Phytochemical investigation and in vitro antioxidant activity of an indigenous medicinal plant Alpinia nigra B.L. Burtt

Objective

To investigate antioxidant potential of methanol extract of Alpinia nigra leaves.

Methods

The study was done by using various in vitro methods such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), nitric oxide and hydrogen peroxide radical scavenging assays. Phytochemical constituents, total phenolic content and total flavonoid content of the extract at different concentrations (10-500 µg/mL) were determined.

Results

Alpinia nigra leaves showed high free radical scavenging activity as evidenced by the low IC₅₀ values in DPPH (64.51 µg/mL), in ABTS (28.32 µg/mL), in nitric oxide (80.02 µg/mL) and in H₂O₂ (77.45 µg/mL) scavenging assays. Furthermore the TPC and TFC of the extract were found to be 69.25 mg gallic acid equivalent per gram of extract and 78.84 mg quercetin equivalent per gram of extract respectively.

Conclusions

The results of present comprehensive analysis demonstrated that Alpinia nigra leaves possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a viable source of natural antioxidants and might be exploited for functional foods and neutraceutical applications.     

Pedalium murex Linn (Pedaliaceae) fruits: a comparative antioxidant activity of its different fractions

Objective

To examine the antioxidant activity and total phenolic content of different solvent fractions of Pedalium murex (P. murex) Linn fruits (Family: Pedaliaceae) as well as the correlation between the total antioxidant capacity and total phenolic content.

Methods

In the present study, the antioxidant activities of P. murex were evaluated using six in-vitro assays, namely total antioxidant assay, DPPH assay, reducing power, nitric oxide scavenging, hydrogen peroxide scavenging and deoxyribose scavenging assays, and total phenol contents were also investigated.

Results

The ethyl acetate (EA) fraction was found to have high levels of phenolic content (298.72±2.09 mg GAE/g). The EA fraction exhibit higher total antioxidant capacity, higher percentage of DPPH radical scavenging activity (135.11±2.95µg/mL), nitric oxide (200.57±4.51µg/mL), hydrogen peroxide (217.91±6.12 µg/mL), deoxyribose (250.01±4.68µg/mL) and higher reducing power. Correlation coefficient (r²=0.914) was found to be significant between total phenolic content and total antioxidant activity.

Conclusions

In general, the results indicate that the EA fractions are rich in phenolic antioxidants with potent free radical scavenging activity implying their importance to human health.     

Screening of flavonoid “quercetin” from the rhizome of Smilax china Linn. for anti-psoriatic activity

Objective

To assess anti-psoriatic activity of the methanol extract and the isolated flavonoid quercetin from the rhizome of Smilax china (S. china) Linn.

Methods

Mouse tail test was used for the evaluation of anti-psoriatic activity. Methanol extract (100 and 200 mg/kg b.w.) and isolated flavonoid quercetin (25 and 50 mg/kg b.w.) were tested in Swiss albino mice. Parameters studied in the mouse tail test were changes in epidermal thickness and percentage orthokeratotic values. The anti-inflammatory role of the methanol extract and isolated flavonoid quercetin was evaluated using carrageenan-induced pleurisy in rats. In vitro antiproliferant assay on HaCaT cell lines was also carried out.

Results

The isolated flavonoid quercetin from the rhizome of S. china produced significant orthokeratosis (P<0.01) in the mouse tail test. In epidermal thickness, a significant reduction with respect to control was observed in groups treated with retinoic acid and isolated flavonoid quercetin. The methanol extract (200 mg/kg) and isolated flavonoid quercetin (50 mg/kg) showed anti-inflammatory effect in terms of significant inhibition (P<0.001) in leukocyte migration. Maximum antiproliferant activity was shown by isolated flavonoid quercetin (IC₅₀, 62.42±10.20 µg/mL).

Conclusions

From the above data, the flavonoid quercetin shows significant orthokeratosis, anti-inflammatory and maximum antiproliferant activities. To our knowledge, this is the first report on the anti-psoriatic effect of the flavonoid quercetin which is promising for further investigations to prove its anti-psoriatic activity.     

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta,Sargassaceae) collected from Gulf of Mannar

Objective

To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp. [Turbinaria conoides (T. conoides) and Turbinaria ornata (T. ornata) collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.

