Acridone alkaloids from the stem bark of Citrus aurantium display selective cytotoxicity against breast, liver, lung and prostate human carcinoma cells

Predicting herb-disease associations using network-based measures in human protein interactome

BACKGROUND

Natural herbs are frequently used to treat diseases or to relieve symptoms in many countries. Moreover, as their safety has been proven for a long time, they are considered as main sources of new drug development. However, in many cases, the herbs are still prescribed relying on ancient records and/or traditional practices without scientific evidences. More importantly, the medicinal efficacy of the herbs has to be evaluated in the perspective of MCMT (multi-compound multi-target) effects, but most efforts focus on identifying and analyzing a single compound experimentally. To overcome these hurdles, computational approaches which are based on the scientific evidences and are able to handle the MCMT effects are needed to predict the herb-disease associations.

RESULTS

In this study, we proposed a network-based in silico method to predict the herb-disease associations. To this end, we devised a new network-based measure, WACP (weighted average closest path length), which not only quantifies proximity between herb-related genes and disease-related genes but also considers compound compositions of each herb. As a result, we confirmed that our method successfully predicts the herb-disease associations in the human protein interactome (AUROC = 0.777). In addition, we observed that our method is superior than the other simple network-based proximity measures (e.g. average shortest and closest path length). Additionally, we analyzed the associations between Brassica oleracea var. italica and its known associated diseases more specifically as case studies. Finally, based on the prediction results of the WACP, we suggested novel herb-disease pairs which are expected to have potential relations and their literature evidences.

CONCLUSIONS

This method could be a promising solution to modernize the use of the natural herbs by providing the scientific evidences about the molecular associations between the herb-related genes targeted by multiple compounds and the disease-related genes in the human protein interactome.

Citrus limon (L.) Osbeck Fruit Peel Extract Attenuates Carbon Tetrachloride-Induced Hepatocarcinogenesis in Sprague-Dawley Rats

Background

Traditional herbal medicine practitioners in the Ashanti region of Ghana use the fruit peels of Citrus limon (L.) Osbeck (C. limon) in preventive and curative treatment of many cancers including liver cancer. This ethnobotanical claim remains to be verified scientifically. Aim of the Study. This study investigated prophylactic hepatoprotective and anti-HCC effects of C. limon peel extract (LPE) in CCl4/olive oil-induced HCC-like rats.

Materials and Methods

After preparation of LPE, it was subjected to phytochemical screening using standard phytochemical methods. A total of 30 healthy adult male Sprague-Dawley rats (weighing 150-200 g) were randomly assigned into six groups of 5 rats each. Rats in the control group received olive oil (5 mL/kg ip) twice weekly for 16 weeks. Rats in the model group received CCl4/olive oil (2 mL/kg, ip) twice weekly for 16 weeks. Rats in capecitabine (10 mg/kg po) and LPE (50, 100, and 200 mg/kg po) groups received CCl4/olive oil (2 mL/kg, i.p) in the morning and their respective treatments in the afternoon twice a week for 16 weeks. Rats in all groups had free access to food and water ad libitum. Body weight and survival rates were monitored. Rats were sacrificed under deep anesthesia, blood was collected, and liver and other organs were isolated. Aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), prothrombin time, bilirubin, C-reactive protein (CRP), alpha- (α-) fetoprotein (AFP), and liver histology were assessed.

Results

Alkaloids, tannins, flavonoids, terpenoids, and saponins were detected in LPE. Model rats demonstrated increased serum levels of AFP, CRP, ALP, GGT, ALT, and AST, prothrombin time, total bilirubin, direct bilirubin, blood lymphocyte, and monocyte counts, but decreased serum albumin and total protein compared to control rats. Unlike the control, model rats demonstrated fat accumulation in periportal and centrilobular hepatocytes and neoplastic transformation. Semiquantitation of periodic acid Schiff- (PAS-) stained liver sections showed decreased glycogen storage in hepatocytes of model rats compared to control rats. Compared to the model, LPE treatment protected against CCl4-induced hepatocarcinogenesis, which was evidenced by decreased AFP, CRP, liver enzymes, total and direct bilirubin, prothrombin time, and blood lymphocyte and monocyte counts; attenuation of fat accumulation; and increased glycogen storage, albumin, and total protein.

