Antidiabetic properties of aqueous barks extract of Parinari excelsa in alloxan-induced diabetic rats

Anti-inflammatory effects of naringenin 8-sulphonate from Parinari excelsa Sabine stem bark and its semi-synthetic derivatives

The inflammatory response is a vital mechanism for repairing damage induced by aberrant health states or external insults; however, persistent activation can be linked to numerous chronic diseases. The nuclear factor kappa β (NF-κB) inflammatory pathway and its associated mediators have emerged as critical targets for therapeutic interventions aimed at modulating inflammation, necessitating ongoing drug development. Previous studies have reported the inhibitory effect of a hydroethanol extract derived from Parinari excelsa Sabine (Chrysobalanaceae) on tumour necrosis factor-alpha (TNF-α), but the phytoconstituents and mechanisms of action remained elusive. The primary objective of this study was to elucidate the phytochemical composition of P. excelsa stem bark and its role in the mechanisms underpinning its biological activity. Two compounds were detected via HPLC-DAD-ESI(Ion Trap)-MS2 analysis. The predominant compound was isolated and identified as naringenin-8-sulphonate (1), while the identity of the second compound (compound 2) could not be determined. Both compound 1 and the extract were assessed for anti-inflammatory properties using a cell-based inflammation model, in which THP-1-derived macrophages were stimulated with LPS to examine the treatments' effects on various stages of the NF-κB pathway. Compound 1, whose biological activity is reported here for the first time, demonstrated inhibition of NF-κB activity, reduction in interleukin 6 (IL-6), TNF-α, and interleukin 1 beta (IL-1β) production, as well as a decrease in p65 nuclear translocation in THP-1 cells, thus highlighting the potential role of sulphur substituents in the activity of naringenin (3). To explore the influence of sulphation on the anti-inflammatory properties of naringenin derivatives, we synthesized naringenin-4'-O-sulphate (4) and naringenin-7-O-sulphate (5) and evaluated their anti-inflammatory effects. Naringenin derivatives 4 and 5 did not display potent anti-inflammatory activities; however, compound 4 reduced IL-1β production, and compound 5 diminished p65 translocation, with both exhibiting the capacity to inhibit TNF-α and IL-6 production. Collectively, the findings demonstrated that the P. excelsa extract was more efficacious than all tested compounds, while providing insights into the role of sulphation in the anti-inflammatory activity of naringenin derivatives.

Antidiabetic plant-derived nutraceuticals: a critical review

Diabetes mellitus (DM) is one of the major health problems in the world, especially amongst the urban population. Chemically synthesized drugs used to decrease the ill effects of DM and its secondary complications cause adverse side effects, viz., weight gain, gastrointestinal disturbances, and heart failure. Currently, various other approaches, viz., diet control, physical exercise and use of antidiabetic plant-derived molecules/foods are advocated to manage DM, as they are economical with fewer or no side effects. This review mainly focuses on antidiabetic plants, chemically characterized plant molecules and plant-based foods in the treatment of DM. Very little science-based evidence is available on the mechanism of action of plant-derived food molecules on the DM targets. Critical DM targets include α-amylase, α-glucosidase, DPP-IV, aldose reductase, PPAR-γ, AMP kinase and GLUT4. In-depth studies carried out on a few of those targets with specific mechanisms of action are addressed in this review. This review may help future researchers in identifying a right plant molecule to treat DM or to develop food formulations for DM management.

A New Ceramide and Biflavonoid from the Leaves of Parinari hypochrysea (Chrysobalanaceae)

A new ceramide and a new biflavonoid named parinaramide (1) and sparinaritin (2), respectively, have been isolated along with ten known compounds, kaempferol, quercetin, taxifolin, taxifolin-3- O-rhamnoside, lupeol, betulinic acid, ursolic acid, 2α-hydroxy-ursolic acid, 2,3-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone, and sucrose, from the leaves of Parinari hypochrysea (Chrysobalanaceae). Structures were determined using 1D- and 2D-NMR, MS and by chemical analysis. The methanol extract of leaves, stem bark and roots of P. hypochrysea were screened for their antioxidant and lipoxygenase inhibition potential and found to be inactive.

Antioxidant plants and diabetes mellitus

The incidence of diabetes mellitus (DM) is increasing rapidly and it is expected to increase by 2030. Other than currently available therapeutic options, there are a lot of herbal medicines, which have been recommended for its treatment. Herbal medicines have long been used for the treatment of DM because of the advantage usually having no or less side-effects. Most of these plants have antioxidant activities and hence, prevent or treat hard curable diseases, other than having the property of combating the toxicity of toxic or other drugs. In this review other than presenting new findings of DM, the plants, which are used and have been evaluated scientifically for the treatment of DM are introduced.

In vitro antileishmanial, antiplasmodial and cytotoxic activities of a new ventiloquinone and five known triterpenes from Parinari excelsa

CONTEXT

Parinari excelsa Sabine (Chrysobalanaceae) is an indigenous tree from West and Eastern Africa. This tree is used in Ivory Coast as an antimalaria remedy.

OBJECTIVE

The in vitro antiplasmodial and antileishmanial activities of the stem bark, the leaf and the major compounds from the stem bark were investigated.

MATERIALS AND METHODS

The leaves and stem bark from P. excelsa were separately collected, air-dried and powdered. Two extracts (methylene chloride and methanol) were realized for both powders. Every extract was tested for its antiplasmodial and antileishmanial activities. Only the stem bark crude extracts were fractionated by column chromatography and their major components were analyzed by NMR, HRESIMS and IR methods. The compounds were tested for their antiplasmodial and antileishmanial activities.

RESULTS

The comparison of the IC(50) values of the crude extracts were in this order: 3.41 (IC(50) of PeBMc) <4.10 (IC(50) of PeBMc) <4.42 (IC(50) of PeLMe) against P. falciparum and 5.19 (IC(50) of PeBMc) <12.32 (IC(50) of PeBMe) <19.33 (IC(50) of PeLMc) <32.37 (IC(50) of PeLMe) against L. donovani. The stem bark crude extracts were the most active against both parasites. Their fractionation leaded to a new ventiloquinone, five triterpenes and one chlorogenic acid. All these compounds were isolated for the first time from P. excelsa. High activities were observed with (3β)-3-hydroxyolean-12-en-28-oic acid (IC(50) = 8.2 µM) and 3β-hydroxyolean-5,12-dien-28-oic acid (IC(50) = 7.7 µM) against L. donovani. With the antiplasmodial activity, the best activity was observed with 16β-hydroxylupane-1,20(29)-dien-3-one (IC(50) = 28.3 µM).

DISCUSSION AND CONCLUSION

These findings demonstrated that the constituents of P. excelsa stem bark have in vitro antiplasmodial and antileishmanial activities.