Antimalarial,antiplasmodial and analgesic activities of root extract of Alchornea laxiflora

Context: Alchornea laxiflora (Benth.) Pax. &; Hoffman (Euphorbiaceae) root decoctions are traditionally used in the treatment of malaria and pain in Nigeria.

Objective: To assess the antimalarial, antiplasmodial and analgesic potentials of root extract and fractions against malarial infections and chemically-induced pains.

Material and methods: The root extract and fractions of Alchornea laxiflora were investigated for antimalarial activity against Plasmodium berghei infection in mice, antiplasmodial activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method and analgesic activity against experimentally-induced pain models. Acute toxicity study of the extract, cytotoxic activity against HeLa cells and GCMS analysis of the active fraction were carried out.

Results: The root extract (75–225?mg/kg, p.o.) with LD₅₀ of 748.33?mg/kg exerted significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The root extract and fractions also exerted moderate activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ value of 38.44?±?0.89?μg/mL (Pf 3D7) and 40.17?±?0.78?μg/mL (Pf INDO). The crude extract was not cytotoxic to HeLa cells with LC₅₀ value >100?μg/mL. The crude extract and ethyl acetate fraction exerted significant (p?Discussion and conclusions: These results suggest that the root extract/fractions of A. laxiflora possess antimalarial, antiplasmodial and analgesic potentials and these justify its use in ethnomedicine to treat malaria and pain.     

Antipyretic and antimalarial activities of Solenostemon monostachyus

Context: Solenostemon monostachyus P. Beauv (Lamiaceae) is an important herb used traditionally in the treatment of malaria, fever, and other diseases.

Objectives: Antiplasmodial and antipyretic activities of S. monostachyus aerial extract were evaluated to ascertain the folkloric claim of its antimalarial and antipyretic activities.

Materials and methods: The extract (75–225?mg/kg) and fractions (chloroform and aqueous; 150?mg/kg) of S. monostachyus were investigated for suppressive, prophylactic, and curative antiplasmodial activities against chloroquine-sensitive Plasmodium berghei infections in Swiss albino mice and for antipyretic activity against 2,4-dinitrophenol and yeast-induced pyrexia. Artesunate (5?mg/kg) and pyrimethamine (1.2?mg/kg) were used as positive controls for antiplasmodial models. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice.

Results: The extract/fractions progressively reduced parasitaemia induced by chloroquine sensitive P. berghei infection in prophylactic (28.48–71.72%), suppressive (12.52–72.47%), and curative (22.4–82.34%) models in mice. These reductions were statistically significant (p?<?0.01–0.001). They also improved significantly (p?<?0.01–0.001) the mean survival time (MST) from 12.26 to 25.63?d relative to control (11.36?d). The activities of extract/fractions were incomparable with that of the standard drugs used (artesunate and pyrimethamine). The extract exerted prominent inhibition of pyrexia on dinitrophenol (87.33–90.11%, 5?h) and yeast (56.22–65.33, 5?h) induced pyrexia. Inhibition was significant (p?<?0.05–0.001) from 3 to 5?h post-administration of extract and in a dose-dependent fashion.

Conclusion: The plant may possess antiplasmodial and antipyretic effects which may in part be mediated through the chemical constituents of the plant.     

Landolphia owariensis leaf extracts reduce parasitemia in Plasmodium berghei-infected mice

Context Landolphia owariensis P. Beauv. (Apocyanaceae) leaf is used in southeast Nigeria to treat malaria.

Objective This study evaluated the antiplasmodial activity of L. owariensis leaf extract and fractions, also the phytoconstituents were standardized and analyzed.

Methods The effects of daily, oral administrations of 200, 400 and 800?mg/kg of L. owariensis leaf extract (LOE), its hexane (LOHF), ethyl acetate (LOEF) and methanol (LOMF) fractions on early, established and residual infections in Plasmodium berghei-infected albino mice were evaluated in vivo. The extract and fractions were subjected to phytochemical analysis and HPLC fingerprinting, and the acute toxicity of LOE was evaluated.

