Neuroprotection by Alstonia boonei De Wild., Anacardium occidentale L., Azadirachta indica A.Juss. and Mangifera indica L

Mango (Mangifera indica L.) By-products in Food Processing and Health Promotion

The edible and nonedible parts of the mango (Mangifera indica L.) contain vitamins, phytocompounds, fiber, and fatty acids. This review highlights the uses of mango by-products in the food industry and their effects on human health. The literature offers many new possibilities for the usage of mango secondary products in the food industry, such as the production of functional foods and bakery products, in addition to the potential for extraction of antioxidants and enzymes. Furthermore, due to their antioxidant and anti-inflammatory properties, the consumption of various mango by-products, in the form of peel and leaf (powder or extract), can improve glycemia, plasma lipid levels, satiety, and endothelial function, suggesting that these compounds can prevent or improve various risk factors for cardiovascular complications and metabolic syndrome. Clinical trials show that the discarded parts of mango fruits and leaves can be used to treat diabetes mellitus, obesity, and cardiovascular disorders. Moreover, mango by-products can be utilized to improve the functional characteristics of foods, may be incorporated as fat replacers, and have the potential to leverage agribusiness and reduce environmental damage resulting from the disposal of discarded materials, in addition to reducing waste and the complex chain of environmental damage. Mango by-products also have the potential to produce nutraceutical food items. The use of new technologies can bring to light the production of numerous products made from by-products, contributing to the development of industrial functional foods. In addition, products for the pharmaceutical and cosmetics industries may also be developed. Nutraceutical and pharmaceutical products could have lower prices and could, therefore, be used by low-income populations. The utilization of mango by-products meets the current trend and growing market for better and healthier products. However, more clinical trials are necessary to evaluate the effectiveness of mango by-products on human health, and new technologies can improve industrial applications.

Antibacterial Properties of Phytochemicals Isolated from Leaves of Alstonia boonei and Aerial Parts of Ipomoea cairica

Objective

The leaves of Alstonia boonei and aerial parts of Ipomoea cairica are used for treatment of microbial infections among other ailments in African traditional medicine. The aim of this study was to investigate the antimicrobial phytochemicals in A. boonei leaves and Ipomoea cairica aerial parts to validate their traditional use in Ugandan herbal medicine.

Methods

The plant materials were separately extracted using a dichloromethane/methanol (1:1) solvent system and subjected to repeated chromatographic separation to isolate pure compounds. The chemical structures of the isolated compounds were determined through 1H NMR, 13C NMR and 2D NMR (COSY, HSQC and HMBC). The antibacterial activity of the extracts and pure compounds were assessed using the agar well diffusion method.

Results

Chromatographic fractionation of the extracts yielded trans-fagaramide and a pentacyclic lupane-type triterpenoid, lupeol, from A. boonei, and friedelin from I. cairica. Trans-fagaramide was identified for the first time in the Alstonia genus while friedelin was identified for the first time in I. cairica. The isolated compounds demonstrated antibacterial activity, with trans-fagaramide showing a minimum inhibitory concentration (MIC) of 125 μg/mL against Pseudomonas aeruginosa and 250 μg/mL against Staphylococcus aureus, Salmonella typhi and Escherichia coli. Friedelin exhibited a MIC of 125 μg/mL against Escherichia coli and 250 μg/mL against Pseudomonas aeruginosa, Staphylococcus aureus and Salmonella typhi.

Conclusion

The antibacterial activities observed in this study support the traditional use of A. boonei and I. cairica by indigenous communities in Uganda for treating microbial infections.

Neuroprotective Effect of Sterculia setigera Leaves Hydroethanolic Extract

Plants are a valuable source of information for pharmacological research and new drug discovery. The present study aimed to evaluate the neuroprotective potential of the leaves of the medicinal plant Sterculia setigera. In vitro, the effect of Sterculia setigera leaves dry hydroethanolic extract (SSE) was tested on cultured cerebellar granule neurons (CGN) survival when exposed to hydrogen peroxide (H2O2) or 6-hydroxydopamine (6-OHDA), using the viability probe fluorescein diacetate (FDA), a lactate dehydrogenase (LDH) activity assay, an immunocytochemical staining against Gap 43, and the quantification of the expression of genes involved in apoptosis, necrosis, or oxidative stress. In vivo, the effect of intraperitoneal (ip) injection of SSE was assessed on the developing brain of 8-day-old Wistar rats exposed to ethanol neurotoxicity by measuring caspase-3 activity on cerebellum homogenates, the expression of some genes in tissue extracts, the thickness of cerebellar cortical layers and motor coordination. In vitro, SSE protected CGN against H2O2 and 6-OHDA-induced cell death at a dose of 10 µg/mL, inhibited the expression of genes Casp3 and Bad, and upregulated the expression of Cat and Gpx7. In vivo, SSE significantly blocked the deleterious effect of ethanol by reducing the activity of caspase-3, inhibiting the expression of Bax and Tp53, preventing the reduction of the thickness of the internal granule cell layer of the cerebellar cortex, and restoring motor functions. Sterculia setigera exerts neuroactive functions as claimed by traditional medicine and should be a good candidate for the development of a neuroprotective treatment against neurodegenerative diseases.