Black Seed (Nigella sativa): A Favourable Alternative Therapy for Inflammatory and Immune System Disorders.

In the recent years, various food additives, medicinal plants, and their bioactive components have been utilized in anti-inflammatory and immunomodulatory therapy. Nigella sativa is a key dietary supplement and food additive which has a strong traditional background. It is also one of the most broadly studied seeds in the global pharmaceutical and nutraceutical sector. N. sativa seeds are potential sources of natural metabolite such as phenolic compounds and alkaloids. The anti-inflammatory and immunomodulatory abilities of these seeds, most peculiarly with reference to some inflammatory and immune mediators, are reviewed. N. sativa and its bioactive compounds modulate inflammatory and immunomodulatory mediators including tumor necrosis factor-alpha (TNF-α), interferon gamma (IFN-γ), nuclear factor kappa B (NF-kB) cyclooxygenase (COX), lipoxygenase (LOX), transforming growth factor beta (TGF-ß), interleukins, and immunoglobulin levels. This paper comprehensively describes the biomarkers and signaling pathways underlying the anti-inflammatory and immunomodulatory potential of N. sativa. This review also explains the scientific basis and the pharmacological properties of core bioactive ingredients of N. sativa responsible for these biological activities which indicates that their bioactive components could be possibly regarded as favorable therapy for disorders linked to inflammation and immune-dysregulation.

The modulatory effects of alkaloid extracts of Cannabis sativa, Datura stramonium, Nicotiana tabacum and male Carica papaya on neurotransmitter, neurotrophic and neuroinflammatory systems linked to anxiety and depression.

This study investigated the modulatory effects of alkaloid extracts of Cannabis sativa (CSAE), Datura stramonium (DSAE), Nicotiana tabacum (NTAE) and male Carica papaya (CMAE) on neurotransmitter, neurotrophic and neuro-inflammatory systems linked to anxiety and depression. Male Wistar rats were orally administered the alkaloid extracts in doses of 5, 50, 500, and 2000 mg/kg for 90 days. On day 91, neurobehavioural studies were evaluated, rats were sacrificed, brain hippocampus removed and tissue homogenate prepared. Biochemical, cytokine and neurotransmitter metabolisms were estimated in the hippocampus. Expressions of genes linked to anxiety and depression were evaluated by RT-qPCR. Results showed CSAE, NTAE and CMAE act as anxiolytic and antidepressant agents by depleting TNF-α, IL-1ß and reactive oxygen species concentrations, and monoamine oxidase, angiotensin 1-converting enzyme and acetylcholinesterase activities while elevating IL-10 and dopamine concentrations and glutamate dehydrogenase activity at doses of 5, 50 and 500. Same doses of CSAE, NTAE and CMAE also depleted the gene expressions of GSK3ß, JNK, NF-ĸB, and Nesfatin-1 while increasing expressions of CREB, BDNF, serotonin and Nrf2. However, administration of DSAE and 2000 mg/kg CSAE, NTAE and CMAE had adverse modulatory effects on the neurochemical concentrations and activities as well as the gene expressions of the evaluated neurotransmitter, neurotrophic and inflammatory systems. In conclusion, the study established the sub-chronic instrumentalization potential of CSAE, CMAE, and NTAE for anxiolytic and anti-depressive moods, though their use may be associated with dependence and addiction, which may result in more detrimental effects than any therapeutic potential they may proffer.

Fig (Ficus exasperata and Ficus asperifolia)-Supplemented diet improves sexual function, endothelial nitric oxide synthase and suppresses tumour necrosis factor-alpha genes in hypertensive rats.

We measured the effect of varieties of Fig leaves, Ficus exasperata Vahl. (FE) and Ficus asperifolia Miq (FA), commonly found in Sub-sahara Africa for managing hypertension on sexual performance in hypertensive rats, which is unknown. Hypertensive rats experienced erectogenic damage after exposure to 40 mg kg-1  bw-1 , N(G)-nitro-l-arginine-methyl-ester (L-NAME). Experimental rats were grouped into eight groups (n = 6) namely: control rats, hypertensive rats, hypertensive treatment groups with atenolol (10 mg kg-1  day-1 ) and sildenafil (5.0 mg/kg), rats treated with FE- and FA-formulated biscuits at proportions of 2.5 g and 5.0 g respectively. Furthermore, we measured the level of sexual performance (Intromission number, latency, Mounting number, and latency), hormonal levels, phosphodiesterase-5 enzyme (PDE-5) activity and genes expressed using real-time quantitative polymerase chain reaction (RT-qPCR) in hypertensive rats. The result deduced revealed that treated hypertensive rats showed significantly reduced follicle-stimulating hormone, luteinising hormone levels, PDE-5 enzyme activity, tumour necrosis factor-alpha (TNF-α) expression while having a marked increase in testosterone level, sexual performance and endothelial nitric oxide synthase (eNOS) expression. Therefore, this study revealed the comparative dietary enhancing effect of FE- and FA-formulated biscuit on sexual behaviour activity, hormonal levels and the level of eNOS and TNF-α genes expressed in hypertensive rats.

Inhibitory Effect of Garlic, Purple Onion, and White Onion on Key Enzymes Linked with Type 2 Diabetes and Hypertension.