Results The extract and fractions elicited 29–86, 18–95 and 75–96% significant (p?<?0.001) suppression of parasitemia in early, established and residual infections, respectively. The ED₅₀ values for suppressive activity of LOE, LOHF, LOEF and LOMF were 266.56, 514.93, 392.95 and 165.70?mg/kg, respectively. The post-day 30-survival index was 16.7–50, 16.7, 16.7–66.7 and 50–83.3% for LOE, LOHF, LOEF, and LOMF, respectively. Extract-treated mice significantly (p?<?0.001) gained weight and had reduced mortality compared with negative control (untreated) mice. An oral LD₅₀ value >5000?mg/kg in mice was established for LOE. The LOMF showed the greatest antiplasmodial activity in all the models, suggesting that the antimalarial activity of the plant may be attributed to alkaloids, flavonoids, saponins and tannins present in the fraction.

Conclusion Results demonstrate the antiplasmodial activity of L. owariensis leaf, and provide a pharmacological rationale for its ethnomedicinal use as an antimalarial agent.     

Antiprotozoal screening of the Cuban native plant Scutellaria havanensis

Context: Scutellaria havanensis Jacq. (Lamiaceae) is a native medicinal herb with a history of use in Cuba.

Objective: This study screens the antiprotozoal activity of S. havanensis.

Materials and methods: Chloroform and methanol extracts from leaves and stems were evaluated in vitro at doses between 0.015 and 200?μg/mL against protozoan parasites: Plasmodium berghei, Trichomonas vaginalis and Leishmania amazonensis. Chloroform and methanol extracts were characterized by GC/MS. Cytotoxicity against mouse peritoneal macrophages was tested in parallel.

Results: Scutellaria havanensis extracts exhibited IC₅₀ values between 7.7 and 32.2?μg/mL against trophozoites of P. berghei and T. vaginalis; while the extracts were inactive against L. amazonensis promastigotes. Trichomonicidal activity of methanol extract exhibited the best selectivity but chloroform extract showed the highest antiplasmodial, trichomonicidal and cytotoxic activity. The majority of compounds in the chloroform extract were hydroxy and/or methoxyflavones (77.96%), in particular, wogonin (48.27%). In methanol extract, wogonin (5.89%) was detected. Trichomonicidal effect of wogonin was moderate (IC_50?=_?56?μM) and unspecific with respect to macrophages (SI?=?2). On the contrary, antiplasmodial activity of wogonin were particularly active (IC_50?=_?15?μM) demonstrating a higher selectivity index (SI?=?7.4).

Conclusions: Wogonin is an active principle compound of the chloroform extract of S. havanensis against P. berghei and T. vaginalis trophozoites, whereas the methanol extract of S. havanensis should be investigated more deeply as a trichomonicide. Our findings suggest that wogonin is potentially useful for the development of antimalarial alternative treatments.     

Antiplasmodial activity of aqueous extract of Berberis aristata roots against Plasmodium berghei-infected BALB/c mice

Abstract

Context: The rising problem of resistance to present antimalarial drugs stresses the need to look for newer antiplasmodial components with effective modes of action. The roots of Berberis aristata DC. (Berberidaceae) are used in the traditional medicine for malaria in various parts of India.

Objective: The objective of this study was to evaluate antiplasmodial activity of B. aristata roots extract for the validation of its traditional medicinal use.

Material and methods: Aqueous root extract of Berberis aristata (AREBA) was screened for its in vitro as well as in vivo antiplasmodial activity against lethal rodent malaria parasite Plasmodium berghei NK65. In vitro activity was evaluated against schizont maturation of P. berghei using various concentrations ranging from 1 to 100?µg/mL. For in vivo studies, AREBA at the doses of 150, 250, 350, and 650?mg/kg/d was administered to P. berghei infected BALB/c mice orally for 4 consecutive days (D0–D3).

Results: AREBA showed in vitro antiplasmodial activity with an IC₅₀ value of 40?µg/mL. In vivo studies demonstrated a variable dose-dependent chemosuppression with higher efficacy at lower doses. At a dose of 350?mg/kg/d, the suppressive and preventive activities were found to be 67.1% and 53.9%, respectively, followed by enhancing mean survival period up to 12.8?d for the curative assay versus 7.5?d for the untreated mice.

Discussion and conclusion: These results provide relevant scientific evidences for the traditional medicinal use of this plant as malaria remedy and further advocates the isolation and characterization of active antiplasmodial principle from this plant.     

