In Vitro and In Vivo Anticancer Activity of Root Extracts of Sansevieria liberica Gerome and Labroy (Agavaceae)

Genotoxic and antiproliferative properties of Endopleura uchi bark aqueous extract

The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.

Potential of Selected African Medicinal Plants as Alternative Therapeutics against Multi-Drug-Resistant Bacteria

Antimicrobial resistance is considered a "One-Health" problem, impacting humans, animals, and the environment. The problem of the rapid development and spread of bacteria resistant to multiple antibiotics is a rising global health threat affecting both rich and poor nations. Low- and middle-income countries are at highest risk, in part due to the lack of innovative research on the surveillance and discovery of novel therapeutic options. Fast and effective drug discovery is crucial towards combatting antimicrobial resistance and reducing the burden of infectious diseases. African medicinal plants have been used for millennia in folk medicine to cure many diseases and ailments. Over 10% of the Southern African vegetation is applied in traditional medicine, with over 15 species being partially or fully commercialized. These include the genera Euclea, Ficus, Aloe, Lippia. And Artemisia, amongst many others. Bioactive compounds from indigenous medicinal plants, alone or in combination with existing antimicrobials, offer promising solutions towards overcoming multi-drug resistance. Secondary metabolites have different mechanisms and modes of action against bacteria, such as the inhibition and disruption of cell wall synthesis; inhibition of DNA replication and ATP synthesis; inhibition of quorum sensing; inhibition of AHL or oligopeptide signal generation, broadcasting, and reception; inhibition of the formation of biofilm; disruption of pathogenicity activities; and generation of reactive oxygen species. The aim of this review is to highlight some promising traditional medicinal plants found in Africa and provide insights into their secondary metabolites as alternative options in antibiotic therapy against multi-drug-resistant bacteria. Additionally, synergism between plant secondary metabolites and antibiotics has been discussed.

Anti-Inflammatory Potential of Seasonal Sonoran Propolis Extracts and Some of Their Main Constituents

Biological properties of Sonoran propolis (SP) are influenced by harvest time. Caborca propolis showed cellular protective capacity against reactive oxygen species, which might be implicated in anti-inflammatory effects. However, the anti-inflammatory activity of SP has not been investigated so far. This study investigated the anti-inflammatory activity of previously characterized seasonal SP extracts (SPE) and some of their main constituents (SPC). The anti-inflammatory activity of SPE and SPC was evaluated by measuring nitric oxide (NO) production, protein denaturation inhibition, heat-induced hemolysis inhibition, and hypotonicity-induced hemolysis inhibition. SPE from spring, autumn, and winter showed a higher cytotoxic effect on RAW 264.7 cells (IC₅₀: 26.6 to 30.2 µg/mL) compared with summer extract (IC₅₀: 49.4 µg/mL). SPE from spring reduced the NO secretion to basal levels at the lowest concentration tested (5 µg/mL). SPE inhibited the protein denaturation by 79% to 100%, and autumn showed the highest inhibitory activity. SPE stabilized erythrocyte membrane against heat-induced and hypotonicity-induced hemolysis in a concentration-dependent manner. Results indicate that the flavonoids chrysin, galangin, and pinocembrin could contribute to the anti-inflammatory activity of SPE and that the harvest time influences such a property. This study presents evidence of SPE pharmacological potential and some of their constituents.

Toxicological potential of Aloysia gratissima: Insights from chemical analysis and in vitro studies

ETHNOPHARMACOLOGICAL RELEVANCE

Aloysia gratissima leaves are popularly used to treat respiratory, digestive, and nervous system disorders. Several studies have been carried out to determine the biological activity of A. gratissima, such as its antibacterial and anti-edematogenic activities, but despite the beneficial uses of A. gratissima, few studies have examined the toxicological profile of this plant.

AIM OF THE STUDY

This study aimed to determine the chemical composition, cytotoxic, genotoxic, mutagenic potential, and antioxidant activity of an aqueous extract of A. gratissima leaves (AG-AEL).

MATERIAL AND METHODS

The phytochemical constitution of AG-AEL was assessed by colorimetric analyses and High-performance liquid chromatography (HPLC). The inorganic elements were detected by Particle-Induced X-ray Emission (PIXE). The antioxidant, cytotoxicity, genotoxic, and mutagenic activities were evaluated in vitro by Di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH), Sulforhodamine B (SRB) assay, comet assay, and Salmonella/microsome assays.

