Senna occidentalis leaf extract possesses antitrypanosomal activity and ameliorates the trypanosome-induced anemia and organ damage

In vitro antidermatophytic activity of bioactive compounds from selected medicinal plants

Fungal infections are among the most difficult diseases to manage in humans. Eukaryotic fungal pathogens share many similarities with their host cells, which impairs the development of antifungal compounds. Therefore, it is desirable to harness the pharmaceutical potential of medicinal plants for antifungal drug discovery. In this study, the antifungal activity of sixteen plant extracts was investigated against selected dermatophytic fungi. Of the sixteen plants, the cladode (leaf) of Asparagus racemosus, and seed extract of Cassia occidentalis showed antifungal activity against Microsporum gypseum, Microsporum nanum, Trichophyton mentagrophytes and Trichophyton terrestre. The plant antifungal compounds were located by direct bioassay against Cladosporium herbarum. IR and NMR spectrometry analyses of these compounds identified the presence of saponin (in A. racemosus) and hydroxy anthraquinone (in C. occidentalis) in these antifungal compounds. The antidermatophytic activity of plant anthraquinone and saponins with reports of little or no hemolytic activity, makes these compounds ideal for alternative antifungal therapy and warrants further in-depth investigation in vivo.

Use of herbal remedies in the management of sleeping sickness in four northern provinces of Angola

ETHNOPHARMACOLOGICAL RELEVANCE

This study reports for the first time on the use of folk medicine to treat sleeping sickness and its symptoms in four endemic provinces in northern Angola. By interviewing both traditional practitioners and confirmed patients, it highlights reasons to recourse to folk medicine, the plant species used for this affection as well as arises awareness about the use of particular plants showing potential risks.

AIM OF THE STUDY

The aims of this explorative study were three-fold. Firstly, it informed on access to, and use of plant-based medicine as first-choice treatment by infected persons. Secondly, it aimed at collecting comprehensive data from patients and traditional healers on herbal remedies in order to identify plant species used in the management of the disease. Thirdly, it served as contribution for primary indication of potential risk of use associated with the studied plants and their preparation.

MATERIALS AND METHODS

The study was conducted in 4 endemic provinces of Angola, namely Bengo, Zaire, Kwanza Norte and Uíge. We explored the use of herbal remedies by conducting structured and semi-structured interviews within two distinct study populations. The first group comprises 30 patients who had been diagnosed for trypanosomiasis and treated by the reference treatment. The second group included 9 traditional practitioners who had already treated sleeping sickness. The plants that were cited during the interviews were collected during field walks under supervision of a traditional healer, then authenticated and deposited at the National Herbarium in Luanda.

RESULTS

Of the 30 included patients, 12 (40%) had turned to folk medicine in the management of trypanosomiasis and related symptoms. 7 medicinal plants were reported by this group. Considering the key motivation to consult a traditional practitioner, two main factors accounted for half of the cases: "past experience with folk medicine" and "family habit". Out of 9 traditional practitioners' interviewees, 26 medicinal plants were cited. Roots and leaves were the most used plant parts, and decoction was the common mode of preparation. Evidence for antitrypanosomal activity in the scientific literature was found for 56% (17 of 30) of the identified plant species. The most cited plant was Crossopteryx febrifuga (UR = 6). Some of the cited plants, as for example Aristolochia gigantea, raised concern about potential toxicity.

CONCLUSIONS

With 40% of infected persons having turned first to folk medicine before consulting a medical doctor, this explorative study points out that plant-based medicines play an important role in local dynamics of health care. It highlights the need for primary assessment of potential risk of use related to the herbal recipes, and for reporting it to the concerned population. This first ethnobotanical study on trypanosomiasis in endemic provinces of Angola provides information on 30 plants, of which some had been identified as promising for further pharmacological research. Our results provide a first step towards the validation and valorization of Angolan herbal remedies for sleeping sickness.

