Effects of Selected Nigerian Medicinal Plants on the Viability, Mobility, and Multidrug-Resistant Mechanisms in Liver, Colon, and Skin Cancer Cell Lines

Isolation, cytotoxicity evaluation, and molecular docking of 3,4,3'-tri-O-methylflavellagic acid from Anogeissus leiocarpus (DC.) Guill. & Perr. root

Cancer kills about 10 million people every year. Medicinal plants remain a major source in the global search for anticancer drugs. In this study, 3,4,3'-tri-O-methylflavellagic acid (MFA) was isolated from the methanol root extract of Anogeissus leiocarpus. The structure was determined by 1D- and 2D-NMR data. The cytotoxic effects of MFA were evaluated against human breast (MCF-7), colorectal (Caco-2), and cervical (HeLa) cancer cell lines using the 3-[4,5-dimethylthiazole-2-yl] 3,5-diphenyltetrazolium bromide assay. A multi-protein target screening via molecular docking was conducted against ten cancer-related proteins, and ADMET properties were evaluated. MFA exhibited the most potent activity against Caco-2 (IC50: 46.75 ± 13.00 µM). Molecular docking analysis showed that MFA had a strong binding affinity for the colchicine-binding site of αβ-tubulin and polo-like kinase-1 (binding energies: -8.5 and -8.4 kcal/mol, respectively). MFA also satisfied the Lipinski's Rule of Five. MFA could, therefore, potentially serve as a scaffold for developing new anticancer molecules.

Antibacterial Properties of Phytochemicals Isolated from Leaves of Alstonia boonei and Aerial Parts of Ipomoea cairica

Objective

The leaves of Alstonia boonei and aerial parts of Ipomoea cairica are used for treatment of microbial infections among other ailments in African traditional medicine. The aim of this study was to investigate the antimicrobial phytochemicals in A. boonei leaves and Ipomoea cairica aerial parts to validate their traditional use in Ugandan herbal medicine.

Methods

The plant materials were separately extracted using a dichloromethane/methanol (1:1) solvent system and subjected to repeated chromatographic separation to isolate pure compounds. The chemical structures of the isolated compounds were determined through 1H NMR, 13C NMR and 2D NMR (COSY, HSQC and HMBC). The antibacterial activity of the extracts and pure compounds were assessed using the agar well diffusion method.

Results

Chromatographic fractionation of the extracts yielded trans-fagaramide and a pentacyclic lupane-type triterpenoid, lupeol, from A. boonei, and friedelin from I. cairica. Trans-fagaramide was identified for the first time in the Alstonia genus while friedelin was identified for the first time in I. cairica. The isolated compounds demonstrated antibacterial activity, with trans-fagaramide showing a minimum inhibitory concentration (MIC) of 125 μg/mL against Pseudomonas aeruginosa and 250 μg/mL against Staphylococcus aureus, Salmonella typhi and Escherichia coli. Friedelin exhibited a MIC of 125 μg/mL against Escherichia coli and 250 μg/mL against Pseudomonas aeruginosa, Staphylococcus aureus and Salmonella typhi.

Conclusion

The antibacterial activities observed in this study support the traditional use of A. boonei and I. cairica by indigenous communities in Uganda for treating microbial infections.

Anogeissus leiocarpus (DC.) Guill. & Perr. (Combretaceae): A review of the traditional uses, phytochemistry and pharmacology of African birch

