Antimicrobial,anti-inflammatory and mutagenic investigation of the South African tree aloe (Aloe barberae)

Ethnopharmacology relevance

In recent times, many products ranging from aloe drinks to aloe gels, powders, capsules, and creams have appeared on the commercial market prepared from different aloe species including Aloe barberae. These products are used in ethnomedicine to treat various conditions including gastrointestinal disorders, insect bites, skin burns and other skin injuries by traditional communities.

Aim of the study

This study was aimed at evaluating the antibacterial, antifungal and anti-inflammatory activities as well as genotoxic effects of different extracts of Aloe barberae.

Materials and methods

Organic and water extracts of the upper stem, young bark, mature bark, leaves and roots of the South African tree aloe (Aloe barberae) were evaluated for their antimicrobial [Gram-positive (Bacillus subtilis and Staphylococcus aureus), Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria as well as the fungus Candida albicans], anti-inflammatory (COX-1 and COX-2) and mutagenic properties (Ames test). Thin layer chromatography (TLC) was used to compare the phytochemical profiles of different extracts of Aloe barberae.

Results

The petroleum ether (PE) and dichloromethane (DCM) extracts of the mature bark, leaves and roots exhibited good activity against all the bacteria and fungus Candida albicans with minimum inhibitory concentrations (MIC) ranging from 0.195 to 1.56 mg/ml. All the PE extracts evaluated showed a high activity (>70%) in both COX-1 and COX-2 assays. Apart from the organic extracts of the root with consistently good activity (>70%), all the remaining extracts showed moderate activity (40–69%) in COX-1 assay. The PE extracts also showed a dose dependent increase in activity. Ultraviolet (UV) spectrum of the leaves and root EtOH extracts indicated the presence of compounds that could absorb UV light (wavelength: 190–820 nm). None of the extracts had a mutagenic effect in the Salmonella/microsome assay against a tester strain, TA98.

Conclusion

Activity observed in the bark, leaves and roots of Aloe barberae validates its use in commercial herbal products, ethnobotany and ethnoveterinary medicine by South African communities and small scale farmers to treat various conditions.     

Screening of the topical anti-inflammatory activity of the bark of Acacia cornigera Willdenow, Byrsonima crassifolia Kunth, Sweetia panamensis Yakovlev and the leaves of Sphagneticola trilobata Hitchcock

Ethnopharmacological relevance

An investigation of topical anti-inflammatory activity was undertaken on plants used in Central America traditional medicine.

Aim of study

Four herbal drugs used in the folk medicine of Central America to treat inflammatory skin affections (Acacia cornigera bark, Byrsonima crassifolia bark, Sphagneticola trilobata leaves and Sweetia panamensis bark) were evaluated for their topical anti-inflammatory activity.

Materials and methods

Petroleum ether, chloroform and methanol extracts were obtained for herbal medicines and then extracts were tested on Croton oil-induced ear dermatitis model in mice.

Results

Almost all the extracts reduced the Croton oil-induced ear dermatitis in mice and the chloroform ones showed the highest activity, with ID₅₀ (dose giving 50% oedema inhibition) values ranging from 112 μg/cm² (Byrsonima crassifolia) to 183 μg/cm² (Sphagneticola trilobata). As reference, ID₅₀ of the non-steroidal anti-inflammatory drug indomethacin was 93 μg/cm².

Conclusions

Lipophilic extracts from these species can be regarded as potential sources of anti-inflammatory principles.     

Contribution to the ethnopharmacological and anti-Helicobacter pylori knowledge of Cyrtocarpa procera Kunth (Anacardiaceae)

Ethnopharmacological relevance

Cyrtocarpa procera Kunth (Anacardiaceae) is a Mexican endemic tree; its bark has been traditionally employed in Mexico since prehispanic times to relieve digestive disorders.

Aim of the study

To perform an acute evaluation of the toxicity, gastroprotective, and anti-inflammatory properties, as well as the anti-Helicobacter pylori action of C. procera bark extracts, in order to determine polypharmalcological activities.

Materials and methods

Five different polarity extracts (hexanic, CH₂Cl₂, CH₂Cl₂-MeOH, methanolic, and aqueous) were prepared. Each of them was evaluated in the following acute mice models: toxicity Lorke test, ethanol-induced gastric ulcer, TPA-induced ear edema; and the in vitro anti-H. pylori activity with a broth dilution method.