In vitro antiprotozoan activity and mechanisms of action of selected Ghanaian medicinal plants against Trypanosoma, Leishmania, and Plasmodium parasites

Trypanosomiasis, leishmaniasis, and malaria are protozoan infections of public health importance with thousands of new cases recorded annually. Control of these infection(s) with existing chemotherapy is limited by drug toxicity, lengthy parenteral treatment, affordability, and/or the emergence of resistant strains. Medicinal plants on the other hand are used in the treatment of various infectious diseases although their chemical properties are not fully evaluated. In this study, we screened 112 crude extracts from 72 selected Ghanaian medicinal plants for anti-Trypanosoma, anti-Leishmania, and anti-Plasmodium activities in vitro and investigated their mechanisms of action. Twenty-three extracts from 20 plants showed significant antiprotozoan activity against at least 1 of 3 protozoan parasites screened with IC₅₀ values less than 20 μg/ml. Eleven extracts showed high anti-Trypanosoma activity with Bidens pilosa whole plant and Morinda lucida leaf extracts recording the highest activities. Their IC₅₀ (selectivity index [SI]) values were 5.51 μg/ml (35.00) and 5.96 μg/ml (13.09), respectively. Nine extracts had high anti-Leishmania activity with Annona senegalensis and Cassia alata leaf extracts as the most active. Their IC₅₀ (SI) values were 10.8 μg/ml (1.50) and 10.1 μg/ml (0.37), respectively. Six extracts had high anti-Plasmodium activity with the leaf and stem-bark extracts of Terminalia ivorensis recording the highest activity. Their IC₅₀ (SI) values were 7.26 μg/ml (129.36) and 17.45 μg/ml (17.17), respectively. Only M. lucida at 25 μg/ml induced significant apoptosis-like cell death in Trypanosoma parasites. Anti-Leishmania active extracts induced varying morphological changes in Leishmania parasites such as multiple nuclei and/or kinetoplast, incomplete flagella division, or nuclear fragmentation. Active extracts may be potential sources for developing new chemotherapy against these infections.

Trypanosuppresive effects of ellagic acid and amelioration of the trypanosome-associated pathological features coupled with inhibitory effects on trypanosomal sialidase in vitro and in silico

BACKGROUND

The search for novel antitrypanosomal agents had previously led to the isolation of ellagic acid as a bioactive antitrypanosomal compound using in vitro studies. However, it is not known whether this compound will elicit antitrypanosomal activity in in vivo condition which is usually the next step in the drug discovery process.

PURPOSE

Herein, we investigated the in vivo activity of ellagic acid against bloodstream form of Trypanosoma congolense and its ameliorative effects on trypanosome-induced anemia and organ damage as well as inhibitory effects on trypanosomal sialidase.

METHODS

Rats were infected with T. congolense and were treated with 100 and 200mg/kg body weight (BW) of ellagic acid for fourteen days. The levels of parasitemia, packed cell volume and biochemical parameters were measured. Subsequently, T. congolense sialidase was partially purified on DEAE cellulose column and the mode of inhibition of ellagic acid on the T. congolense sialidase determined. Molecular docking study was also conducted to determine the mode of interaction of the ellagic acid to the catalytic domain of T. rangeli sialidase.

RESULTS

At a dose of 100 and 200mg/kg (BW), ellagic acid demonstrated significant (P < 0.05) trypanosuppressive effect for most of the 24 days experimental period. Further, the ellagic acid significantly (P < 0.05) ameliorated the trypanosome-induced anemia, hepatic and renal damages as well as hepatomegaly, splenomegaly and renal hypertrophy. The trypanosome-associated free serum sialic acid upsurge alongside the accompanied membrane bound sialic acid reduction were also significantly (P < 0.05) prevented by the ellagic acid treatment. The T. congolense sialidase was purified to a fold of 6.6 with a yield of 83.8%. The enzyme had a K_M and Vmax of 70.12mg/ml and 0.04µmol/min respectively, and was inhibited in a non-competitive pattern by ellagic acid with an inhibition binding constant of 1986.75μM. However, in molecular docking study, ellagic acid formed hydrogen bonding interaction with major residues R³⁹, R³¹⁸, and W¹²⁴ at the active site of T. rangeli sialidase with a predicted binding free energy of -25.584kcal/mol.

CONCLUSION

We concluded that ellagic acid possesses trypanosuppressive effects and could ameliorate the trypanosome-induced pathological alterations.