Conclusion

LPE abates CCl4-induced hepatocarcinogenesis by attenuating liver inflammation and improving metabolic, biosynthetic, and detoxification functions of the liver. The prophylactic hepatoprotective and anti-hepatocarcinogenic effects of LPE are attributable to its phytochemical composition raising hopes of finding potential anticancer bioactive compounds from C. limon fruit peels.

A review of citrus plants as functional foods and dietary supplements for human health, with an emphasis on meta-analyses, clinical trials, and their chemical composition

Fruits, flowers, leaves, essential oils, hydrosols, and juices of citrus spp. Are utilized to prepare various forms of food products. Along with their nutritional values, in the health industry, different parts of the plants of the citrus genus have been used as supplements or remedies to prevent or control diseases. This review focused on reported meta-analyses and clinical trials on the health benefits of citrus plants as functional foods. Also, chemical compounds of various citrus species were reviewed. The following information sources were used for data collection: Google Scholar, the Web of Science, Scopus, and PubMed. Various keywords, including "citrus AND chemical compounds," "citrus AND phytochemicals," "citrus species," "citrus AND meta-analysis," "nutritional and therapeutical values of citrus spp.," "clinical trials AND citrus," "clinical trials AND Rutaceae," "health benefits of citrus spp.," "citrus edible or non-edible applications," and scientific names of the citrus plants were utilized to collect data for the review. The scientific name and common name of all twenty-eight citrus species, along with any of the above keywords, were also searched in the mentioned databases. Scientific papers and data sources were sought to review and discuss the citrus plant's nutritional and therapeutic importance. Several meta-analyses and clinical trials have reported beneficial effects of citrus spices on a variety of cancer risks, cardiovascular risk factors, neurologic disorders, urinary tract conditions, and gastrointestinal tract conditions. They have shown anxiolytic, antimicrobial, and pain-alleviating effects. Some of them can be helpful in managing obesity and cardiovascular risk factors.

Anti-amoebic effects of synthetic acridine-9(10H)-one against brain-eating amoebae

Pathogenic A. castellanii and N. fowleri are opportunistic free-living amoebae. Acanthamoeba spp. are the causative agents of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK), whereas Naegleria fowleri causes a very rare but severe brain infection called primary amebic meningoencephalitis (PAM). Acridinone is an important heterocyclic scaffold and both synthetic and naturally occurring derivatives have shown various valuable biological properties. In the present study, ten synthetic Acridinone derivatives (I-X) were synthesized and assessed against both amoebae for anti-amoebic and cysticidal activities in vitro. In addition, excystation, encystation, cytotoxicity, host cell pathogenicity was also performed in-vitro. Furthermore, molecular docking studies of these compounds with three cathepsin B paralogous enzymes of N. fowleri were performed in order to predict the possible docking mode with pathogen. Compound VII showed potent anti-amoebic activity against A. castellanii with IC₅₀ 53.46 µg/mL, while compound IX showed strong activity against N. fowleri in vitro with IC₅₀ 72.41 µg/mL. Compounds II and VII showed a significant inhibition of phenotypic alteration of A. castellanii, while compound VIII significantly inhibited N. fowleri cysts. Cytotoxicity assessment showed that these compounds caused minimum damage to human keratinocyte cells (HaCaT cells) at 100 µg/mL, while also effectively reduced the cytopathogenicity of Acanthamoeba to HaCaT cells. Moreover, Cathepsin B protease was investigated in-silico as a new molecular therapeutic target for these compounds. All compounds showed potential interactions with the catalytic residues. These results showed that acridine-9(10H)-one derivatives, in particular compounds II, VII, VIII and IX hold promise in the development of therapeutic agents against these free-living amoebae.

