Mineral Fertilization Influences the Growth, Cryptolepine Yield, and Bioefficacy of Cryptolepis sanguinolenta (Lindl.) Schlt.

Cryptolepis sanguinolenta (Lindl.) Schlt., the main source of cryptolepine alkaloid, is intensively exploited in the wild to treat malaria and Lyme disease. In this study, the influence of four inorganic fertilizers (supplying N, P, K, or NPK) and four growth periods (3, 6, 9, and 12 months after transplanting) on the herb’s root biomass, cryptolepine content and yield, and biological activities were investigated in a pot and field trial. The results showed the application of N (in the form of Urea or NPK) increased root biomass yield, cryptolepine content, and cryptolepine yield compared to unfertilized plants. The 9-month-old plants recorded the maximum cryptolepine content (2.26 mg/100 mg dry root) and cryptolepine yield (304.08 mg/plant), indicating the perfect time to harvest the herb. Plant age at harvest had a more significant influence (50.6–55.7%) on cryptolepine production than fertilizer application (29.2–33.3%). Cryptolepine extracts from 9- to 12-month-old plants had the highest antiplasmodial activity (IC50 = 2.56–4.65 µg/mL) and drug selectivity index (2.15–3.91) against Plasmodium falciparum Dd2. These extracts were also cytotoxic to Jurkat leukaemia cell lines (CC50 < 62.56 µg/mL), indicating the possible use of cryptolepine for cancer management. Growing the herb in the field increased cryptolepine yield 2.5 times compared to growth in a pot, but this did not influence the antiplasmodial activity of the extract. Commercial cultivation of C. sanguinolenta for 9 months combined with N application could be a promising solution to the sustainable use of this threatened medicinal species.

Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signalling

Background Diverse signalling pathways are involved in carcinogenesis and one of such pathways implicated in many cancers is the interleukin 6/signal transducer and activator of transcription 3 (IL-6/STAT3) signalling pathway. Therefore, inhibition of this pathway is targeted as an anti-cancer intervention. This study aimed to establish the effect of cryptolepine, which is the main bioactive alkaloid in the medicinal plant Cryptolepis sanguinolenta, on the IL-6/STAT3 signalling pathway. Methods First, the effect of cryptolepine on the IL-6/STAT3 pathway in human hepatoma cells (HepG2 cells) was screened using the Cignal Finder Multi-Pathway Reporter Array. Next, to confirm the effect of cryptolepine on the IL-6/STAT3 signalling pathway, the pathway was activated using 200 ng/mL IL-6 in the presence of 0.5–2 μM cryptolepine. The levels of total STAT3, p-STAT3 and IL-23 were assessed by ELISA. Results Cryptolepine downregulated 12 signalling pathways including the IL-6/STAT3 signalling pathway and upregulated 17 signalling pathways. Cryptolepine, in the presence of IL-6, decreased the levels of p-STAT3 and IL-23 in a dose-dependent fashion. Conclusion Our results demonstrated that cryptolepine inhibits the IL-6/STAT3 signalling pathway, and therefore cryptolepine-based remedies such as Cryptolepis sanguinolenta could potentially be used as an effective immunotherapeutic agent for hepatocellular carcinoma and other cancers.

Botanical Medicines Cryptolepis sanguinolenta, Artemisia annua, Scutellaria baicalensis, Polygonum cuspidatum, and Alchornea cordifolia Demonstrate Inhibitory Activity Against Babesia duncani

Human babesiosis is a CDC reportable disease in the United States and is recognized as an emerging health risk in multiple parts of the world. The current treatment for human babesiosis is suboptimal due to treatment failures and unwanted side effects. Although Babesia duncani was first described almost 30 years ago, further research is needed to elucidate its pathogenesis and clarify optimal treatment regimens. Here, we screened a panel of herbal medicines and identified Cryptolepis sanguinolenta, Artemisia annua, Scutellaria baicalensis, Alchornea cordifolia, and Polygonum cuspidatum to have good in vitro inhibitory activity against B. duncani in the hamster erythrocyte model. Furthermore, we found their potential bioactive compounds, cryptolepine, artemisinin, artesunate, artemether, and baicalein, to have good activity against B. duncani, with IC50 values of 3.4 μM, 14 μM, 7.4 μM, 7.8 μM, and 12 μM, respectively, which are comparable or lower than that of the currently used drugs quinine (10 μM) and clindamycin (37 μM). B. duncani treated with cryptolepine and quinine at their respective 1×, 2×, 4× and 8× IC50 values, and by artemether at 8× IC50 for three days could not regrow in subculture. Additionally, Cryptolepis sanguinolenta 90% ethanol extract also exhibited no regrowth after 6 days of subculture at doses of 2×, 4×, and 8× IC50 values. Our results indicate that some botanical medicines and their active constituents have potent activity against B. duncani in vitro and may be further explored for more effective treatment of babesiosis.

