Antibacterial, anti-HIV-1 protease and cytotoxic activities of aqueous ethanolic extracts from Combretum adenogonium Steud. Ex A. Rich (Combretaceae)

Plant-Derived Epi-Nutraceuticals as Potential Broad-Spectrum Anti-Viral Agents

Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to their inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances in which vaccination is not accessible or in individuals with compromised immune systems, drugs can provide additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Moreover, targeting host factors allows us to develop compounds that are effective against different viral variants as well as against newly emerging virus strains. In recent years, the globe has experienced climate change, which may contribute to the emergence and spread of infectious diseases through a variety of factors. Warmer temperatures and changing precipitation patterns can increase the geographic range of disease-carrying vectors, increasing the risk of diseases spreading to new areas. Climate change may also affect vector behavior, leading to a longer breeding season and more breeding sites for disease vectors. Climate change may also disrupt ecosystems, bringing humans closer to wildlife that transmits zoonotic diseases. All the above factors may accelerate the emergence of new viral epidemics. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds, including those with anti-viral activity. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Interest in herbal antiviral products has increased. More than 50% of approved drugs originate from herbal sources. Plant-derived compounds offer diverse structures and bioactive molecules that are candidates for new drug development. Combining these therapies with conventional drugs could improve patient outcomes. Epigenetics modifications in the genome can affect gene expression without altering DNA sequences. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses recruit cellular epitranscriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we explore the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing their modulation processes and anti-viral effects on DNA and RNA viruses, as well as addressing future research objectives in this rapidly emerging field.

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.

Antimicrobial and Cytotoxicity Activities of Medicinal Plants against Salmonella gallinarum Isolated from Chickens

Medicinal plants have been the good source of treatment for different ailments of humans as well as animals for centuries. However, in Tanzania, few plants were investigated for their efficacy against various diseases of chickens. In the present study, four medicinal plants were investigated against Salmonella gallinarum isolated from chickens. The minimum inhibitory concentration (MIC) using the broth microdilution methods and minimum bactericidal concentration (MBCs) were used to evaluate the activities of plants against chicken salmonellosis. For the safety of chickens against the toxicity of plants, the cytotoxicity assay was determined using a brine shrimp lethality test. Aloe secundiflora leaf ethyl acetate (ALEA), Aloe rabaiensis leaf methanolic (ArM), Aloe rabaiensis leaf ethyl acetate (ArLEA), and Punica granatum leaf ethyl acetate (PGLEA) extracts exhibited the highest MIC (0.3906 mg/mL) and MBC (3.125 mg/mL), respectively. The Dolichos kilimandscharicus tuber ethyl acetate (DTEA) and Dolichos kilimandscharicus tuber pet ether (DTPE) extracts displayed MIC of 1.563 mg/mL and 12.50 mg/mL and MBC of 12.50 mg/mL and 25.50 mg/mL, respectively. The highest LC₅₀ values exhibited in Dolichos kilimandscharicus ranged from 7.937 × 10⁻⁴ mg/mL to 7.242 × 10⁻² mg/mL for pet ether and methanolic extracts, respectively, while ALEA extract exhibited LC₅₀ of 7.645 × 10⁻³ mg/mL. Generally, the extracts with MIC 0.3906 mg/mL and MBC 3.125 mg/mL demonstrated the highest antibacterial activity with low toxicity efficient to manage chicken salmonellosis. Dolichos kilimandscharicus, which exhibited higher toxicity, warrants further investigation on insecticidal and anticancer agents.

Phytochemical screening, phenolic and flavonoid contents, antioxidant and cytogenotoxicity activities of Combretum leprosum Mart. (Combretaceae)