Methods

The antioxidant activity was evaluated using different in vitro systems, viz., 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2′-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt (ABTS), H₂O₂/HO radical scavenging, Fe²⁺ ion chelating ability, and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts, and the results were expressed as mg of gallic acid equivalents (GE)/g of the seaweed extracts. Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.

Results

Ethyl acetate (EtOAc) fraction of T. conoides registered significantly higher phenolic content (105.97 mg GE/g) than that of T. ornata (69.63 mg GE/g). Significantly higher antioxidant potential as determined by DPPH (64.14%) radical scavenging activity was registered in EtOAc fraction of T. ornata. A higher ABTS^•+ radical scavenging (IC₅₀ 3.16 µg/mL), Fe²⁺ chelating (IC₅₀ 0.46 mg/mL), H₂O₂ scavenging (IC₅₀ 4.25 mg/mL), lipid peroxidation inhibitory (TBARS, IC₅₀ 0.21 mg/mL), and reducing abilities (IC₅₀ 52.67 mg/mL) (P<0.05) were realized in EtOAc fraction of T. ornata than other fractions.

Conclusions

This study indicated the potential use of T. conoides and T. ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption, and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.     

A comparative study of the antioxidant,antimicrobial, cytotoxic and thrombolytic potential of the fruits and leaves of Spondias dulcis

Objective

To investigate the antioxidant, antimicrobial, cytotoxic and thrombolytic property of the fruits and leaves of Spondias dulcis (S. dulcis).

Methods

Methanolic extracts of fruits and leaves of S. dulcis were partitioned with chloroform and dichloromethane. The antioxidant potential of the crude extract and partitioned fractions were evaluated in terms of total phenolic content, total flavonoid content, DPPH radical scavenging potential, reducing potential and total antioxidant capacity by specific standard procedures. The antimicrobial activity was evaluated using disc diffusion method. The cytotoxicity was evaluated by using brine shrimp lethality bioassay and compared with vincristine sulfate. The thrombolytic activity was compared with streptokinase.

Results

The methanolic fruit extract exhibited the highest phenolic content, flavonoid content and antioxidant capacity, among the other extracts, with the highest DPPH radical scavenging activity at a concentration of 10 µg/mL (IC₅₀: 1.91 µg/mL) and maximum reducing power at a concentration of 100 µg/mL (EC₅₀: 3.58 µg/mL). Though all extract showed moderate antimicrobial activity against the bacterial strains, weak or no activity against fungus. The range of LC₅₀ value of all extracts was 1.335-14.057 µg/mL which was far lower than the cut off index for cytotoxicity. All extracts exhibited statistically significant (P<0.001) thrombolytic activity.

Conclusions

Our study suggested that S. dulcis exhibits antimicrobial activities against a wide variety of strains while it possesses significant antioxidant, cytotoxic and thrombolytic activity.     

African eggplant (Solanum anguivi Lam.) fruit with bioactive polyphenolic compounds exerts in vitro antioxidant properties and inhibits Ca2+-induced mitochondrial swelling

Objective

To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit (SAG) and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential (ΔΨ_m) isolated from rat liver.

Methods

Antioxidant activity of SAG was assayed by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, iron chelation and ability to inhibit lipid peroxidation in both liver and brain homogenate of rats. Also, the effect of SAG on mitochondrial membrane potential and mitochondrial swelling were determined. Identification and quantification of bioactive polyphenolics was done by HPLC-DAD.

Results

SAG exhibited potent and concentration dependent free radical-scavenging activity (IC₅₀/DPPH=275.03±7.8 µg/mL). Reductive and iron chelation abilities also increase with increase in SAG concentration. SAG also inhibited peroxidation of cerebral and hepatic lipids subjected to iron oxidative assault. SAG protected against Ca²⁺ (110 µmol/L)-induced mitochondrial swelling and maintained the ΔΨ_m. HPLC analysis revealed the presence of gallic acid [(17.54±0.04) mg/g], chlorogenic acid (21.90±0.02 mg/g), caffeic acid (16.64±0.01 mg/g), rutin [(14.71±0.03) mg/g] and quercetin [(7.39±0.05) mg/g].

