New biflavonoids isolated from Xylia kerrii leaves extract with selective cytotoxicity against MH7A human rheumatoid arthritis synovial fibroblast cells.

Three new biflavonoids (1-3) and two known flavonoids (4, 5) were isolated from Xylia kerrii collected in Thailand. Compounds 1-5 showed selective cytotoxicity against the rheumatoid fibroblast-like synovial MH7A cell line, and these compounds showed weak cytotoxicity against the human lung synovial fibroblast WI-38 VA13 sub 2 RA cell line. Notably, compound 1 was highly selective toward MH7A cells with an IC50 value of 6.9 µM, whereas the IC50 value for WI-38 VA13 sub 2 RA cells was > 100 µM. The western blotting analysis of MH7A cells treated with compound 1 showed increased CDKN2A /p16INK4A and caspase-8 levels.

Identifying the temporal contributors and their interactions during dynamic formation of black tea cream.

Tea cream formed in hot and strong tea infusion while cooling deteriorates quality and health benefits of tea. However, the interactions among temporal contributors during dynamic formation of tea cream are still elusive. Here, by deletional recombination experiments and molecular dynamics simulation, it was found that proteins, caffeine (CAF), and phenolics played a dominant role throughout the cream formation, and the contribution of amino acids was highlighted in the early stage. Furthermore, CAF was prominent due to its extensive binding capacity and the filling complex voids property, and caffeine-theaflavins (TFs) complexation may be the core skeleton of the growing particles in black tea infusion. In addition to TFs, the unidentified phenolic oxidation-derived products (PODP) were confirmed to contribute greatly to the cream formation.

Advances in the Anti-Tumor Activity of Biflavonoids in Selaginella.

Despite the many strategies employed to slow the spread of cancer, the development of new anti-tumor drugs and the minimization of side effects have been major research hotspots in the anti-tumor field. Natural drugs are a huge treasure trove of drug development, and they have been widely used in the clinic as anti-tumor drugs. Selaginella species in the family Selaginellaceae are widely distributed worldwide, and they have been well-documented in clinical practice for the prevention and treatment of cancer. Biflavonoids are the main active ingredients in Selaginella, and they have good biological and anti-tumor activities, which warrant extensive research. The promise of biflavonoids from Selaginella (SFB) in the field of cancer therapy is being realized thanks to new research that offers insights into the multi-targeting therapeutic mechanisms and key signaling pathways. The pharmacological effects of SFB against various cancers in vitro and in vivo are reviewed in this review. In addition, the types and characteristics of biflavonoid structures are described in detail; we also provide a brief summary of the efforts to develop drug delivery systems or combinations to enhance the bioavailability of SFB monomers. In conclusion, SFB species have great potential to be developed as adjuvant or even primary therapeutic agents for cancer, with promising applications.

Screening for α-glucosidase inhibitors from Selaginella uncinata based on the ligand fishing combined with ultra-high-performance liquid chromatography-quadrupole time-of-flight-tandem mass spectrometry.

Biflavonoids are naturally occurring compounds consisting of two flavonoid moieties that have received substantial attention from researchers. Although many kinds of biflavonoids are typically distributed in Selaginella uncinata with hypoglycemic effect, their anti-α-glucosidase activities are not yet clear. In this study, a ligand fishing strategy for fast screening of α-glucosidase inhibitors from S. uncinata was proposed. α-Glucosidase was first immobilized on Fe3 O4 magnetic nanoparticles (MNPs) and then the α-glucosidase-functionalized MNPs were incubated with crude extracts of S. uncinata to fish out the ligands. Furthermore, considering the similarity and easy confusion of the structures of biflavonoids, the fragmentation patterns of different types of biflavonoids were studied. Based on this, 11 biflavonoids ligands with α-glucosidase inhibitory activities were accurately and quickly identified from S. uncinata with ultra-high-performance liquid chromatography-quadrupole time-of-flight-tandem mass spectrometry. Furthermore, these ligands were confirmed to be potential inhibitors through the in vitro inhibitory assay and molecular docking.

Siamenflavones A-C, three undescribed biflavonoids from Selaginella siamensis Hieron. and biflavonoids from spike mosses as EGFR inhibitor.