Combretum leprosum Mart. (Combretaceae), a shrub popularly known as mofumbo, is used in folk medicine for treatment of uterine bleeding, pertussis, gastric pain, and as a sedative. The aim of this study was to (1) determine the phytochemical profile,(2) identify chemical constituents and (3) examine antioxidant and cytogenotoxic activity of ethanolic extracts and fractions of stem bark and leaves. The plant material (leaf and stem bark) was submitted to extraction with ethanol, followed by partition using hexane, chloroform, and ethyl acetate. It was possible to identify and quantify the epicatechin in the ethanolic stem bark extract (0.065 mg/g extract) and rutin in the leaf extract (3.33 mg/g extract). Based upon in vitro tests a significant relationship was noted between findings from antioxidant tests and levels of total phenolic and flavonoid. Comparing all samples (extracts and fractions), the ethyl acetate fractions of stem bark (411.40 ± 15.38 GAE/g) and leaves (225.49 ± 9.47 GAE/g) exhibited higher phenolic content, whereas hexanic fraction of stem bark (124.28 ± 56 mg/g sample) and ethyl acetate fraction of leaves (238.91 ± 1.73 mg/g sample) demonstrated a higher content of flavonoids. Among the antioxidant tests, the intermediate fraction of stem bark (28.5 ± 0.60 μg/ml) and ethyl acetate fraction of leaves (40 ± 0.56 μg/ml) displayed a higher % inhibition of free radical DPPH activity, whereas intermediate fraction of stem bark (27.5 ± 0.9 μg/ml) and hydromethanol fraction of leaves (81 ± 1.4 μg/ml) demonstrated inhibition of the free radical ABTS. In biological tests (Allium cepa and micronucleus in peripheral blood), data showed that none of the tested concentrations of ethanolic extracts of leaves and stem bark produced significant cytotoxicity, genotoxicity, and mutagenic activity.Abbreviations AA%: percentage of antioxidant activity; ABTS: 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid); CEUA: Ethics Committee in the Use of Animals; TLC: Thin Layer Chromatography; DNA: deoxyribonucleic acid; DPPH: 1,1-diphenyl-2-picrylhydrazyl; ROS: Reactive oxygen species; EEB: ethanol extract of the stem bark; HFB: Hexanic fraction of stem bark; IFB: Intermediate fraction of stem bark; CFB: Chloroform fraction of stem bark; EAFB: Ethyl acetate fraction of stem bark; HMFB: Hydromethanol fraction of the stem bark; EEL: Ethanol extract from leaves; HFL: Hexane fraction of leaves; CFL: Chloroform fraction of leaves; EAFL: Ethyl acetate fraction of leaves; HMFL: Hydromethanol fraction of leaves; GAE: Gallic Acid Equivalent; IC₅₀: 50% inhibition concentration; HCOOH: Formic acid; HCl: hydrochloric acid; HPLC: High-performance liquid chromatography; MN: micronucleus; WHO: World Health Organization; UFLC: Ultra-Fast Liquid Chromatography; UESPI: State University of Piauí.

Investigating antimicrobial compounds in South African Combretaceae species using a biochemometric approach

ETHNOPHARMACOLOGICAL RELEVANCE

Many species within the family Combretaceae are popular medicinal plants that are used traditionally to treat various conditions, of which many are related to bacterial infections. Global concerns regarding the increasing resistance of pathogens towards currently available antibiotics have encouraged researchers to find new drugs with antibacterial activity, particularly from plant sources.

AIM OF THE STUDY

This study was aimed at exploring the broad-spectrum antibacterial potential of methanol extracts of species representing four genera of Combretaceae (Combretum, Pteleopsis, Quisqualis, Terminalia), indigenous to South Africa, using a biochemometric approach.

MATERIALS AND METHODS

The microdilution assay was used to determine the antibacterial activities, measured as minimum inhibitory concentrations (MICs), of the 51 methanol extracts representing 35 Combretaceae species, against nine species of pathogenic bacteria. Integrative biochemometric analysis was performed, thereby correlating the MIC values with the metabolomic data obtained from ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. Orthogonal projections to latent structures-discriminant analysis (OPLS-DA) models were constructed for six pathogens displaying variation in their susceptibility towards the extracts.

RESULTS

Evaluation of the overall MIC values obtained indicated that extracts of species from the four genera displayed the highest activity towards Bacillus cereus ATCC 11778 (average MIC 0.52 mg/mL) and Salmonella typhimurium ATCC 14028 (average MIC 0.63 mg/mL). These bacteria were the most sensitive Gram-positive and Gram-negative bacteria, respectively. Extracts from Combretum acutifolium, Combretum imberbe and Combretum elaeagnoides were the most active, with average MIC values of 0.70 mg/mL, 0.52 mg/mL and 0.45 mg/mL, respectively. Five triterpenoid compounds were tentatively identified as biomarkers from the biochemometric analysis.

CONCLUSION

Correlation of the phytochemistry of species from four genera in the Combretaceae family with antibacterial activity revealed that triterpenoids are responsible for the broad-spectrum antibacterial activity observed.

