabrata), Candida auris, Candida guilliermondii, and Pichia kudriavzevii (previously named as Candida krusei), have also gained great importance in recent years. The increasing frequency of the isolation of this non-albicans Candida species is associated with different factors, such as constant exposure to antifungal drugs, the use of catheters in hospitalized patients, cancer, age, and geographic distribution. The main concerns for the control of these pathogens include their ability to evade the mechanisms of action of different drugs, thus developing resistance to antifungal drugs, and it has also been shown that some of these species also manage to evade the host's immunity. These biological traits make candidiasis treatment a challenging task. In this review manuscript, a detailed update of the recent literature on the six most relevant non-albicans Candida species is provided, focusing on the immune response, evasion mechanisms, and new plant-derived compounds with antifungal properties.

Anti-Candida Activity of Extracts Containing Ellagitannins, Triterpenes and Flavonoids of Terminalia brownii, a Medicinal Plant Growing in Semi-Arid and Savannah Woodland in Sudan

Various parts of Terminalia brownii (Fresen) are used in Sudanese traditional medicine against fungal infections. The present study aimed to verify these uses by investigating the anti-Candida activity and phytochemistry of T. brownii extracts. Established agar diffusion and microplate dilution methods were used for the antifungal screenings. HPLC-DAD and UHPLC/QTOF-MS were used for the chemical fingerprinting of extracts and for determination of molecular masses. Large inhibition zones and MIC values of 312 µg/mL were obtained with acetone, ethyl acetate and methanol extracts of the leaves and acetone and methanol extracts of the roots. In addition, decoctions and macerations of the leaves and stem bark showed good activity. Sixty compounds were identified from a leaf ethyl acetate extract, showing good antifungal activity. Di-, tri- and tetra-gallotannins, chebulinic acid (eutannin) and ellagitannins, including an isomer of methyl-(S)-flavogallonate, terflavin B and corilagin, were detected in T. brownii leaves for the first time. In addition, genipin, luteolin-7-O-glucoside, apigenin, kaempferol-4’-sulfate, myricetin-3-rhamnoside and sericic acid were also characterized. Amongst the pure compounds present in T. brownii leaves, apigenin and β-sitosterol gave the strongest growth inhibitory effects. From this study, it was evident that the leaf extracts of T. brownii have considerable anti-Candida activity with MIC values ranging from 312 to 2500 µg/mL.

In vitro antiplasmodial activity-directed investigation and UPLC-MS fingerprint of promising extracts and fractions from Terminalia ivorensis A. Chev. and Terminalia brownii Fresen

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Medicinal plants from the Terminalia genus are widely used as remedies against many infectious diseases, including malaria. As such, Terminalia ivorensis A. Chev. and Terminalia brownii Fresen. are famous due to their usefulness in traditional medicines to treat malaria and yellow fever. However, further information is needed on the extent of anti-Plasmodium potency of extracts and fractions from these plants and their phytochemical profile.

AIM OF THE STUDY

This study was designed to investigate the in vitro antiplasmodial activity and to determine the chemical profile of promising extracts and fractions from T. ivorensis and T. brownii stem bark.

MATERIALS AND METHODS

Crude aqueous, ethanolic, methanolic, hydroethanolic and ethyl acetate extracts were prepared by maceration from the stem barks of T. brownii and T. ivorensis. They were subsequently tested against chloroquine-sensitive (Pf3D7) and multidrug-resistant (PfDd2) strains of P. falciparum using the parasite lactate dehydrogenase (PfLDH) assay. Extracts showing very good activity on both plasmodial strains were further fractionated using column chromatography guided by evidence of antiplasmodial activity. All bioactive extracts and fractions were screened for their cytotoxicity on Vero and Raw cell lines using the resazurin-based assay and on erythrocytes using the hemolysis assay. The phytochemical profiles of selected potent extracts and fractions were determined by UPLC-QTOF-MS analysis.

RESULTS

Of the ten extracts obtained from both plant species, nine showed inhibitory activity against both P. falciparum strains (Pf3D7 and PfDd2), with median inhibitory concentration (IC₅₀) values ranging from 0.13 μg/ml to 10.59 μg/ml. Interestingly, the aqueous extract of T. ivorensis (Ti^W) and methanolic extract of T. brownii (Tb^M) displayed higher antiplasmodial activities against both strains (IC₅₀ 0.13-1.43 μg/ml) and high selectivity indices (SI > 100). Their fractionation led to two fractions from T. ivorensis and two from T. brownii that showed very promising antiplasmodial activity (IC₅₀ 0.15-1.73 μg/mL) and SI greater than 100. The hemolytic assay confirmed the safety of crude extracts and fractions on erythrocytes. UPLC-MS-based phytochemical analysis of the crude aqueous extract of T. ivorensis showed the presence of ellagic acid (1) and leucodelphidin (2), while analysis of the crude methanol extract of T. brownii showed the presence of ellagic acid (1), leucodelphinidin (2), papyriogenin D (3), dihydroactinidiolide (4) and miltiodiol (5).

CONCLUSIONS

The extracts and fractions from T. ivorensis and T. brownii showed very good antiplasmodial activity, thus supporting the traditional use of the two plants in the treatment of malaria. Chemical profiling of the extracts and fractions led to the identification of chemical markers and the known antimalarial compound ellagic acid. Further isolation and testing of other pure compounds from the active fractions could lead to the identification of potent antiplasmodial compounds.

Effects of Plant Metabolites on the Growth of COVID-19 (Coronavirus Disease-19) Including Omicron Strain

According to recent reports out of India, a new strain of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) B1.1.529 Omicron virus has emerged. In comparison to the Wuhan (WHU) strain and the delta variant, this variant showed a far stronger effect on the angiotensin converting enzyme2 (ACE2) receptor. There are several medicinal compounds in plant metabolites, and their diverse chemical structures make them ideal for the treatment of serious illnesses. It's possible that some of these could be useful alternative pharmaceuticals, as well as a starting point for the repurposing of existing medications and new chemical discoveries. SARS-CoV-2 infection triggered a worldwide epidemic of the severe acute respiratory syndrome (SARS). There have been trials for different therapies for SARS-CoV-2 and so also there are recent announcements of extensive research into the development of viable medicines for this global health calamity. After a thorough examination of plant-derived treatments for COVID-19, investigators in the current study decided to focus on plant-derived secondary metabolites (PSMs). According to some researchers, new MDR (Multi-Drug Resistant) antibiotics may one day be developed due to the adaptability of secondary metabolites. Identifying plant metabolites that can treat a wide range of viral infections was one of the study's aims. Many natural medications that could be recommended for the treatment of COVID-19 were discovered as a result of this research, including remedies from plant families, viral candidates that are susceptible, antiviral assays, and mechanisms of therapeutic action. The findings of this study will inspire further research and speed up the development of new antiviral plant-based medications.