Conclusions

These effects could be attributed to the bioactive polyphenolic compounds present in the extract. Our results suggest that SAG extract is a potential source of natural antioxidants that may be used not only in pharmaceutical and food industry but also in the treatment of diseases associated with oxidative stress.     

Hepatoprotective and antioxidant activity of a mangrove plant Lumnitzera racemosa

Objective

To identify the hepatoprotective and in vitro antioxidant activity of Lumnitzera racemosa (L. racemosa) leaf extract.

Methods

Animals in Group 1 served as vehicle control, Group 2 served as hepatotoxin (CCL₄ treated) group, Group 3 served as positive control (Silymarin) group, and Group 4, 5 and 6 served as (75, 150 and 300 mg/kg bw p.o.) L. racemosa leaf extract treated groups. Moreover, in vitro antioxidant DPPH, hydroxyl radical scavenging activity (HRSA), NO, ferric reducing antioxidant power (FRAP), lipid hydroperoxide (LPO) and super oxide dismutase (SOD) were also analyzed for the leaf extract.

Results

The levels of the serum parameters such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), bilirubin, cholesterol (CHL), sugar and lactate dehydrogenase (LDH) were significantly increased in CCL₄ treated rats when compared with the control group (P<0.05). But the L. racemosa leaf extract treated rats showed maximum reduction of SGOT [(210.36±19.63) IU/L], SGPT [(82.37±13.87) IU/L], ALP [(197.63±23.43) IU/L], bilurubin [(2.15±0.84) mg/dL], cholesterol [(163.83±15.63) mg/dL], sugar [(93.00±7.65) mg/dL] and LDH [(1134.00±285.00) IU/L] were observed with the high dose (300 mg/kg bw) of leaf extract treated rats. Histopathological scores showed that, no visible changes were observed with high dose (300 mg/kg bw) of leaf extract treated rats except few mild necrosis. The IC₅₀ values were observed as (56.37±4.87) µg/mL, (57.68±1.98) µg/mL, (64.15±2.90) µg/mL, (61.94±3.98) µg/mL, (94.53±1.68) µg/mL and (69.7±2.65) µg/mL for DPPH, HRSA, NO, FRAP, LPO and SOD radical scavenging activities, respectively.

Conclusions

In conclusion, the hepatoprotective effect of the L. racemosa leaf extract might be due to the presence of phenolic groups, terpenoids and alkaloids and in vitro antioxidant properties.     

In vitro activity of natural honey alone and in combination with curcuma starch against Rhodotorula mucilaginosa in correlation with bioactive compounds and diastase activity

Objective

To evaluate the in vitro activity and synergism of the combinations of natural honey and curcuma starch against Rhodotorula mucilaginosa in correlation with total phenolic, flavonoid contents, and diastase activity.

Methods

The Folin-Ciocalteu test was used to determine the total polyphenols content and the flavonoid content was analyzed using by the aluminum chloride method. The antifungal activity of the natural honey, determined by an agar well diffusion assay and agar incorporation method.

Results

Total phenolic content varied from (63.93±0.11) to (95.36±6.08) mg GAE/100 g honey as gallic acid equivalent. Total flavonoids content varied from (5.41±0.04) to (9.94±0.54) mg CE/100 g. Diastase activity values were between (7.3±2.8) and (26±2.8). The zone inhibition diameter for the six honey samples without starch ranged between 6 and 20 mm. When starch was mixed with honey and then added to well, a zone inhibition increase diameter 7 and 21 mm. The percentage increase was noticed with each variety and it ranged between 5% and 62.5%. The minimal inhibitory concentrations for the six varieties of honey without starch against Rhodotorula mucilaginosa ranged between 28% and 36% (v/v). When starch was incubated with honey and then added to media, a minimal inhibitory concentration drop has been noticed with each variety. It ranged between 6.66 % and 20% (w/v). No significant correlation was established between diastase activity and bioactive compounds.

Conclusions

The mixture of curcuma starch and honey could lead to the development of new combination antibiotics against Rhodotorula infections     

Phytochemical analysis and antioxidants activities of aqueous stem bark extract of Schotia latifolia Jacq

Objective

To evaluate the phytochemical constituents and antioxidant activities of aqueous extract of Schotia latifolia (S. latifolia) bark locally used for the treatment of oxidative stress-induced ailments in South Africa.