Overall assessment of antibiotic substitutes for pigs: a set of meta-analyses

Background

Antibiotic growth promoters are widely used to improve weight gain. However, the abuse of antibiotics can have many negative effects on people. Developing alternatives to antibiotics is an urgent need in livestock production. We aimed to perform a meta-analysis and network meta-analysis (NMA) to investigate the effects of feed additives as potential antibiotic substitutes (ASs) on bacteriostasis, growth performance, intestinal morphology and immunity. Furthermore, the primary, secondary, and tertiary ASs were defined by comparing their results with the results of antibiotics.

Results

Among 16,309 identified studies, 37 were summarized to study the bacteriostasis effects of feed additives, and 89 were included in the meta-analysis and NMA (10,228 pigs). We summarized 268 associations of 57 interventions with 32 bacteria. The order of bacteriostasis effects was as follows: antimicrobial peptides (AMPs) ≈ antibiotics>organic acids>plant extracts>oligosaccharides. We detected associations of 11 feed additives and 11 outcomes. Compared with a basal diet, plant extract, AMPs, probiotics, microelements, organic acids, bacteriophages, lysozyme, zymin, and oligosaccharides significantly improved growth performance (P < 0.05); organic acids, probiotics, microelements, lysozyme, and AMPs remarkably increased the villus height:crypt depth ratio (V/C) (P < 0.05); and plant extracts, zymin, microelements, probiotics, and organic acids notably improved immunity (P < 0.05). The optimal AMP, bacteriophage, lysozyme, microelements, oligosaccharides, organic acids, plants, plant extracts, probiotics, and zymin doses were 0.100%, 0.150%, 0.012%, 0.010%, 0.050%, 0.750%, 0.20%, 0.040%, 0.180%, and 0.100%, respectively. Compared with antibiotics, all investigated feed additives exhibited no significant difference in effects on growth performance, IgG, and diarrhoea index/rate (P > 0.05); AMPs and microelements significantly increased V/C (P < 0.05); and zymin significantly improved lymphocyte levels (P < 0.05). Furthermore, linear weighting sum models were used to comprehensively estimate the overall impact of each feed additive on pig growth and health.

Conclusions

Our findings suggest that AMPs and plant extracts can be used as primary ASs for weaned piglets and growing pigs, respectively. Bacteriophages, zymin, plants, probiotics, oligosaccharides, lysozyme, and microelements can be regarded as secondary ASs. Nucleotides and organic acids can be considered as tertiary ASs. Future studies should further assess the alternative effects of combinational feed additives.

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.

CYTOTOXIC PROPERTIES OF TRITERPENE SAPONIN TAUROSID SX1 AND ITS EFFECT ON HUMAN IMMUNODEFICIENCY VIRUS AND INFLUENZA VIRUS INFECTION IN MICE

Triterpene saponin Taurosid Sx1 purified from leaves of the plant Crimean Ivy Hedera taurica Carr. (Araliaceae) was evaluated for its cytotoxic activity against lymphoblastoid cell lines MT-4, Jurkat-tat, U937, and human peripheral blood monocytes. The ability of saponin to influence HIV-1 replication was studied as well. In addition, the ability of Taurosid Sx1 to increase survival of mice infected with influenza virus А/WSN/1/33(H1N1) and its capacity for strengthening the immune responses in mice immunized with the influenza vaccine Grippol® have been studied. Taurosid Sx1 has been shown to inhibit MT-4 cell line at 25 μg ml-1 concentration, IC50 33,3 μmol l-1 (MTT assay). The saponin concentration of 5 μg ml-1 was non-toxic for all the cell lines studied and demonstrated a moderate inhibitory effect on HIV p24 production in Jurkat-tat cells. In the lower concentrations Taurosid Sx1 did not stimulate HIV p24 production. It was shown that oral administration of 200 μg Taurosid Sx1 to the influenza virus infected mice caused 1.5-fold increase in their survival. Taurosid Sx1 given orally amplified immunopotentiating ability of an intramusculary administered subunit influenza vaccine. Antibody production was significantly higher in animals fed Taurosid Sx1 after primary or secondary immunizatuion. In mice given 2 doses of vaccine, from 1 to 3 weeks apart, feeding 200 μg saponin resulted in 2 to 10-fold enhancement in production of anti-H1, anti-H3, and anti-inluenza type B hemagglutinin antibodies. Thus, Taurosid Sx1 can be considered as low-toxic promising immunopotentiating agent uncapable of enhancing HIV-1 replication.