Results

None of the extracts were toxic under acute administration. The methanolic, hexanic, and aqueous extracts possess remarkable gastroprotective activity. All the extracts inhibit H. pylori growth, being the hexanic the most active, and only this one showed significant anti-inflammatory effect.

Conclusions

This work demonstrates that C. procera bark has polypharmacological activities; which makes it a promising asset to the development of an integral treatment for gastritis or peptic ulcer related or not to H. pylori. Our findings contribute to the ethnopharmacological knowledge about this species.     

Pharmacological properties and protein binding capacity of phenolic extracts of some Venda medicinal plants used against cough and fever

Ethnopharmacology relevance

Several ailments are caused by infectious bacteria and in other diseases; they act as co-infection which complicate human life by causing health hazards. In Venda (South Africa), many plants are used in traditional medicine to treat cough and fever.

Aim of the study

This study was aimed at evaluating the antibacterial and antifungal properties, cyclooxygenases (COX), acetylcholinesterase (AChE) enzyme inhibitory effects and the phenolic composition as well as mutagenic properties of six medicinal plants used by the Venda people of Limpopo Province of South Africa against cough and fever.

Materials and methods

The petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water extracts of six plants were tested against four infectious bacteria (Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus) and a fungus Candida albicans. The same extracts were evaluated for their ability to inhibit COX-1 and -2 enzymes. Methanolic and water extracts of the same plant were tested for acetylcholinesterase inhibitory effects. Total phenolics, flavonoids, gallotannins and condensed tannins were determined. The ability of the extracts to bind and precipitate proteins was also investigated. The extracts were investigated for genotoxicity with and without S9 (metabolic activation) against three Salmonella typhimurium tester strains TA98, TA100 and TA102.

Results

The organic extracts of Rhus lancea leaves exhibited the best antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.0061 to 0.049 mg/ml. The best antifungal activity was observed from a DCM extract of Syzygium cordatum leaves with a MIC value of 0.195 mg/ml. The methanolic and water extracts of the same plant exhibited high inhibitory effects towards AChE with IC₅₀ values of 0.22 and 0.26 mg/ml, respectively. The highest levels of flavonoids and gallotannins were detected in Spirostachys africana bark; 11.57 and 48.88 μg/g, respectively. The highest percentages (1.2%) of condensed tannins were detected in Uvaria caffra leaves. The high levels of phenolic compounds may have been responsible for high antimicrobial activities for extracts of S. africana bark and U. caffra leaves. S. cordatum leaves represented the highest affinity for protein binding with 93%. All the extracts were non-mutagenic towards the three tested strains with and without S9 metabolic activation.

Conclusion

The result obtained in this study goes a long way in validating the ethnobotanical usage of these medicinal plants in the treatment of cough and fever by the Venda people. However, more evidence obtainable from other assays not performed here are urgently required to confirm these results.     

Pharmacological and phytochemical study on a Sisymbrium officinale Scop. extract

Ethnopharmacological relevance

The aerial parts of Sisymbrium officinale Scop. are commonly used to treat airway ailments, moreover in antiquity the herbal drug was reputed to possess anticancer properties. The results obtained in present work support the traditional use and the properties ascribed to Sisymbrium officinale.

Aim of the study

In order to give a scientific basis to the traditional uses of Sisymbrium officinale, this study was aimed to evaluate in vitro the myorelaxant activity, the antimicrobial properties and the antimutagenic effect of an aqueous dry extract of the aerial parts of the plant. A phytochemical characterization of the extract was also performed.

Materials and methods

The myorelaxant activity was studied against the contractions induced by carbachol, histamine and leukotriene C₄, in isolated guinea-pig trachea. The antimicrobial activity was tested against six bacteria and one yeast. The Ames test, performed by the preincubation method, was used to study the antimutagenic activity of the extract by its capability to inhibit the mutagenic effect of 2-nitrofluorene, sodium azide, methyl methanesulfonate and 2-aminoanthracene, in Salmonella typhimurium TA98, Salmonella typhimurium TA100 and Escherichia coli WP2uvrA strains. The chemical composition of the extract was analyzed by TLC and HPLC.

Results

Sisymbrium officinale showed to reduce the chemically-induced contractions of isolated guinea-pig trachea with major potency against leukotriene C₄ and histamine. The extract did not show any antibacterial activity. The Ames test showed a strong antimutagenic activity against 2-aminoanthracene, in Escherichia coli WP2uvrA and in Salmonella typhimurium TA98 strains. The phytochemical study highlighted the presence of putranjivine, the glucosinolate marker of Sisymbrium officinale, and of proline.