Severinia buxifolia-isolated acridones inhibit lung cancer invasion and decrease HIFα protein synthesis involving 5'UTR-mediated translation inhibition

BACKGROUND

Lung cancer is one of the most common cancers worldwide and is by far the leading cause of cancer death attributed to its rapid metastasis and poor prognosis. Given that hypoxia-inducible factors (HIFs) are associated with cancer metastasis, discovering agents to inhibit HIF-mediated invasive cancer is highly desired.

PURPOSE

This study aimed to investigate the natural acridone compounds isolated from Severinia buxifolia for the potential to delay hypoxia-induced lung cancer invasiveness by HIF inhibition.

METHODS

Using a hypoxia-responsive element (HRE) luciferase reporter, cell migration and invasion assays, real-time PCR, Western blot, and DNA recombinant clones, compound effect on HIF activity, cancer metastasis, HIF-1α mRNA transcription, HIFs protein stability, and HIF-1α translation were observed under hypoxia conditions.

RESULTS

Atalaphyllidine (Sbs-A) and atalaphyllinine (Sbs-B) were found to show the most potent effects on HIF transcriptional activity and HIF-1α protein expression in NSCLC cell line A549, although Sbs-A and Sbs-B might not attribute decreasing HIF-1α mRNA expression to potent inhibition of HIF activity. HIF-1α protein stability was not affected by Sbs-A; also, prolyl hydroxylase and proteasome inhibitors could not reverse the inhibitory effect from compounds. Furthermore, 3 - 10 μM low concentrations of Sbs-A inhibited HIF target gene expression, gelatin zymography activity, and A549 cancer invasion. Ultimately, Sbs-A inhibited HIF-1α 5'UTR-mediated translation independent of oxygen concentration, underlying the mechanism of compounds inhibiting HIF-1α protein expression.

CONCLUSION

Our study proposed Severinia buxifolia-isolated acridone compounds inhibited 5'-mRNA HIFA-mediated translation and provided evidence supporting the ability of acridone compounds in targeting HIFα for delayed lung cancer metastasis.

Anti-inflammatory constituents from the stems and leaves of Glycosmis ovoidea Pierre

Seven undescribed compounds, including four acridones, two coumarins, and a phenylpropanoid, together with 13 known acridone analogues were isolated from the ethanolic extract of the stems and leaves of Glycosmis ovoidea Pierre. Their structures were elucidated on the basis of comprehensive analysis of 1D and 2D NMR and HRESIMS spectroscopic data, and the absolute configurations were assigned by comparison of the experimental and calculated ECD data. Five compounds showed moderate inhibitory effects on nitric oxide production stimulated by lipopolysaccharide in BV-2 microglial cells with IC₅₀ values in the range of 18.30-30.84 μM, and three compounds showed potent inhibition on 5-lipoxygenase (5-LOX) with IC₅₀ values in the range of 2.08-10.26 μM. The possible binding sites of the active compounds with 5-LOX were further performed by molecular docking.

Naming of new natural products: Standard, pitfalls and tips-and-tricks

Naming a newly discovered natural product (NP) is a pleasant but difficult exercise. In most cases, the NP name will be given with reference to the species of origin, be it a plant, a marine organism, a mammalian or microbial species. For a long time, the use of biologically-based trivial names has been recommended to identify the parental linkage between the product and the originating genus or species. But the recommendation is not always followed and a multiplicity of trivial names have been attributed to NP, based on locations (country, region, city), foods, music, animals, forenames, etc. Tips-and-tricks associated with the naming of NP are underlined here. Usually, NP are differentiated across a homogeneous chemical series with a letter (from the Latin or Greek alphabet), followed or not with a number. In other cases, the change of a single letter distinguishes a series of NP. Common pitfalls associated with the naming of NP are enumerated, including the complexity of names, use of synonyms, duplicated names, confusing names and inappropriate terminology. The difficulties regularly encountered with the naming of NP are discussed. Four essential recommendations are recalled: (i) a thorough analysis of the existing products to avoid duplicated names and confusion, (ii) the use of a biologically-based trivial name to retrace the origin of the product, (iii) the strict adherence to the codes of chemical nomenclature, and (iv) the preference for simple names to facilitate transmission. Naming a new NP is a rewarding task, which shall be performed with all due skill, care and diligence.