RESULTS

AG-AEL indicated the presence of terpenoids, flavonoids, and phenolic acids. HPLC detected rutin at 2.41 ± 0.33 mg/100 mg. PIXE analysis indicated the presence of Mg, Si, P, S, K, Ca, Mn, and Zn. The 50% inhibitory concentration was 84.17 ± 3.17 μg/mL in the DPPH assay. Genotoxic effects were observed using the Comet assay in neuroblastoma (SH-SY5Y) cells and mutations were observed in TA102 and TA97a strains. The extract showed cytotoxic activities against ovarian (OVCAR-3), glioblastoma (U87MG), and colon (HT-29) cancer cell lines.

CONCLUSIONS

In conclusion, AG-AEL increased DNA damage, induced frameshift, and oxidative mutations, and showed cytotoxic activities against different cancer cells. The in vitro toxicological effects observed suggest that this plant preparation should be used with caution, despite its pharmacological potential.

In vitro Evaluation of Selective Cytotoxic Activity of Chaerophyllum macropodum Boiss. on Cultured Human SH-SY5Y Neuroblastoma Cells

Neuroblastoma is the most common solid tumor in children. New treatment approaches are needed because of the harmful side effects and costs of the methods used in the treatment of neuroblastoma. Medicinal and aromatic plants are important for new treatment approaches due to their minimal side effects and economic advantages. Therefore, the present study was carried out to examine the cytotoxic effect of Chaerophyllum macropodum extract on human neuroblastoma (SH-SY5Y) and fibroblast (HDFa) cell lines. 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase release (LDH) assays were used to determine the cytotoxic effect of C. macropodum. The extracts were analyzed for their phenolic content by HPLC-PDA. Major components were determined as 63.600% o-coumaric acid, 15.606% catechine hydrate, 8.713% rosmarinic acid, 4.376% clorogenic acid, and 3.972% salicylic acid. The obtained results from cytotoxicity testing revealed that C. macropodum exerted a significant cytotoxic effect on human neuroblastoma cells at all tested concentrations (p < 0.05). But it did not lead to any cytotoxic potential on human fibroblasts. As a result, the obtained data clearly revealed C. macropodum exerted a selective cytotoxic action on neuroblastoma cells for the first time.

Cobalt (III) complex exerts anti-cancer effects on T cell lymphoma through induction of cell cycle arrest and promotion of apoptosis

PURPOSE

Cobalt-based compounds are emerging as a non-platinum-based anti-cancer effective therapeutic agent. However, there is a limited study regarding the therapeutic efficacy of Cobalt-based drugs against Non-Hodgkin's Lymphoma (NHLs) such as T cell lymphoma. Therefore, in the present study we investigated the anti-tumor role of cobalt(III) complex [Co(ptsm)NH₃(o-phen)]·CH₃OH on Dalton's Lymphoma (DL) cells.

MATERIALS AND METHODS

Cytotoxicity of the cobalt complex was estimated by MTT assay. Analysis of mitochondrial membrane potential, cell cycle and Reactive oxygen species (ROS) generation, and Annexin V/PI staining was done by Flow cytometry, while AO/EtBr staining by fluorescence microscopy in cobalt complex treated DL cell. Expression of cell cycle and apoptosis regulatory protein was analyzed by Western blotting. In addition, in vivo study of the cobalt complex was evaluated in well-established DL bearing mice by monitoring physiological parameters and mean survival time.

RESULTS

Our study showed that cobalt complex triggered apoptosis and induced cell cycle arrest in DL cells. Furthermore, this also decreased mitochondrial membrane potential and increased intracellular ROS generation in cancer cells. In addition, changed expression of cell cycle and apoptosis regulatory protein was found with enhanced activity of caspase-3 and 9 in the treated cells. Additionally, administration of cobalt complex showed a significant increase in the survivability of tumor-bearing host, which was accomplished by decreasing physiological parameters.

CONCLUSION

Taken together, these data revealed anti-tumor potential of cobalt complex against DL cells through cell cycle arrest and mitochondrial-dependent apoptosis. Henceforth, cobalt-based drugs could be a new generation therapeutic drug to treat hematological malignancies.