Three undescribed biflavonoids (BFVs), siamenflavones A-C along with twelve BFVs were isolated from Selaginella siamensis Hieron. and Selaginella bryopteris (L.) Baker (Selaginellaceae). The chemical structures of undescribed compounds were established through comprehensive spectroscopic techniques, chemical correlations, and X-ray crystallography. The ten isolated BFVs, siamenflavones A-C, delicaflavone, chrysocauflavone, robustaflavone, robustaflavone-4-methylether, amentoflavone, tetrahydro-amentoflavone, and sciadopitysin were evaluated for the antiproliferative effects against four human cancer cell lines A549, H1975, HepG2 and T47D. Delicaflavone and robustaflavone 4'-methylether exerted strong effects on the four human cancer cell lines. Siamenflavone B, delicaflavone and robustaflavone 4'-methylether showed potent inhibitory activities against wild-type EGFR. The inhibition of the compounds was further supported by molecular docking and predictive intermolecular interactions. Molecular dynamics simulation studies of siamenflavone B and robustaflavone-4'-methylether complexed to EGFR-TK further supported inhibition of the compounds to the ATP binding site. Finally, analysis of pharmacokinetic and electronic properties using density-functional theory and known drug index calculations suggest that the compounds are pharmaceutically compatible for drug administration.

Biflavonoids from Ginkgo biloba leaves as a novel anti-atherosclerotic candidate: Inhibition potency and mechanistic analysis.

BACKGROUND: Ginkgo biloba L. is one of the oldest trees on earth, and its leaves have been used since ages as herbal medicine to treat cerebrovascular disorders. It is worth noting that in addition to the widely concerned flavonoids and terpenoids, it also contains various thus far neglected biflavonoids. In fact, biflavonoids are flavonoids consisting of apigenin or its derivatives as monomeric scaffold, and are linked via C-C or C-O-C bond. PURPOSE: Based on the structural similarity of flavonoids, we hypothesized that biflavonoids may play a potential role in the treatment of cerebrovascular diseases. Here, we describe the effectiveness and underlying mechanisms for prevention and treatment of atherosclerosis (AS) by biflavonoids. STUDY DESIGN AND METHODS: Four main biflavonoids in Ginkgo biloba leaves were screened by oleic acid-induced lipid production in HepG2 cells. The non-covalent effects of biflavonoids on the potential targets of atherosclerosis were screened by reverse targeting and molecular dynamics simulation. The interactions between biflavonoids and potential targets were evaluated by an exogenous cell model, which verified the consistency of the simulation results. CONCLUSION: Among all four biflavonoids, ginkgetin significantly inhibited oleic acid-induced lipid production in HepG2 cells and reduced total cholesterol and triglyceride levels. The interaction of ginkgetin with CDK2 through π-alkyl and hydrogen bonds increased the binding of molecules and proteins. Ginkgetin arrested the cells in the G1-S phase, which significantly inhibited abnormal cell growth which closely related to the occurrence and development of atherosclerosis. Biflavonoids could be a promising natural medicine for the treatment of atherosclerosis.

Discovery and characterization of amentoflavone as a naturally occurring inhibitor against the bile salt hydrolase produced by Lactobacillus salivarius.

Bile salt hydrolases (BSHs), a group of cysteine-hydrolases produced by gut microbes, play a crucial role in the hydrolysis of glycine- or taurine-conjugated bile acids and have been validated as key targets to modulate bile acid metabolism. This study aims to discover one or more efficacious inhibitors against a BSH produced by Lactobacillus salivarius (lsBSH) from natural products and to characterize the mechanism of the newly identified BSH inhibitor(s). Following screening of the inhibition potentials of more than 100 natural compounds against lsBSH, amentoflavone (AMF), a naturally occurring biflavone isolated from various medicinal plants, was discovered to be an efficacious BSH inhibitor (IC50 = 0.34 µM). Further investigation showed that AMF could strongly inhibit the lsBSH-catalyzed hydrolytic reaction in living gut microbes. Inhibition kinetic analyses demonstrated that AMF reversibly inhibited the lsBSH-catalyzed hydrolytic reaction in a mixed-inhibition manner, with an apparent Ki value of 0.65 µM. Fluorescence quenching assays suggested that AMF could quench the fluorescence of lsBSH via a static quenching procedure. Docking simulations suggested that AMF could be fitted into lsBSH at two distinct ligand-binding sites, mainly via hydrophobic interactions and hydrogen bonding, which explained well the mixed inhibition mode of this agent. Animal tests showed that the hydrolytic activities of BSHs in mice feces could be significantly blocked by AMF. In summary, this study reports that AMF is a strong, naturally occurring inhibitor of lsBSH, which offers a promising lead compound to develop novel agents for modulating bile acid metabolism in the host via targeting BSHs.

