Sakina Yagi

Anti-inflammatory activities of cucurbitacin E isolated from Citrullus lanatus var. citroides: Role of reactive nitrogen species and cyclooxygenase enzyme inhibition

The in vivo and in vitro mechanistic anti-inflammatory actions of cucurbitacin E (CE) (Citrullus lanatus var. citroides) were examined. The results showed that LPS/INF-γ increased NO production in RAW264.7 macrophages, whereas L-NAME and CE curtailed it. CE did not reveal any cytotoxicity on RAW264.7 and WRL-68 cells. CE inhibited both COX enzymes with more selectivity toward COX-2. Intraperitoneal injection of CE significantly suppressed carrageenan-induced rats paw edema. ORAC and FRAP assays showed that CE is not a potent ROS scavenger. It could be concluded that CE is potentially useful in treating inflammation through the inhibition of COX and RNS but not ROS.

Toxicity of Senna obtusifolia fresh and fermented leaves (kawal), Senna alata leaves and some products from Senna alata on rats

The present study investigated the effects induced on albino rats by Senna obtusifolia fresh leaves and fermented (kawal) leaves, S. alata leaves, as well as the ethanol extract and pure compounds, namely, emodin, kaempferol, aloe‐emodin, and rhein from the latter species. The present results indicate that the leaves of both S. obtusifolia and S. alata can cause marked toxic effects on rats, and that the processing of the leaves of the former species by fermentation to produce kawal did not alter the toxic activity of the ingredients in the leaves. Also the ethanol extract and compounds isolated from S. alata can cause subtle hepatorenal toxicity. Moreover, the present study suggests that anthraquinones have a mechanism of synergistic action when used collectively as present in the leaves.

The antidiabetic effect of Geigeria alata is mediated by enhanced insulin secretion, modulation of β-cell function and improvement of antioxidant activity in streptozotocin-induced diabetic rats

In Sudanese folk medicine, Geigeria alata roots have been used for the management of diabetes for a long time. However, its antidiabetic activity is unreported. In this study, G. alata methanolic extract was tested for its antidiabetic, antioxidant, and β-cell modulatory effects in a streptozotocin-induced diabetic rat model. In this model of diabetic rats, the oral glucose tolerance test with G. alata extract at 125, 250, and 500  mg/kg doses revealed the efficacy of the 250  mg/kg dose in improving glucose tolerance comparable to the standard drug glibenclamide. Diabetic rats were treated with a 250  mg/kg dose of G. alata extract orally for 2  h (acute) or 14 days (chronic). In the case of acute treatment, the extract lowered blood glucose levels significantly at 120  min both in nondiabetic and diabetic rats. Chronic treatment of diabetic rats with 250  mg/kg of G. alata extract resulted in a significant decrease in blood glucose level closer to that of nondiabetic rats. Interestingly, increased serum insulin, improved β-cell function, and antioxidant status were observed in G. alata-treated diabetic rats. G. alata also showed strong antioxidant and α-glucosidase inhibitory activities in in vitro assays. These data show direct evidence that G. alata has antidiabetic activity and suggest that the antidiabetic activity is due to enhanced insulin secretion, modulation of β-cell function, and improvement of antioxidant status.

Comparative antioxidant activity appraisal of traditional Sudanese kisra prepared from two sorghum cultivars

The effect of fermentation and heating on the antioxidant activity of the fermented and fermented baked (kisra) dough prepared from two Sorghum cultivars (Tabat and Wad Ahmed) was evaluated. Kisra prepared from Tabat cultivar showed higher DPPH (1,1-diphenyl-2-picrylhydrazyl radical) scavenging and ferric reducing/antioxidant power (FRAP) than that of the Wad Ahmed cultivar. Baking improves the DPPH and FRAP of the kisra prepared from two cultivars. Baking caused a variable effect on the total phenol, tannins and flavonoids content across different periods of fermentation where an increase was mainly observed for samples subjected to longer periods of fermentation. A positive high correlation between the total phenol and antioxidant activity, using the DPPH and FRAP assays, was obtained for kisra prepared from both cultivars. The same observation was obtained for tannin content. In conclusion, fermentation and heating improve the antioxidant capacity of the sorghum grains from Tabat and Wad Ahmed cultivars.