Anti-Cancerous Potential of Polysaccharides Derived from Wheat Cell Culture

There is a global need to discover effective anti-cancerous compounds from natural sources. Cultivated wheat cells can be a valuable source of non-toxic or low toxic plant-derived polysaccharides. In this study, we evaluated the anti-cancer ability of seven fractions of wheat cell culture polysaccharides (WCCPSs) in the HCT-116 colon cancer cell line. Almost all (6/7) fractions had an inhibitory effect on the proliferation of colon cancer cells, and two fractions (A-b and A-f) had considerable therapeutic indexes. The WCCPS fractions induced cell cycle arrest in the G1 phase and induced different rates of apoptosis (≤48%). Transmission and scanning electron microscopy revealed that WCCPS fractions caused apoptotic changes in the nucleus and cytoplasm, including damage to mitochondria and external morphological signs of apoptosis. In addition, the WCCPSs induced an increase in the levels of Bax, cytochrome c, and caspases 8 and 3, indicating that cell death progressed through intrinsic and extrinsic pathways of apoptosis. Furthermore, some fractions caused a significant decrease of c-Myc, b-catenin, NFkB2, and HCAM (CD 44) levels, indicating enhanced cell differentiation. Thus, for the first time, our results provide a proof of concept of the anti-cancer capacity of WCCPS fractions in colorectal cancer.

Immunomodulatory peptides-A promising source for novel functional food production and drug discovery

Immunomodulatory peptides are a complex class of bioactive peptides that encompasses substances with different mechanisms of action. Immunomodulatory peptides could also be used in vaccines as adjuvants which would be extremely desirable, especially in response to pandemics. Thus, immunomodulatory peptides in food of plant origin could be regarded both as valuable suplements of novel functional food preparation and/or as precursors or possible active ingredients for drugs design for treatment variety of conditions arising from impaired function of immune system. Given variety of mechanisms, different tests are required to assess effects of immunomodulatory peptides. Some of those effects show good correlation with in vivo results but others, less so. Certain plant peptides, such as defensins, show both immunomodulatory and antimicrobial effect, which makes them interesting candidates for preparation of functional food and feed, as well as templates for design of synthetic peptides.

Antimalarial, Antioxidant Activities and Chemoprofile of Sansevieria liberica Gerome and Labroy (Agavaceae) Leaf Extract

Background

Sansevieria liberica Gerome and Labroy (Agavaceae) is a religious and ornamental perennial plant with highly valued medicinal usage in Nigeria. Sansevieria liberica is used in the management of malarial fever. The ease of development of resistance to available antimalarial drugs has resulted in increased clinical failure and mortality. The study investigated the antimalarial effects of Sansevieria liberica (SL) leaf extract in mice infected with Plasmodium berghei.

Materials and Methods

The ability of SL leaf extract to suppress the growth of malaria parasites in early (suppressive) and established (curative) infections was established using animal models. The mean survival time (MST) was determined. The antioxidant potential was established using two standard in vitro models. High-performance liquid chromatography (HPLC) and phytochemical analysis methods were used to create a chemoprofile fingerprint of SL hydroethanolic leaf extract.

Results

At 200, 400, and 400·mg kg⁻¹, SL produced 68.71, 70.74, and 75.09% parasite suppression in the suppressive model while the curative model gave a percentage of cure of 71.09, 72.60, and 62.09, respectively. The animals lived longer compared to both negative and positive controls but were not fully protected. The IC₅₀ values of SL and vitamin C were calculated to be 3.599 µg mL⁻¹ and 3.08 µg mL⁻¹, respectively. The reducing power of vitamin C was significantly (P < 0.05) higher than that of SL extract. Some flavonoids were established as possible marker compounds for SL leaf extract. Discussion and Conclusions. The antimalarial assay results demonstrated that the use of SL in folk medicine may have scientific support.

Isolation, identification, and cytotoxicity evaluation of phytochemicals from chloroform extract of Spathodea campanulata

Background

Spathodea campanulata P. Beauv. known as the African tulip tree has potential medicinal properties that have been shown traditionally for the treatment of various ailments. The aim of the present study was isolation, identification, and evaluation of the cytotoxic activity of phytochemicals from the chloroform extract of S. campanulata.