In vivo antiplasmodial activities of aqueous extract of Bridelia ferruginea stem bark against Plasmodium berghei berghei in mice

Context: Bridelia ferruginea Benth (Euphorbiaceae) is an indigenous medicinal plant in Nigeria. It is usually a gnarled shrub which sometimes reaches the size of a tree in suitable condition. Decoctions of parts of this plant have been employed in ethno medicine in many parts of Africa for treatment of many ailments including malaria fever.

Objective: In vivo antiplasmodial activity of aqueous stem bark extract of BF was investigated against Plasmodium berghei-infected mice.

Materials and methods: The aqueous stem bark extract of BF (100–400?mg/kg) was administered orally to P. berghei-infected mice in both early and established models of antiplasmodial studies.

Results: The extract exhibited significant (p?<?0.05) antiplasmodial activity in early and established infection tests with a considerable mean survival time comparable to that of chloroquine, 10?mg/kg. The oral LD₅₀ obtained was greater than 5000?mg/kg in mice.

Discussion and conclusions: The findings show that aqueous stem bark extract of Bridelia ferruginea possesses considerable antiplasmodial activity which can be developed in malaria therapy.     

Antiplasmodial activity of extracts of 25 cyanobacterial species from coastal regions of Tamil Nadu

Context: Marine cyanobacteria offer considerable potential to isolate new antimalarials to meet a pressing need of our times.

Objective: To explore the antiplasmodial properties of marine cyanobacteria.

Materials and methods: Cyanobacterial samples collected from the coastal regions of Tamil Nadu were identified using light microscopy, and the strains were cultivated in ASN-III medium. Organic extracts (0–100?µg?mL^?1) of 25 in vitro mass-cultivated cyanobacteria, prepared using methanol: chloroform mixture (1:1?v/v) were evaluated for their antiplasmodial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum by fluorescence-based SYBR Green I assay where chloroquine was used as a control. To detect the toxic effects of cyanobacterial extracts against red blood cells, the invasion, maturation, and growth rate of malarial parasites in cyanobacterial extracts pre-treated versus untreated erythrocytes were quantified microscopically. Mammalian cell line (HeLa) was used to determine cyanobacterial extract toxicity using the MTT assay.

Results: The extracts of Lyngbya aestuarii Liebm. ex Gomont CNP 1005 (C12) Oscillatoria boryana BDU 91451 (C22) and Oscillatoria boryana Bory ex Gomont BDU 141071 (C18) showed promising antiplasmodial activity (IC₅₀?=?18, 18, and 51?μg?mL^?1 respectively) against Pf3D7. Pretreatment of red blood cells with IC₁₀₀ of C12, C18, and C22 (40, 100, and 40?µgmL^?1, respectively) did not significantly influence the invasion, maturation, and growth rate of malarial parasites in comparison with untreated RBC controls suggesting a lack of toxicity to host cells. MTT assay based IC₅₀ (>200?μg?mL^?1) of these extracts against HeLa cell line also indicates their high selectivity against the malaria parasite.

Discussion and conclusion: These exploratory studies suggest the possibilities of development of new antimalarial compounds from marine cyanobacteria.     

Antiproliferative and apoptotic activities of extracts of Asclepias subulata

Abstract

Context: Asclepias subulata Decne. (Apocynaceae) is a shrub used in the Mexican traditional medicine for the treatment of cancer.

Objective: The objective of this study was to evaluate the antiproliferative activity of methanol extract of aerial parts of A. subulata and its fractions against different cancer cell lines. Additionally, we analyzed the mechanism of action of the active fractions.

Materials and methods: Methanol extract fractions were prepared by serial extraction with n-hexane, ethyl acetate, and ethanol. The antiproliferative activity of methanol extract and its fractions was evaluated, against several murine (M12.C3.F6, RAW 264.7, and L929) and human (HeLa, A549, PC-3, LS 180, and ARPE-19) cell lines by the MTT assay, using concentrations of 0.4–400?µg/mL for 48?h. Ethanol and residual fractions were separated using silica gel column. Apoptosis induction of cancer cells was evaluated by Annexin and JC-1 staining using flow cytometry.