Evaluation of antidiabetic activity of plants used in Western Sudan

ABSTRACT Objective To investigate the traditional antidiabetic uses of some indigenous Sudanese plants on streptozotocin-induced diabetes rats. Methods Diabetic rats were treated with a 400 mg/kg dose of aqueous extracts of five plant species orally for 2 h (acute) or 14 days (chronic). In acute model blood glucose levels were monitored at specific intervals. In the chronic model blood samples were collected from overnight fasted diabetic rats on day 15 to estimate blood glucose level. And the body weight, serum lipid profile and activities of liver and kidney enzymes were measured. Histopathological observations of liver sections were also studied. Results In the case of acute treatment, aqueous extracts of Tinospora bakis ( T. bakis ), Nauclea latifolia ( N. latifolia ) and Randia nilotica ( R. nilotica ) at 400 mg/kg significantly lowered ( P 0.05) blood glucose levels in diabetic rats whereas, chronic treatment of diabetic rats with 400 mg/kg of T. bakis, N. latifolia, R. nilotica and Mitragyna inremis proved to have significant ( P 0.05) antihyperglycemic effect and have the capacity to correct the metabolic disturbances associated with diabetes. Histopathological studies showed that the aqueous extracts of these four plants reinforced the healing of liver. However, Striga hermonthica aqueous extract did not exert any antihyperglycemic effect to diabetic rats. Conclusions This study demonstrated that T. bakis, N. latifolia, R. nilotica and Mitragyna inremis have therapeutic value in diabetes and related complications and thus supporting the traditional uses of these plants in Sudanese traditional medicine.

Toxicity of Hydnora johannis Becca. dried roots and ethanol extract in rats

AIM OF THE STUDY Hydnora johannis Becca. (Hydnoraceae) commonly is used for the treatment of dysentery, diarrhoea, cholera and swelling tonsillitis in the folk medicine of Sudan and other African countries. This study evaluates the toxicological effects of Hydnora johannis roots on Wistar rats. MATERIALS AND METHODS Rats were randomized into control, groups fed with 2, 10, 20% of dried roots for 8 weeks and other groups given ethanol extract (50, 100, 200 and 400mg/kg/day) through oral and intramuscularly administration for 2 weeks. Toxicity was evaluated using biochemical and histopathological assays. RESULTS Alterations in the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, cholesterol and urea were observed. Histopathological analysis revealed that the toxic effect were mainly on the liver, kidney and spleen on all treated groups. However, the impact of the dried roots was mild compared to the ethanol extract. Remarkably, there was a drop in cholesterol level in all treatment groups suggesting the antiartherogenic effect of Hydnora johannis roots. CONCLUSION The results from this study suggest that the powder preparation as well as ethanolic extract of Hydnora johannis roots induced toxic effect on Wistar rats. The observed toxic effect might be due to the dose and/or frequency of administration. Although in traditional medicine the extract is administrated in low dose, the results suggest the necessity of standardization of the drug.

Cucurbitacin L 2-O-β-Glucoside Demonstrates Apoptogenesis in Colon Adenocarcinoma Cells (HT-29): Involvement of Reactive Oxygen and Nitrogen Species Regulation

Emerging evidence suggests that reactive oxygen (ROS) and nitrogen (RNS) species can contribute to diverse signalling pathways of inflammatory and tumour cells. Cucurbitacins are a group of highly oxygenated triterpenes. Many plants used in folk medicine to treat cancer have been found to contain cucurbitacins displaying potentially important anti-inflammatory actions. The current study was designed to investigate the anti-ROS and -RNS effects of cucurbitacin L 2-O-β-glucoside (CLG) and the role of these signaling factors in the apoptogenic effects of CLG on human colon cancer cells (HT-29). This natural cucurbitacin was isolated purely from Citrullus lanatus var. citroides (Cucurbitaceae). The results revealed that CLG was cytotoxic to HT-29. CLG increased significantly (P < 0.05) RNA and protein levels of caspase-3 in HT-29 cells when verified using a colorimetric assay and realtime qPCR, respectively. The results showed that lipopolysaccharide/interferon-gamma (LPS/INF-γ) increased nitrous oxide (NO) production inR AW264.7macrophages, whereas N(G)-nitro-L-argininemethyl ester (L-NAME) and CLG curtailed it. This compound did not reveal any cytotoxicity on RAW264.7 macrophages and human normal liver cells (WRL-68) when tested using the MTT assay. Findings of ferric reducing antioxidant power (FRAP) and oxygen radical absorption capacity (ORAC) assays demonstrate the antioxidant properties of CLG. The apoptogenic property of CLG on HT-29 cells is thus related to inhibition of reactive nitrogen and oxygen reactive species and the triggering of caspase-3-regulated apoptosis.