Result

Three compounds were isolated by using column chromatography and preparative TLC from chloroform extract of leaves of S. campanulata. The structures of the isolated compounds were elucidated by using spectroscopic methods, including, FTIR, ESI-TOF MS, 1H NMR, and 13C NMR spectroscopy. In vitro cytotoxic activity of compounds was evaluated by using SRB assay against human leukemia cancer cell lines (HL-60). Results were expressed in IC50 values. Stigmasta-5,22-dien-3-ol, octadecenamide, and umbelliferone were isolated and identified from chloroform extract. The isolated compounds showed cytotoxicity with decreasing cell viability in a dose-dependent manner, but it was found low as compared to positive control, i.e., Adriamycin against HL-60 cell lines.

Conclusion

The results indicate that isolated compounds, i.e., stigmasta-5,22-dien-3-ol (44.12μg/ml), octadecenamide (35.65μg/ml), and umbelliferone (80.60μg/ml) showed antiproliferative activity, but it was low compared to positive control Adriamycin (10.09 μg/ml). Also, according to our knowledge, this study is the first report on the isolation and identification of octadecenamide and umbelliferone from the leaves of S. campanulata.

Graphical abstract

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

In vivo Pharmacokinetic and Anticancer Studies of HH-N25, a Selective Inhibitor of Topoisomerase I, and Hormonal Signaling for Treating Breast Cancer

PURPOSE

Breast cancer is the most frequently diagnosed cancer globally, and the leading cause of cancer-associated mortality among women. The efficacy of most clinical chemotherapies is often limited by poor pharmacokinetics and the development of drug resistance by tumors. In a continuing effort to explore small molecules as alternative therapies, we herein evaluated the therapeutic potential of HH-N25, a novel nitrogen-substituted anthra[1,2-c][1,2,5]thiadiazole-6,11-dione derivative.

METHODS

We evaluated the in vivo pharmacokinetic properties and maximum tolerated dose (MTD) of HH-N25 in rats. We also characterized the compound for in vitro and in vivo anticancer activities and its inhibitory effects against DNA topoisomerases and hormonal signaling in breast cancer. Furthermore, we used molecular docking to analyse the ligand-receptor interactions between the compound and the targets.

RESULTS

The maximum serum concentration (Cmax), half-life (t1/2 beta), mean residence time (MRT), oral clearance (CL/f), and apparent volume of distribution (VD/f) of HH-N25 were 1446.67 ± 312.05 ng/mL, 4.51 ± 0.27 h, 2.56 ± 0.16 h, 8.32 ± 1.45 mL/kg/h, and 1.26 ± 0.15 mL/kg, respectively, after single-dose iv administration at 3 mg/kg body weight. HH-N25 had potent anticancer activity against a panel of human breast cancer cell lines with 50% inhibitory concentrations (IC50) ranging 0.045±0.01~4.21±0.05 µM. The drug also demonstrated marked in vivo anticancer activity at a tolerated dose and prolonged the survival duration of mice without unacceptable toxicities based on body weight changes in human tumor xenograft models. In addition, HH-N25 exhibited a dose-dependent inhibition of topoisomerase I and ligand-mediated activities of progesterone and androgen receptors.

CONCLUSION

HH-N25 represents a new molecular entity that selective suppressed TOP1 and hormonal signaling, and shows potent antitumor activities in human breast cancer cells in vitro and in vivo. HH-N25 thus represents a promising anticancer agent that warrants further preclinical and clinical exploration.

Ganoderma applanatum mushroom provides new insights into the management of diabetes mellitus, hyperlipidemia, and hepatic degeneration: A comprehensive analysis

This study was undertaken to evaluate the antidiabetic, hypolipidemic, and hepatoprotective effects of methanol and aqueous extracts of Ganoderma applanatum (MEGA, AEGA) in alloxan-induced diabetic rats. The antidiabetic study was implemented by the induction of alloxan to the rats. The analysis of the hypolipidemic and liver-protective effects of fungus extracts was studied by estimating the lipid profile and the liver marker enzymes. Besides, in silico screening of the compounds of Ganoderma applanatum has been incorporated thus to check the binding affinity of compounds and enzymes affinity. The Discovery Studio 2020, UCSF Chimera, and PyRx AutoDock Vina have been used to implement the docking analysis. Nine days of oral feeding of MEGA and AEGA of Ganoderma applanatum resulted in a significant (p < .001) reduction in blood glucose, lipid profile, and liver marker enzymes. Besides, Myrocin C scored the highest score in the docking study. The biological and computational approaches suggested the MEGA and AEGA could be a potential source for antidiabetic, hypolipidemic, and hepatoprotective effects.