A comprehensive review on acridone based derivatives as future anti-cancer agents and their structure activity relationships

The development of drug resistance and severe side-effects has reduced the clinical efficacy of the existing anti-cancer drugs available in the market. Thus, there is always a constant need to develop newer anti-cancer drugs with minimal adverse effects. Researchers all over the world have been focusing on various alternative strategies to discover novel, potent, and target specific molecules for cancer therapy. In this direction, several heterocyclic compounds are being explored but amongst them one promising heterocycle is acridone which has attracted the attention of medicinal chemists and gained huge biological importance as acridones are found to act on different therapeutically proven molecular targets, overcome ABC transporters mediated drug resistance and DNA intercalation in cancer cells. Some of these acridone derivatives have reached clinical studies as these heterocycles have shown huge potential in cancer therapeutics and imaging. Here, the authors have attempted to compile and make some recommendations of acridone based derivatives concerning their cancer biological targets and in vitro-cytotoxicity based on drug design and novelty to increase their therapeutic potential. This review also provides some important insights on the design, receptor targeting and future directions for the development of acridones as possible clinically effective anti-cancer agents.

Potential Therapeutic Applications of Plant-Derived Alkaloids against Inflammatory and Neurodegenerative Diseases

Alkaloids are a type of natural compound possessing different pharmacological activities. Natural products, including alkaloids, which originate from plants, have emerged as potential protective agents against neurodegenerative disorders (NDDs) and chronic inflammations. A wide array of prescription drugs are used against these conditions, however, not free of limitations of potency, side effects, and intolerability. In the context of personalized medicine, further research on alkaloids to unravel novel therapeutic approaches in reducing complications is critical. In this review, a systematic survey was executed to collect the literature on alkaloids and their health complications, from which we found that majority of alkaloids exhibit anti-inflammatory action via nuclear factor-κB and cyclooxygenase-2 (COX-2), and neuroprotective interaction through acetylcholinesterase (AChE), COX, and β-site amyloid precursor protein activity. In silico ADMET and ProTox-II-related descriptors were calculated to predict the pharmacological properties of 280 alkaloids isolated from traditional medicinal plants towards drug development. Out of which, eight alkaloids such as tetrahydropalmatine, berberine, tetrandrine, aloperine, sinomenine, oxymatrine, harmine, and galantamine are found to be optimal within the categorical range when compared to nicotine. These alkaloids could be exploited as starting materials for novel drug synthesis or, to a lesser extent, manage inflammation and neurodegenerative-related complications.

Antioxidant and Antiproliferative Activity of Selected Medicinal Plants of Lower Assam, India: An In Vitro and In Silico Study

BACKGROUND

The use of medicinal plants for general wellbeing and disease treatment is a common practice among tribal communities of Kokrajhar districts of Assam. However, little works have been done to study the pharmacological aspect of the plants.

OBJECTIVES

The present study intends to study the antioxidant and antiproliferative properties of selected medicinal plants used by the tribal communities of the Kokrajhar district of Assam since ancient times.

METHODS

Five traditionally important medicinal plants, namely, Cassia fistula, Citrus grandis, Lindernia crustacea, Sacciolepis myosuroides, and Zingiber zerumbet were investigated for antioxidant, antiproliferative (cytotoxic) and apoptosis-inducing potential in the malignant cancer cell line. Phytochemical content, such as phenolic and flavonoid content, were estimated following standard protocol. The methanolic extract of plants was investigated following the phosphomolybdate method (TAC), FRAP, DPPH, ABTS, and TBARS assays. Antiproliferative activities of the plants were carried out by MTT assay in DL and PBMC cells. The apoptotic study was carried out following the acridine orange and ethidium bromide staining method and fluorescent microscopic imaging. Based on the significant (P≤0.05) high apoptotic inducing potential of the plant and to further dissect the molecular mode of action, including downstream biological action, major phytochemicals derived from L. crustacea were investigated for its prospective binding affinity with anti-apoptotic cancer target proteins.