Medicinal Plants Used in the Treatment of Human Immunodeficiency Virus

Since the beginning of the epidemic, human immunodeficiency virus (HIV) has infected around 70 million people worldwide, most of whom reside is sub-Saharan Africa. There have been very promising developments in the treatment of HIV with anti-retroviral drug cocktails. However, drug resistance to anti-HIV drugs is emerging, and many people infected with HIV have adverse reactions or do not have ready access to currently available HIV chemotherapies. Thus, there is a need to discover new anti-HIV agents to supplement our current arsenal of anti-HIV drugs and to provide therapeutic options for populations with limited resources or access to currently efficacious chemotherapies. Plant-derived natural products continue to serve as a reservoir for the discovery of new medicines, including anti-HIV agents. This review presents a survey of plants that have shown anti-HIV activity, both in vitro and in vivo.

Phenanthrenes: A Promising Group of Plant Secondary Metabolites

Although phenanthrenes are considered to constitute a relatively small group of natural products, discovering new phenanthrene derivatives and evaluating their prospective biological activities have become of great interest to many research groups worldwide. Based on 160 references, this review covers the phytochemistry and pharmacology of 213 naturally occurring phenanthrenes that have been isolated between 2008 and 2016. More than 40% of the 450 currently known naturally occurring phenanthrenes were identified during this period. The family Orchidaceae is the most abundant source of these compounds, although several new plant families and genera have been involved in the search for phenanthrenes. The presence of certain substituent patterns may be restricted to specific families; vinyl-substituted phenanthrenes were reported only from Juncaceae plants, and prenylated derivatives occur mainly in Euphorbiaceae species. Therefore, these compounds also can serve as chemotaxonomic markers. Almost all of the newly isolated compounds have been studied for their biological activities (e.g., potential cytotoxic, antimicrobial, anti-inflammatory, and antioxidant effects), and many of them showed multiple activities. According to the accumulated data, denbinobin, with a novel mechanism of action, has great potential as a lead compound for the development of a new anticancer agent.

Alkaloid extracts from Combretum zeyheri inhibit the growth of Mycobacterium smegmatis

Background

Current tuberculosis regimens have failed to combat the issue of drug resistance and ethno medicines may represent a possible source of antimycobacterial agents. Combretum species are well known in African traditional medicines and used for various ailments including pneumonia, venereal diseases like syphilis, mental problems, relief of sore throats and colds, fever, and chest coughs associated with tuberculosis. Alkaloids function as either hydrogen-acceptor or hydrogen-donor in hydrogen bonding critical for the interaction between targets thus, potentiating effects of curative agents on diseases. Alkaloid extracts from leaves of Combretum zeyheri, Combretum platypetalum, Combretum molle and Combretum apiculatum, were assessed for antimycobacterial activity to establish rationale for their use in traditional medicines for various ailments including pneumonia, relief of sore throats and colds, fever, and chest coughs associated with tuberculosis.

Methods

Alkaloids were extracted from the leaves of Combretum zeyheri, Combretum platypetalum, Combretum molle and Combretum apiculatum. The broth microdilution method was used for the screening of growth inhibitory activity. The standard drug rifampicin was used as the positive control. Alkaloid extracts from the most potent plant species, Combretum zeyheri were further investigated for time-kill dependency effects on drug transport in Mycobacterium smegmatis.

Results

Using the broth microdilution susceptibility method, C. zeyheri alkaloid extract, was found to have the most antimycobacterial effects with an MIC value of 125 μg/ml whilst MICs for C. molle and C. platypetalum were above 1000 μg/ml. An MBC value of 250 μg/ml was observed with alkaloid extracts from Combretum zeyheri whilst the remaining three Combretum species showed no bactericidal activity. It was also shown that C. zeyheri had potential efflux pump inhibitory activity. Determination of the time-kill kinetics of extracts from C. zeyheri showed not only a concentration-dependent activity but time-dependent bactericidal effect as well.

Conclusions

Alkaloid extracts from the leaves of C. zeyheri have potential as a source of lead compounds that may be developed further into antimycobacterial compounds. The mechanism of action of may be due to inhibition of transport across the cell membrane. Further work needs to be done to isolate the active components in these extracts.

