**8. Conclusion**

with doum has a promising anti-inflammatory influence on attenuating the complications associated with the renal dysfunction. Moreover, anti-inflammatory status of animals injected with cyclo sporine and supplemented with doum showed a significant amelioration in the kidney functions as compared to animals injected with the cyclosporine only [60]. The antiinflammatory activity of doum was possibly due to its saponin content which acts against the oxidative damage and suppresses the serum transforming growth factor-ß1 (TGF-beta1) expression [61]. Therefore, doum administration declines the oxidative damage and the renal interstitial fibrosis in rats [60]. The significant increase in white blood cells caused by crude mesocarp extract of *H. thebaica* could be due to stimulation of bone marrow stem cells to produce these cells, which is an indication of immune—modulatory effect as was observed by other researchers exhibited by some plants [62]. The presence of phytochemicals such as glycosides and reducing sugars could be the reason for the leukocytosis [63]. Flavonoids protect both the hematopoietic committed stem cells and the formed blood cells from the attack of the reactive free radicals hence improving leucocytic production [64]. In *H. thebaica*, flavonoid conjugates, oxygenated fatty acids, and sphingolipids enriched in fruits are likely to mediate

Doum extracts treatments inhibited the activity of cyclooxygenase (COX-1), an enzyme

Methanol and aqueous extracts of doum fruit showed higherantibacterial activity against Gram-positive bacteria and Gram-positive bacteria except for *Listeria monocytogenes*, where only a slight inhibition was observed [27]. Moreover, the ethyl acetate extract of doum fruit was active against five pathogenic bacteria, *Staphylococcus aureus*, *Escherichia coli*, *Bacellussubtilis*, *Pseudomonas aeruginosa* and *Klebsiella pneumonia* while methanol extract was active against *Pseudomonas aeruginosa* and *Klebsiella pneumonia*. Penicillium sp. growth was slightly affected by high concentration of methanolic extract [67]. *H. thebaica* fruit extracts reduced the growth of Erwiniacarotovora and produced inhibition zones up to 38 mm in diameter [68]. All doum extracts showed strong antibacterial activity against *Staphylococcus aureus* and Salmonella typhi, while methanol/ultrasonic (MU) extract inhibited the growth of all pathogenic bacteria used in the study. However, all doum fruit extracts demonstrated no antibacterial activity against *E. coli* colonies except the methanol/ultrasonic (MU) extract, which had slight activity [16]. The antibacterial activities against both Gram-positive and Gram-negative bacteria may indicate the presence of broad spectra antibiotic compounds or simply metabolic toxins in plant extracts [69]. Doum fruits showed antimicrobial and antihypertensive activities, and these activities were attributed to the presence of flavonoids [70]. The mechanism of polyphenol toxicity against microbes may be related to inhibition of hydrolytic enzymes (proteases) or other interactions that inactivate microbial adhesins, cell envelope transport proteins, and non-specific interactions with carbohydrates [71]. Also, the methanolic extract of *H. thebaica* showed stronger antifungal and anti-yeast activities than aqueous extracts [27]. Similar results were observed in previous studies, which showed that polar solvent extract of H. Tobacco has high antifungal activity against a wide range of fungal isolates, including *Aspergillus niger*, *Microsporum gypseum*, *Trichlorophyton rubrum*, *Mucor* sp., *Fusarium solani* and *Candida albicans* [72]. Antimicrobial activity may involve complex mechanisms, like the

for its anti-inflammatory effect [65, 66].

60 Antioxidants in Foods and Its Applications

known to be involved in inflammation [33].

**7.4. Antimicrobial activity of doum fruit extracts**

*Hyphaene thebaica*, a well-known plant for its antioxidant, anticancer and anti-Inflammatory potential because of its phenolic and flavonoid content was explored for its antimicrobial potential against various Gram-positive and Gram-negative bacteria and fungal pathogens. This chapter evidently reveals that the doum (leaf and fruit) extracts are effective antimicrobial and pharmacological agents. Further detailed study on its mechanism and safety profile may develop them as good candidates for food preservation or functional foods, as well as for pharmaceutical and natural plant-based products.