Conclusions

The myorelaxant activity of Sisymbrium officinale offers a scientific basis to its use in traditional medicine. The strong antimutagenic effect suggests further studies to evaluate its possible chemopreventive activity.     

Anti-inflammatory effects of methanol extracts of the root of Lilium lancifolium on LPS-stimulated Raw264.7 cells

Aim of the study

Lilium lancifolium is commonly used to treat bronchitis, pneumonia, etc. In this study, we investigated the anti-inflammatory effects of methanol extracts of the root of Lilium lancifolium (LL extracts) in LPS-stimulated Raw264.7 cells.

Material and methods

Levels of NO, PGE₂ and pro-inflammatory cytokines (IL-6 and TNF-α) in the supernatant fraction were determined using sandwich ELISA. Expression of COX-2 and iNOS, phosphorylation of MAPK subgroups (ERK and JNK), and NF-κB activation in extracts were detected via Western blot and immunocytochemistry assays.

Results

The LL extract significantly inhibited NO, PGE₂, IL-6 and TNF-α production in LPS-stimulated cells, and suppressed iNOS and COX-2 expression. A mechanism-based study showed that phosphorylation of ERK1/2 and JNK and translocation of the NF-κB p65 subunit into nuclei were inhibited by the LL extract. Furthermore, interleukin-4 and interleukin-13 production in Con A-induced splenocytes was suppressed.

Conclusion

These results indicate that anti-inflammatory effects of methanol extracts from Lilium lancifolium are due to downregulation of iNOS and COX-2 via suppression of NF-κB activation and nuclear translocation as well as blocking of ERK and JNK signaling in LPS-stimulated Raw264.7 cells.     

Antimycobacterial,anti-inflammatory and genotoxicity evaluation of plants used for the treatment of tuberculosis and related symptoms in South Africa

Ethnopharmacological relevance

Emergence of drug-resistant tuberculosis strains and long duration of treatment has established an urgent need to search for new effective agents. The great floral diversity of South Africa has potential for producing new bioactive compounds, therefore pharmacological screening of plant extracts within this region offers much potential. To assess the in vitro antimycobacterial, anti-inflammatory and genotoxicity activity of selected plants that are used for the treatment of TB and related symptoms in South Africa.

Materials and methods

Ground plant materials from 10 plants were extracted sequentially with four solvents (petroleum ether, dichloromethane, 80% ethanol and water) and a total of 68 extracts were produced. A broth microdilution method was used to screen extracts against Mycobacterium tuberculosis H37Ra. The cyclooxygenase-2 (COX-2) enzyme was used to evaluate the anti-inflammatory activity of the extracts and the Salmonella microsome assay using two Salmonella typhimurium strains (TA98 and TA100) to establish genotoxicity.

Results

Six out of 68 extracts showed good antimycobacterial activity. Three extracts showed good inhibition (>70%) of COX-2 enzyme. All the extracts tested were non-genotoxic against the tested Salmonella strains.

Conclusion

The results observed in this study indicate that some of the plants such as Abrus precatorius subsp. africanus, Ficus sur, Pentanisia prunelloides and Terminalia phanerophlebia could be investigated further against drug-resistant TB strains.     

In vitro pharmacological evaluation of three Barleria species

Ethnopharmacological relevance

Various parts of Barleria prionitis L. (Acanthaceae) are used in traditional medicine to treat infection-related ailments. A comparison of their activities and knowledge of their mechanisms of action are important for drug development and conservation.

Aims of the study

This study investigated the antibacterial effects and underlying mechanisms of action of the anti-inflammatory activities of different parts of three Barleria species of South African origin.

Materials and methods

Crude extracts of different parts of three Barleria species were investigated in vitro for their biological activity. Antibacterial activity was evaluated using the micro-dilution assay against two Gram-positive and two Gram-negative bacteria. Anti-inflammatory activity was evaluated using the cyclooxygenase COX-1 and COX-2 assays.

Results

All the extracts showed broad-spectrum antibacterial activity with minimum inhibitory concentrations ranging from 0.059 to 6.25 mg/ml. Twelve out of 21 crude extracts evaluated showed good activity (>70%) in the COX-1 assay while 10 extracts showed good activity in the COX-2 assay. All the petroleum ether extracts (except B. prionitis stem) exhibited good inhibition of prostaglandin synthesis in COX-1.