Methods

The antioxidant and free radical scavenging activity of aqueous extract of the plant was assessed against 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the ferric reducing agent. Total phenolics, flavonoids, flavonols and proanthocyanidins were also determined to assess their corresponding effect on the antioxidant activity of this plant.

Results

The activities of plant extract against DPPH, ABTS and NO radicals were concentration dependent with IC₅₀ value of 0.06, 0.05 and 0.05 mg/mL, respectively. The reducing power of the extract was greater than that of butylated hydroxyl toluene (BHT) and ascorbic acid which were used as standard drugs in a concentration dependent manner. The total phenolics content of the aqueous bark extract was (193.33±0.03 TE/g), followed by flavonoids (72.70±0.01 QE/g), proanthocyanidins (48.76±0.00 CE/g) and flavonols (47.76±0.21 QE/g). Phytochemical analysis revealed the presence of percentage tannin (11.40±0.02), alkaloid (9.80±0.01), steroids (18.20±0.01), glycosides (29.80±0.01) and saponins (6.80±0.00). The results exhibited a positive linear correlation between these polyphenols and the free radical scavenging activities.

Conclusions

Our findings provide evidence that the crude aqueous extract of S. latifolia is a potential source of natural antioxidants and this justifies its uses in folkloric medicines.     

Acute and subacute oral toxicity study on the flavonoid rich fraction of Monodora tenuifolia seed in albino rats

Objective

To investigate the effects of the flavonoid rich fraction of Monodora tenuifolia seed on the haematology, histopathology and liver profile of Wistar albino rats.

Methods

Toxicity study was investigated on the flavonoid rich fraction of Monodora tenuifolia in rats administered different concentrations orally for 28 d using standard laboratory procedures.

Results

The LD₅₀ of the flavonoid rich fraction was found to be above 5 000 mg/kg body weight in mice observed for 48 h. After the Day 14, biochemical markers of liver injury such as serum alanine aminotransferase, and aspartate aminotransferase decreased significantly (P<0.05 at doses of 100 and 200 mg/kg body weight and P<0.01 at 400 mg/kg) while serum alkaline phosphatase increased non-significantly (P>0.05). There was non-significant (P>0.05) effect observed across the groups in the levels of serum total protein, albumin, globulin, urea and creatinine. The result of histological examination showed various degrees of peribiliary hepatitis after the Day 14 which fizzled out after the Day 28.

Conclusions

The result therefore suggests that the seed extract is potentially safe.     

Bioactivity of seagrass against the dengue fever mosquito Aedes aegypti larvae

Objective

To identify the larvicidal activity of the seagrass extracts.

Methods

Seagrass extracts, Syringodium isoetifolium (S. isoetifolium), Cymodocea serrulata and Halophila beccarii, were dissolved in DMSO to prepare a graded series of concentration. Batches of 25 early 4th instars larvae of Aedes aegypti (Ae. aegypti) were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01 mg – 0.1 mg). After 24 h the mortality rate was identified with the formulae [(% of test mortality – % of control mortality)/(100 – % of control mortality)] × 100. Each experiment was conducted with three replicates and a concurrent control group. A control group consisted of 1 mL of DMSO and 199 mL of distilled water only.

Results

: The root extract of S. isoetifolium showed maximum larvicidal activity with minimum concentration of extract of LC₅₀= 0.0 604 ± 0.0 040)µg/mL with lower confidence limit (LCL) – upper confidence limit (UCL) = (0.051–0.071) and LC₉₀=0.0 972µg/mL followed by leaf extract of S. isoetifolium showed LC₅₀= (0.062 ± 0.005)µg/mL. The regression equation of root and leaf extract of S. isoetifolium for 4th instar larvae were Y= 4.909 + 1.32x (R²= 0.909) and Y= 2.066 + 1.21x (R² =0.897) respectively. The results of the preliminary phytochemical constituents shows the presence of saponin, steroids, terpenoid, phenols, protein and sugars.

Conclusions

From the present study the ethanolic extracts of seagrass of S. isoetifolium possesses lead compound for development of larvicidal activity.     