Results: Methanol extract and its fractions showed antiproliferative activity against all human cancer cell lines tested. Methanol extract had the highest antiproliferative activity on A549 and HeLa cells (IC₅₀ values?<?0.4 and 8.7?µg/mL, respectively). Ethanol and residual fractions exerted significant antiproliferative effect on A549 (IC₅₀?<?0.4?µg/mL) and PC3 cells (IC₅₀ 1.4 and 5.1?µg/mL). Apoptotic assays showed that CEF7, CEF9, CRF6, and CRF5 fractions induced mitochondrial depolarization in A549 cells, 70, 73, 77, and 80%, respectively. Those fractions triggered the apoptosis mitochondrial pathway.

Conclusion: Our data show that A. subulata extracts have potent antiproliferative properties on human cancer cell lines. This plant should be considered an important source of potent anticancer compounds.     

Evaluation of herbal antimalarial MAMA decoction-amodiaquine combination in murine malaria model

Context: Co-administration of amodiaquine with MAMA decoction (MD), an herbal antimalarial drug comprising the leaves of Mangifera indica L. (Anacardiaceae), Alstonia boonei De Wild (Apocynaceae), Morinda lucida Benth (Rubiaceae) and Azadirachta indica A. Juss (Meliaceae) was investigated. The practice of concurrent administration of herbal medicines with orthodox drugs is currently on the increase globally.

Objective: The study was designed to investigate the possible enhancement of the antimalarial potency as well as possible herb–drug interaction resulting from concurrent administration of MAMA decoction with amodiaquine (AQ).

Materials and methods: Combinations of MD with AQ were investigated in chloroquine (CQ)-sensitive Plasmodium berghei NK 65 in varying oral doses (mg/kg) at: sub-therapeutic [MD30?+?AQ1.25], therapeutic [MD120?+?AQ10] and median effective [MD40?+?AQ3.8], using chemosuppressive and curative antimalarial test models. Secondly, P. berghei ANKA (CQ-resistant)-infected mice were orally treated with MD 120, 240, [MD120?+?AQ10] and [MD240?+?AQ10] mg/kg, using both models. The survival times of mice were monitored for 28 d.

Results: ED₅₀ values of MD and AQ were 48.8 and 4.1?mg/kg, respectively. A total parasite clearance of CQ-sensitive P. berghei NK65 was obtained with the therapeutic combination dose in the curative test giving an enhanced survival time. In CQ-resistant P. berghei ANKA-infected mice, [MD120?+?AQ10] and [MD240?+?AQ10] mg/kg gave comparable activities with AQ (10?mg/kg) in both models.

Conclusion: The therapeutic combination dose gave total parasite clearance of CQ-sensitive P. berghei NK65, whereas none of the doses tested showed notable activity against CQ-resistant P. berghei ANKA.     

In vitro antiplasmodial and antimicrobial potential of Tagetes erecta roots

Context: Among strategies to combat malaria, the search for newer antimalarial compounds is a priority. Traditionally, Tagetes erecta Linn. (Compositae) has been used for the treatment of various diseases and ailments including malaria.

Objective: Five successive extracts (petroleum ether, chloroform, ethyl acetate, methanol and aqueous) of the roots of T. erecta and a new bithienyl compound, 2-hydroxymethyl-non-3-ynoic acid 2-[2,2']-bithiophenyl-5-ethyl ester from the roots of the plant, were evaluated for in vitro antiplasmodial activity against chloroquine sensitive and resistant strains of Plasmodium falciparum. The extracts were also tested for in vitro antimicrobial activity against seven microbial strains.

Materials and methods: The antiplasmodial screening was carried out using the schizont maturation inhibition assay. Preliminary antimicrobial screening was carried out using the agar well assay followed by determination of minimum inhibitory concentration (MIC) using two-fold serial dilutions.

Results: Among all the extracts tested, the ethyl acetate fraction exhibited significant antiplasmodial efficacy with the 50% inhibitory concentrations (IC₅₀) of 0.02 and 0.07?mg/mL against the chloroquine sensitive and resistant strains of Plasmodium falciparum respectively. The new bithienyl compound also showed significant schizonticidal activity against both chloroquine sensitive and resistant strains of Plasmodium falciparum with the IC₅₀ values of 0.01 and 0.02?mg/mL. Additionally, all extracts exhibited significant antimicrobial activity against three Gram-positive and two Gram-negative bacterial and two fungal strains with MIC values ranging between 12.5-100 µg/mL.