RESULTS

Antioxidant studies by FRAP, DPPH, ABTS, and TBARS assay revealed that all five plants contain considerable free radical scavenging activity. C. fistula showed the strongest free radical scavenging activity while the fruit peel extract of C. grandis showed poor activity. The overall antioxidant activities of plants such as TAC, FRAP, DPPH, ABTS, and TBARS may be arranged in decreasing activity as C. fistula > Z. zerumbet > L. crustacea > S. myosuroides > C. grandis. MTT based cell proliferation study showed that all the plants extract significantly (P≤0.05) inhibited cell viability with negligible cytotoxicity (~5-12%) in normal cells. Moreover, L. crustacea showed promising antiproliferative and apoptosis-inducing ability against Dalton's lymphoma. It is worth mentioning that the major bioactive compounds of the most potent plant extract, L. crustacea interacted with anti-apoptotic proteins (cancer target) with higher affinity and the results are compared with reference inhibitors.

CONCLUSION

It is worth noting that these plants have the potential to consider for further scientific studies in different cell lines and animal models. Furthermore, isolation and characterization of bioactive compound(s) may promise the discovery of new and valuable drugs candidate to tackle various human diseases.

Features, Pharmacological Chemistry, Molecular Mechanism and Health Benefits of Lemon

Background:

Citrus limon, a Mediterranean-grown citrus species of plants belonging to the Rutaceae family, occupies a place of an impressive range of food and medicinal uses with considerable value in the economy of the fruit of the country. Citrus fruits are economically important with large-scale production of both the fresh fruits and industrially processed products. The extracts and phytochemicals obtained from all parts of C. limon have shown immense therapeutic potential because of their anticancer, anti-tumor and anti-inflammatory nature, and also serve as an important ingredient in the formulation of several ethnic herbal medicines. These properties are mediated by the presence of different phytochemicals, vitamins and nutrients in the citrus fruits.

Material and Methods:

The methods involved in the preparation of the present article included the collection of information from various scientific databases, indexed periodicals, and search engines such as Medline Scopus google scholar PubMed, PubMed central web of science, and science direct.

Results:

This communication presents an updated account of different pharmacological aspects of C. limon associated with its anti-oxidative, antiulcer, antihelmintic, insecticidal, anticancer, cytotoxic, and estrogenic activities. In addition, C. limon extracts possess hepatoprotective, anti-hyperglycemic, and antimicrobial properties. The present article includes the structure and function of different key chemical constituents from different parts of C. limon. Also, the possible molecular mechanisms of actions of bioactive compounds from C. limon are displayed.

Conclusion:

The traditional and ethno-medicinal literature revealed that C. limon is very effective in different pathologies. Most of these compounds possessing antioxidant properties would be implicated in offering health benefits by acting as potential nutraceuticals to humans with special reference to disease management of health and disease.

Application of Lanthanide Shift Reagent to the 1H-NMR Assignments of Acridone Alkaloids

This study investigates the application of the paramagnetic shift reagent tris(dipivaloylmethanato)-europium(III) in NMR spectral studies of permethoxyacridone alkaloids (1–3) and pyranoacridone alkaloids (4–6). The induced chemical shifts (∆δ) of all protons were observed for the same molecule, and were compared to deduce the positions resulting from the distance nearby the Eu(dpm)₃. Assignment of the H-2, H-4 and H-8 of polysubstituted acridones could be distinguished based on the least-squares method of lanthanide-induced shifts plotted against the mole ratios of Eu(dpm)₃ to the substrate. The developed method is not only potentially useful for determining the planar structures of polysubstituted compounds, such as acridones, anthraquinones, xanthones, flavonoids, and phenanthrenes, but also applicable for their stereochemistry.