In vitro analysis on bactericidal screening and antioxidant potentiality of leaf and root extracts of Thottea siliquosa (Lam.) Ding Hou. An ethnobotanical plant

Objective

Natural products of plant origin are potential source of novel antimicrobial and antioxidative agents. Thottea siliquosa (Lam.) Ding Hou. (T. siliquosa). A medicinal herb used by local tribals for treating various ailments. The present study aims at the phytochemical screening, GC-MS analysis, in vitro antibacterial activity and antioxidant potentiality of root and leaf extracts of T. siliquosa.

Methods

Hot continuous Soxhlet extraction, GC-MS analysis, antibacterial analysis by disc diffusion, microdilution assay and antioxidant potentialities by hydroxyl radical and nitric oxide radical scavenging. The data was statistically analyzed.

Results

Phytochemical screening of the ethyl acetate and methanolic extract of leaf and root revealed the presence of phenols, alkaloids, tannins and saponin. The extract revealed a pool of phytochemicals by comparison with authentic standards from spectral library. Both the extracts has shown their broad spectrum of inhibition against the selected bacteria Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia compared with standard antibiotic drug streptomycin. The extracts showed antioxidant activity by scavenging of free radicals such as hydroxyl and nitric oxide. The IC₅₀ values of the ethyl acetate extracts leaf and root and standard in this assay were 167.5±0.67, 99.4±1.2, 192±2.5 µg/mL respectively. Similarly those methanolic extracts of leaf and root were 269.5±0.89 and 289.1±2.66 µg/mL respectively. Similarly, ethyl acetate and methanolic extracts also caused a moderate dose-dependent inhibition of nitric oxide with an IC₅₀ range 65.5±1.55 to 148 ±3.09 µg/mL. The inhibitory activities were found to be dose dependent.

Conclusion

The present study provides evidence that ethyl acetate and methanol extract of leaf and root of T. siliquosa are potential source of natural antioxidants and bactericidal nature. It is essential that research should continue to isolate and purify the bio active components of this natural plant and use in drug discovery and development.     

Antioxidant properties and inhibitory effects of Satureja khozestanica essential oil on LDL oxidation induced-CuSO4 in vitro

Objective

To assess various antioxidative activities of Satureja khozestanica essential oil (SKE) and its effect on oxidation of low density lipoprotein (LDL) induced by CuSO₄ in vitro by monitoring the formation of conjugated dienes and malondialdehyde (MDA).

Methods

The formation of conjugated dienes, lag time and MDA were measured. Inhibition of this Cu-induced oxidation was studied in the presence of several concentrations of SKE. Also total antioxidant activity and free radical scavenging of SKE were determinated.

Results

It was demonstrated that SKE was able to inhibit LDL oxidation and decrease the resistance of LDL against oxidation. The inhibitory effects of SKE on LDL oxidation were dose-dependent at concentrations ranging from 50 to 200 µg/mL. Total antioxidant capacity of SKE was (3.20±0.40) nmol of ascorbic acid equivalents/g SKE. The SKE showed remarkable scavenging activity on 2, 2-diphenyl-picrylhydrazyl, IC₅₀ (5.30±0.11) ng/mL.

Conclusions

This study shows that SKE is a source of potent antioxidants and prevents the oxidation of LDL in vitro and it may be suitable for use in food and pharmaceutical applications.     

Antiplasmodial,cytotoxic activities and characterization of a new naturally occurring quinone methide pentacyclic triterpenoid derivative isolated from Salacia leptoclada Tul. (Celastraceae) originated from Madagascar

Objective

To validate scientifically the traditional use of Salacia leptoclada Tul. (Celastraceae) (S. leptoclada) and to isolate and elucidate the structure of the biologically active compound.

Methods

Bioassay-guided fractionation of the acetonic extract of the stem barks of S. leptoclada was carried out by a combination of chromatography technique and biological experiments in viro using Plasmodium falciparum and P388 leukemia cell lines as models. The structure of the biologically active pure compound was elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.

Results

Biological screening of S. leptoclada extracts resulted in the isolation of a pentacyclic triterpenic quinone methide. The pure compound exhibited both in vitro a cytotoxic effect on murine P388 leukemia cells with IC₅₀ value of (0.041±0.020) µg/mL and an antiplasmodial activity against the chloroquine-resistant strain FC29 of Plasmodium falciparum with an IC₅₀ value of (0.052±0.030) µg/mL. Despite this interesting anti-malarial property of the lead compound, the therapeutic index was weak (0.788). In the best of our knowledge, the quinone methide pentacyclic triterpenoid derivative compound is reported for the first time in S. leptoclada.