Chemical constituents of Desmodium triflorum and their antifungal activity against various phytopathogenic fungi

In the course of finding new antifungal natural compounds against plant pathogens, the methanol extract of Desmodium triflorum was investigated phytochemically. From n-butanol-soluble fraction, seven compounds (1-7) were isolated and structurally elucidated. Of which, six compounds belong to flavone 6- or 8-C-glycoside class (1-6). Three major compounds (1-3) exhibited moderate in vitro antifungal activity against Sclerotium rolfsii, Fusarium oxysporum f. sp. cubense, and Phytophthora palmivora. Compound 1 (IC₅₀ = 162.1 μg/mL) was most active against S. rolfsii in a dose-dependent manner. At 300 μg/mL, compounds 1 and 2 significantly inhibited P. palmivora, whereas compound 3 lacked effectiveness. In addition, the nanoemulsion of the methanol extract with a droplet size of 12.2 nm displayed an excellent inhibition against S. rolfsii and P. palmivora compared with the normal extract. The presence of 1 (0.846%) and 2 (0.759%) in the methanol extract may attribute to the antifungal activity of D. triflorum. These results proved the potential of D. triflorum and its C-glycoside flavonoids against phytopathogenic fungi for the first time. Besides, an enhancement in the effectiveness of nanoemulsion containing D. triflorum extract against the fungi was confirmed. The structural characteristics of 1 and 2 could be considered to develop new fungicidal substances in the future.

Antifungal and Anti-inflammatory Effect of Punicalagin on Murine Aspergillus fumigatus Keratitis

PURPOSE

This study aimed to investigate the anti-inflammatory effect and antifungal effect of punicalagin in murine fungal keratitis.

METHODS

We used in vitro and in vivo protocols to assess the anti-inflammatory effect and antifungal effect of punicalagin. In vitro, time kill and mycelial stain were done. In vivo, murine fungal keratitis was established and treated with PBS or PUN. Clinical scores were taken on days 1, 3, and 5 post infection. The mRNA and protein levels of inflammatory factors were detected by RT-PCR and Western blot, and the number and location of macrophages were analyzed by flow cytometry and immunofluorescence. Also, fungal plate counting was used to assess the antifungal effect. The DCFH-DA fluorescence probe detected the ROS level.

RESULTS

In vitro, PUN showed activity against A.fumigatus. (A.F.), with MIC90 values of 250 μg/ml, and significantly reduced A.F. biofilm formation (p < .001). In vivo, the mouse fungal keratitis model after punicalagin treatment exhibited less disease, lower clinical scores (p < .05), lower reduced macrophage infiltrate (p < .001), and fungal load (p < .001) than those treated with PBS. Treatment with punicalagin also reduced the mRNA expression and protein level of pro-inflammatory factors. At the cellular level, PUN significantly reduced the mRNA expression of inflammatory factors and ROS production caused by the stimulation of mycelia in RAW264.7 (p < .001).

CONCLUSIONS

The results show that punicalagin is beneficial in the treatment of murine fungal keratitis. The mechanism of its anti-inflammatory effect was synthetical, including antifungal activity, an inhibitory effect of proinflammatory factor and macrophages, and anti-oxidation.

In vitro Antileishmanial, Antitrypanosomal, and Anti-inflammatory-like Activity of Terminalia mollis Root Bark

This study aims at determining the in vitro antitrypanosomal, antileishmanial, antioxidant, and anti-inflammatory-like activities of Terminalia mollis root crude extracts. The antitrypanosomal and antileishmanial activities on Trypanosoma brucei brucei (strain 427) and promastigotes of Leishmania mexicana mexicana (MHOM/BZ/84/BEL46) were evaluated in vitro. The methanolic root bark extract and standards were profiled by HPLC-PDA, and the majority of compounds identified using literature data. The in vitro antioxidant and anti-inflammatory-like activities were determined by evaluating the effect of crude extracts on reactive oxygen species produced by phorbol 12-myristate 13-acetate-stimulated equine neutrophils using lucigenin-enhanced chemiluminescence and on purified equine myeloperoxidase activity measured by specific immunological extraction followed by enzymatic detection. The methanolic, aqueous crude extract, and aqueous crude extract free of tannins exhibited good growth inhibition on Trypanosoma brucei brucei (IC₅₀ 3.72, 6.05, and 4.45 µg/mL respectively) but were inactive against Leishmania mexicana mexicana (IC₅₀ > 100 µg/mL). Suramin (IC₅₀ 0.11 µg/mL) and amphotericin (IC₅₀ 0.11 µg/mL) were used as standard respectively for the antitrypanosomal and antileishmanial activity. Very interesting antioxidant and anti-inflammatory-like activities were observed with 50% hydroethanolic, aqueous crude extracts, and aqueous crude extract free of tannins as well as with pure punicalagin, gallic, and ellagic acid (IC₅₀ 0.38 - 10.51 µg/mL for 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), chemiluminescence, and specific immunological extraction followed by enzymatic detection assays. The study results support traditional medicinal use of the plant for the treatment of parasitical disorders and revealed for the first time the antitrypanosomal potential, anti-inflammatory-like, and antioxidant activity of Terminalia mollis root.