Anogeissus leiocarpus (DC.) Guill. & Perr. belongs to the family Combretaceae and is used both by African traditional medical practitioners and livestock rearers to treat diseases such as African trypanosomiasis, animal diarrhoea, asthma, cancer, cough, diabetes, dysentery, erectile dysfunction, fever, giardiasis, helminthiases, meningitis, menstrual disorders, monkeypox, oral infections, poliomyelitis, sickle cell anaemia, snake bites, toothache, urinary schistosomiasis, and yellow fever. Some of these activities have been associated with the presence of polyphenols in the plant which include ellagic acid derivatives, flavonoids, stilbenes, tannins, and triterpenes. Several bioactive molecules have been identified from A. leiocarpus. These include the main active constituents, ellagitannins, ellagic acid derivates, flavonoids and triterpenes. Pharmacological studies have confirmed its antibacterial, antifungal, antihyperglycemic, antihypertensive, antimalarial, antioxidative, antiparasitic, antitumour and anti-ulcer effects. The stem bark has been investigated mainly for biological activities and phytochemistry, and it is the most mentioned plant part highlighted by the traditional users in ethnomedicinal surveys. In vitro and in vivo models, which revealed a wide range of pharmacological actions against parasites causing helminthiasis, leishmaniasis, malaria and trypanosomiasis, have been used to study compounds from A. leiocarpus. Because of its uses in African traditional medicine and veterinary practices, A. leiocarpus has received considerable attention from researchers. The current review provides a comprehensive overview and critical appraisal of scientific reports on A. leiocarpus, covering its traditional uses, pharmacological activities and phytochemistry.

The Composition and Biochemical Properties of Strophantus (Apocynaceae), with a Focus on S. sarmentosus

The genus Strophantus belongs to the Apocynaceae family of flowering plants which grows primarily in tropical Africa. The plants are widely used in traditional herbal medicine. S. sarmentosus, in particular, is used for the treatment of, e.g., joint pain and rheumatoid arthritis, wound infections, head lice, diarrhea, snake bite, and eye conditions. Despite its widespread use, dedicated research characterizing its bioactive plant components is scarce. Investigations have focused mainly on its cardenolides because of their cardioactivity and historical use as cardiotonic. There are also studies concerning the antibacterial, antioxidant, and anti-inflammatory activity of plant extracts. This review summarizes the present knowledge surrounding the biochemical and analytical research on Strophantus, in general, and S. sarmentosus, in particular, and describes the current state of the field based on the available scientific literature.

In vitro activities and mechanisms of action of anti-cancer molecules from African medicinal plants: a systematic review

Cancer is one of the leading causes of death worldwide. In recent years, African countries have been faced with a rapid increase in morbidity and mortality due to this pathology. Management is often complicated by the high treatment costs, side effects and the increasing occurrence of resistance to treatments. The identification of new active ingredients extracted from endemic medicinal plants is definitively an interesting approach for the implementation of new therapeutic strategies: their extraction is often lower cost; their identification is based on an ethnobotanical history and a tradipratic approach; their use by low-income populations is simpler; this can help in the development of new synthetic molecules that are more active, more effective and with fewer side effects. The objective of this review is to document the molecules derived from African medicinal plants whose in vitro anti-cancer activities and the mechanisms of molecular actions have been identified. From the scientific databases Science Direct, PubMed and Google Scholar, we searched for publications on compounds isolated from African medicinal plants and having activity on cancer cells in culture. The data were analyzed in particular with regard to the cytotoxicity of the compounds and their mode of action. A total of 90 compounds of these African medicinal plants were selected. They come from nine chemical groups: alkaloids, flavonoids, polyphenols, quinones, saponins, steroids, terpenoids, xanthones and organic sulfides. These compounds have been associated with several cellular effects: i) Cytotoxicity, including caspase activation, alteration of mitochondrial membrane potential, and/or induction of reactive oxygen species (ROS); ii) Anti-angiogenesis; iii) Anti-metastatic properties. This review points out that the cited African plants are rich in active ingredients with anticancer properties. It also stresses that screening of these anti-tumor active ingredients should be continued at the continental scale. Altogether, this work provides a rational basis for the selection of phytochemical compounds for use in clinical trials.

Plumbagin has an inhibitory effect on the growth of TSCC PDX model and it enhances the anticancer efficacy of cisplatin

BACKGROUND

Head and neck squamous cell carcinomas are the sixth most common malignant tumors worldwide. Tongue squamous cell carcinoma is a common malignant tumor of this type, and it is associated with poor prognosis, a high rate of recurrence and a low survival rate. Plumbagin is derived from Plumbago zeylanica L, several studies report that plumbagin could inhibit cell, tumor metastasis, induce apoptosis in various cancer cells. Patient-derived xenograft (PDX) model can maintain the heterogeneity and microenvironment of human tumors, is a powerful research tool for developing potentially effective therapies for TSCC.