Conclusions

The results suggest that furthers studies involving antineoplastic activity is needed for the development of this lead compound as anticancer drug.     

Anticancer effect of the extracts from Polyalthia evecta against human hepatoma cell line (HepG2)

Objective

To investigate the anticancer activity of Polyalthia evecta (P. evecta) (Pierre) Finet & Gagnep against human hepatoma cell line (HepG2).

Methods

The anticancer activity was based on (a) the cytotoxicity against human hepatoma cells (HepG2) assessed using a neutral red assay and (b) apoptosis induction determined by evaluation of nuclei morphological changes after DAPI staining. Preliminary phytochemical analysis of the crude extract was assessed by HPLC analysis.

Results

The 50% ethanol-water crude leaf extract of P. evecta (EW-L) showed greater potential anticancer activity with high cytotoxicity [IC₅₀ = (62.8 ± 7.3)µg/mL] and higher selectivity in HepG2 cells than normal Vero cells [selective index (SI) = 7.9]. The SI of EW-L was higher than the positive control, melphalan (SI = 1.6) and the apoptotic cells (46.4 ± 2.6) % induced by EW-L was higher than the melphalan (41.6 ± 2.1)% (P<0.05). The HPLC chromatogram of the EW-L revealed the presence of various kinds of polyphenolics and flavonoids in it.

Conclusions

P. evecta is a potential plant with anticancer activity. The isolation of pure compounds and determination of the bioactivity of individual compounds will be further performed.     

Screening of biological activities of Polygonum maritimum L. from Algerian coast

Objective

To investigate the antioxidant and the antibacterial activities of crude extract from aerial part of Polygonum maritimum L. (Polygonaceae) (P. maritimum) and to find new actives biomolecules.

Methods

The whole plant was collected from the Rechgoune coast (West of Algeria), and methanolic crude extract of aerial parts of P. maritimum (PMCE) was prepared. The extract was tested against different bacterial strain and tested for his ability to neutralize free radical (DPPH) and to scavenge the H₂O₂.

Results

PMCE had a very high content of total phenol, which was (352.49±18.03) mg/g dry weight, expressed as gallic acid equivalent. PMCE exhibited excellent antioxidant activity, as measured using DPPH and H₂O₂ scavenging assays. It also showed a high antibacterial activity against gram-positive bacterial strains: Bacillus cereus, Bacillus subtilis and Staphylococcus aureus with an highest MIC of 120 µg/mL.

Conclusions

The antioxidant and antibacterial activity of the PMCE is probably due to phenolic compounds present in the extract. The contemporary presence of antioxidant and antibacterial activities in the PMCE suggests that this plant may be a source of bioactive substances with multifaceted activity.     

Cytotoxicity evaluation and hepatoprotective potential of bioassay guided fractions from Feronia limmonia Linn leaf

Objective

To evaluate the cytotoxicity and hepatoprotective potentials of extracts, fractions or isolated compound from the leaves of Feronia limonia (F. limonia).

Methods

Qualitative phytochemical analysis of extracts, fractions or compound was performed by means of thin layer chromatography and spectroscopic assays. The % purity of compound was measured by analytical HPLC. Extracts, fractions or compound have been individually evaluated for their cytotoxicity effects (10, 20, 100, 250, 500, 750 and 1 000 µg/mL). Based on the inhibitory concentration (IC₅₀) obtained from the cell viability assay, graded concentrations of extracts, fractions or isolated compound were assessed (10, 20, 50, 100, 200 µg/mL) for its hepatoprotective potential against CCl₄-induced hepatotoxicity by monitoring activity levels of serum glutamatic pyruvatic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT).

Results

Results indicated that the methanol extract of F. limonia was non-toxic and hepatoprotective in nature as compared with the petroleum ether extract. The acetone fraction of methanolic extract also showed similar properties but the subsequent two fractions were cytotoxic. However, the pure compound isolated from the penultimate fraction of methanolic extract was non-toxic and hepatoprotective in nature. Biochemical investigations (SGOT, SGPT) further corroborated these cytological observations.