Discussion: The new bithienyl compound was profoundly able to arrest the ring stages of the malarial parasites thereby exerting its antiplasmodial effect.

Conclusion: The observations provide support for the ethnobotanical use of the plant.     

In vivo Antimalarial Activities of Russelia Equisetiformis in Plasmodium Berghei Infected Mice

The rising problem of resistance to most commonly used antimalarials remains a major challenge in the control of malaria suggesting the need for new antimalarial agents. This work explores the antiplasmodial potential of ethanol extract of Russelia equisetiformis in chloroquine Plasmodium berghei infected mice. Swiss albino mice were intraperitoneally infected with chloroquine-resistant P. berghei (ANKA). Experimental mice were treated for four days consecutively with graded doses of plant extracts and standard antimalarial drugs (artesunate and chloroquine) at a dose of 10 mg/kg body weight used as control. The extract showed a dose-dependent activity in the chemosuppression of P. berghei parasites by 31.6, 44.7, 48.4 and 86.5% at doses of 100, 200, 400 and 800 mg/kg, while chloroquine (10 mg/kg) and artesunate produced 59.4 and 68.4%, respectively. The extract showed a significant decrease in parasitaemia (P<0.05). The level of parasitemia and decrease in weight in all the treated groups was significantly lower (P<0.05) compared with the infected but untreated mice. The plant extract was devoid of toxicity at the highest dose tested (5000 mg/kg). The study concluded that the ethanol extract of R. equisetiformis possesses antimalarial effect, which supports the folk medicine claim of its use in the treatment of malaria.     

Zea mays,Stigma maydis prevents and extenuates acetaminophen-perturbed oxidative onslaughts in rat hepatocytes

Context: Zea mays L. (Poaceae) Stigma maydis is an underutilized product of corn cultivation finding therapeutic applications in oxidative stress-related disorders.

Objectives: This study investigated its aqueous extract against acetaminophen (APAP)-perturbed oxidative insults in rat hepatocytes.

Materials and methods: Hepatotoxic rats were orally pre- and post-treated with the extract (at 200 and 400?mg/kg body weight) and vitamin C (200?mg/kg body weight), respectively, for 14 days. Liver function, antioxidative and histological analyses were thereafter evaluated.

Results: The APAP-induced marked (p?<?0.05) increases in the activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase and the concentrations of bilirubin, oxidized glutathione, protein carbonyls, malondialdehyde, conjugated dienes, lipid hydroperoxides and fragmented DNA were dose-dependently extenuated in the extract-treated animals. The extract also significantly (p?<?0.05) improved the reduced activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase as well as total protein, albumin and glutathione concentrations in the hepatotoxic rats. These improvements may be attributed to the bioactive constituents as revealed by the gas chromatography–mass spectrometric chromatogram of the extract. The observed effects compared favourably with vitamin C and are informative of hepatoprotective and antioxidative attributes of the extract and were further supported by the histological analysis.

Conclusion: The data from the present findings suggest that Stigma maydis aqueous extract is capable of preventing and ameliorating APAP-mediated oxidative hepatic damage via enhancement of antioxidant defence systems.     

HPLC-DAD phenolic profile,cytotoxic and anti-kinetoplastidae activity of Melissa officinalis

Context Melissa officinalis subsp. inodora Bornm. (Lamiaceae) has been used since ancient times in folk medicine against various diseases, but it has not been investigated against protozoa.

Objective To evaluate the activities of M. officinalis against Leishmania braziliensis, Leishmania infantum and Trypanosoma cruzi as well as its cytotoxicity in fibroblast cell line.

Materials and methods The fresh leaves were chopped into 1?cm² pieces, washed and macerated with 99.9% of ethanol for 72?h at room temperature. Antiparasitic activity of M. officinalis was accessed by direct counting of cells after serial dilution, while the cytotoxicity of M. officinalis was evaluated in fibroblast cell line (NCTC929) by measuring the reduction of resazurin. The test duration was 24?h. High-performance liquid chromatography (HPLC) was used to characterise the extract.