Terminalia bentzoë, a Mascarene Endemic Plant, Inhibits Human Hepatocellular Carcinoma Cells Growth In Vitro via G0/G1 Phase Cell Cycle Arrest

Tropical forests constitute a prolific sanctuary of unique floral diversity and potential medicinal sources, however, many of them remain unexplored. The scarcity of rigorous scientific data on the surviving Mascarene endemic taxa renders bioprospecting of this untapped resource of utmost importance. Thus, in view of valorizing the native resource, this study has as its objective to investigate the bioactivities of endemic leaf extracts. Herein, seven Mascarene endemic plants leaves were extracted and evaluated for their in vitro antioxidant properties and antiproliferative effects on a panel of cancer cell lines, using methyl thiazolyl diphenyl-tetrazolium bromide (MTT) and clonogenic cell survival assays. Flow cytometry and comet assay were used to investigate the cell cycle and DNA damaging effects, respectively. Bioassay guided-fractionation coupled with liquid chromatography mass spectrometry (MS), gas chromatography-MS, and nuclear magnetic resonance spectroscopic analysis were used to identify the bioactive compounds. Among the seven plants tested, Terminaliabentzoë was comparatively the most potent antioxidant extract, with significantly (p < 0.05) higher cytotoxic activities. T. bentzoë extract further selectively suppressed the growth of human hepatocellular carcinoma cells and significantly halted the cell cycle progression in the G0/G1 phase, decreased the cells' replicative potential and induced significant DNA damage. In total, 10 phenolic compounds, including punicalagin and ellagic acid, were identified and likely contributed to the extract's potent antioxidant and cytotoxic activities. These results established a promising basis for further in-depth investigations into the potential use of T. bentzoë as a supportive therapy in cancer management.

Medicinal plants used by 'root doctors', local traditional healers in Bié province, Angola

ETHNOPHARMACOLOGICAL RELEVANCE

This study is one of the first post-civil war efforts to document traditional botanical knowledge in Bié province, central Angola, in a first step to bring more studies on the use of medicinal plant resources in this area so as to bring new insights into Angolan bio-cultural diversity.

AIM OF THE STUDY

Examine the variety of plant species used for medical purposes, as well as characterize their social and cultural values. Also, it is aimed to compare their uses in the studied region with those in Sub-Saharan Africa and report new ethnomedicinal uses.

MATERIALS AND METHODS

We documented traditional medicinal plant knowledge among professional herbalists in two areas in Bié province through participatory observation, semi-structured interviews and transect walks. Ethnobotanical information was quantified based on Use Reports to (1) rate traditional knowledge; and (2) determine most useful taxa.

RESULTS

In total, 10 traditional healers shared information on their knowledge. A total of 87 plant species distributed among 57 genera and 36 botanical families were documented with Fabaceae being the best-represented family with 18 species, followed by Phyllanthaceae (6), Apocynaceae (5), Asteraceae (5), Rubiaceae (5), Lamiaceae (4), and Ochnaceae (3). Most medicinal plants are usually gathered at a distance from human settlements because of the belief in the higher efficacy of 'wild' plants shared by all herbalists. Roots are the most common plant part used (79%), explaining why the consulted herbalists call themselves 'root doctors'.

CONCLUSIONS

The culturally most important medicinal species identified in this study, i.e. Securidaca longepedunculata, Garcinia huillensis, Annona stenophylla, Afzelia quanzensis and Strychnos cocculoides, were previously reported for the same use in neighbouring countries and elsewhere in Africa. Our study also indicates that there are several locally valuable species that have not yet been studied for their medical potential, to name a few: Alvesia rosmarinifolia, Diplorhynchus condylocarpon, Eriosema affine, Paropsia brazzaeana, Rhus squalida, Sclerocroton cornutus or Xylopia tomentosa. Moreover, the ethnomedicinal use of 26 species was reported for the first time to sub-Saharan Africa.

CLASSIFICATION

Ethnopharmacological field studies.

Plants Metabolites: Possibility of Natural Therapeutics Against the COVID-19 Pandemic

COVID-19, a disease induced by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2), has been the cause of a worldwide pandemic. Though extensive research works have been reported in recent days on the development of effective therapeutics against this global health crisis, there is still no approved therapy against SARS-CoV-2. In the present study, plant-synthesized secondary metabolites (PSMs) have been prioritized to make a review focusing on the efficacy of plant-originated therapeutics for the treatment of COVID-19. Plant metabolites are a source of countless medicinal compounds, while the diversity of multidimensional chemical structures has made them superior to treat serious diseases. Some have already been reported as promising alternative medicines and lead compounds for drug repurposing and discovery. The versatility of secondary metabolites may provide novel antibiotics to tackle MDR (Multi-Drug Resistant) microbes too. This review attempted to find out plant metabolites that have the therapeutic potential to treat a wide range of viral pathogens. The study includes the search of remedies belonging to plant families, susceptible viral candidates, antiviral assays, and the mode of therapeutic action; this attempt resulted in the collection of an enormous number of natural therapeutics that might be suggested for the treatment of COVID-19. About 219 plants from 83 families were found to have antiviral activity. Among them, 149 plants from 71 families were screened for the identification of the major plant secondary metabolites (PSMs) that might be effective for this pandemic. Our investigation revealed that the proposed plant metabolites can serve as potential anti- SARS-CoV-2 lead molecules for further optimization and drug development processes to combat COVID-19 and future pandemics caused by viruses. This review will stimulate further analysis by the scientific community and boost antiviral plant-based research followed by novel drug designing.

Plant Phytochemicals in Food Preservation: Antifungal Bioactivity: A Review

Synthetic food additives generate a negative perception in consumers. This fact generates an important pressure on food manufacturers, searching for safer natural alternatives. Phytochemicals (such as polyphenols and thiols) and plant essential oils (terpenoids) possess antimicrobial activities that are able to prevent food spoilage due to fungi (e.g., Aspergillus, Penicillium) and intoxications (due to mycotoxins), both of which are important economic and health problems worldwide. This review summarizes industrially interesting antifungal bioactivities from the three main types of plant nutraceuticals: terpenoids (as thymol), polyphenols (as resveratrol) and thiols (as allicin) as well as some of the mechanisms of action. These phytochemicals are widely distributed in fruits and vegetables and are very useful in food preservation as they inhibit growth of important spoilage and pathogenic fungi, affecting especially mycelial growth and germination. Terpenoids and essential oils are the most abundant group of secondary metabolites found in plant extracts, especially in common aromatic plants, but polyphenols are a more remarkable group of bioactive compounds as they show a broad array of bioactivities.