Ethnopharmacological appraisal of culturally important medicinal plants and polyherbal formulas used against communicable diseases in Rodrigues Island

ETHNOPHARMACOLOGICAL RELEVANCE

The tropical island of Rodrigues is one of three islands that constitute the Mascarene archipelago in the Indian Ocean. Currently considered as a biodiversity hotspot, the island has also a resilient history in the use of traditional medicine. However, there has been no ethnopharmacological study to document quantitatively such traditional practice against communicable diseases (CD), which currently accounts for 6.61% annual death and 30.7% attendances in public hospitals. The aim of the present study was to collect, analyse, and document traditionally used medicinal plants (MP) and polyherbal formulas from key informants and traditional medicine practitioners (TMP) in Rodrigues to treat and/or manage common CD.

MATERIALS AND METHODS

Data was collected via face-to-face interviews with MP users (n=113) and TMP (n=9) from 17 key sites. Seven quantitative ethnopharmacological indices, namely family use value (FUV), use value (UV), informant agreement ratio (IAR), relative frequency of citation (RFC), fidelity level (FL), relative importance (RI), and ethnobotanicity index (EI) were calculated.

RESULTS

Ninety-seven plants belonging to 49 families were recorded to be in common use as monotherapy (80 plants) and/or as part of polyherbal preparation (23 plants) for the treatment and/or management of 16 different CD. Thirteen MPs were found to have a maximum FL of 100% for CD. The highest IAR (0.98) was observed for diseases of the eye and adnexa and skin and subcutaneous tissue. The highest FUV was for Arecaceae. Ayapana triplinervis (Vahl) R.M. king et H.Rob. scored the highest UV (UV=2.72). Seven endemic medicinal plants have been recorded to be employed in cultural rituals for the management of common CDs, whereas 14 polyherbal preparations were used to treat and/or manage 6 different types of CDs. Side effects were also reported following use of some these medicinal plants.

CONCLUSION

Given the dearth of updated information on traditional medicine from Rodrigues, this work has provided an opportunity to establish valuable primary information on the different MP used by the local people. Further research is needed to probe into the possible active constituents that could open new perspectives for further pharmacological research and hence be the basis of an evidence-based investigation to discover new drugs.

A comparative ethnopharmacological analysis of traditional medicine used against respiratory tract diseases in Mauritius

ETHNOPHARMACOLOGICAL RELEVANCE

Despite laudable advances in conventional medicine, respiratory tract diseases (RTD) induced morbidity and mortality continue to inflict a substantial burden on healthcare systems worldwide. Similarly, in the tropical island of Mauritius, 13,320 hospital admissions and 8.2% mortality rates were attributed to RTD solely in the year 2013. Consequently, the therapeutic benefits and relief experienced with traditional medicine (TM) against RTD by the local inhabitants cannot be underestimated. The present study aims to report and quantitatively determine the extent of utilization of plant based therapies and other miscellaneous TM preparations concocted against RTD over the island. Additionally, a similarity index was generated which is indicative of the extent of harmonisation of individual plant species against RTD when the uses mentioned in the study are compared to previous ethnobotanical studies.

MATERIALS AND METHODS

Data was compiled using a semi-structured questionnaire via face-to-face interviews with TM users and practitioners (n=384). Three quantitative ethnopharmacological indices (the use value (UV), informant consensus factor (ICF), and ethnobotanicity index (EI)) were calculated. We also calculated the similarity ratio, similarity percentage, new uses for each plant species and percentage of new use against RTD to compare primary data collected in the present study.

RESULTS

Fifty five plants were documented to be in use against 18 RTD. The most used plant species belonged to the following taxa; Lamiaceae (9%), Fabaceae (7%) and Rutaceae (7%). Thirty two plants recorded in this study have been reported to be used against RTD in previous ethnobotanical studies, of which 22 of these plants have been attributed new uses against RTD based on the results of the present study. The remaining 23 plants species have been recorded for the first time to be used traditionally against RTD. Altogether, 81 different recipes were concocted from the medicinal plants and the most common route of administration was oral intake. Common methods of obtaining medicinal plants were from the wild, cultivation and as imported herbal products. Cough was the most common RTD managed by plant species. The largest proportion of plants were employed against cold. The preference ranking both for UV placed Curcuma longa L., Zingiber officinale Roscoe, Citrus×limonia Osbeck and Cymbopogon citratus (DC.) Stapf as the most useful plant species. Only a small proportion of the indigenous plants (7.73%) proved to be useful in TM.