Purification of biflavonoids from Selaginelladoe derleinii Hieron by special covalent organic polymers material.

Herein, a novel covalent organic polymers (COP) material based on acylhydrazone bond (AB-COP) was prepared as an efficient extraction material for enriching natural medicine biflavonoids from Selaginella doederleinii Hieron. The obtained AB-COP structure was characterized in detail. And it was the first time to investigate the effect of AB-COP on the adsorption of biflavonoids. The effects of initial concentration of solution, adsorption temperature, solid-liquid ratio, adsorption time on the adsorption of biflavonoids were studied. In addition, adsorption kinetic model, adsorption thermodynamic model and density functional theory (DFT) were also investigated to evaluate the adsorption mechanism. At the same time, the static desorption and reusability of AB-COP were investigated. Finally, the dynamic enrichment effect of AB-COP for biflavonoids was investigated. The results showed that AB-COP was successfully synthesized by Fourier transform infrared spectroscopy (FT-IR), solid state nuclear magnetism (NMR), X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), laser particle size analysis and Brunner Emmet Teller (BET) specific surface area test. The optimized adsorption parameters of AB-COP were initial concentration of 0.5 mg/mL, temperature of 45 °C, solid-liquid ratio of 10:10 (mg/mL), adsorption time of 60 min. The Langmuir adsorption isotherm could effectively describe the adsorption process, the pseudo-secondary adsorption model could accurately explain the adsorption mechanism, and the DFT calculations revealed that the interaction forces of AB-COP and biflavonoids were π-π stacking and hydrogen bonding. In addition, AB-COP successfully resolved biflavonoids through urea-methanol (1.3 mol/L), and the material can be reused at least four times. Finally, the solid phase extraction (SPE) chromatographic column prepared by AB-COP was successfully applied to the enrichment of biflavonoids from S. doederleinii, and the effect was significantly better than traditional chromatography materials, andthis method was also successfully applied to the enrichment of flavonoids in other plant extracts including Flos sophorae, Pericarpium viride, Lophatheri herba, Herba cuscutae. These results provide references for further purification of bioactive ingredients from plant extracts by using AB-COP.

A new biflavonoids from Aster tataricus induced non-apoptotic cell death in A549 cells.

A new biflavonoids, (2R,2''R)-7-O-methyl-2,3,2'',3''-tetrahydrorobustaflavone (1), along with five known flavonoids (2-6) were isolated from the MeOH extract of Aster tataricus. Among them, compounds 1-2 were the C-3'-C-6'' type biflavonoids obtained from the genus Aster for the first time. The structures and absolute configurations of compound 1 was confirmed based on extensive spectroscopic and circular dichroism analyses. Compound 1 exhibited moderate cytotoxicity against seven human cancer A549, HepG2, PC3, DU145, MCF-7, LOVO and NCI-H1975 cell lines. Compound 1 remarkably inhibited the proliferation of A549 cancer cells with IC50 value of 5.4 µM. Further preliminary pharmacological study, 1 induces A549 cell death by non-apoptotic forms through flow cytometry and cell scratch assay data.

Trichocladabiflavone A, a chalcone-flavonone type biflavonoid from Selaginella trichoclada Alsto.

A chalcone-flavonone type biflavonoid, trichocladabiflavone A (1), along with eight known biflavonoids (2-9) were isolated from the 70% EtOH extract of Selaginella trichoclada. Their structures were elucidated by extensive spectroscopic analyses. Compound 1 was the first chalcone-flavonone type biflavonoid reported in the genus Selaginella. Moreover, compound 1 exhibited moderate cytotoxicity against DU145, MCF-7 and PC3 human cancer cell lines.

Cytotoxic effects of the biflavonoids isolated from Selaginella trichoclada on MCF-7 cells and its potential mechanism.