Conclusion

The results demonstrated the therapeutic potential of these plants as antibacterial and anti-inflammatory agents. Their anti-inflammatory properties are mediated by the inhibition of the cyclooxygenase enzymes.     

Analgesic and anti-inflammatory effects of Cassia siamea Lam. stem bark extracts

Aim of the study

The present study was carried out to investigate analgesic and anti-inflammatory activities of Cassia siamea Lam stem bark extracts. We have also determined the cytotoxicity of each extract.

Materials and methods

C. siamea, a widespread medicinal plant traditionally used in sub-Saharan Africa, was collected in Congo Brazzaville. Stem bark was extracted with petroleum ether (CSE1), chloroform (CSE2), ethanol (CSE3) and water (CSE4). Analgesic, anti-inflammatory and antipyretic activities of these extracts were assessed in rats with hot plate test, paw pressure and carrageenan induced paw oedema. Cytotoxicity was assessed against KB and Vero cells.

Results

At the doses used (100, 200, and 400 mg/kg) ethanol and water extracts showed significant and dose-dependent analgesic and anti-inflammatory effects. None of the extracts had cytotoxic activity on KB and Vero cell lines and the most active extracts (CSE3 and CSE4) had no acute toxicity.

Conclusions

The study highlighted the analgesic and anti-inflammatory of C. siamea stem bark. Four major families of compounds present in the plant may explain these activities: triterpenes (lupeol, oleanolic acid, ursolic acid, friedelin, betulin), flavonoids (apigenin, kaempferol, luteolin), anthraquinones (emodin), phytosterols (stigmasterol, beta-sitosterol).     

In vitro biological activities of niloticane,a new bioactive cassane diterpene from the bark of Acacia nilotica subsp. kraussiana

Ethnopharmacological relevance

Acacia nilotica subsp. kraussiana was reported in African traditional medicine for the treatment of various ailments. Isolation of an active compound in this study from the bark extract may lead to the validation of its efficiency as a traditional crude drug.

Aims of the study

This study aimed to isolate active compound(s) from an ethyl acetate bark extract of Acacia nilotica subsp. kraussiana and to investigate some of its biological activity.

Materials and methods

The isolation process was carried out using bioassay-guided fractionation. The isolated compound was tested for antibacterial activity using the micro-dilution assay; anti-inflammatory activity using the COX-1 and COX-2 assays and investigated for inhibitory effect against acetylcholinesterase using the microplate assay.

Results

A new bioactive compound was isolated and identified as a cassane diterpene, niloticane. Niloticane showed antibacterial activity against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus with MIC values of 4 and 8 μg/mL, respectively. With Gram-negative bacteria, niloticane showed weak activity. MIC values obtained were 16 and 33 μg/mL against Klebsiella pneumonia and Escherichia coli, respectively. In the cyclooxygenase test, niloticane possessed activity with IC₅₀ values of 28 and 210 μM against COX-1 and COX-2, respectively. IC₅₀ values observed with indomethacin (positive control) were 3.6 μM for COX-1 and 189 μM for COX-2. In the acetylcholinesterase test, niloticane showed anti-cholinesterase activity with an IC₅₀ value of 4 μM. IC₅₀ values obtained by the galanthamine (positive control) was 2.0 μM.

Conclusion

The results obtained support the traditional uses of the bark of Acacia nilotica subsp. kraussiana in African traditional medicine for the treatment of some ailments that relate to microbial diseases, inflammation and central nervous system disorders.     

In vitro antiprotozoal and cytotoxic activity of 33 ethonopharmacologically selected medicinal plants from Democratic Republic of Congo

Ethnopharmacological relevance

The antiprotozoal and cytotoxic activity of the aqueous extracts from 33 medicinal plants, used by traditional healers for the treatment of various parasitic diseases and collected after an ethnopharmacological inventory conducted in the Bolongo area, Bandundu province in DR Congo, was evaluated.

Materials and methods

Decoctions were prepared, lyophilized and evaluated for in vitro antiprotozoal activity against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum, and the chloroquine- and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Cytotoxicity against MRC-5 cells was included to assess selectivity of activity.