METHODS

Tumor tissues obtained from TSCC patients were implanted into immunodeficient mice to establish TSCC PDX models. Subsequently, the PDX models were used to evaluate the anti-tumor effects of plumbagin on TSCC. Furthermore, we conducted next-generation sequencing (NGS) and explored the mRNA expression profiles between the treatment and control groups. We selected eight mRNAs related to the characteristics and prognosis of TSCC patients for further analysis.

RESULTS

Plumbagin could inhibit the growth of TSCC PDX models and inhibit expression of Akt/mTOR pathway. In addition, plumbagin was shown to increase drug sensitivity to cisplatin. The eight mRNAs selected for further analysis, AXL, SCG5, VOPP1, DCBLD2 and DRAM1 are cancer-promoting genes, DUSP1, AQP5 and BLNK are cancer suppressor genes. And they were related to the diagnosis, growth, prognosis, and immune cell infiltration in TSCC patients.

CONCLUSION

Plumbagin exhibits an inhibitory effect on the growth of the PDX model of TSCC. Moreover, plumbagin enhances the inhibitory effects of cisplatin.

In Vitro Anticancer and Antibacterial Activities of the Essential Oil of Forsskal’s Basil Growing in Extreme Environmental Conditions

Many species belonging to the genus Ocimum are used for aromatic, medicinal, and cosmetic purposes. The essential oil (OFEO) obtained by hydrodistillation of the flowering aerial parts of Forsskal’s Basil “Ocimum forskolei Benth” growing in extreme environmental conditions in Mecca Region, Saudi Arabia was analyzed by GC-MS. The main constituents were phenylpropanoids (methyl eugenol 55.65% and eugenol 11.66%), monoterpene (linalool 9.75%), and sesquiterpenes (germacrene D 3.72% and β-caryophyllene 2.57%). The OFEO was tested against MCF7, HT29, and HCT116 cancer cells and compared with normal fibroblast cells (MRC5). The MTT assay showed that HCT116 was more sensitive to OFEO (IC50 5.34 μg/mL), which reduced the number of HCT116 colonies at 6 μg/mL, while causing complete colony death at 12 and 24 μg/mL. Western Blotting and qRT-PCR were used to evaluate the level change of different proteins with respect to GAPDH. OFEO upregulated the apoptotic protein (caspase 3), and downregulated the cell proliferation proteins (AKT and pAKT), cell cycle arrest (PCNA, Cyclin D1), and the anti-apoptotic Bcl2 proteins. OFEO was also tested against reference strains of Gram-negative and Gram-positive bacteria including Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, and Staphylococcus aureus by using the well-diffusion and assessing their MICs, which ranged from 250 to 500 μg/mL.

Natural Inhibitors of P-glycoprotein in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) remains an insidious neoplasm due to the percentage of patients who develop resistance to both classic chemotherapy and emerging drugs. Multidrug resistance (MDR) is a complex process determined by multiple mechanisms, and it is often caused by the overexpression of efflux pumps, the most important of which is P-glycoprotein (P-gp). This mini-review aims to examine the advantages of using natural substances as P-gp inhibitors, focusing on four molecules: phytol, curcumin, lupeol, and heptacosane, and their mechanism of action in AML.

Anticancer of genus Syzygium: a systematic review

Aim

One in eight fatalities globally are considered cancer-related. The need for cancer therapy is growing. Natural products continue to play a role in drug development, as up to 50% of authorized drugs in the last 30 years have been isolated from natural sources.

Methods

Anticancer, antioxidant, antibacterial, antifungal, antiviral, analgesic, anti-inflammatory, and other actions have all been reported in research papers using plants from the Syzygium genus in the treatment and prevention of disease.