A potential treatment option for elderly non-Hodgkin lymphoma patients with multiple comorbidities: Two case reports and literature review

Non-Hodgkin lymphoma (NHL) is a heterogeneous lymphoproliferative malignancy. More than half of the NHL cases occur in patients over 65 years of age. As elderly patients have a poor performance status and multiple comorbidities, the use of standard chemotherapy is often limited, leading to poor clinical outcomes and an increasing need for an alternate therapeutic modalities. A 73-year-old man was diagnosed with extranodal NK/T-cell lymphoma concurrently combined with recurrent gastric adenocarcinoma and metastatic prostate cancer. A 79-year-old woman was diagnosed with T-cell and B-cell dual-phenotype NHL on the right chest wall showing tumor thrombosis and multiple enlarged lymph nodes under chronic emphysema with extensive pleural calcification. Both elderly patients had multiple comorbidities and pathologically confirmed non-Hodgkin lymphoma. Both patients achieved tumor responses following anticancer treatment with Korean medicine (KM), suggesting that the extracts of Angelica gigas Nakai and Geopungtang are potential options for treating NHL in elderly patients with multiple comorbidities. Considering the clinical outcomes of KM treatment in the two elderly patients with NHL and multiple comorbidities, this study generates a research hypothesis for future prospective clinical studies in patients with NHL who are ineligible for conventional anticancer therapy.

Ailanthone: A novel potential drug for treating human cancer

Cancer is the second leading cause of death after cardiovascular disease. In 2015, >8.7 million people died worldwide due to cancer, and by 2030 this figure is expected to increase to ~13.1 million. Tumor chemotherapy drugs have specific toxicity and side effects, and patients can also develop secondary drug resistance. To prevent and treat cancer, scientists have developed novel drugs with improved antitumor effects and decreased toxicity. Ailanthone (AIL) is a quassinoid extract from the traditional Chinese medicine plant Ailanthus altissima, which is known to have anti-inflammatory and antimalarial effects. An increasing number of studies have focused on AIL due to its antitumor activity. AIL can inhibit cell proliferation and induce apoptosis by up- or downregulating cancer-associated molecules, which ultimately leads to cancer cell death. Antitumor effects of AIL have been observed in melanoma, acute myeloid leukemia, bladder, lung, breast, gastric and prostate cancer and vestibular neurilemmoma. To the best of our knowledge, the present study is the first review to describe the antitumor mechanisms of AIL.

Alkaloids from Traditional Chinese Medicine against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become one of the major diseases that are threatening human health in the 21st century. Currently there are many approaches to treat liver cancer, but each has its own advantages and disadvantages. Among various methods of treating liver cancer, natural medicine treatment has achieved promising results because of their superiorities of high efficiency and availability, as well as low side effects. Alkaloids, as a class of natural ingredients derived from traditional Chinese medicines, have previously been shown to exert prominent anti-hepatocarcinogenic effects, through various mechanisms including inhibition of proliferation, metastasis and angiogenesis, changing cell morphology, promoting apoptosis and autophagy, triggering cell cycle arrest, regulating various cancer-related genes as well as pathways and so on. As a consequence, alkaloids suppress the development and progression of liver cancer. In this study, the mechanisms of representative alkaloids against hepatocarcinoma in each class are described systematically according to the structure classification, which mainly divides alkaloids into piperidine alkaloids, isoquinoline alkaloids, indole alkaloids, terpenoids alkaloids, steroidal alkaloids and other alkaloids. Besides using them alone, synergistic effects created together with other chemotherapy drugs and some special preparation methods also have been demonstrated. In this review, we have summarized the potential roles of several common alkaloids in the prevention and treatment of HCC, by revising the preclinical studies, highlighting the potential applications of alkaloids when they function as a therapeutic choice for HCC treatment, and integrating them into clinical practices.