The Genus Terminalia (Combretaceae): An Ethnopharmacological, Phytochemical and Pharmacological Review

Terminalia Linn, a genus of mostly medium or large trees in the family Combretaceae with about 250 species in the world, is distributed mainly in southern Asia, Himalayas, Madagascar, Australia, and the tropical and subtropical regions of Africa. Many species are used widely in many traditional medicinal systems, e.g., traditional Chinese medicine, Tibetan medicine, and Indian Ayurvedic medicine practices. So far, about 39 species have been phytochemically studied, which led to the identification of 368 compounds, including terpenoids, tannins, flavonoids, phenylpropanoids, simple phenolics and so on. Some of the isolates showed various bioactivities, in vitro or in vivo, such as antitumor, anti HIV-1, antifungal, antimicrobial, antimalarial, antioxidant, diarrhea and analgesic. This review covers research articles from 1934 to 2018, retrieved from SciFinder, Wikipedia, Google Scholar, Chinese Knowledge Network and Baidu Scholar by using "Terminalia" as the search term ("all fields") with no specific time frame setting for the search. Thirty-nine important medicinal and edible Terminalia species were selected and summarized on their geographical distribution, traditional uses, phytochemistry and related pharmacological activities.

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.

Antifungal and anti-mycotoxigenic activity of selected South African medicinal plants species

Antifungal and anti-mycotoxigenic activity of 25 acetone leaf extracts of South African medicinal plants with potent antioxidant activity were investigated against three phytopathogenic fungal strains. The extracts exhibited varying degrees of in vitro anti-mycotoxigenic effect against Fusarium verticillioides, Aspergillus flavus and Aspergillus ochraceous. Markhamia obtusifolia (Baker) Sprague exhibited the lowest minimum inhibitory concentration (MIC) values as low as 0.08 mg/ml against Aspergillus flavus and Furasium verticilloides at both 24 and 48 hr incubation period, while Curtisia dentata exhibited similar MIC value against Aspergillus ochraceous. Curtisia dentata further yielded the highest total activity of 1583 ml/g against Aspergillus ochraceous at 24 and 48 hr incubation period. In the mycelial growth inhibition (MGI) evaluation, Fusarium verticilloides was more sensitive to plants extracts, while Kirkia wilmsii exhibited highest MGI of 50.08% against Fusarium verticilloides on the 6th day of incubation. Five acetone extracts from Acokanthora oppositifolia, Bauhinia galpinii, Combretum caffrum, Ricinus communis and Solanum aculeastrum exhibited lowest IC50 value of 0.01 mg/ml against (2,2'-azinobis-3-ethylbenzthiazoline-6-suphonic acid (ABTS). Curtisia dentata and Markhamia obtusifolia extracts were further subjected to gas chromatography mass-spectrophotometry (GC-MS) analysis. Curtisia dentata revealed the presence of triterpenoid compounds, β-amyrin (53.30%) and α-amyrin (6.42%), while Markhamia obtusifolia yielded the presence of neophytadiene (4.38%) and palmitic acid (3.61%) The results suggest that natural products from plants may well be used as possible substitutes for synthetic fungicides. Given the antifungal and antioxidant potential of the selected plants, they may have potential as possible leads for the development of biofungicides that may well prevent oxidation related food spoilage.

Terminalia laxiflora and Terminalia brownii contain a broad spectrum of antimycobacterial compounds including ellagitannins, ellagic acid derivatives, triterpenes, fatty acids and fatty alcohols

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia laxiflora Engl. & Diels, (Sudanese Arabic name: Darout الدروت) and Terminalia brownii Fresen (Sudanese Arabic name: Alshaf ألشاف) (Combretaceae) are used in Sudanese traditional folk medicine and in other African countries for treatment of infectious diseases, TB and its symptoms, such as cough, bronchitis and chest pain.

AIM OF STUDY

Because of the frequent use of T. laxiflora and T. brownii in African traditional medicine and due to the absence of studies regarding their antimycobacterial potential there was a need to screen extracts of T. laxiflora and T. brownii for their growth inhibitory potential and to study the chemical composition and compounds in growth inhibitory extracts.

MATERIALS AND METHODS

The plant species were collected in Sudan (Blue Nile Forest, Ed Damazin Forestry areas) and selected according to their uses in traditional medicine for the treatment of bacterial infections, including TB. Eighty extracts and fractions of the stem bark, stem wood, roots, leaves and fruits of T. laxiflora and T. brownii and nine pure compounds present in the active extracts were screened against Mycobacterium smegmatis ATCC 14468 using agar diffusion and microplate dilution methods. Inhibition zones and MIC values were estimated and compared to rifampicin. HPLC-UV/DAD, GC/MS and UHPLC/Q-TOF MS were employed to identify the compounds in the growth inhibitory extracts.

RESULTS

The roots of T. laxiflora and T. brownii gave the best antimycobacterial effects (IZ 22-27 mm) against Mycobacterium smegmatis. The lowest MIC of 625 µg/ml was observed for an acetone extract of the root of T. laxiflora followed by methanol and ethyl acetate extracts, both giving MIC values of 1250 µg/ml. Sephadex LH-20 column chromatography purification of T. brownii roots resulted in low MIC values of 62.5 µg/ml and 125 µg/ml for acetone and ethanol fractions, respectively, compared to 5000 µg/ml for the crude methanol extract. Methyl (S)-flavogallonate is suggested to be the main active compound in the Sephadex LH- 20 acetone fraction, while ellagic acid xyloside and methyl ellagic acid xyloside are suggested to give good antimycobacterial activity in the Sephadex LH-20 ethanol fraction. RP-18 TLC purifications of an ethyl acetate extract of T. laxiflora roots resulted in the enrichment of punicalagin in one of the fractions (Fr5). This fraction gave a five times smaller MIC (500 µg/ml) than the crude ethyl acetate extract (2500 µg/ml) and this improved activity is suggested to be mostly due to punicalagin. 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone and β-sitosterol were found in antimycobacterial hexane extracts of the stem bark of both studied species. Of these compounds, 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone have not been previously identified in T. brownii and T. laxiflora. Moreover, both plant species contained friedelin, betulinic acid, β-amyrine and two unknown oleanane-type triterpenoids. Of the listed compounds, friedelin, triacontanol and sitostenone gave a MIC of 250 µg/ml against M. smegmatis, whereas stigmasterol and β-sitosterol gave MIC values of 500 µg/ml.

CONCLUSIONS

Our results show that T. laxiflora and T. brownii contain antimycobacterial compounds of diverse polarities and support the traditional uses of various parts of T. laxiflora and T.brownii as decoctions for treatment of tuberculosis. Further investigations are warranted to explore additional (new) antimycobacterial compounds in the active extracts of T. laxiflora and T. brownii.