A new biflavonoid, (2''S)-6''-methyl-2'',3''-dihydroochnaflavone (1), along with two known ochnaflavones (2, 3), four known amentoflavones (4-7) and two known robustaflavones (8, 9) were obtained from the 70% EtOH extract of Selaginella trichoclada. The chemical structures of isolated compounds were elucidated by extensive spectroscopic analyses. Overall, compounds 1-9 displayed moderate cytotoxic effects against human breast cancer MCF-7 cell lines. Among them, compounds 2 and 8 exhibited relatively strong cytotoxic effects against MCF-7 cells with an IC50 value of 7.7 and 6.9 µΜ, respectively. The results of RNA-sequencing and KEGG functional enrichment analysis showed that 8 could induce ferroptosis in MCF-7 cells by down-regulating the expression of ferroptosis-related genes including ACSL4, NOXO1, NOXA1, ACSL5, STEAP3, LPCAT3, ATG7 and TP53. Then 8 could inhibit the expression of ACSL4 proteins through molecule docking analysis, which showed a strong interaction of - 11.89 Kcal/mol binding energy. Those results indicate that 8 could be chemotherapy agents to fight drug resistance in breast cancer by down-regulating the expression level of ACSL4 proteins via ferroptosis, which needs to be further certified in vitro.

Chamaejasmenin E from Stellera chamaejasme induces apoptosis of hepatocellular carcinoma cells by targeting c-Met in vitro and in vivo.

Hepatocellular carcinoma (HCC), the most prevalent liver cancer, is considered one of the most lethal malignancies with a dismal outcome. There is an urgent need to find novel therapeutic approaches to treat HCC. At present, natural products have served as a valuable source for drug discovery. Here, we obtained five known biflavones from the root of Stellera chamaejasme and evaluated their activities against HCC Hep3B cells in vitro. Chamaejasmenin E (CE) exhibited the strongest inhibitory effect among these biflavones. Furthermore, we found that CE could suppress the cell proliferation and colony formation, as well as the migration ability of HCC cells, but there was no significant toxicity on normal liver cells. Additionally, CE induced mitochondrial dysfunction and oxidative stress, eventually leading to cellular apoptosis. Mechanistically, the potential target of CE was predicted by database screening, showing that the compound might exert an inhibitory effect by targeting at c-Met. Next, this result was confirmed by molecular docking, cellular thermal shift assay (CETSA), as well as RT-PCR and Western blot analysis. Meanwhile, CE also reduced the downstream proteins of c-Met in HCC cells. In concordance with above results, CE is efficacious and non-toxic in tumor xenograft model. Taken together, our findings revealed an underlying tumor-suppressive mechanism of CE, which provided a foundation for identifying the target of biflavones.

Theaflavin Chemistry and Its Health Benefits.

Huge epidemiological and clinical studies have confirmed that black tea is a rich source of health-promoting ingredients, such as catechins and theaflavins (TFs). Furthermore, TF derivatives mainly include theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B), and theaflavin-3,3'-digallate (TF3). All of these TFs exhibit extensive usages in pharmaceutics, foods, and traditional medication systems. Various indepth studies reported that how TFs modulates health effects in cellular and molecular mechanisms. The available literature regarding the pharmacological activities of TFs has revealed that TF3 has remarkable anti-inflammatory, antioxidant, anticancer, antiobesity, antiosteoporotic, and antimicrobial properties, thus posing significant effects on human health. The current manuscript summarizes both the chemistry and various pharmacological effects of TFs on human health, lifestyle or aging associated diseases, and populations of gut microbiota. Furthermore, the biological potential of TFs has also been focused to provide a deeper understanding of its mechanism of action.

Structurally diverse biflavonoids from the fruits of Citrus medica L. var. sarcodactylis Swingle and their hypolipidemic and immunosuppressive activities.

The fruit of Citrus medica L. var. sarcodactylis Swingle is not only used as a traditional medicinal plant, but also served as a delicious food. Six new (3'→7″)-biflavonoids (1-6), and twelve known biflavonoid derivatives (7-18) were isolated and characterized from the fruits of C. medica L. var. sarcodactylis Swingle for the first time. Their structures were determined by extensive and comprehensive analyzing NMR, HR-ESI-MS, UV, and IR spectral data coupled with the data described in the literature. Compounds (1-18) were evaluated for their hypolipidemic activities with Orlistat as the positive control, and assayed for their immunosuppressive activities with Dexamethasone as the positive control, respectively. Among them, compounds (1-3) exhibited moderate inhibition of pancreatic lipase activity by inhibiting 68.56 ± 1.40%, 56.18 ± 1.57%, 53.51 ± 1.59% of pancreatic lipase activities at the concentration of 100 µM, respectively. Compounds (4-6) and 8 showed potent immunosuppressive activities with the IC50 values from 16.83 ± 1.32 to 50.90 ± 1.79 µM. The plausible biogenetic pathway and preliminary structure activity relationship of the selected compounds were scientifically summarized and discussed in this study.