CONCLUSION

This study provides empirical primary ethnopharmacological data on the use of TM to manage and/or treat RTD and can contribute in preserving indigenous knowledge in Mauritius. It is anticipated that these primary data will open new avenues to identify novel drugs that can help to alleviate sufferings.

Mosquitocidal and antiplasmodial activity of Senna occidentalis (Cassiae) and Ocimum basilicum (Lamiaceae) from Maruthamalai hills against Anopheles stephensi and Plasmodium falciparum

Each year, mosquito-borne diseases infect nearly 700 million people, resulting to more than 1 million deaths. In this study, we evaluated the larvicidal, pupicidal, and smoke toxicity of Senna occidentalis and Ocimum basilicum leaf extracts against the malaria vector Anopheles stephensi. Furthermore, the antiplasmodial activity of plant extracts was evaluated against chloroquine (CQ)-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. In larvicidal and pupicidal experiments, S. occidentalis LC50 ranged from 31.05 (I instar larvae) to 75.15 ppm (pupae), and O. basilicum LC50 ranged from 29.69 (I instar larvae) to 69 ppm (pupae). Smoke toxicity experiments conducted against adults showed that S. occidentalis and O. basilicum coils evoked mortality rates comparable to the pyrethrin-based positive control (38, 52, and 42%, respectively). In antiplasmodial assays, Senna occidentalis 50% inhibitory concentration (IC50) were 48.80 μg/ml (CQ-s) and 54.28 μg/ml (CQ-r), while O. basilicum IC50 were 68.14 μg/ml (CQ-s) and 67.27 μg/ml (CQ-r). Overall, these botanicals could be considered as potential sources of metabolites to build newer and safer malaria control tools.

Anti-trypanosomal activity of nigerian plants and their constituents

African trypanosomiasis is a vector-borne parasitic disease causing serious risks to the lives of about 60 million people and 48 million cattle globally. Nigerian medicinal plants are known to contain a large variety of chemical structures and some of the plant extracts have been screened for antitrypanosomal activity, in the search for potential new drugs against the illness. We surveyed the literatures on plants and plant-derived products with antitrypanosomal activity from Nigerian flora published from 1990 to 2014. About 90 plants were identified, with 54 compounds as potential active agents and presented by plant families in alphabetical order. This review indicates that the Nigerian flora may be suitable as a starting point in searching for new and more efficient trypanocidal molecules.

Ethnopharmacological analysis of medicinal plants and animals used in the treatment and management of pain in Mauritius

ETHNOPHARMACOLOGICAL RELEVANCE

Pain is a multi-faceted and multi-factorial condition which is challenging to manage and treat. Conventional therapies such as analgesics, Non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids amongst others have been successful to some extent in its management and treatment. Nonetheless, such therapies tend to be accompanied by undesirable effects and have a limited therapeutic range. Consequently, there is a pressing need to probe for novel analgesic and anti-nociceptive drugs from traditional medicines (TM). This study was designed to record, document and analyze herbal and animal-based therapies used for the management and treatment of pain in the tropical of Mauritius.

MATERIALS AND METHODS

Data was collected via face-to-face interviews with TM users (n=332) and practitioners (n=20). Seven quantitative ethnopharmacological indexes, namely family use value (FUV), use value (UV), informant agreement ratio (IAR), relative frequency of citation (RFC), fidelity level (FL), relative importance (RI) and ethnobotanicity index (EI) were calculated.

RESULTS

A total of 79 plant species distributed within 40 families and 20 polyherbal preparations was recorded. Interestingly, 6 indigenous/endemic plants have been reported for the first time to be in common use for pain management and treatment in Mauritius. The most significant biologically important plant family was Xanthorrhoeaceae with highest FUV. The species which ranked highest according to its UV was Morinda citrifolia L. Morinda citrifolia L. and Ricinus communis L. also scored the highest RFC. The IAR values for the disease categories were high (0.95-0.97). Based on EI, plants species which are known to be useful in TM accounted for 11.5% of the total flora in Mauritius. Coix lacryma-jobi L. (FL=100%) had highest FL for lower back ache. Morinda citrifolia L. scored highest on most of the quantitative indices calculated including RI, which is endorsed by extensive documentation on its versatility and particularly its anti-nociceptive properties. Seven animal species were recorded to be in common use.