Results The extract at concentrations of 250 and 125?μg/mL inhibited 80.39 and 54.27% of promastigote (LC_50? value?=_?105.78?μg/mL) form of L. infantum, 80.59 and 68.61% of L. brasiliensis (LC₅₀ value _?=_?110.69?μg/mL) and against epimastigote (LC₅₀ value _?=_?245.23?μg/mL) forms of T. cruzi with an inhibition of 54.45 and 22.26%, respectively, was observed. The maximum toxicity was noted at 500?μg/mL with 95.41% (LC_50? value?=_?141.01?μg/mL). The HPLC analysis identified caffeic acid and rutin as the major compounds.

Discussion The inhibition of the parasites is considered clinically relevant (<?500?μg/mL). Rutin and caffeic acids may be responsible for the antiprotozoal effect of the extract.

Conclusion The ethanol extract of M. officinalis can be considered a potential alternative source of natural products with antileishmania and antitrypanosoma activities.     

Antimalarial potential of extracts and isolated compounds from four species of genus Ammannia

The plants of genus Ammannia (Lythraceae) are being frequently used in traditional Chinese and Indian medicine to cure various diseases. The present study was designed to investigate the antimalarial potential of extracts and compounds from four species of genus Ammannia viz., A. multiflora, A. baccifera, A. verticillata, and A. coccinea. Properly dried and milled samples comprising of various plant parts were separately extracted with methanol and the extracts were fractionated with n-hexane, chloroform, and n-butanol. The chloroform (BR2), n-butanol (BR3) fractions of A. baccifera roots and methanol extract of A. coccinea (AC) showed potent in vitro antiplasmodial activity against Plasmodium falciparum NF-54 (IC₅₀ 3.5, 2.7, and 4.5 μg/ml, respectively) with nontoxicity to Vero cells as evident from their high selectivity index (>57.41, >74.07, and >44.44, respectively). Apart from these, 11 extracts/fractions possessed significant (IC₅₀ 14.5–40.2 μg/ml) antiplasmodial potential; most of which were nontoxic to Vero cells. The methanol extracts of A. verticillata aerial parts (VL) and AC, n-butanol fraction of A. multiflora (AM3) were evaluated for in vivo activity against rodent malaria parasite P. berghei, which showed percentage chemosuppression of parasitaemia in mice by 98.99, 63.33, and 60.00 %, respectively. The detailed phytochemical investigation of A. multiflora and A. baccifera afforded a total of 11 compounds; among them 4-hydroxy-α-tetralone, tetralone-4-O-β-d-glucopyranoside, and ammaniol exhibited moderate antiplasmodial activities (IC₅₀ 31.5, 36.1, and 22.6 μg/ml, respectively). Due to high degree of selective antiplasmodial activity, these plants may find their use in antimalarial phytopharmaceuticals as well as in the development and discovery of safer and novel antimalarial leads.     

Effects of Aphloia theiformis on key enzymes related to diabetes mellitus

Context: Aphloia theiformis (Vahl.) Benn. (Flacourtiaceae) (AT) is traditionally used for the management of diabetes mellitus (DM), but there is no scientific data regarding activity against enzymes linked to this condition.

Objective: To evaluate the kinetics of AT on key enzymes inhibition related to DM, and establish the antioxidant profile of AT.

Materials and methods: Dried powdered AT leaves were used to prepare crude methanol extract (70% v/v) (CME). Kinetics of CME (5000 to 156.25?μg/mL) on α-amylase, α-glucosidase, and lipase inhibition were studied. CME was partitioned using solvents of increasing polarity and kinetics of enzyme inhibition of each fraction (1000–31.25?μg/mL) was evaluated. Potent fractions were combined to assess any synergistic effect. Total phenol, flavonoid, tannin, anthocyanin contents, and antioxidant capacity of AT was evaluated using standard spectrophotometric methods.

Results: CME, ethyl acetate, and n-butanol fractions showed potent inhibitory activities against the enzymes with IC₅₀ ranging from 22.94–939.97?μg/mL. Significant (p?50 (15.72 and 157.03?μg/mL against α-amylase and lipase, respectively) was observed when ethyl acetate and n-butanol fractions were combined; showing synergism. The extracts showed noncompetitive inhibition against α-amylase and α-glucosidase. Ethyl acetate, n-butanol fractions, and CME showed highest antioxidant capacities (0.44–1.41?μg GAE/mg sample), and phenol content (211.74-675.53?μg GAE/mg sample).