Study on mechanism of low bioavailability of black tea theaflavins by using Caco-2 cell monolayer.

This study aimed to clarify the bioavailability mechanism of theaflavins by using the Caco-2 monolayer in vitro model. Prior to the transport of theaflavin (TF), theaflavin-3-gallate (TF3G), theaflavin-3'-gallate (TF3'G), and theaflavin-3, 3'-digallate (TFDG), we found the cytotoxicity of theaflavins was in the order of TF3'G > TFDG > TF3G > TF, suggesting the galloyl moiety enhances the cytotoxicity of theaflavins. Meantime, the galloyl moiety made theaflavins unstable, with the stability in the order of TF > TFDG > TF3G/TF3'G. Four theaflavins showed poor bioavailability with the Papp values ranging from 0.44 × 10-7 to 3.64 × 10-7 cm/s in the absorptive transport. All the theaflavins showed an efflux ratio of over 1.24. And it is further confirmed that P-glycoprotein (P-gp), multidrug resistance associated proteins (MRPs) and breast cancer resistance protein (BCRP) were all shown to contribute to the efflux transport of four theaflavins, with P-gp playing the most important role, followed by MRPs and BCRP. Moreover, theaflavins increased the expression of P-gp, MRP1, MPR3, and BCRP while decreased the expression of MRP2 at the transcription and translation levels. Additionally, the gallated theaflavins were degraded into simple theaflavins and gallic acids when transported through Caco-2 monolayers. Overall, the structural instability, efflux transporters, and cell metabolism were all responsible for the low bioavailability of four theaflavins in Caco-2 monolayers.

Severe Acute Respiratory Syndrome Coronavirus-2 Inactivation Activity of the Polyphenol-Rich Tea Leaf Extract with Concentrated Theaflavins and Other Virucidal Catechins.

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is producing a large number of infections and deaths globally, the development of supportive and auxiliary treatments is attracting increasing attention. Here, we evaluated SARS-CoV-2-inactivation activity of the polyphenol-rich tea leaf extract TY-1 containing concentrated theaflavins and other virucidal catechins. The TY-1 was mixed with SARS-CoV-2 solution, and its virucidal activity was evaluated. To evaluate the inhibition activity of TY-1 in SARS-CoV-2 infection, TY-1 was co-added with SARS-CoV-2 into cell culture media. After 1 h of incubation, the cell culture medium was replaced, and the cells were further incubated in the absence of TY-1. The viral titers were then evaluated. To evaluate the impacts of TY-1 on viral proteins and genome, TY-1-treated SARS-CoV-2 structural proteins and viral RNA were analyzed using western blotting and real-time RT-PCR, respectively. TY-1 showed time- and concentration-dependent virucidal activity. TY-1 inhibited SARS-CoV-2 infection of cells. The results of western blotting and real-time RT-PCR suggested that TY-1 induced structural change in the S2 subunit of the S protein and viral genome destruction, respectively. Our findings provided basic insights in vitro into the possible value of TY-1 as a virucidal agent, which could enhance the current SARS-CoV-2 control measures.

Significant Inactivation of SARS-CoV-2 In Vitro by a Green Tea Catechin, a Catechin-Derivative, and Black Tea Galloylated Theaflavins.

Potential effects of tea and its constituents on SARS-CoV-2 infection were assessed in vitro. Infectivity of SARS-CoV-2 was decreased to 1/100 to undetectable levels after a treatment with black tea, green tea, roasted green tea, or oolong tea for 1 min. An addition of (-) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while the same concentration of theasinensin A (TSA) and galloylated theaflavins including theaflavin 3,3'-di-O-gallate (TFDG) had more remarkable anti-viral activities. EGCG, TSA, and TFDG at 1 mM, 40 µM, and 60 µM, respectively, which are comparable to the concentrations of these compounds in tea beverages, significantly reduced infectivity of the virus, viral RNA replication in cells, and secondary virus production from the cells. EGCG, TSA, and TFDG significantly inhibited interaction between recombinant ACE2 and RBD of S protein. These results suggest potential usefulness of tea in prevention of person-to-person transmission of the novel coronavirus.

Kolaflavanone, a biflavonoid derived from medicinal plant Garcinia, is an inhibitor of mitotic kinesin Eg5.