Results

Results from the anticancer test showed that the genus, especially Syzygium aqueum, Syzygium samarangense, and Syzygium cumini had significant promise as an anticancer agent in vitro against several cancer cell lines. Numerous factors, including phytochemical composition, increased apoptotic activity, decreased cell proliferation, stopped angiogenesis, and reduced inflammation.

Conclusions

These results, despite preliminary, show promise for further purification and investigation of bioactive compounds and extracts within the genus Syzygium for their anticancer properties.

Tapinanthus species: A review of botany and biology, secondary metabolites, ethnomedical uses, current pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Tapinanthus species are hemiparasites that grow on diverse hosts in African regions. Tapinanthus species are locally known as "all purpose herbs" as they are traditionally used to treat various diseases such as diabetes, hypertension, cancer, inflammation, malaria, anemia, anxiety, itching, and so on.

AIM OF THE STUDY

A comprehensive review on research outcomes and future perspectives of Tapinanthus species are presented to provide a reference for relevant researchers.

MATERIALS AND METHODS

The references regarding Tapinanthus species were retrieved from Google Scholar, Web of Science, Sci-finder, PubMed, Elsevier, Wiley, China National Knowledge Infrastructure, Open Access Library, and SpringerLink between 1963 and 2022. Scientific plant names were provided by "The Plant List" (www.theplantlist.org) and "The world Flora Online" (www.worldfloraonline.org).

RESULTS

Even though Tapinanthus species are regarded as notorious pests that can undermine various hosts, they are, as omnipotent herbs in folklore, meaningful for the development of potential phytomedicine sources. Phytochemistry screening has revealed the presence of glycosides, triterpenoids, flavonoids, alkaloids, tannins, steroids, anthraquinones. Among them, the chemical structures of 40 compounds have been elucidated by phytochemical methods without alkaloids and anthraquinones. These secondary metabolites might be responsible for ethnomedical uses and bioactivities of Tapinanthus species. Current research has provided scientific evidence for traditional uses of Tapinanthus species, especially unraveling hypoglycemic, hepatoprotective, antioxidant, antibacterial, anti-anxiety, anti-depression, anti-inflammatory, and other pharmacological properties. Given the fact that ethnomedical uses served as a valuable reference for pharmacology, however, some records to treat arthritis, fever, itching, dysentery, stomach pain, and anemia, have not been confirmed in current research. Furthermore, the toxic effects of Tapinanthus species were susceptible to the dosages, with relative safety across a wide range.

CONCLUSIONS

To reasonably yield Tapinanthus species, artificial culture might be a promising method to develop in the future. The discrepancies between phytochemistry screening and structure elucidation, as well as between ethnomedical uses and current pharmacology, need to be further clarified. The identification of bioactive compounds in crude extracts and fractions, the illustration of the underlying mechanisms of pharmacology, along with the addition of cytotoxicity, genotoxicity, and clinical trials of toxic tests, should be carried out in depth. This review highlights that Tapinanthus species can be considered promising phytomedicine sources as long as we adhere to digging more deeply into their potential role.

Portuguese Propolis Antitumoral Activity in Melanoma Involves ROS Production and Induction of Apoptosis

Melanoma is the most aggressive and life-threatening skin cancer type. The melanoma genome is the most frequently mutated, with the BRAF mutation present in 40–60% of melanoma cases. BRAF-mutated melanomas are characterized by a higher aggressiveness and progression. Adjuvant targeted treatments, such as BRAF and MEK inhibitors, are added to surgical excision in BRAF-mutated metastatic melanomas to maximize treatment effectiveness. However, resistance remains the major therapeutic problem. Interest in natural products, like propolis, for therapeutic applications, has increased in the last years. Propolis healing proprieties offer great potential for the development of novel cancer drugs. As the activity of Portuguese propolis has never been studied in melanoma, we evaluated the antitumoral activity of propolis from Gerês (G18.EE) and its fractions (n-hexane, ethyl acetate (EtOAc), and n-butanol) in A375 and WM9 melanoma cell lines. Results from DPPH•/ABTS• radical scavenging assays indicated that the samples had relevant antioxidant activity, however, this was not confirmed in the cell models. G18.EE and its fractions decreased cell viability (SRB assay) and promoted ROS production (DHE/Mitotracker probes by flow cytometry), leading to activation of apoptotic signaling (expression of apoptosis markers). Our results suggest that the n-BuOH fraction has the potential to be explored in the pharmacological therapy of melanoma.