Antifungal potential of punicalagin against Cryptococcus neoformans species complex

This study evaluated the antifungal activity and cytotoxicity profile of the ellagitannin punicalagin, a compound extracted from the L. pacari A. St.-Hil (Lythraceae) leaf, against Cryptococcus neoformans species complex. Minimum inhibitory concentrations (MIC) were checked using the broth microdilution method. Minimum fungicidal concentrations (MFC) and time of death were used to confirm the antifungal activity of the compound. The in vitro cytotoxicity of punicalagin was tested in BALB/c3T3 fibroblasts and A549 human lung cancer cell line, while the hemolytic potential was tested on sheep erythrocytes. The morphological changes induced in yeast strains by the presence of punicalagin were also analyzed. Tested on eight isolates of the C. neoformans complex punicalagin showed MIC of 0.5 to 4.0 μg/mL and MFC> 256 μg/mL. Punicalagin also demonstrated a good growth inhibitory activity in time-kill curves, but it was not able to achieve a statistically significant reduction of fungal growth suggesting a fungistatic effect of the compound. In vitro cytotoxicity studies using the two cell lines showed that punicalagin has low activity on these cells and no activity on sheep erythrocytes. Morphological changes were seen in the yeasts strains studied when treated with punicalagin. Therefore, punicalagin is a potential antifungal for important pathogenic yeasts and presents a low cytotoxicity profile associated with no hemolytic effects.

LC-MS/MS Tandem Mass Spectrometry for Analysis of Phenolic Compounds and Pentacyclic Triterpenes in Antifungal Extracts of Terminalia brownii (Fresen)

Decoctions and macerations of the stem bark and wood of Terminalia brownii Fresen. are used in traditional medicine for fungal infections and as fungicides on field crops and in traditional granaries in Sudan. In addition, T. brownii water extracts are commonly used as sprays for protecting wooden houses and furniture. Therefore, using agar disc diffusion and macrodilution methods, eight extracts of various polarities from the stem wood and bark were screened for their growth-inhibitory effects against filamentous fungi commonly causing fruit, vegetable, grain and wood decay, as well as infections in the immunocompromised host. Ethyl acetate extracts of the stem wood and bark gave the best antifungal activities, with MIC values of 250 µg/mL against Nattrassia mangiferae and Fusarium verticillioides, and 500 µg/mL against Aspergillus niger and Aspergillus flavus. Aqueous extracts gave almost as potent effects as the ethyl acetate extracts against the Aspergillus and Fusarium strains, and were slightly more active than the ethyl acetate extracts against Nattrassiamangiferae. Thin layer chromatography, RP-HPLC-DAD and tandem mass spectrometry (LC-MS/MS), were employed to identify the chemical constituents in the ethyl acetate fractions of the stem bark and wood. The stem bark and wood were found to have a similar qualitative composition of polyphenols and triterpenoids, but differed quantitatively from each other. The stilbene derivatives, cis- (3) and trans- resveratrol-3-O-β-galloylglucoside (4), were identified for the first time in T. brownii. Moreover, methyl-(S)-flavogallonate (5), quercetin-7-β-O-di-glucoside (8), quercetin-7-O-galloyl-glucoside (10), naringenin-4'-methoxy-7-pyranoside (7), 5,6-dihydroxy-3',4',7-tri-methoxy flavone (12), gallagic acid dilactone (terminalin) (6), a corilagin derivative (9) and two oleanane type triterpenoids (1) and (2) were characterized. The flavonoids, a corilagin derivative and terminalin, have not been identified before in T. brownii. We reported earlier on the occurrence of methyl-S-flavogallonate and its isomer in the roots of T. brownii, but this is the first report on their occurrence in the stem wood as well. Our results justify the traditional uses of macerations and decoctions of T. brownii stem wood and bark for crop and wood protection and demonstrate that standardized extracts could have uses for the eco-friendly control of plant pathogenic fungi in African agroforestry systems. Likewise, our results justify the traditional uses of these preparations for the treatment of skin infections caused by filamentous fungi.

Compounds from Terminalia mantaly L. (Combretaceae) Stem Bark Exhibit Potent Inhibition against Some Pathogenic Yeasts and Enzymes of Metabolic Significance

Background: Pathogenic yeasts resistance to current drugs emphasizes the need for new, safe, and cost-effective drugs. Also, new inhibitors are needed to control the effects of enzymes that are implicated in metabolic dysfunctions such as cancer, obesity, and epilepsy. Methods: The anti-yeast extract from Terminalia mantaly (Combretaceae) was fractionated and the structures of the isolated compounds established by means of spectroscopic analysis and comparison with literature data. Activity was assessed against Candida albicans, C. parapsilosis and C. krusei using the microdilution method, and against four enzymes of metabolic significance: glucose-6-phosphate dehydrogenase, human erythrocyte carbonic anhydrase I and II, and glutathione S-transferase. Results: Seven compounds, 3,3'-di-O-methylellagic acid 4'-O-α-rhamnopyranoside; 3-O-methylellagic acid; arjungenin or 2,3,19,23-tetrahydroxyolean-12-en-28-oïc acid; arjunglucoside or 2,3,19,23-tetrahydroxyolean-12-en-28-oïc acid glucopyranoside; 2α,3α,24-trihydroxyolean-11,13(18)-dien-28-oïc acid; stigmasterol; and stigmasterol 3-O-β-d-glucopyranoside were isolated from the extract. Among those, 3,3'-di-O-methylellagic acid 4'-O-α-rhamnopyranoside, 3-O-methylellagic acid, and arjunglucoside showed anti-yeast activity comparable to that of reference fluconazole with minimal inhibitory concentrations (MIC) below 32 µg/mL. Besides, Arjunglucoside potently inhibited the tested enzymes with 50% inhibitory concentrations (IC50) below 4 µM and inhibitory constant (Ki) <3 µM. Conclusions: The results achieved indicate that further SAR studies will likely identify potent hit derivatives that should subsequently enter the drug development pipeline.

Ethnobotanical survey and toxicity evaluation of medicinal plants used for fungal remedy in the Southern Highlands of Tanzania

Background/Aim:

Some of the antifungal drugs used in the current treatments regime are responding to antimicrobial resistance. In rural areas of Southern Tanzania, indigenous people use antifungal drugs alone or together with medicinal plants to curb the effects of antibiotic resistance. This study documented ethnobotanical information of medicinal plants used for managing fungal infections in the Southern Highlands of Tanzania and further assess their safety.