Saponaria officinalis L. extract: Surface active properties and impact on environmental bacterial strains

Plant-derived surfactants are characterised by low toxicity, high biodegradability and environmental compatibility. They therefore have many applications; for instance, they can be used in bioremediation to accelerate biodegradation processes, especially of hydrophobic pollutants. This paper analyses the properties of an extract from Saponaria officinalis L. containing saponins and its impact on bacterial strains isolated from soil, as well as its potential for application in hydrocarbon bioremediation. The tested extract from Saponaria officinalis L. contains gypsogenin, hederagenin, hydroxyhederagenin and quillaic acid aglycone structures and demonstrates good emulsification properties. Contact with the extract led to modification of bacterial cell surface properties. A decrease in cell surface hydrophobicity and an increase in membrane permeability were recorded in the experiments. An increase of up to 63% in diesel oil biodegradation was also recorded for Pseudomonas putida DA1 on addition of 1gL^-1 of saponins from Saponaria officinalis L. Saponaria extract showed no toxic impact on the tested environmental bacterial strains at the concentration used in the biodegradation process.

The efficacy and safety of nine South African medicinal plants in controlling Bacillus anthracis Sterne vaccine strain

BACKGROUND

Anthrax is a zoonotic disease caused by Bacillus anthracis, a Gram-positive spore-forming bacterium. The presence of the bacteria and the toxins in the blood of infected hosts trigger a cascade of pathological events leading to death. Nine medicinal plants with good activities against other bacteria were selected to determine their in vitro antibacterial activity against Bacillus anthracis Sterne strain. The cytotoxicity of the extracts on Vero kidney cells was also determined.

RESULTS

The minimum inhibitory concentration (MIC) values of the extracts against Bacillus anthracis Sterne strain ranged from 0.02 to 0.31 mg/ml. Excellent MIC values were observed for the following plant species: Maesa lanceolata (0.02 mg/ml), Bolusanthus speciosus, Hypericum roeperianum, Morus mesozygia (0.04 mg/ml) and Pittosporum viridiflorum (0.08 mg/ml). The total antibacterial activity of the extracts ranged from 92 to 5562 ml/g. Total activity presents the volume to which the extract from 1 g of plant material can be diluted and still inhibit microbial growth. Maesa lanceolata and Hypericum roeperianum had the highest total activity with values of 5562 and 2999 ml/g respectively. The extracts of Calpurnia aurea had the lowest total activity (92 ml/g). The cytotoxicity determined on Vero cells indicated that most of the extracts were relatively non-toxic compared to doxorubicin (LC50 8.3 ± 1.76 μg/ml), except for the extracts of Maesa lanceolata, Elaeodendron croceum and Calpurnia aurea with LC50 values at 2.38 ± 0.25, 5.20 ± 0.24 and 13 ± 2.26 μg/ml respectively. The selectivity index (SI) ranged from 0.02 to 1.66. Hypericum roeperianum had the best selectivity index, (SI = 1.66) and Elaeodendron croceum had lowest value (SI = 0.02).

CONCLUSIONS

The crude acetone extracts of the selected plant species had promising antibacterial activity against Bacillus anthracis. Maesa lanceolata extracts could be useful as a disinfectant and Hypericum roeperianum could be useful to protect animals based on its high total activity and selectivity index. Further investigation of these plant extracts may lead to the development of new therapeutic agents to protect humans or animals against anthrax.

Exploration of Phytochemicals Found in Terminalia sp. and their Antiretroviral Activities

The human immunodeficiency virus (HIV) infects cells of the immune system and destroys their function. Approximately, 2 million people die every year from HIV as reported by the World Health Organization. HIV/AIDS is difficult to treat as the virus continuously develops resistance to drugs being developed. Approach is now turning toward natural products for the development of anti-HIV drugs. Although HIV/AIDS is not a new disease, but research based on plant-derived products is still under clinical trials. Experimentally, it has been proven that plants have the potential for HIV treatment. The process involves identification of the active ingredients responsible for the reported anti-HIV activities, testing of the extract, and development of appropriate bioassays. Further development would require optimization of the formulation and manufacturing in compliance with preclinical safety and efficacy testing. The most challenging task for the natural product scientists is to separate these highly complex extracts containing several compounds into its individual components that are biologically active. Recently developed direct binding assay with mass spectrometry (MS) technology (viz., real-time time-of-flight-MS) is helpful in this respect but needs extensive optimization. At present, we have compiled all the information for the various phytochemicals present in Terminalia catappa having anti-HIV properties. These include tannins, gallotannins, ellagitannins, cyanidin, and flavonoids. Further, we have also discussed their pharmacological as well as pharmacokinetics studies.