Dandelion Root and Lemongrass Extracts Induce Apoptosis, Enhance Chemotherapeutic Efficacy, and Reduce Tumour Xenograft Growth In Vivo in Prostate Cancer

Many conventional chemotherapies have indicated side effects due to a lack of treatment specificity and are thus not suitable for long-term usage. Natural health products are well-tolerated and safe for consumption, and some have pharmaceutical uses particularly for their anticancer effects. We have previously reported the anticancer efficacy of dandelion (Taraxacum officinale) root and lemongrass (Cymbopogon citratus) extracts. However, their efficacy on prostate cancer and their interactions with standard chemotherapeutics have not been studied to determine if they will be suitable for adjuvant therapies. If successful, these extracts could potentially be used in conjunction with chemotherapeutics to minimize the risk of drug-related toxicity and enhance the efficacy of the treatment. We have demonstrated that both dandelion root extract (DRE) and lemongrass extract (LGE) exhibit selective anticancer activity. Importantly, DRE and LGE addition to the chemotherapeutics taxol and mitoxantrone was determined to enhance the induction of apoptosis when compared to individual chemotherapy treatment alone. Further, DRE and LGE were able to significantly reduce the tumour burden in prostate cancer xenograft models when administered orally, while also being well-tolerated. Thus, the implementation of these well-tolerated extracts in adjuvant therapies could be a selective and efficacious approach to prostate cancer treatment.

Julichrome derivatives and gliotoxin from a soil derived Streptomyces sp

Six julichrome derivatives including a new monomeric julichrome named as julichrome Q₁₀ (1), and previous reported julichrome Q₆ (2), julichrome Q_6.6 (4), julichrome Q_3.5 (5), julichrome Q_5.6 (6), julichrome Q_2.3 (7), along with a diketopiperazine gliotoxin (3) were isolated from a soil derived strain Streptomyces sp. The structures of these compounds were identified by HR-ESI-MS, UV, IR and NMR methods. The isolated compounds were tested for their in vitro cytotoxicity against human hepatocarcinoma HepG-2 and SMMC-7721 cell lines, human breast cancer MCF-7 and MDA-MB-231 cell lines, and human normal heptical LO2 cell line. Gliotoxin (3) showed the most cytotoxic activity against the tested tumor cell lines, with IC₅₀ values ranging from 0.11 to 1.45 μM. Julichrome Q_6.6 (4) displayed selective cytotoxic activity against SMMC-7721, MCF-7 and MDA-MB-231 cell lines.

Resveratrol derivatives from Commiphora africana (A. Rich.) Endl. display cytotoxicity and selectivity against several human cancer cell lines

Commiphora africana (A. Rich.) Endl. (Burseraceae) is a medicinal plant widely used in Nigerian ethnomedicine. The in vitro cytotoxicity of the stem bark extract of C. africana and isolated cytotoxic compounds was investigated. Three resveratrol derivatives: (E)-resveratrol 3-O-rutinoside (1), 5-methoxy-(E)-resveratrol 3-O-rutinoside (2), and pinostilbene (3), together with 3-hydroxy-5-methoxybenzoic acid (4) were isolated from the methanol fraction of C. africana. Their structures were determined by extensive analysis of their HREIMS and NMR spectra. The cytotoxicity of the isolated compounds against four human carcinoma cells was determined using the MTT assay. Compound 1 displayed the highest antiproliferative effect on the cell lines, with IC₅₀ values of 16.80, 21.74, 17.89, and 17.44 μM, against MCF7, A549, PC3, and HepG2 human cancer cell lines, respectively. In addition, compounds 1-3 showed low toxicity against normal human prostate cell line, with selectivity indices greater than five across the carcinoma cells, indicating that the compounds possess potential in the development of low-toxicity chemotherapeutic agents. These results support the traditional use of this plant in the treatment of cancer.