Skin cancer biology and barriers to treatment: Recent applications of polymeric micro/nanostructures

Background

Skin cancer has been the leading type of cancer worldwide. Melanoma and non-melanoma skin cancers are now the most common types of skin cancer that have been reached to epidemic proportion. Based on the rapid prevalence of skin cancers, and lack of efficient drug delivery systems, it is essential to surge the possible ways to prevent or cure the disease.

Aim of review

Although surgical modalities and therapies have been made great progress in recent years, however, there is still an urgent need to alleviate its increased burden. Hence, understanding the precise pathophysiological signaling mechanisms and all other factors of such skin insults will be beneficial for the development of more efficient therapies.

Key scientific concepts of review

In this review, we explained new understandings about onset and development of skin cancer and described its management via polymeric micro/nano carriers-based therapies, highlighting the current key bottlenecks and future prospective in this field. In therapeutic drug/gene delivery approaches, polymeric carriers-based system is the most promising strategy. This review discusses that how polymers have successfully been exploited for development of micro/nanosized systems for efficient delivery of anticancer genes and drugs overcoming all the barriers and limitations associated with available conventional therapies. In addition to drug/gene delivery, intelligent polymeric nanocarriers platforms have also been established for combination anticancer therapies including photodynamic and photothermal, and for theranostic applications. This portfolio of latest approaches could promote the blooming growth of research and their clinical availability.

Evaluation of Antimalarial Potential of Extracts from Alstonia boonei and Carica papaya in Plasmodium berghei-Infected Mice

Extracts of Alstonia boonei and Carica papaya are used in herbal medicine for the treatment of malaria. This work investigated the phytochemical, antioxidant, and antimalarial effects of hydromethanolic extracts of Alstonia boonei and Carica papaya. A four-day chemosuppressive test was conducted to assess the ability of the extracts to prevent establishment of infection. Three doses of the extracts were administered—100, 200, and 400 mg/kg bw—prior to Plasmodium berghei challenge. Change in body weight, parasitemia, packed cell volume (PCV), and mean survival time was determined. A three-day curative test was also carried out on Plasmodium berghei-infected mice to determine the effects of the plant extracts (200 mg/kg bw) on parasitemia and biochemical indices of liver and kidney functions, lipid metabolism, and oxidative stress. The study revealed that the extracts possessed phenolic compounds (34.13 ± 1.90 mg GAE/g for Alstonia boonei and 27.99 ± 1.46 mg GAE/g for Carica papaya) and flavonoids (19.47 ± 1.89 mg QE/g for Alstonia boonei and 18.24 ± 1.36 mg QE/g for Carica papaya). In vitro antioxidant activity measured as total antioxidant power, total reducing power, and DPPH radical scavenging activity showed that the extracts possessed higher antioxidant activity than the reference compounds. The outcome of the chemosuppressive test revealed that whereas Plasmodium berghei-infected mice had high parasitemia, decreased mean survival time, exhibited loss of weight, and had low PCV, treatment with the extracts reversed the effects in a concentration-dependent manner. Similarly, the curative test revealed that the extracts significantly suppressed parasitemia compared with the malaria negative control group. This was mirrored by reversal of indices of hepatic toxicity (AST, ALT, and ALP levels), nephropathy (urea and creatinine levels), oxidative stress (SOD, CAT, GPx, GSH, and lipid peroxides), and dyslipidemia (TC, HDL, and TG levels and HMG-CoA reductase activity) in infected but treated mice compared with negative control. Put together, the results of this study demonstrate that the extracts of Alstonia boonei and Carica papaya possess antimalarial properties and are able to ameliorate metabolic dysregulations that characterize Plasmodium berghei infection. The phytoconstituents in these extracts are believed to be responsible for the pharmacological activity reported in this study.