In Vitro Antioxidant and Cytotoxic Activities of 18 Plants from the Erkowit Region, Eastern Sudan

We investigated the antioxidant potential and cytotoxicity towards human CCRF-CEM leukemia cells of 57 extracts obtained from 18 plants collected in the Erkowit region, eastern Sudan. The antioxidant activity was determined by measuring the radical scavenging effects against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and N,N-dimethyl-p-phenylendiamine (DMPD), metal-chelation capacity, ferric-reducing (FRAP) and phosphomolibdenum-reducing antioxidant power (PRAP) methods using ELISA microtiter assays. Total phenol and flavonoid amounts of the extracts were determined spectrophotometrically. Cytotoxicity towards CCRF-CEM cells was evaluated by the resazurin reduction assay. Geranium favosum followed by Kalanchoe glaucescens, Malva parviflora, Aizoon canariense, and Coleus barbatus, respectively, possessed the highest antioxidant activity among the studied plants. Chrozophora oblongifolia and K. glaucescens exerted considerable cytotoxicity against CCRF-CEM leukemia cells. These plants may serve as source for the further development of natural antioxidant and antitumor agents.

Total phenolic and flavonoid contents and antioxidant activity of ginger ( Zingiber officinale Rosc.) rhizome, callus and callus treated with some elicitors

The present study was aimed at determining total phenolic and flavonoid contents and studying the antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome and callus, 6-gingerol and 6-shogaol and callus treated with elicitors. Petroleum ether (PE) and chloroform: methanol (1:1, v/v) (CM) extracts were prepared by maceration. Highest total phenolic content was obtained from the CM extract (60.34 ± 0.43 mg gallic acid/g) of rhizome while callus showed lower content detected in the CM extract (33.6 ± 0.07 mg gallic acid/g). Flavonoids were only detected in rhizome (CM extract 40.25 ± 0.21 mg quercetin/g). Both rhizome extracts exhibited good antioxidant activity with higher activity recorded in PE extract (IC50 value 8.29 ± 1.73 μg/mL). Callus extracts revealed lower antioxidant activity (IC50 value 1265.49 ± 59.9 μg/mL obtained from CM extract). 6-gingerol and 6-shogaol displayed high antioxidant activity in both assays with IC50 4.85 + 0.58DPPH and 5.35 ± 0.33ABTS μg/mL for the former and IC50 7.61 ± 0.81DPPH and IC50 7.05 ± 0.23ABTS μg/mL for the latter. Treatment of callus with elicitors showed significant (p < 0.05) effects in enhancing phenolic content and related antioxidant activity. The highest significant increase in phenolic content (37% and 34%) and antioxidant activity in DPPH assay (34% and 30%) was observed in callus treated with 100 mg/L yeast extract and 50 mg/L salicylic acid respectively. Therefore, studying the effect of the elicitation of ginger cultured tissues in phenolic accumulation would be of immense importance for pharmacological, cosmetic and agronomic industries.

Callus induction, direct and indirect organogenesis of ginger ( Zingiber officinale Rosc)

The present study aimed to induce callus, direct and indirect organogenesis of ginger (Zingiber officinale Rosc) by using Murashige and Skoog (MS) medium fortified with different concentrations and combinations of growth regulators. Shoot tip, in vitro leaf and root segments were used as explants to induce callus by MS medium containing (0.00 as control, 0.5, 1.00, 2.00 and 3.00 mg/L) of 2,4-dichloro-phenoxyacetic acid (2,4-D). Callus induced was subcultured on MS+2,4-D at different concentrations (0.5, 1.00, 2.00 and 3.00 mg/L) and one concentration 0.5 mg/L of 6-benzyl amino purine (BAP) was used. The sprouting buds (about 1 to 1.5 cm) were used as explants for direct shoots and roots induction by MS medium + 2.00, 3.00 and 4.5 mg/L of BAP. Callus induced by 1.00 mg/L 2,4-D was regenerated on MS + 0.5 mg/L 2,4-D to obtain a green callus, this callus was transferred to MS medium with combinations of 0.5 mg/L 1-naphthaleneacetic acid (NAA) with different concentrations of BAP (1.00, 2.00,3.00 and 4.00 mg/L) for indirect organogenesis. The results reveals that, for callus induction, callus was only induced from shoot tip explant in all concentrations of 2,4-D. The highest callus fresh weight was obtained by 1.00 mg/L of 2,4-D (1.302 ± 0.09) g than that induced by other treatment (p < 0.05). In the case of callus induced by subculture, the highest callus fresh weight initiated was 1.509 ± 0.00 g by 0.5 mg/L 2,4-D. For direct organogenesis, 4.5 mg/L BAP showed the highest number of in vitro shoots and roots, 4 ± 0.35 shoots and 15 ± 0.46 roots per explants. For indirect organogenesis, the best shoots and roots initiated were 2 ± 0.21 shoots and 22 ± 0.33 roots by combination of 1.00 mg/L BAP+0.5 mg/L NAA. Key words: Callus induction, growth regulators, Zingiber officinale Rosc, organogenesis.