Cryptolepine consolidates its anticancer potential by increasing the anti-cancer pathway genes and decreasing that of pro-cancer pathway genes

Background: Cancers are one of the commonest causes of deaths globally. Reports indicate that greater than sixty percent of cancers in the world occur in low and middle-income countries with about seventy percent of all cancer deaths occurring in these regions. Conventional cancer treatments involve surgery, radiotherapy, chemotherapy, etc. However, the negative side effects such as high cost and toxicity associated with these treatment options have increased the demand for less toxic and less expensive anti-cancer drugs from natural sources. One of such natural products believed to have anti-cancer potential is cryptolepine (CRYP), an alkaloid extracted from the roots of Western and Central African plant Cryptolepis sanguinolenta. In addition to its anti-cancer potential, CRYP has been reported to possess a myriad of pharmacological activities. However, the mechanisms underlying the anti-cancer and pharmacological activities of CRYP have not been fully explored. Methods: We screened 45 immune and cancer signalling pathways for their regulation following treatment with CRYP using the dual-luciferase based Cignal Finder Multi-Pathway Reporter Arrays to pinpoint which pathways are regulated by CRYP. Additionally, the effects of CRYP on the transcript levels of interferon regulatory factor 1 (IRF-1), progesterone receptor (PR), hypoxia-inducible factor-1 alpha (HIF-1α) and signal transducer and activator of transcription 3 (STAT 3) were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). Results: We observed that of the 45 immune and cancer signalling pathways screened, nine were up-regulated while twenty-seven were down-regulated by CRYP. However, CRYP had no effect on nine of the pathways screened. We also observed that CRYP induced an increase in the transcript levels of IRF1 and PR but decreased that of HIF1-α and STAT3. Conclusion: The upregulation of human anti-cancer pathway genes including IRF-1 and PR and concomitant down-regulation of pro-cancer pathway genes including HIF1-α and STAT3 suggest additional mechanisms through which CRYP could exhibits its anti-cancer potential.

Cryptolepine consolidates its anticancer potential by increasing the anti-cancer pathway genes and decreasing that of pro-cancer pathway genes

Background: Cancers are one of the commonest causes of deaths globally. Reports indicate that greater than sixty percent of cancers in the world occur in low and middle-income countries with about seventy percent of all cancer deaths occurring in these regions. Conventional cancer treatments involve surgery, radiotherapy, chemotherapy, etc. However, the negative side effects such as high cost and toxicity associated with these treatment options have increased the demand for less toxic and less expensive anti-cancer drugs from natural sources. One of such natural products believed to have anti-cancer potential is cryptolepine (CRYP), an alkaloid extracted from the roots of Western and Central African plant Cryptolepis sanguinolenta. In addition to its anti-cancer potential, CRYP has been reported to possess a myriad of pharmacological activities. However, the mechanisms underlying the anti-cancer and pharmacological activities of CRYP have not been fully explored. Methods: We screened 45 immune and cancer signalling pathways for their regulation following treatment with CRYP using the dual-luciferase based Cignal Finder Multi-Pathway Reporter Arrays to pinpoint which pathways are regulated by CRYP. Additionally, the effects of CRYP on the transcript levels of interferon regulatory factor 1 (IRF-1), progesterone receptor (PR), hypoxia-inducible factor-1 alpha (HIF-1α) and signal transducer and activator of transcription 3 (STAT 3) were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). Results: We observed that of the 45 immune and cancer signalling pathways screened, nine were up-regulated while twenty-seven were down-regulated by CRYP. However, CRYP had no effect on nine of the pathways screened. We also observed that CRYP induced an increase in the transcript levels of IRF1 and PR but decreased that of HIF1-α and STAT3. Conclusion: The upregulation of human anti-cancer pathway genes including IRF-1 and PR and concomitant down-regulation of pro-cancer pathway genes including HIF1-α and STAT3 suggest additional mechanisms through which CRYP could exhibits its anti-cancer potential.