Materials and Methods:

Ethnobotanical survey was conducted in Makete and Mufindi districts between July 2014 and December 2015 using semi-structured questionnaires followed by two focus group discussions to verify respondents’ information. Cytotoxicity study was conducted on extracts of collected plants using brine shrimp lethality test and analyzed by MS Excel 2013 program.

Results:

During this survey about 46 plant species belonging to 28 families of angiosperms were reported to be traditionally useful in managing fungal and other health conditions. Among these, Terminalia sericea, Aloe nutii, Aloe lateritia, Zanthoxylum chalybeum, Zanthoxylum deremense, and Kigelia africana were frequently mentioned to be used for managing fungal infections. The preparation of these herbals was mostly by boiling plant parts especially the leaves and roots. Cytotoxicity study revealed that most of the plants tested were nontoxic with LC₅₀ > 100 which implies that most compounds from these plants are safe for therapeutic use. The dichloromethane extract of Croton macrostachyus recorded the highest with LC₅₀ value 12.94 µg/ml. The ethnobotanical survey correlated well with documented literature from elsewhere about the bioactivity of most plants.

Conclusions:

The ethnobotanical survey has revealed that traditional healers are rich of knowledge to build on for therapeutic studies. Most of the plants are safe for use; and thus can be considered for further studies on drug discovery.

Furofuran Lignan Glucosides with Estrogen-Inhibitory Properties from the Bangladeshi Medicinal Plant Terminalia citrina

Extracts from the leaves of the Bangladeshi medicinal plant Terminalia citrina were prepared, and 13 new furofuran lignan glucosides, terminalosides A-K (1-4, 6-12), 2-epiterminaloside D (5), and 6-epiterminaloside K (13), were characterized using various spectroscopic techniques. Twelve of the isolates were found to contain rare tetraoxygenated aryl groups in their structures. Analysis of the NMR chemical shifts for the oxymethine signals in the furofuran ring suggested a pragmatic approach to determining the relative configuration of these compounds. The ECD and NOESY spectroscopic data obtained allowed for the deduction of the absolute configurations and conformations of the compounds. The isolates were tested for their estrogenic/antiestrogenic activity using the MCF-7 and T47D estrogen-responsive human breast cancer cell lines. Terminalosides B (2) and G (8) exhibited inhibitory effects for both cell lines, and estradiol-enhanced cell proliferation was suppressed by 90% at concentrations lower than 10 μM. Terminaloside E (6) showed inhibitory activity against the T47D cell line, whereas terminalosides C (3), F (7), and I (10) and 6-epiterminaloside K (13) displayed antiestrogenic activity against MCF-7 cells.

Antifungal activity of extracts and isolated compounds from Buchenavia tomentosa on Candida albicans and non-albicans

AIM

This study aimed to evaluate the antifungal activity of Buchenavia tomentosa extract and bioactive compounds on six Candida species.

MATERIALS & METHODS

The antimicrobial activity of extract was evaluated using standard strains and clinical isolates. Cytotoxicity was tested in order to evaluate cell damage caused by the extract. Extract was chemically characterized and the antifungal activity of its compounds was evaluated.

RESULTS

Extract showed antifungal activity on Candida species. Candida non-albicans were more susceptible than Candida albicans. Low cytotoxicity for extract was observed. The isolated compounds presented antifungal activity at least against one Candida spp. and all compounds presented antifungal effect on Candida glabrata.

CONCLUSION

Extracts from Buchenavia tomentosa showed promising antifungal activity on Candida species with low cytotoxicity. Gallic acid, corilagin and ellagic acid showed promising inhibitory activity on Candida glabrata.

Potential Use of Phenolic Acids as Anti-Candida Agents: A Review

There has been a sharp rise in the occurrence of Candida infections and associated mortality over the last few years, due to the growing body of immunocompromised population. Limited number of currently available antifungal agents, undesirable side effects and toxicity, as well as emergence of resistant strains pose a considerable clinical challenge for the treatment of candidiasis. Therefore, molecules that derived from natural sources exhibiting considerable antifungal properties are a promising source for the development of novel anti-candidal therapy. Phenolic compounds isolated from natural sources possess antifungal properties of interest. Particularly, phenolic acids have shown promising in vitro and in vivo activity against Candida species. However, studies on their mechanism of action alone or in synergism with known antifungals are still scarce. This review attempts to discuss the potential use, proposed mechanisms of action and limitations of the phenolic acids in anti-candidal therapy.

Anti-Arthritic Effect of Chebulanin on Collagen-Induced Arthritis in Mice

Rheumatoid arthritis is a chronic degenerative autoimmune disease characterized by persistent inflammation of synovial membranes, which leads to cartilage destruction and bone erosion. To date, there are no effective therapies to slow the progress of this degenerative condition. Here, we evaluate the anti-arthritic effect of chebulanin, an abundant anti-inflammatory agent isolated from Terminalia chebula, in collagen induced arthritis in DBA/1 mice by intragastric administration. Arthritic severity was scored by performing histopathological evaluation of the joints and measuring the expression of inflammatory cytokines and relative enzymes by immunohistochemical staining. In parallel, bone destruction and erosion were confirmed by micro-CT. Our data revealed that chebulanin significantly improved the severity of arthritis. Specifically, the histopathological characteristics of the tissues were improved and expression of TNF-α, IL-6, MMP-3 and COX-2 in the paws and joints of the treated mice decreased in a dose-dependent manner compared with control mice. Furthermore, micro-CT analysis revealed that chebulanin induced a dose-dependent reduction in cartilage destruction and bone erosion. Taken together, our findings suggest that chebulanin suppresses the expression of inflammatory mediators and prevents cartilage destruction and bone erosion in mice. Therefore, chebulanin is a strong therapeutic alternative for the treatment of RA.

A New Aromatic Compound from the Stem Bark of Terminalia catappa

A new aromatic compound 3,4,5-trimethoxyphenyl-1- O-(4-sulfo)-β-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3- O-β-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Their cytotoxicity and anti-inflammatory activity, together with the antioxidant capacity of compound 1 were also evaluated.

Antifungal activity of pomegranate peel extract and isolated compound punicalagin against dermatophytes

BACKGROUND

Dermatophyte species infect the epidermis and appendages, often with serious social and health-economic consequences. The hydroalcoholic extract of pomegranate fruit peel showed activity against the dermatophyte fungi Trichophyton mentagrophytes, T. rubrum, Microsporum canis and M. gypseum.

