Anti-inflammatory activity of endophytic bacterial isolates from Emilia sonchifolia (Linn.) DC

ETHNOPHARMACOLOGICAL RELEVANCE

In the traditional medicine system, plants have been utilized as a rich source of anti-microbial, anti-inflammatory, anti-cancer, anti-viral and anti-oxidant compounds. The biological properties of plant-based drugs depend on their interaction with endophytes which persist as an important provider of bioactive secondary metabolites. Bacterial endophytes secrete anti-inflammatory molecules whose activity can be the base for the anti-inflammatory property of the plant.

AIM OF THE STUDY

During the screening of endophytes from Emilia sonchifolia, we isolated six different bacteria whose potential as the sources of anti-inflamamtory compounds have been aimed at in this study.

MATERIALS AND METHODS

Anti-inflammatory activity of the ethyl acetate extract of endophytes was studied by both in vitro and in vivo analyses. In vitro study was done using protein denaturation, COX, LOX, iNOS, myeloperoxidase and nitric oxide assays and in vivo analysis was carried out by carrageenan-induced and formalin-induced paw oedema tests. The expression level of anti-inflammatory genes such as COX-2 and NfKb was confirmed by real time PCR.

RESULTS

We confirmed anti-inflammatory activity of the ethyl acetate extract of bacterial endophytes of E sonchifolia by both in vitro and in vivo experiments. Carrageenan- and formalin-induced inflammations in mice were effectively reduced by the administration of the bacterial extract. Among the isolates, strain ES1effectively reduced inflammation. Gene expression studies confirmed reduction in the expression of COX-2 and NfKb genes in the presence of ES1 extract.

CONCLUSION

The present investigation demonstrated the anti-inflammatory property of the isolated bacterial endophyte ES1 (Bacillus subtilis strain-MG 692780) and thus justifies the possible role of endophytes in contributing anti-inflammatory property to E sonchifolia which is ethno-botanically important as a source of anti-inflammatory drug.

Neuroprotective and anti-inflammatory activity of DAT inhibitor R-phenylpiracetam in experimental models of inflammation in male mice

R-phenylpiracetam (R-PhP, (4R)-2-(4-phenyl-2-oxopyrrolidin-1-yl)acetamide) is an optical isomer of phenotropil, a clinically-used nootropic drug that improves physical condition and cognition. Recently, R-PhP was shown to bind to the dopamine transporter (DAT). Since growing evidence suggests that dysfunction of the dopaminergic system is associated with persistent neuroinflammation, the aim of this study was to determine whether R-PhP, an inhibitor of DAT, has neuroprotective and anti-inflammatory effects in male mice. The pharmacokinetic profiles of R-PhP in mouse plasma and its bioavailability in brain tissue were assessed. To study possible molecular mechanisms involved in the anti-inflammatory activity of R-PhP, target profiling was performed using radioligand binding and enzymatic activity assays. To clarify the neuroprotective and anti-inflammatory effects of R-PhP, we used a lipopolysaccharide (LPS)-induced endotoxaemia model characterized by reduced body temperature and overexpression of inflammatory genes in the brain. In addition, the antinociceptive and anti-inflammatory effects of R-PhP were tested using carrageenan-induced paw oedema and formalin-induced paw-licking tests. R-PhP (50 mg/kg) reached the brain tissue 15 min after intraperitoneal (ip) and peroral (po) injections. The maximal concentration of R-PhP in the brain tissues was 28 µg/g and 18 µg/g tissue after ip and po administration, respectively. In radioligand binding assays, DAT was the only significant molecular target found for R-PhP. A single ip injection of R-PhP significantly attenuated the LPS-induced body temperature reduction and the overexpression of inflammatory genes, such as tumour necrosis factor-α (TNF-α), interleukin 1 beta (IL-1β) and inducible nitric oxide synthase (iNOS). Seven-day po pretreatment with R-PhP dose-dependently reduced paw oedema and the antinociceptive response, as shown by the carrageenan-induced paw oedema test. In addition, R-PhP decreased the nociceptive response during the inflammatory phase in the formalin-induced paw-licking test. Our study showed that R-PhP possesses neuroprotective and anti-inflammatory effects, demonstrating the potential of DAT inhibitors as effective therapeutics.