In-vitro Anti-proliferative Effects of Ethanolic Extract of Vanilla Planifolia Leaf Extract against A431 Human Epidermoid Carcinoma Cells

Squamous cell carcinoma is the second largest among skin cancer diseases. The aim of the present study is to reveal the antiproliferative property of vanilla leaf extract against A431 cells. Antiproliferative property was assessed by MTT assay. Apoptotic property was assessed by DNA fragmentation assay. Antiproliferative property of extract was revealed in a dose dependent manner. IC50 of the extract against A431 cells was revealed at 31.2µg/ml. This study revealed the cancer suppression capability of vanilla leaf extract in skin cancer cell lines.

Efficacy of Aloe vera, Ananas comosus, and Sansevieria masoniana Cream on the Skin Wound Infected with MRSA

The tropical area has a lot of herbal medicines such as Aloe vera (AV), Ananas comosus (AC), and Sansevieria masoniana (SM). All the three have a unique potential effect as an antibacterial and wound-healing promoter. The aim of this study is to explore the role of AV, AC, and SM on the skin wound infected with methicillin-resistant Staphylococcus aureus (MRSA). Forty-five adult female Sprague Dawley rats weighing 250–300 grams were divided into 5 groups. All the groups were exposed to two round full-thickness punch biopsy and infected with MRSA. The group C was the control group/untreated; group BC was treated with base cream/without extract; group AV was treated with 75% AV cream; group AC was treated with 75% AC cream, and group SM was treated with 75% SM cream. The wounds were observed on days 5, 10, and 15. The healing of skin wounds was measured by a percentage of closure, skin tensile strength, and histopathology. The result showed that AV, AC, and SM have a similar potential effect on healing in the wound that was infected with MRSA compared to the groups C and BC (P < 0.05). It shows that all the three herbal formulations can be used as the alternative therapy to the wound infected with MRSA.

Process optimization and photostability of silymarin nanostructured lipid carriers: effect on UV-irradiated rat skin and SK-MEL 2 cell line

The objective of the present work was to formulate a novel stable delivery system which would not only overcome the solubility issue of silymarin, but also help to increase the therapeutic value by better permeation, anticancer action and reduced toxicity. This was envisaged through the recent developments in nanotechnology, combined with the activity of the phytoconstituent silymarin. A 2(3) full factorial design based on three independent variables was used for process optimization of nanostructured lipid carriers (NLC). Developed formulations were evaluated on the basis of particle size, morphology, in vitro drug release, photostability and cell line studies. Optimized silymarin-NLC was incorporated into carbopol gel and further assessed for rheological parameters. Stable behaviour in presence of light was proven by photostability testing of formulation. Permeability parameters were significantly higher in NLC as compared to marketed phytosome formulation. The NLC based gel described in this study showed faster onset, and prolonged activity up to 24 h and better action against edema as compared to marketed formulation. In case of anticancer activity of silymarin-NLC against SK-MEL 2 cell lines, silymarin-NLC proved to possess anticancer activity in a dose-dependent manner (10-80 μM) and induced apoptosis at 80 μM in SK-MEL 2 cancer cells. This work documents for the first time that silymarin can be formulated into nanostructured lipoidal carrier system for enhanced permeation, greater stability as well as anticancer activity for skin.

Biological activities and chemical compositions of slime tracks and crude exopolysaccharides isolated from plasmodia of Physarum polycephalum and Physarella oblonga

BACKGROUND

The myxomycetes derive their common name (slime molds) from the multinucleate trophic stage (plasmodium) in the life cycle, which typically produces a noticeable amount of slimy materials, some of which is normally left behind as a "slime track" as the plasmodium migrates over the surface of a particular substrate. The study reported herein apparently represents the first attempt to investigate the chemical composition and biological activities of slime tracks and the exopolysaccharides (EPS) which cover the surface of the plasmodia of Physarum polycephalum and Physarella oblonga.