Results

Most of the tested extracts exhibited pronounced (IC₅₀ ≤ 5 μg/ml) or good (5 < IC₅₀ ≤ 10 μg/ml) antiprotozoal activity against one or more of the selected protozoa. A total of 19 plant extracts inhibited Trypanosoma b. brucei, especially the extract from Isolona hexaloba stem bark (IC₅₀ = 1.95 μg/ml, SI = 16.5); 8 plant extracts were active against Trypanosoma cruzi, the extracts from Enanatia chlorantha stem bark and Quassia africana root bark being the most active with IC₅₀ values of 1.87 and 1.88 μg/ml, respectively (SI = 3.0 and 3.3, respectively); 8 plant extracts showed activity against Leishmania infantum, with extracts from Napoleona vogelii stem bark and Quassia africana root bark as the most active with IC₅₀ values of 5.66 and 5.04 μg/ml (SI = 11.3 and 1.2). Finally, 9 plant extracts inhibited Plasmodium falciparum K1 with the extracts from Quassia africana (root bark and stem bark) being the most active ones with IC₅₀ values of 0.46 and 1.27 μg/ml (SI = 13.7 and 13.6). Extracts from Enantia chlorantha stem bark, Piptadeniastrum africanum stem bark and Quassia africana root bark were cytotoxic for MRC-5 cells (CC₅₀ < 10 μg/ml).

Conclusions

These results can partly support and justify the traditional use of some of these plant species for the treatment of parasitic diseases.     

Investigation for anti-inflammatory and anti-thrombotic activities of methanol extract of Capparis ovata buds and fruits

Ethnopharmacological relevance

Capparis ovata Desf. has wide natural distribution in Turkey and it is consumed in pickled form. Flower buds, root bark, and fruits of the plant are used traditionally due to their analgesic, anti-inflammatory, wound healing, anti-rheumatismal, tonic, and diuretic effects.

Aim of the study

The aim of this study was to investigate the possible anti-inflammatory and anti-thrombotic effects of methanol extracts prepared from flower buds (CBE) and fruits (CFE) of C. ovata.

Materials and methods

Anti-inflammatory effects of CBE and CFE were assessed using carrageenan-induced and prostaglandin E₂-induced mouse paw edema models. For the anti-thrombotic effect evaluation, carrageenan-induced tail thrombosis model was performed in mice. The extracts were administered intraperitonally (i.p.) at the doses of 100, 200, and 300 mg/kg. The anti-inflammatory effect of Capparis extracts were tested in comparison to 10 mg/kg diclofenac and anti-thrombotic activity to 10 and 100 IU heparin.

Results

CBE at the doses of 200, and 300 mg/kg and CFE at the doses of 100, 200, and 300 mg/kg showed significant anti-inflammatory activity and CFE reached therapeutic concentration early than CBE in carrageenan inflammation model. In prostaglandin E₂ inflammation model, CBE and CFE exhibited significant inhibitory effects. The C. ovata extracts did not show remarkable anti-thrombotic effect.

Conclusions

Based on the results obtained, it can be concluded that fruits of C. ovata have more potent anti-inflammatory effect than flower buds. It has been suggested that inhibition of cyclooxygenase pathway is one of the mechanisms of the activity. C. ovata may be potentially used as therapeutic agents for inflammatory diseases.     

Effect of Rhizoma Polygonati on 12-O-tetradecanoylphorbol-acetate-induced ear edema in mice

Ethnopharmacological relevance

Rhizoma Polygonati is originated from the dried rhizomes of Polygonatum sibircum Red. It has long been used in traditional Chinese medicine for the treatment of inflammatory disorders.

Aim of the study

The present study aims to investigate the anti-inflammatory effect of aqueous extract of Rhizoma Polygonati (ERP) in a mouse model of inflammation induced by 12-O-tetradecanoylphorbol-acetate (TPA).

Materials and methods

The anti-inflammatory effect was evaluated by measuring the ear thickness and activity of myeloperoxidase (MPO). The anti-inflammatory mechanism was explored by determining the protein and mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6.

Results

The results showed that ERP significantly decreased the ear thickness and MPO activity in mouse model of inflammation induced by TPA. In addition, ERP also remarkably inhibited the protein and mRNA levels of iNOS, COX-2, TNF-α, IL-1β, and IL-6.