Conclusions

It can be concluded from this study that F. limonia methanol extract, some fractions and pure isolated compound herein exhibit hepatoprotective activity. However, cytotoxicity recorded in the penultimate fraction and investigation of structural details of pure compound warrants further study.     

Tagetes erecta Linn. and its mosquitocidal potency against Culex quinquefasciatus

Objective

To investigate mosquitocidal effects of ethanolic extract of flowers of Tagetes erecta (T. erecta) and its chloroform and petroleum ether soluble fractions against the larvae of Culex quinquefasciatus (Cx. quinquefasciatus).

Methods

The fresh flowers of T. erecta were extracted in cold with ethanol (5.0 L) and after concentration, the ethanol extract was fractionated with chloroform and petroleum ether to afford a brownish syrupy suspension of ethanol extract (50.0 g), petroleum ether soluble fraction (18.6 g) and chloroform soluble fraction (23.8 g). The larvicidal effect of ethanol extract and their solvent fractions were determined by the standard procedure of WHO against different instars of Cx. quinquefasciatus.

Results

Among the tested samples the chloroform soluble fractions showed the highest toxicity and consequently, the lowest LC₅₀ values (14.14 µg/mL, 17.06 µg/mL, 36.88 µg/mL and 75.48 µg/mL) for all the instars larvae of Cx. quinquefasciatus. The larvae showed comparative tolerance in the course of increasing age and time.

Conclusions

It can be concluded that the flowers of T. erecta are very effective natural larvicide and could be useful against Cx. quinquefasciatus.     

Phytochemical analysis and in vitro antioxidant acitivity of hydroalcoholic seed extract of Nymphaea nouchali Burm. f.

Objective

To evaluate the phytochemical constituents and the antioxidant activity of hydroalcoholic extract of Nymphaea nouchali seed locally prescribed as a diet for diabetes mellitus.

Methods

The antioxidant and free radical scavenging activity of hydroalcoholic extract of the plant was assessed against 1,1 diphenyl-2-picryl hydrazyl (DPPH), nitric oxide and lipid peroxidation using standard protocols. Total phenolics, flavonoids and tannins were also determined.

Results

Phytochemical analysis revealed the presence of phenols, flavones, tannins, protein, reducing sugars, glycosides, saponins, alkaloids and steroids. The activities of plant extract against DPPH, nitric oxide and lipid peroxidation was concentration dependent with IC₅₀ value of 42.82, 23.58 and 54.65 µg/mL respectively. The total antioxidant capacity was high with 577.73 mg vitamin E/g of the extract and showed a moderately high vitamin C content of 197.22 mg/g. The total tannin content of hydroalcoholic seed extract was high (195.84 GE/g), followed by phenolics (179.56 GE/g) and flavonoids (23.55 QE/g).

Conclusion

Our findings provide evidence that the crude extract of Nymphaea nouchali is a potential source of natural antioxidants and this justifies its use in folkloric medicine.     

Isolation and structural elucidation of cytotoxic compounds from the root bark of Diospyros quercina (Baill.) endemic to Madagascar

Objective

To isolate and characterize the cytotoxic compounds from Diospyros quercina (Baill.) G.E. Schatz & Lowry (Ebenaceae).

Methods

An ethno-botanical survey was conducted in the south of Madagascar from July to August 2010. Bio-guided fractionation assay was carried out on the root bark of Diospyros quercina, using cytotoxicity bioassay on murine P388 leukemia cell lines as model. The structures of the cytotoxic compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.

Results

Biological experiments resulted in the isolation of three bioactive pure compounds (named TR-21, TR-22, and TR-23) which exhibited very good in vitro cytotoxic activities with the IC₅₀ values of (0.017 5±0.0060) µg/mL, (0.089±0.005) µg/mL and (1.027±0.070) µg/mL respectively. Thus, they support the claims of traditional healers and suggest the possible correlation between the chemical composition of this plant and its wide use in Malagasy folk medicine to treat cancer.

Conclusions

The ability of isolated compounds in this study to inhibit cell growth may represent a rational explanation for the use of Diospyros quercina root bark in treating cancer by Malagasy traditional healers. Further studies are, therefore, necessary to evaluate the in vivo anti-neoplastic activity of these cytotoxic compounds as effective anticancer drugs.