RESULTS

Chemical analyses indicated that the slime tracks and samples of the EPS consist largely of carbohydrates, proteins and various sulphate groups. Galactose, glucose and rhamnose are the monomers of the cabohydrates present. The slime tracks of both species and the EPS of Phy. oblonga contained rhamnose, but the EPS of Ph. polycephalum had glucose as the major monomer. In term of biological activities, the slime tracks displayed no antimicrobial activity, low anticancer activity and only moderate antioxidant activity. However, EPSs from both species showed remarkable antimicrobial activities, especially toward Candida albicans (zone of inhibition ≥20 mm). Minimum inhibitory concentrations of this fungus were found to be 2560 μg/mL and 1280 μg/mL for EPS from Phy. oblonga and Ph. polycephalum, respectively. These EPS samples also showed moderate antioxidant activities. However, they both displayed cytotoxicity towards MCF-7 and HepG2 cancer cells. Notably, EPS isolated from the plasmodium of Phy. oblonga inhibited the cell growth of MCF-7 and HepG2 at the half inhibitory concentration (IC50) of 1.22 and 1.11 mg/mL, respectively.

CONCLUSIONS

EPS from Ph. polycephalum plasmodium could be a potential source of antifungal compounds, and EPS from Phy. oblonga could be a potential source of anticancer compounds.

RANDOMIZED ANTICANCER AND CYTOTOXICITY ACTIVITIES OF GUIBOURTIA COLEOSPERMA AND DIOSPYROS CHAMAETHAMNUS

BACKGROUND

Plants have consistently proven to be a reliable and yet not fully explored source of medicines. In light of this, there is a constant demand for new treatment regimens for cancer. Namibia has a rich diversity of plant species of over 4300 with 17 % of them being endemic to Namibia. Plants growing in Namibia's diverse climatic zones produce many secondary metabolites as part of adaptation to their environment. This article focused on the screening of such phytochemicals and their cytotoxic and anticancer properties in vitro. Two Namibian plants Diospyros chamaethamnus and Guibourtia coleosperma were randomly selected for this purpose.

MATERIALS AND METHODS

The plants were screened for the presence of coumarins, alkaloids, flavonoids, anthraquinones, steroids and terpenoids using thin layer chromatography. Anticancer screening was performed on a panel of three cancer cell lines, while cytotoxicity was determined using a human fibroblast cell line, both using the SRB method.

RESULTS

Alkaloids, anthraquinones, flavonoids and steroids were detected in both organic and aqueous extracts of the two plants. The organic plant extracts had a greater anti-proliferative effect on the cancer cell lines than the aqueous extracts; the D. chamaethamnus organic root extract was the most potent with an IC₅₀ of 16.08, 29.12 and 24.67 µg/mL against TK10, UACC62 and MCF7 cells, respectively. Furthermore, cytotoxicity analysis revealed the non-toxic nature of the extracts, except for the organic root extract of D. chamaethamnus that showed significant cytotoxicity (IC₅₀ 13.03 µg/mL).

CONCLUSION

D. chamaethamnus is a potential candidate for the development of a plant based cancer treatment. The study showed the value of random screening in drug discovery from plants for pharmacological activity that is unrelated to their ethnomedicinal uses.

Lead Phytochemicals for Anticancer Drug Development

Cancer is a serious concern at present. A large number of patients die each year due to cancer illnesses in spite of several interventions available. Development of an effective and side effects lacking anticancer therapy is the trending research direction in healthcare pharmacy. Chemical entities present in plants proved to be very potential in this regard. Bioactive phytochemicals are preferential as they pretend differentially on cancer cells only, without altering normal cells. Carcinogenesis is a complex process and includes multiple signaling events. Phytochemicals are pleiotropic in their function and target these events in multiple manners; hence they are most suitable candidate for anticancer drug development. Efforts are in progress to develop lead candidates from phytochemicals those can block or retard the growth of cancer without any side effect. Several phytochemicals manifest anticancer function in vitro and in vivo. This article deals with these lead phytomolecules with their action mechanisms on nuclear and cellular factors involved in carcinogenesis. Additionally, druggability parameters and clinical development of anticancer phytomolecules have also been discussed.