Conclusion: This study supports the use of AT in the management of DM and provides the rationale for bioactivity guided isolation and characterization of compounds from the ethyl acetate and n-butanol fractions.     

Brine shrimp cytotoxicity and antimalarial activity of plants traditionally used in treatment of malaria in Msambweni district

Abstract

Context: In Kenya, most people use traditional medicine and medicinal plants to treat many diseases including malaria. To manage malaria, new knowledge and products are needed. Traditional herbal medicine has constituted a good basis for antimalarial lead discovery and drug development.

Objectives: To determine in vivo antimalarial activity and brine shrimp toxicity of five medicinal plants traditionally used to treat malaria in Msambweni district, Kenya.

Materials and methods: A 0.2?ml saline solution of 100?mg/kg aqueous crude extracts from five different plant parts were administered orally once a day and evaluated for their in vivo chemosuppressive effect using Plasmodium berghei berghei-infected Swiss mice for four consecutive days. Their safety was also determined using Brine shrimp lethality test: Grewia trichocarpa Hochst ex A. Rich (Tiliaceae) root, Dicrostachys cinerea (L) Wight et Am (Mimosaceae) root, Tamarindus indica L. (Caesalpiniaceae) stem bark, Azadirachta indica (L) Burn. (Meliaceae) root bark, and Acacia seyal Del. (Mimosaceae) root.

Results: Parasitaemia was as follows: A. indica, 3.1%; D. cinerea, 6.3%; T. indica, 25.1%; A. seyal, 27.8%; and G. trichocarpa, 35.8%. In terms of toxicity, A. indica root bark extract had an LC₅₀ of 285.8?µg/ml and was considered moderately toxic. T. indica stem bark extract and G. trichocarpa root extract had an LC₅₀ of 516.4 and 545.8?µg/ml, respectively, and were considered to be weakly toxic while A. seyal and D. cinerea root extracts had a LC₅₀ >1000?µg/ml and were, therefore, considered to be non-toxic.

Discussion and conclusion: All extracts had antimalarial activity that was not significant compared to chloroquine (p?≥?0.05). No extract was toxic to the arthropod invertebrate, Artemia salina L. (Artemiidae) larvae, justifying the continued use of the plant parts to treat malaria.     

Phytochemical analysis,antiproliferative and antioxidant activities of Chrozophora tinctoria: a natural dye plant

Context: Chrozophora tinctoria (L.) A. Juss. (Euphorbiaceae) is known as ‘dyer’s-croton’ and used to obtain dye substances. Recently, natural antioxidants and colorants have been of interest because of their safety and therapeutic effects.

Objective: This study investigates the antiproliferative and antioxidant activities of the various extracts and fractions from C. tinctoria and analyzes their phytochemical contents.

Materials and methods: The aerial parts of C. tinctoria were extracted with water, ethyl acetate, n-butanol, and methanol/chloroform. Phenolic compounds and other constituents of the extracts were analyzed by HPLC/TOF-MS. The ethyl acetate extract (EA) was fractionated by flash chromatography. The extracts, fractions, and major phenolic compounds were investigated for their antiproliferative activities on human cervical adenocarcinoma (HeLa) cell line at the concentrations of 5–100?μg/mL by using BrdU ELISA assay during 24?h of incubation. DPPH radical scavenging activities (5–150?μg/mL) and total phenolic contents of the samples were also evaluated.

Results: 4-Hydroxybenzoic acid (268.20?mg/kg), apigenin-7-glucoside (133.34?mg/kg), and gallic acid (68.92?mg/kg) were the major components of EA. CT/E-F6 (IC₅₀?=?64.59?±?0.01?μg/mL) exhibited the highest antiproliferative activity. CT/E-F2 (IC₅₀=?14.0?±?0.0?μg/mL) and some fractions displayed higher radical scavenging activity compared to synthetic antioxidant BHT (IC_50?=_?23.1?±?0.0?μg/mL). Among the main phenolics, gallic acid exhibited the highest antiproliferative and radical scavenging abilities (IC_50?<_?5?μg/mL).

Conclusion: In this study, we have determined the biologically active fractions and their high effects may be attributed to the presence of gallic acid.     