CONCLUSION

The present ethnopharmacological study revealed a panoply of TM to be in common use for pain management and treatment in Mauritius. This study has documented for the first time medicinal plants and animal species with potential analgesic and/or anti-nociceptive properties. This study has therefore provided important baseline primary data for the discovery of new lead molecules for drug development geared towards pain management and treatment.

Anti-trypanosomal activity of African medicinal plants: a review update

ETHNOPHARMACOLOGICAL RELEVANCE

African trypanosomiasis is one of the neglected tropical diseases caused by different species of trypanosomes that affect both human and livestock with devastating consequences in the continent. Most of the affected populations commonly use traditional medicinal plants for the treatment of the disease. Consequently, this prompted ethnopharmacological research activities on the anti-trypanosomal activity of a number of these African medicinal plants in order to validate their ethnomedicinal use. Furthermore, such studies could lead to the identification of chemical leads for the development of newer anti-trypanosomal agents from those plants. This review aims to provide updated information on the ethnopharmacological evidence of African medicinal plants with anti-trypanosomal activity.

METHODS

Literature was collected via electronic search (PubMed, Sciencedirect, Medline and Google Scholar) from published articles that report on the in vitro or in vivo anti-trypanosomal activity of plants that were collected from different parts of Africa.

RESULTS

African medicinal plants investigated for in vitro and in vivo anti-trypanosomal activity from January 1993 to October 2013 are systematically compiled and all the in vivo studies are critically discussed. A total of 264 plant species belonging to 79 families were investigated for anti-trypanosomal activity. However, only 48 bioactive anti-trypanosomal compounds were successfully isolated in pure forms. Furthermore, some of the plants were investigated for possible ameliorative effects on the trypanosome-induced pathological changes out of which 18 plants were reported to be effective while a few others were not. In spite of interesting preclinical ethnopharmacological evidence for anti-trypanosomal activity, not a single African medicinal plant was investigated in a clinical study.

CONCLUSION

Several African medicinal plants have demonstrated promising anti-trypanosomal effects but the studies on the anti-trypanosomal potentials of these plants are not taken beyond proof of concept stage. It is hoped that the article would stimulate future clinical studies because of the paucity of knowledge in this area.

Saponins-rich fraction of Calotropis procera leaves elicit no antitrypanosomal activity in a rat model

OBJECTIVE

To examine the in vitro and in vivo anti-Trypanosoma evansi (T. evansi ) activity of saponins-rich fraction of Calotropis procera (cpsf) leaves as well as the effect of the fraction on the parasite-induced anemia.

METHODS

A 60-minutes time course experiment was conducted with various concentrations of the fraction using a 96-well microtiter plate technique, and subsequently used to treat experimentally T. evansi infected rats at 100 and 200 mg/kg body weight. Index of anemia was analyzed in all animals during the experiment.

RESULTS

The cpsf did not demonstrate an in vitro antitrypanosomal activity. Further, the cpsf treatments did not significantly (P>0.05) keep the parasites lower than the infected untreated groups. At the end of the experiment, all T. evansi infected rats developed anemia whose severity was not significantly (P>0.05) ameliorated by the cpsf treatment.

CONCLUSIONS

It was concluded that saponins derived from Calotropis procera leaves could not elicit in vitro and in vivo activities against T. evansi.

Phenolics-rich fraction of Khaya senegalensis stem bark: antitrypanosomal activity and amelioration of some parasite-induced pathological changes

CONTEXT

The stem bark of Khaya senegalensis A. Juss (Meliaceae) is currently used for the treatment of trypanosomiasis by traditional practitioners in Nigeria.

OBJECTIVES

The present study investigated the anti-Trypanosoma brucei brucei activity of phenolics-rich fraction of K. senegalensis (pfks) and its ameliorative effects on trypanosome-induced pathological changes.

