Immunomodulatory effect of Moringa peregrina leaves, ex vivo and in vivo study

Phytochemical analysis, antioxidant, and antimicrobial activities of Jordanian Pomegranate peels

Pomegranate (Punica granatum) peels have shown numerous health benefits such as antioxidant, anti-inflammatory, and antimicrobial activities. These health activities are owed to the unique phytochemical components present in pomegranate peels. Variations in the pomegranate cultivar, geographical region, and extraction methods significantly affect the phytochemical composition and concentrations of pomegranate fruits and their peels, hence their health outcomes. Therefore, this study aimed to examine the phytochemical contents of pomegranate peels of Jordanian origin and their antioxidant and antimicrobial activities. Among the 6 extracts of pomegranate peels tested, the ethanol extract exhibited the highest total phenolic content (TPC = 297.70 ± 1.73 mg GAE/g DW), highest total flavonoids content (TFC = 116.08 ± 3.46 mg RE/g DW), highest hydrolyzable tannins (HT) contents (688.50 ± 3.54 mg TE/g DW). Whereas the highest condensed tannins (CT) content was found in both the ethanol (13.87 ± 0.58 mg CE/g DW) and methanol (13.84 ± 0.55 mg CE/g DW) extracts. For the antioxidant activities, the water extract of pomegranate peels displayed the highest inhibitory effect on DPPH radicals (9.43 ± 0.06 μmole TE/g DW), while for the ABTS+ assay the methanol and ethanol extracts exhibited the highest activities of 11.09 ± 0.02 and 11.09 ± 0.06 μmole TE/g DW, respectively. For the FRAP assay, the aqueous methanol extract exhibited the highest reducing activity (1.60 ± 0.09 mmole Fe (II)/g DW). As for the antimicrobial activities of various extracts of pomegranate peels, the highest antimicrobial activity against Micrococcus luteus was achieved by the ethanol extract (MIC = 6.25 mg/mL), whereas the lowest antimicrobial activity was observed against Candida krusei using the methanol extract (MIC = 100 mg/mL). These results indicate that pomegranate peels of Jordanian origin are rich in phytochemical content and exhibited strong antioxidant and antimicrobial activities making these agroindustrial by-products potential candidates for various medical applications and possible safe sources for important bioactive components.

Antinociceptive Action of Moringa peregrina is Mediated by an Interaction with α2-Adrenergic Receptor

Background:

Moringa peregrina (M. peregrina) is an edible, drought-resistant tree that is native to semi-arid countries. It is used as a painkiller in folk medicine.

Aims:

To study the antinociceptive effects of the leaf extract of M. peregrina in mice.

Study Design:

Animal experimentation.

Methods:

We employed thermal (hot plate and tail-immersion tests) and chemical (writhing and formalin tests) pain models in male BALB/c mice (eight animals per group) to investigate the mechanisms involved in the antinociceptive actions of M. peregrina. Additionally, we identified the chemical constituents present in the extract of M. peregrina by using liquid chromatography-mass spectrometry analysis, and predicted the possible active constituents that interact with the receptor based on molecular docking simulations.

Results:

In the writhing test, 200 mg/kg of M. peregrina extract restricted abdominal cramps by up to 55.97% (p<0.001). Further, it reduced the time of paw-licking in the early and late phases of formalin test by up to 56.8% and 65.5%, respectively, as compared to the percentage inhibitions of 50.5% and 48.4% produced by 30 mg/kg diclofenac sodium in the early and late phases, respectively (p<0.05). This effect was abrogated by yohimbine (1 mg/kg, intraperitoneally), but not by methysergide (5 mg/kg, intraperitoneally), in the late phase only, which indicates that the action of M. peregrina in formalin test is not mediated by 5-HT2 serotonin receptors, but rather via α₂-adrenergic receptors. In the hot plate test, but not on tail-immersion test, the high dose (400 mg/kg) of the extract increased the latency time after 30 minutes of its administration. Yohimbine antagonized the action of M. peregrina in the hot plate test. Based on LC-MS analysis, the major constituents found in M. peregrina methanolic extract were chrysoeriol 7-O-diglucoside, lupeol acetate, quercetin, and rutin. Depending on the molecular docking results, the activity of M. peregrina extract could be due to the binding of chrysoeriol 7-O-diglucoside, quercetin, and rutin to the α₂-adrenergic receptor.

Conclusion:

Interaction with the α₂-adrenergic receptor serves as a possible mechanism of the M. peregrina analgesic effect.

In Vitro Macrophage Nitric Oxide and Interleukin-1 Beta Suppression by Moringa peregrina Seed

Objectives

Moringa peregrina has long been used in folk medicine to treat diseases including fever, headache, burns, constipation, gut pains, and inflammation. Nitric oxide (NO) and interleukin-1β (IL-1β) play an important role in the pathophysiology of inflammation. The objectives of this study were to determine the effect of M. peregrina seed ethanolic extract (MPSE) on the viability of and NO and IL-1β production by lipopolysaccharide (LPS)-activated macrophage (J774A.1) cell line.

Materials and Methods

The 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay was used to determine the cytotoxic effect of MPSE treatment at concentrations ranging from 31.15 to 1000 μg/mL. The NO concentration was determined by Griess assay and IL-1β proinflammatory cytokine concentration by enzyme-linked immunosorbent assay in the supernatant of MPSE-treated LPS-activated J774A.1 cell culture.

Results

The results show that the MPSE was not cytotoxic at 1000 μg/mL but significantly (p<0.001) inhibited NO and IL-1β production by the LPS-activated macrophage J774A.1 cells.

Conclusion

These findings suggest that M. peregrina seed extract can be used to treat and prevent inflammatory diseases through the inhibition of inflammatory mediators.