Evaluation of the antiplasmodial and cytotoxicity potentials of husk fiber extracts from Cocos nucifera, a medicinal plant used in Nigeria to treat human malaria

Nigeria is an African country where transmission of malaria occurs all year round and where most inhabitants use plants as remedies against parasitic diseases, including malaria. Some of such medicinal plants have their antimalarial efficacies already demonstrated experimentally, active compounds isolated and the mechanism of drug action suggested. Decoction of Cocos nucifera husk is used in the middle belt region of Nigeria as an antimalarial remedy. In our current studies, we tested extracts from husks of four varieties of C. nucifera, all collected in Brazil, where the plant fruit is popularly named 'coco'. The husks of coco mesti?o, amarelo, an?o and gigante collected in the Northeast of Brazil were used to prepare extracts at the Chemistry Department, Federal University of Alagoas (UFAL), which were then tested for their antiplasmodial activities, cytotoxicities and hemolytic activities in vitro. Only the hexane extract of coco mesti?o was active against the blood forms of Plasmodium falciparum human malaria parasite maintained in continuous culture. Most extracts presented selectivity indices of <10, while hexane extract of coco mesti?o had a selectivity index of 35, meaning that the extract is not toxic. The isolation of the active compounds from coco mesti?o husks has not yet been done.     

Bioassay-Guided Isolation of Antimalarial Triterpenoid Acids from the Leaves of Morinda lucida.

Abstract

The EtOH, CH₂Cl₂, and petroleum ether extracts from Morinda lucida. Benth. leaves have been shown to exhibit an in vitro. antiplasmodial activity against a chloroquine-sensitive Plasmodium falciparum. strain with IC₅₀ values 5.7 ± 1.3, 5.2 ± 0.8, and 3.9 ± 0.3 µg/mL, respectively. In vivo., at a daily oral dose of 200 mg/kg body weight, they produced at least 62.5%, 67.5%, and 72.2% reduction of parasitemia in mice infected with Plasmodium berghei berghei., respectively. A bioassay-guided fraction of the most active petroleum ether extract resulted in the isolation of two known triterpenic acids as ursolic acid 1 and oleanolic acid 2. In vitro., 1 and 2 exhibited an antiplasmodial activity with IC₅₀ values of 3.1 ± 1.3 and 15.2 ± 3.4 µg/mL, respectively. In vivo., at a daily dose of 200 mg/kg body weight, they produced 97.7% and 37.4% chemosuppression, respectively. However, all tested samples were inactive in vitro. against chloroquine-resistant Plasmodium falciparum. (K1) at the highest tested concentration of 25 µg/mL.     

Evaluation of antinociceptive and antidiarrhoeal properties of Manilkara zapota leaves in Swiss albino mice

Context Manilkara zapota (L.). P. Royen. (Sapotaceae) has been used in folk medicine to treat pain, diarrhoea, inflammation, arthralgia, and other disorders.

Objective Screening of Manilkara zapota leaves ethanol extract and its different solvent soluble fractions for possible antinociceptive and antidiarrhoeal activities in Swiss albino mice.

Materials and methods The extract and various fractions (200 and 400?mg/kg body weight; p.o.) were tested for peripheral and central antinociceptive activity by acetic acid-induced writhing and radiant heat tail-flick method, respectively; castor oil-induced diarrhoeal model was used to evaluate antidiarrhoeal activity at both doses. All the samples were administered once in a day and the duration of study was approximately 5?h.

Results Ethanol extract (400?mg/kg), petroleum ether fraction (400?mg/kg), and ethyl acetate fraction (400?mg/kg) showed significant peripheral antinociceptive activity having 59.89, 58.24, and 46.7% (p?<?0.001) of writhing inhibition, respectively, which is comparable with that of standard diclofenac (59.34% inhibition). The ethanol extract (400?mg/kg) and petroleum ether fraction (400?mg/kg) also showed promising central analgesic activity having 74.15 and 82.15% (p?<?0.001) elongation of reaction time, respectively, at 90?min after administration of sample which is also similar to that obtained by morphine (85.84% elongation). In antidiarrhoeal activity screening, ethanol extract (200 and 400?mg/kg) showed significant inhibition of defecation by 53.57 and 60.71%, respectively (p?<?0.001) compared with that of loperamide (71.42%).

Discussion and conclusion The findings of the studies demonstrated antinociceptive and antidiarrhoeal activities of M. zapota leaves which could be the therapeutic option against pain and diarrhoeal disease.