METHODS

Hydroalcoholic extract was prepared with pomegranate peels. This crude extract was fractionated and submitted to liquid-liquid partition, resulting in an active fraction which was fractionated in a Sephadex LH-20 column, followed by a Lobar column. The structure of the active compound was established with the use of spectroscopic methods.

RESULTS

The crude extract of pomegranate fruit peel showed activity against the dermatophytes Trichophyton mentagrophytes, T. rubrum, Microsporum canis, and M. gypseum, with MICs values of 125 μg/ml and 250 μg/ml, respectively for each genus. Punicalagin was isolated and identified by spectroscopic analysis. The crude extract and punicalagin showed activity against the conidial and hyphal stages of the fungi. The cytotoxicity assay showed selectivity for fungal cells than for mammalian cells.

CONCLUSIONS

These results indicated that the crude extract and punicalagin had a greater antifungal activity against T. rubrum, indicating that the pomegranate is a good target for study to obtain a new antidermatophyte medicine.

Early state research on antifungal natural products

Nosocomial infections caused by fungi have increased greatly in recent years, mainly due to the rising number of immunocompromised patients. However, the available antifungal therapeutic arsenal is limited, and the development of new drugs has been slow. Therefore, the search for alternative drugs with low resistance rates and fewer side effects remains a major challenge. Plants produce a variety of medicinal components that can inhibit pathogen growth. Studies of plant species have been conducted to evaluate the characteristics of natural drug products, including their sustainability, affordability, and antimicrobial activity. A considerable number of studies of medicinal plants and alternative compounds, such as secondary metabolites, phenolic compounds, essential oils and extracts, have been performed. Thus, this review discusses the history of the antifungal arsenal, surveys natural products with potential antifungal activity, discusses strategies to develop derivatives of natural products, and presents perspectives on the development of novel antifungal drug candidates.

Phytochemical, Antimicrobial and Antiplasmodial Investigations of Terminalia brownii

Phytochemical investigation of the ethyl acetate-soluble fraction of stem bark extract of an African medicinal plant Terminalia brownii led to the isolation of a new oleanane-type triterpenoid, along with seven known triterpenoids, seven ellagic acid derivatives, and 3- O-β-D-glucopyranosyl-β-sitosterol. The new compound was identified using spectroscopic methods, notably 1D- and 2D NMR, as 3β,24- O-ethylidenyl-2α,19α-dihydroxyolean-12-en-28-oic acid. The isolated compounds were evaluated for their antimicrobial and antiplasmodial activities. Two compounds with a galloyl group (4 and 6) were found to be active against chloroquine sensitive (D6) and chloroquine resistant (W2) strains of Plasmodium falciparum, whereas three ellagic acid derivatives (5–7) were found active against three species of fungi and one species of bacteria.

Arjunolic acid: a new multifunctional therapeutic promise of alternative medicine

IMPORTANCE OF THE FIELD

In recent years, a number of studies describing the effective therapeutic strategies of medicinal plants and their active constituents in traditional medicine have been reported. Indeed, tremendous demand for the development and implementation of these plant derived biomolecules in complementary and alternative medicine is increasing and appear to be promising candidates for pharmaceutical industrial research. These new molecules, especially those from natural resources, are considered as potential therapeutic targets, because they are derived from commonly consumed foodstuff and are considered to be safe for humans.

AREAS COVERED IN THIS REVIEW

This review highlights the beneficial role of arjunolic acid, a naturally occurring chiral triterpenoid saponin, in various organ pathophysiology and the underlying mechanism of its protective action. Studies on the biochemistry and pharmacology suggest the potential use of arjunolic acid as a novel promising therapeutic strategy.

WHAT THE READERS WILL GAIN

The multifunctional therapeutic application of arjunolic acid has already been documented by its various biological functions including antioxidant, anti-fungal, anti-bacterial, anticholinesterase, antitumor, antiasthmatic, wound healing and insect growth inhibitor activities. The scientific basis behind its therapeutic application as a cardioprotective agent in traditional medicine is justified by its ability to prevent myocardial necrosis and apoptosis, platelet aggregation, coagulation and lowering of blood pressure, heart rate, as well as cholesterol levels. Its antioxidant property coupled with metal chelating property (by its two hydroxyl groups) protects different organs from metal and drug-induced organ pathophysiology. Arjunolic acid also plays a beneficial role in the pathogenesis of diabetes and its associated complications. The mechanism of cytoprotection of arjunolic acid, at least in part, results from the detoxification of reactive oxygen species (ROS) produced in the respective pathophysiology. In addition to its other biological functions, it also possesses vibrant insecticidal properties and it has the potential to be used as a structural molecular framework for the design of molecular receptors in the general area of supramolecular chemistry and nanochemistry. Esters of arjunolic acid function as organogelators which has wide application in designing thermochromic switches and sensor devices. Arjunolic acid derived crown ether is an attractive candidate for the design of molecular receptors, biomimetics and supramolecular systems capable of performing some biological functions.

HOME MESSAGE

This review would provide useful information about the recent progress of natural product research in the domain of clinical science. This review also aims to untie the multifunctional therapeutic application of arjunolic acid, a nanometer-long naturally occurring chiral triterpenoid biomolecule.

Structural identification of isomallotusinin and other phenolics in Phyllanthus emblica L. fruit hull

The air-dried fruit hull of Phyllanthus emblica L. was extracted with 95% ethanol, and then the extract was partitioned by diethyl ether and ethyl acetate (EA). The EA fraction was then subjected to separation and purification using silica gel and Sephadex LH-20 column chromatography repeatedly to obtain five hydrolysable tannins. They were identified as mucic acid 1,4-lactone 3-o-gallate (C1), isocorilagin (C2), chebulanin (C3), chebulagic acid (C4) and isomallotusinin (C5) using mass spectrometry and nuclear magnetic resonance (NMR) spectrometry. Isomallotusinin and chebulanin were identified from emblica dried fruit hull for the first time, and isomallotusinin was the first time identified from Phyllanthus. Furthermore, the antioxidant abilities of these hydrolysable tannins were investigated using DPPH and ABTS⁺ radical scavenging systems. All hydrolysable tannins showed strong DPPH and ABTS⁺ radical scavenging activities. Isomallotusinin and chebulagic acid exhibited the highest antioxidant activity compared to other purified compounds tested.