Improvement in human immunodeficiency virus-1/acquired immune deficiency syndrome patients’ well-being following administration of “Phyto V7”

AIM: To corroborate the capacity of Phyto V7, a complex of phytochemicals, to improve the physical well-being of human immunodeficiency virus-1 (HIV-1) infected and acquired immune deficiency syndrome (AIDS) patients not undergoing antiretroviral treatment.

METHODS: Two hundred and thirty nine HIV-1 seropositive male and female voluntary inmates were recruited through the Uruguay National Program of AIDS. The study participants received for 90 consecutive days every eight hours two tablets (760 mg/each) of Phyto V7, containing a mix of the following phytochemicals: flavonols (Kaempferol, Quercetin), flavones (Apigenin, Luteolin), hydroxy-cinnamic acids (ferrulic acid), carotenoids (Lutein, Lycopene, Beta carotene) and organosulfur compounds, all from vegetal origin. The participants did not receive any antiretroviral treatment during the study. At days 0, 30, 60 and 90 (± 2 d) the participants were evaluated for body mass index (BMI), tolerance to Phyto V7 and Index of Quality of Life based on the Karfnosky scale. ANOVA, Tukey Post-test, χ² test and Wilcoxon Signed Rank test were used to analyze the effect of treatment.

RESULTS: One hundred and nighty nine study participants finished the study. Already after 30 d of Phyto V7 consumption, the weight, BMI and Karnofsky score statistically significantly improved (P < 0.001), and continued to improve until the end of the study. The mean weight gain per participant during the 90 d was of 1.21 kg (approximately 2% of body weight). The overall increase in the mean Karnofsky score after 90 d was 14.08%. The lower the BMI and Karnofsky score of the participants were at the beginning of the study, the more notorious was the improvement over time. For example, the mean increment of Index of Quality of Life, among the participants with an initial Karnofsky score of 5 or below (n = 33) from day 0 to day 90, was of 35.67% (0.476 ± 0.044 vs 0.645 ± 0.09; P < 0.001). The tolerability to Phyto V7 was very good and no adverse reactions were recorded or reported.

CONCLUSION: Administration of the Phyto V7 can be an important tool to improve the well-being of HIV-1 seropositive individuals and AIDS patients, not undergoing antiretroviral treatment.

Cytotoxic and antimicrobial activities of substituted phenanthrenes from the roots of Combretum adenogonium Steud Ex A. Rich (Combretaceae)

Aim:

The aim of this study was to isolate the bioactive compounds from the roots of Combretum adenogonium and assess for its antibacterial and cytotoxic properties.

Materials and Methods:

The extract was obtained using 20% aqueous ethanol and further subjected to fractionation with 1:1 n-butanol/water. Chromatographic analyses of the n-butanol fraction led to the isolation of compounds (1-3). The compounds (1-3) were assayed for antibacterial activities using two-fold microdilution methods and cytotoxicity using brine shrimps lethality assay.

Results:

Following spectroscopic analyses the compounds were established as 2,3,8-trihydroxy-4,6-dimethoxyphenanthrene (1a) and 2,3,8-trihydroxy-4,6-dimethoxy-9,10-dihydrophenanthrene (1β). Compound 2 was derived from 2,3,8-trihydroxy-4,6-dimethoxyphenanthrene condensation with methyl acetate while Compound 3 was derived from 2,3,8-trihydroxy-4,6-dimethoxy-9,10-dihydrophenanthrene condensation with methyl propionate. These compounds (1-3) were active against Pseudomonas aeruginosa with minimal inhibitory concentration-value of 0.16 mg/ml. The compounds (1-3) also exhibited significant toxicity with LC₅₀ (95% confidence interval [CI]) of 12.11 (7.32-20.05) µg/ml compared to standard anticancer drug, cyclophosphamide which had LC₅₀ (95% CI) value of 16.37 (12.01-22.31) µg/ml.

Conclusion:

These compounds add for a novel structure that can be synthesized, further screened for in vitro and in vivo models and clinical trials in order to evaluate its potential for further development as new anticancer agent.