Alkaloids from Cryptolepis sanguinolenta as Potential Inhibitors of SARS-CoV-2 Viral Proteins: An In Silico Study

The ongoing global pandemic caused by the human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected millions of people and claimed hundreds of thousands of lives. The absence of approved therapeutics to combat this disease threatens the health of all persons on earth and could cause catastrophic damage to society. New drugs are therefore urgently required to bring relief to people everywhere. In addition to repurposing existing drugs, natural products provide an interesting alternative due to their widespread use in all cultures of the world. In this study, alkaloids from Cryptolepis sanguinolenta have been investigated for their ability to inhibit two of the main proteins in SARS-CoV-2, the main protease and the RNA-dependent RNA polymerase, using in silico methods. Molecular docking was used to assess binding potential of the alkaloids to the viral proteins whereas molecular dynamics was used to evaluate stability of the binding event. The results of the study indicate that all 13 alkaloids bind strongly to the main protease and RNA-dependent RNA polymerase with binding energies ranging from -6.7 to -10.6 kcal/mol. In particular, cryptomisrine, cryptospirolepine, cryptoquindoline, and biscryptolepine exhibited very strong inhibitory potential towards both proteins. Results from the molecular dynamics study revealed that a stable protein-ligand complex is formed upon binding. Alkaloids from Cryptolepis sanguinolenta therefore represent a promising class of compounds that could serve as lead compounds in the search for a cure for the corona virus disease.

Botanical Medicines with Activity against Stationary Phase Bartonella henselae

ABSTRACTBartonella henselae is a Gram-negative, facultative intracellular bacterium which is the causative agent of cat scratch disease. In humans, infections with B. henselae can result in acute or chronic systemic infections with various clinical symptoms including local skin lesions, malaise, aches, chills, lymphadenopathy, endocarditis, or meningoencephalitis. The current treatment for Bartonella infections with antibiotics such as doxycycline and rifampin is not always effective presumably due to bacterial persistence. There have been various anecdotal reports of herbal extracts used for treating patients with persistent Bartonella infections but their activity on B. henselae is unknown. To test the potential antimicrobial activity of botanical or herbal medicines and develop better therapies for persistent Bartonella infections, in this study, we screened an herbal product collection against stationary phase B. henselae in vitro using SYBR Green I/ propidium iodide (PI) viability assay. These herbal medicines were selected by the fact that they are commonly used to treat Lyme and co-infections by patients and herbalists, and as a follow-up to our recent study where these herbs were tested against B. burgdorferi. We identified five herbal product extracts that had high activity against stationary phase B. henselae at 0.5% (v/v), including Cryptolepis sanguinolenta, Juglans nigra, Polygonum cuspidatum, Scutellaria baicalensis, and Scutellaria barbata. Among them, Cryptolepis sanguinolenta, Juglans nigra, and Polygonum cuspidatum could eradicate all stationary phase B. henselae cells within 7 days at 0.25% (v/v) in drug exposure time-kill assay, whereas Scutellaria baicalensis and Scutellaria barbata showed relatively poor activity. The minimum inhibitory concentration (MIC) determination of these top hits indicated they were not only active against stationary phase non-growing B. henselae but also had good activity against log phase growing B. henselae. Our findings may help to develop more effective treatments for persistent Bartonella infections.

A Systematic Review of In Vitro Activity of Medicinal Plants from Sub-Saharan Africa against Campylobacter spp.

Introduction. Campylobacter spp. are zoonotic bacteria that cause gastroenteritis in humans and may cause extraintestinal infections such as Guillain-Barré syndrome, reactive arthritis, and bacteremia. Resistance to antibiotics is an increasing concern in the Sub-Saharan Africa; thus, search for alternatives such as plant-based active ingredients is important in order to develop new drugs. Objectives. To present a systematic review of in vitro and in vivo studies of the antibacterial activity of medicinal plants from Sub-Saharan Africa against Campylobacter spp. Methodology. Studies published until March 2020 on medicinal plants used against Campylobacter spp. from each country of Sub-Saharan Africa were searched on PubMed, Science Direct, AJOL, and Google Scholar. Articles were selected based on the existence of information regarding in vitro and in vivo activity of medicinal plants against Campylobacter spp. Results. A total of 47 medicinal plants belonging to 28 families were studied for in vitro activity against Campylobacter spp. No plant was studied in vivo. Plants from Fabaceae family were the most commonly studied. The plants with the strongest antimicrobial activities were Cryptolepis sanguinolenta and Terminalia macroptera. The root extracts from these plants were effective, and both had a minimal inhibitory concentration (MIC) of 25 μg/ml. Seven pure compounds were isolated and analyzed for activity against Campylobacter spp. The compound cryptolepine from C. sanguinolenta was the most effective with MIC values ranging between 6.25 and 25 μg/ml. Conclusion. Several native plants from the Sub-Saharan Africa region were studied for in vitro activity against Campylobacter spp. Some plants seemed very effective against the bacteria. Chemical compounds from three plants have been isolated and analyzed, but further studies are needed in order to produce new and effective drugs.