Subcutaneous antifungal screening of Latin American plant extracts against Sporothrix schenckii and Fonsecaea pedrosoi

CONTEXT

Subcutaneous mycoses are chronic infections caused by slow growing environmental fungi. Latin American plants are used in folk medicine to treat these afflictions. Moreover, the potential of the rich Latin American biodiversity for this purpose has not been fully explored.

OBJECTIVES

The aim of the study was to screen Latin American plant extracts against two species of subcutaneous fungi: Sporothrix schenckii and Fonsecaea pedrosoi.

MATERIALS AND METHODS

One hundred ninety-five organic extracts from 151 Latin American plants were screened against two subcutaneous fungi by the agar dilution method at a concentration of 100 µg/mL, and minimum inhibitory concentrations (MICs) of active extracts were determined. Positive (amphothericin B) and negative (50% ethanol) controls were used.

RESULTS AND DISCUSSION

Twenty eight extracts showed activity at ≤100 µg/mL. Of these, four extracts from Gnaphalium gaudichaudianum DC (Asteraceae), Plumeria rubra L (Apocynaceae), Tecoma stans (L.) Juss. ex Kunth. (Bignoniaceae), and Trichostigma octandum (L.), H. Walter showed activity against F. pedrosoi at MIC 12.5 µg/mL; and, four extracts from Bourreria huanita (Lex.) Hemsl. (Boraginaceae), Phytolacca bogotensis Kunth (Phytolaccaceae), Monnina xalapensis Kunth (Polygalaceae) and Crataegus pubescens (C. Presl) C. Presl (Rosaceae) against S. schenckii. This is the first report on antifungal activity of the Latin American plants against these two subcutaneous fungi.

CONCLUSION

S. schenkii and F. pedrosoi were inhibited by B. huanita (MIC: 12.5 and 25 µg/mL), G. gaudichaudianum (MIC: 50 and 12.5 µg/mL) and T. triflora (MIC: 25 µg/mL).

Time-dependent effects of pomegranate juice and pomegranate polyphenols on foodborne viral reduction

Pomegranate juice (PJ) and pomegranate polyphenolic extracts (PP) have antiviral effects against HIV-1, influenza, herpes, and poxviruses, and we recently demonstrated their effect against human noroviral surrogates. In the present study, the time-dependent effects of two commercial brands of PJ and PP at two concentrations (2 and 4 mg/mL) on the infectivity of foodborne viral surrogates (feline calicivirus FCV-F9, murine norovirus MNV-1, and MS2 bacteriophage) at room temperature for up to 1 h were evaluated. Each virus at ∼5 log(10) plaque-forming units (PFU)/mL was mixed with equal volumes of PJ, or PP at 4 or 8 mg/mL, and incubated for 0, 10, 20, 30, 45, and 60 min at room temperature. Viral titers after each treatment were determined by standardized plaque assays and compared with untreated controls. Virus titer reduction by PJ and PP was found to be a rather rapid process, with ≥50% of titer reduction occurring within the first 20 min of treatment for all three tested viruses. Within the first 20 min, titer reductions of 3.12, 0.79, and 0.23 log(10) PFU/mL for FCV-F9, MNV-1, and MS2, respectively, were obtained using PJ. FCV-F9, MNV-1, and MS2 titers were reduced by 4.02, 0.68, and 0.18 log(10) PFU/mL with 2 mg/mL PP and 5.09, 1.14, and 0.19 log(10) PFU/mL with 4 mg/mL PP, respectively, after 20 min. The mechanism of viral reduction by PJ and PP needs to be elucidated and clinical trials should be undertaken before recommending for therapeutic or preventive purposes.

In vitro effects of pomegranate juice and pomegranate polyphenols on foodborne viral surrogates

Pomegranate juice (PJ) has gained popularity because of its associated antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. However, its effects against epidemiologically significant foodborne viruses have not been investigated. In the absence of culturable human noroviruses, feline calicivirus (FCV-F9), murine norovirus (MNV-1), and MS2 (ssRNA) bacteriophage were used as foodborne viral surrogates. The aim of this research was to study the effects of PJ and pomegranate polyphenols (PP) on foodborne viral infectivity. Viruses at high (∼ 7 log(10) PFU/mL) or low (∼ 5 log(10) PFU/mL) titers were mixed with equal volumes of PJ, 8, 16, and 32 mg/mL of PP, or water (control) and incubated for 1 h at room temperature. Viral infectivity after treatments was evaluated using standardized plaque assays. PJ decreased the titer of FCV-F9, MNV-1, and MS2 by 2.56, 1.32, and 0.32 log(10) PFU/mL, respectively, for low titers and 1.20, 0.06, and 0.63 log(10) PFU/mL, respectively, for high titers. Interestingly, FCV-F9 was undetectable after exposure to the three tested PP solutions using both low and high titers. MNV-1 at low initial titers was reduced by 1.30, 2.11, and 3.61 log(10) PFU/mL and at high initial titers by 1.56, 1.48, and 1.54 log(10) PFU/mL with 4, 8, and 16 mg/mL of PP treatment, respectively. MS2 at low initial titers was reduced by 0.41, 0.45, and 0.93 log(10) PFU/mL and at high initial titers by 0.32, 0.41, and 0.72 log(10) PFU/mL after 4, 8, and 16 mg/mL of PP treatment, respectively. PJ and PP resulted in titer reductions of foodborne virus surrogates after 1 h exposure, showing promise for use in hurdle technologies and/or for therapeutic or preventive use. To suggest the use of PJ and PP as natural remedies for foodborne viral illness prevention, their mechanism of action against viral infectivity needs to be further investigated.

Structural features and biological properties of ellagitannins in some plant families of the order Myrtales

Plant tannins, including hydrolysable and condensed varieties, are well known antioxidants in medicinal plants, foods, and edible fruits. Their diverse biological properties and potential for disease prevention have been demonstrated by various in vitro and in vivo assays. A number of ellagitannins, the largest group of hydrolysable tannins, have been isolated from dicotyledoneous angiosperms and characterized. This diverse class of tannins is sub-grouped into simple ellagitannins, C-glycosidic ellagitannins, complex tannins (condensates of C-glycosidic tannins with flavan-3-ol), and oligomers up to pentamers. This review outlines and describes the chemotaxonomic significance of structural features in various types of ellagitannins found in plants belonging to the Myrtaceae, Onagraceae, and Melastomataceae families, which are all included in the order Myrtales. Any biological activities that have been reported, including antitumor and antibacterial effects as well as enzyme inhibition, are also reviewed.