Spices are used in soup preparation in many homes and serve as ingredients in the preparation of several traditional delicacies endowed with natural antioxidants such as polyphenols. The aim of this study is to evaluate the effect of aqueous extract of garlic, white onion, and purple onion on angiotensin-converting enzyme, α-amylase, and α-glucosidase activity in vitro and determine their antioxidant properties via various antioxidant assays such as OH*, Fe2+ chelation, and 2, 2'-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical-scavenging assays. The results reveal that aqueous extract of garlic, purple onion, and white onion inhibited angiotensin-converting enzyme, α-amylase, and α-glucosidase in a concentration-dependent manner (0-4 mg/ml). However, purple onion (IC50 = 0.59 mg/ml) had higher inhibitory effect on angiotensin-converting enzyme than white onion (IC50 = 0.66 mg/ml) and purple onion (IC50 = 0.96 mg/ml). Furthermore, white onion had significantly (p < .05) stronger inhibitory effect on α-amylase (IC50 = 3.93 mg/mL) than garlic (IC50 = 8.19 mg/ml) and purple onion (IC50 = 8.27 mg/ml). Conversely, garlic (IC50 = 4.50 mg/ml) had no significantly higher inhibitory effect on α-glucosidase activity than white onion and purple onion. In addition, the aqueous extracts were able to scavenge 2,2- diphenyl-1-picrylhydrazyl (DPPH*) free radical and reduce Fe3+ to Fe2+ in a dose-dependent manner. Therefore, a possible mechanism by which garlic, white onion, and purple onion exert antidiabetes and antihypertensive properties could be through the inhibitory effect on ACE, α-amylase, and α-glucosidase coupled with their ability to prevent lipid peroxidation in the pancreas and heart, which justify their strong antioxidant properties.

In vitro inhibition of phosphodiesterase-5 and arginase activities from rat penile tissue by two Nigerian herbs (Hunteria umbellata and Anogeissus leiocarpus).

BACKGROUND: Anogeissus leiocarpus and Hunteria umbellata have been reportedly used in traditional medicine for the management of erectile dysfunction (ED). However, the scientific basis for their use has not been well established. Therefore, this study was designed to investigate the inhibitory effects of water extractable phytochemicals of H. umbellata and A. leiocarpus on phosphodiesterase-5 (PDE-5) and arginase as well as pro-oxidants induced lipid peroxidation in rat penile tissue. METHODS: The effects of the extracts on important enzymes (PDE-5 and arginase) linked with ED and pro-oxidants (Fe2+ and sodium nitroprusside) induced lipid peroxidation were investigated. Also, radicals scavenging and metal chelating abilities were determined. In addition, phenolic contents were determined and characterized using HPLC. RESULTS: The results showed that both extracts inhibited PDE-5 and arginase activities in a dose-dependent manner. Inhibitory property of A. leiocarpus (IC50 - 174.19 µg/mL) was significantly better (p<0.05) than that of H. umbellata (IC50 - 537.72 µg/mL) in PDE-5 assay. The extracts were potent inhibitors of arginase than PDE-5, and these extracts were equally potent in inhibiting arginase. Furthermore, Fe2+ and sodium nitroprusside caused a significant increase in malondialdehyde content; however, both extracts reduced malondialdehyde level in concentration-dependent manner. It is noteworthy that both extracts scavenged radicals (OH* and ABTS*) and chelated Fe2+. HPLC analysis revealed abundance of rutin, chlorogenic acid, gallic acid, caffeic acid, and quercetin, among others. CONCLUSIONS: The ability of the extracts to inhibit PDE-5, arginase and pro-oxidant induced lipid peroxidation, and chelate metal might suggest their folkloric use for the management of ED.

Anticholinesterase and antioxidative properties of water-extractable phytochemicals from some citrus peels.

BACKGROUND: Aqueous extracts from citrus peels are used in many rural communities in Nigeria in treating various degenerative conditions, although the scientific basis for its use has not been well established. This study sought to investigate the anticholinesterase and antioxidant properties of aqueous extracts from some citrus peels [orange (Citrus sinensis), grapefruit (Citrus paradisii), and shaddock (Citrus maxima)]. METHODS: The effects of the extracts on acetylcholinesterase (AChE) activity, as well as Fe2+-induced malondialdehyde (MDA) production in vitro, were investigated. The total phenolic, flavonoid content, and antioxidant activities as typified by 1,1-diphenyl-2 picrylhydrazyl (DPPH) free radical scavenging ability and hydroxyl (OH) radicals scavenging abilities were also investigated. RESULTS: The results revealed that orange peels had the highest total phenol content followed by grapefruit peels, whereas shaddock peels had the least. The extracts inhibited AChE activity in a dose-dependent manner, although there is no significant difference (p>0.05) in their inhibitory abilities of the peels. The extracts exhibited antioxidant activities as typified by their radical (DPPH· and OH·) scavenging abilities as well as the inhibition of Fe2+-induced lipid peroxidation in rat's brain in vitro. CONCLUSIONS: The anticholinesterase activity and inhibition of MDA production by the aqueous extracts of the peels, as well as other antioxidant activities, could make the peels a good dietary means for the management of oxidative-mediated neurodegenerative disorders.