MATERIALS AND METHODS

The fraction was initially analyzed by gas chromatography-mass spectrometry (GC-MS). A 60 min time course experiment was conducted with various concentrations of the fraction using a 96-well microtiter plate technique and was further used to treat T. brucei infected rats at 100, 200 and 300 mg/kg body weight (BW). Indices of anemia as well as hepatic and renal functions were analyzed in all experimental animals at the end of the experiment.

RESULTS

The GC-MS analysis of the pfks revealed that the most abundant phytochemicals are phloroglucinol (40.56%) and 3,4-(dihydroxyphenyl) acetic acid (41.76%). The fraction showed a concentration dependent in vitro antitrypanosomal activity. Interestingly, the fraction completely eliminated the parasites from the bloodstream of infected rats without relapse during the experimental period at the dose of 300 mg/kg BW and also kept the parasites consistently lower at 100 and 200 mg/kg BW than that was recorded in the untreated infected rats. Furthermore, the severity of T. brucei-induced anemia and hepatic damage was significantly (p < 0.05) ameliorated in the 300 mg/kg BW treatment group whereas the parasite-induced renal damage was significantly (p < 0.05) ameliorated in all treatment groups.

CONCLUSION

Data from this study may suggest that phenolics play an important role in the antitrypanosomal activity of K. senegalensis.

Antitrypanosomal potentials of the extract and fractions of Abrus precatorius seeds

OBJECTIVE

To evaluate the in vivo trypanocidal activity of the methanol extract and fractions of Abrus precatorius seeds in mice.

METHODS

Parasiteamia was induced unto mice by intraperitoneal injection of 1.25×10(5)Trypanosoma in normal saline. Five days when a high level of parasiteamia was established treatment commenced until ten days. The mice were treated with 10, 20 and 40 mg/kg bt. of the extract and 5 and 10 mg/kg bt. of the fraction (F(2)), respectively for 5 days. Diminazene aceturate at the dose of 3.5 mg/kg bt. for two days was used as the reference drug. The level of parasitaemia and packed cell volume (PCV) of the animals estimated.

RESULTS

At doses of 10, 20 and 40 mg/kg the crude extract showed a sharp reduction in the level of parasitaemia in mice compared with the untreated group. The mice treated with F(2) at doses of 5 and 10 mg/kg showed a sharp reduction in the level of parasitamia to zero in day 9, and a gradual recovery from the 12th day of treatment. This effect is comparable to that of the mice treated with 7 mg/kg of standard drug diminazene aceturate. The PCV of the treated showed a gradual decrease with time, but not as much as the untreated group. Phytochemical screening revealed the presence of glycosides, alkaloids, carbohydrates, tannins and proteins in the Abrus precatorius powder while F(2) was rich in alkaloids.

CONCLUSIONS

This study shows that both the extract and the fractions of Abrus precatorius seeds exhibited a promising trypanocidal property. Alkaloids may be responsible for the observed activity.

Acute and subacute toxicity of Cassia occidentalis L. stem and leaf in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cassia occidentalis L. (syn. Senna occidentalis; Leguminosae) has been used as natural medicine in rainforests and tropical regions as laxative, analgesic, febrifuge, diuretic, hepatoprotective, vermifuge and colagogo. Herein, we performed a pre-clinical safety evaluation of hydroalcoholic extract of Cassia occidentalis stem and leaf in male and female Wistar rats.

MATERIALS AND METHODS

In acute toxicity tests, four groups of rats (n=5/group/sex) were orally treated with doses of 0.625, 1.25, 2.5 and 5.0 g/kg and general behavior, adverse effects and mortality were recorded for up to 14 days. In subacute toxicity assays, animals received Cassia occidentalis by gavage at the doses of 0.10, 0.50 or 2.5 g/kg/day (n=10/group/sex) for 30 days and biochemical, hematological and morphological parameters were determined.

RESULTS

Cassia occidentalis did not produce any hazardous symptoms or death in the acute toxicity test, showing a LD(50) higher than 5 g/kg. Subacute treatment with Cassia occidentalis failed to change body weight gain, food and water consumption and hematological and biochemical profiles. In addition, no changes in macroscopical and microscopical aspect of organs were observed in the animals.

CONCLUSIONS

Our results showed that acute or subacute administration of Cassia occidentalis is not toxic in male and female Wistar rats, suggesting a safety use by humans.