Mitotic kinesin Eg5 remains a validated target in antimitotic therapy because of its essential role in the formation and maintenance of bipolar mitotic spindles. Although numerous Eg5 inhibitors of synthetic origin are known, only a few inhibitors derived from natural products have been reported. In our study, we focused on identifying novel Eg5 inhibitors from medicinal plants, particularly Garcinia species. Herein, we report the inhibitory effect of kolaflavanone (KLF), a Garcinia biflavonoid, on the ATPase and microtubule-gliding activities of mitotic kinesin Eg5. Additionally, we showed the interaction mechanism between Eg5 and KLF via in vitro and in silico analyses. The results revealed that KLF inhibited both the basal and microtubule-activated ATPase activities of Eg5. The inhibitory mechanism is allosteric, without a direct competition with adenosine-5'-diphosphate for the nucleotide-binding site. KLF also suppressed the microtubule gliding of Eg5 in vitro. The Eg5-KLF model obtained from molecular docking showed that the biflavonoid exists within the α2/α3/L5 (α2: Lys111-Glu116 and Ile135-Asp149, α3: Asn206-Thr226; L5: Gly117-Gly134) pocket, with a binding pose comparable to known Eg5 inhibitors. Overall, our data suggest that KLF is a novel allosteric inhibitor of mitotic kinesin Eg5.

A Prospective of Multiple Biopharmaceutical Activities of Procyanidins-Rich Uapaca togoensis Pax Extracts: HPLC-ESI-TOF-MS Coupled with Bioinformatics Analysis.

The article reports the chemical composition, antioxidant, six key enzymes inhibitory and antimicrobial activities of two solvent extracts (water and methanol) of leaves and stem bark of Uapaca togoensis. For chemical composition, methanol extract of stem bark exhibited significant higher total phenolic (129.86 mg GAE/g) and flavanol (10.44 mg CE/g) contents. Methanol extract of leaves and water extract of stem bark showed high flavonoids (20.94 mg RE/g) and phenolic acid (90.40 mg CAE/g) content, respectively. In addition, HPLC-ESI-TOF-MS analysis revealed that U. togoensis was rich in procyanidins. The methanol and water extracts of stem bark had overall superior antioxidant activity; however, only methanol extract of stem bark showed higher inhibition of cholinesterase (AChE: 2.57 mg GALAE/g; BChE: 4.69 mg GALAE/g), tyrosinase (69.53 mg KAE/g) and elastase (2.73 mmol CE/g). Potent metal chelating ability was showed by water extract of leaves (18.94 mg EDTAE/g), higher inhibition of amylase was detected for water extracts of leaves (0.94 mmol ACAE/g) and stem bark (0.92 mmol ACAE/g). The tested extracts have shown wide-spectrum antibacterial properties and these effects have shown to be more effective against Aspergillus ochraceus, Penicillium funiculosum, Trichoderma viride, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. The results revealed that the antioxidant, enzyme inhibitory and antimicrobial activities depended on the extraction solvents and the parts of plant. Bioinformatics analysis on the 17 major compounds showed modulation of pathway associated with cancer. In brief, U. togoensis might be valuable as potential source of natural agents for therapeutic application.

Antiplasmodial and Cytotoxic Activities of Extract and Compounds from Ozoroa obovata (Oliv.) R. & A. Fern. var. obovata.

Ozoroa obovata (Oliv.) R. & A. Fern. var. obovata found in KwaZulu-Natal in South Africa was investigated for phytochemical constituents, and for antiplasmodial and cytotoxic effects. The plant leaves were collected from the University of KwaZulu-Natal (UKZN) arboretum on the Pietermaritzburg Campus, in March 2019. The inhibitory activity against 3D7 Plasmodium falciparum was determined using the parasite lactate dehydrogenase (pLDH) assay and cytotoxicity against HeLa cells was evaluated using the resazurin assay. The bioactive compounds were isolated by chromatographic purification and their structures were established with spectroscopic and spectrometric techniques. The plant leaf extract displayed significant antiplasmodial activity at 50 µg/mL and was also cytotoxic against HeLa cells. Chromatographic purification of the extract led to the isolation of two biflavonoids, four flavonoid glycosides, a steroid glycoside, and a megastigmene derivative. The compounds displayed antiplasmodial and antiproliferative activities at 50 µg/mL but the activity was substantially reduced at 10 µg/mL. The activities and compounds are being reported in O. obovata for the first time.