In Vivo Anti-Inflammatory, Anti-Bacterial and Anti-Diarrhoeal Activity of Ziziphus Jujuba Fruit Extract

BACKGROUND

Ziziphus jujuba belongs to family Rhamnaceae widely distributed in subtropical and tropical countries. It is used traditionally for several pharmacological purposes including anti-inflammation, antidiarrhoeal and antibacterial, as well as tonic and sometimes as hypnotic (sedative).

AIM

To determine the in vivo antidiarrhoeal, antibacterial and anti-inflammatory activities of Z. jujuba fruit ethanolic extract.

METHOD

The fruit was macerated and extracted by 95% (v/v) ethanol. The antidiarrhoeal activity was evaluated using castor oil and Escherichia coli induced diarrhoea mouse model. The antidiarrhoeal and antibacterial activity was investigated at graded doses (400-1200 mg/kg). The anti-inflammatory effects were tested using the carrageenan-induced paw oedema in female Wistar rats. Rat's treatment groups received tragacanth, 100 mg/kg diclofenac sodium, 800 mg/kg, 1200 mg/kg or 1600 mg/kg of an ethanolic extract of Z. jujuba (EEZJ). All treatment groups were fed with the compounds one hour before carrageenan injection at of rat's paw. Also, the EEZJ was further analysed by HPLC-PDA system for identification of the presence of betulinic acid and quercetin.

RESULTS

EEZJ different doses did not show inhibitory activity against castor oil induced diarrhoea except for the higher (1200 mg/kg) dose. However, the frequency of defecation of stools and watery stool were reduced significantly when compared to control group (P ≤ 0.05 and P ≤ 0.01 respectively), resulted in overall 67% inhibition of diarrhoea. Our anti-inflammatory results demonstrated that EEZJ was able to inhibit the carrageenan-induced paw oedema in rats to a significant degree (p ≤ 0.05) and the paw volume and thickness of both left and right paw were affected compared to the negative control group.

CONCLUSION

EEZJ possesses antidiarrhoeal and antibacterial activity in a dose depending manner and may provide a pharmacological basis for its clinical use in diarrheal diseases. The activity may partially be due to the presence of betulinic acid and quercetin.

Anti-inflammatory activity of Markhamia tomentosa (Benth.) K. Schum. Ex Engl. ethanolic leaf extract

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Markhamia tomentosa (Benth.) K. Schum (Bignoniaceae) are used traditionally for the treatment of oedema and rheumatoid arthritis in Nigeria.

AIM OF THE STUDY

The aim of the work was to investigate the anti-inflammatory activity of the ethanolic leaf extract of Markhamia tomentosa.

MATERIALS AND METHODS

The extract was screened using the carrageenan-induced paw oedema in rats, xylene-induced oedema in mice and the formalin-induced oedema in mice at 50, 100, 200mg/kg doses p.o respectively. The mechanism by which the extract mediated the anti-inflammatory activity was assessed using the histamine-induced rat paw oedema and serotonin-induced rat paw oedema at the highest dose (200mg/kg).

RESULTS

The results showed that the extract produced a significant dose-dependent inhibition in carrageenan-induced, xylene-induced and the formalin tests. The extract exerted a significant inhibition of 54.55% (P<0.0001) and 42.11% (P<0.01) at 90 min in the histamine-induced and serotonin-induced rat paw oedema models respectively.

CONCLUSIONS

These findings suggest that the ethanolic leaf extract of Markhamia tomentosa possesses anti-inflammatory activity possibly mediated by histamine. The results justify the use of the plant in the preparation of ethno medicines used in the treatment of ailments associated with inflammation.