Conclusions

These results indicate that ERP has potential anti-inflammatory effect on TPA-induced inflammatory in mice, and the anti-inflammatory effect may be mediated, at least in part, by inhibiting the mRNA expression of a panel of inflammatory mediators including iNOS, COX-2, TNF-α, IL-1β, and IL-6.     

Inhibition of arachidonic acid metabolism by the Andean crude drug Parastrephia lucida (Meyen) Cabrera

Ethnopharmacological relevance

Parastrephia lucida (Meyen) Cabrera is used in the traditional medicine of Argentinean highlands as an antiseptic and anti-inflammatory medicinal plant. To give scientific support to the ethnopharmacological claim of Parastrephia lucida as an anti-inflammatory crude drug the effect of Parastrephia lucida extracts and fractions was assessed on key enzymes of the biosynthesis of pro-inflammatory eicosanoids mediators from arachidonic acid (AA).

Materials and methods

A bio-guided fractionation of the plant extract was carried out to find out the compounds or mixtures responsible for the anti-inflammatory effect. The extracts and fractions were tested in vitro for their ability to inhibit the enzymes cyclooxygenase (COX)-1 and COX-2, lipoxygenase (LOX) and phospholipase (sPLA2). Fractions were analyzed by HPLC–MS, HPLC–ESI-MS/MS and NMR to relate the effect with groups of secondary metabolites.

Results

Parastrephia lucida was more effective inhibiting COX and sPLA₂ than LOX. Assay-guided isolation led to the active fractions C and F which showed different effect on the selected enzymes. The fraction C was more effective inhibiting LOX while fraction F showed better activity against sPLA₂ and COX-2. Both fractions were further worked-up following the isolation of the anti-inflammatory agents with the selected enzyme assays. The main compounds identified in the most active fractions were 5,4′-dihydroxi-7-methoxyflavanone, apigenin, apigenin methyl ether and apigenin trimethyl ether, methyl and dimethyl ethers from quercetin, kaempferol and luteolin methyl ether, ferulic acid esters, cinnamic acid and vanillin.

Conclusions

Parastrephia lucida extract inhibit AA metabolism via several enzymes. The results give support to the traditional use of this plant for the treatment of inflammatory disorders.     

Aegiceras corniculatum extract suppresses initial and late phases of inflammation in rat paw and attenuates the production of eicosanoids in rat neutrophils and human platelets

Aim of the study

The present study is designed to explore the anti-inflammatory potential of Aegiceras corniculatum Linn. Blanco stems extracts and their mechanism of action against various pro-inflammatory mediators and to validate its traditional use against inflammatory diseases.

Materials and methods

Rat paw edema and peritonitis models were employed for in vivo studies. For in vitro studies human platelets and rat neutrophils were stimulated with Ca²⁺-ionophore A23187 leading to the production of various pro-inflammatory metabolites, i.e., 12-HTT, 12-HETE and LTB₄ and 5-HETE which were quantified by HPLC.

Results

The highly polar methanol extract (100 mg/kg) caused ∼90% reduction in the carrageenan- and prostaglandin E2-induced paw edema in rats. It also caused the inhibition of cycloxygenase-1 metabolite, 12-HHT (IC₅₀ 41.1 ± 1.5 μg/ml) with a concomitant rise in 12-lipoxygenase metabolite, 12-HETE in A23187 stimulated human platelets. Conversely, the non-polar hexane extract attenuated (IC₅₀ 0.36 ± 0.12 μg/ml) 12-HETE formation with a parallel rise in 12-HHT, thereby displaying a selectivity towards 12-lipoxygenase. Non-polar hexane extract also antagonized the production of 5-lipoxygenase metabolites, i.e., leukotriene B₄ and 5-HETE in the rat neutrophils. Furthermore, ethyl acetate extract inhibited both COX and 5-LOX with a marked decline in the production of 12-HHT (IC₅₀ 0.08 ± 0.002 μg/ml) and LTB₄ (IC₅₀ 0.86 ± 0.03 μg/ml), respectively. The anti-inflammatory effect of hexane and ethyl acetate extracts was also reflected by the diminution of carrageenan-induced cell infiltration in rat peritoneum. Additionally, plant extracts caused ∼60% suppression in dextran-induced paw edema implying that they also ameliorate histamine and serotonin release.

Conclusion

Hexane, ethyl acetate and methanol extracts derived from Aegiceras corniculatum possess significant anti-inflammatory activity via multiple mechanisms and validate their traditional use against inflammation-related diseases.