Knowledge, attitudes and practices with regard to prophetic medicine during the COVID-19 pandemic in Saudi Arabia

OBJECTIVE

The current study explores the impact of Prophetic medicine's knowledge, attitudes, and practices on the Saudi population during the COVID-19 pandemic.

SUBJECTS AND METHODS

This study used a web-based cross-sectional design. A self-selected nonprobability sampling technique was utilized to recruit social media users in Saudi Arabia aged ≥18.

RESULTS

Four statements were used to evaluate participants' knowledge of the role of prophetic medicine in preventing and treating COVID-19. The participants had significant levels of knowledge, with an average of 90.3% correct answers. They strongly agreed with prophetic advice, including quarantine, travel bans and hand washing to prevent COVID-19 infection, with a mean of 4.3. In addition, the participants followed prophetic advice, including walking for half an hour, keeping social distance, wearing masks, and taking vaccines to prevent COVID-19 infection, with a mean of 4.2.

CONCLUSIONS

The current study was conducted to evaluate the knowledge, attitudes, and practices of Muslim residents of Saudi Arabia concerning prophetic medicine during the COVID-19 pandemic. The study revealed that participants had good knowledge of prophetic medicine, including the use of natural products such as honey, ginger, garlic, and olive oil, as well as herbal products such as black seeds, and practices such as cupping. The study also showed that participants strongly believed that COVID-19 preventative measures - including quarantine, travel bans, and handwashing - were introduced by prophetic medicine. Practices including self-isolation, hand washing, and travel bans help prevent, treat and control diseases. They assist in maintaining good health and developing resistance to diseases.

MALAT-1/p53/miR-155/miR-146a ceRNA circuit tuned by methoxylated quercitin glycoside alters immunogenic and oncogenic profiles of breast cancer

Triple-Negative Breast Cancer (TNBC) is one of the most aggressive and hot BC subtypes. Our research group has recently shed the light on the utility of natural compounds as effective immunotherapeutic agents. The aim of this study is to investigate the role of a methoxylated quercetin glycoside (MQG) isolated from Cleome droserifolia in harnessing TNBC progression and tuning the tumor microenvironment and natural killer cells cytotoxicity. Results showed that MQG showed the highest potency (IC₅₀ = 12 µM) in repressing cellular proliferation, colony-forming ability, migration, and invasion capacities. Mechanistically, MQG was found to modulate a circuit of competing endogenous RNAs where it was found to reduce the oncogenic MALAT-1 lncRNA and induce TP53 and its downstream miRNAs; miR-155 and miR-146a. Accordingly, this leads to alteration in several downstream signaling pathways such as nitric oxide synthesizing machinery, natural killer cells' cytotoxicity through inducing the expression of its activating ligands such as MICA/B, ULBP2, CD155, and ICAM-1 and trimming of the immune-suppressive cytokines such as TNF-α and IL-10. In conclusion, this study shows that MQG act as a compelling anti-cancer agent repressing TNBC hallmarks, activating immune cell recognition, and alleviating the immune-suppressive tumor microenvironment experienced by TNBC patients.

Potential Mechanisms Involved in the Protective Effect of Dicaffeoylquinic Acids from Artemisia annua L. Leaves against Diabetes and Its Complications

Diabetes mellitus is a chronic disease affecting the globe and its incidence is increasing pandemically. The use of plant-derived natural products for diabetes management is of great interest. Polar fraction of Artemisia annua L. leaves has shown antidiabetic activity in vivo. In the present study, three major compounds were isolated from this polar fraction; namely, 3,5-dicaffeoylquinic acid (1); 4,5-dicaffeoylquinic acid (2), and 3,4- dicaffeoylquinic acid methyl ester (3), using VLC-RP-18 and HPLC techniques. The potential protective effects of these compounds against diabetes and its complications were investigated by employing various in vitro enzyme inhibition assays. Furthermore, their antioxidant and wound healing effectiveness were evaluated. Results declared that these dicaffeoylquinic acids greatly inhibited DPPIV enzyme while moderately inhibited α-glucosidase enzyme, where compounds 1 and 3 displayed the most prominent effects. In addition, compound 3 showed pronounced inhibition of α-amylase enzyme. Moreover, these compounds markedly inhibited aldose reductase enzyme and exerted powerful antioxidant effects, among which compound 3 exhibited the highest activity implying a notable potentiality in impeding diabetes complications. Interestingly, compounds 2 and 3 moderately accelerated scratch wound healing. Our findings suggest that these dicaffeoylquinic acids can be promising therapeutic agents for managing diabetes and its complications.

Niazimicin: A thiocarbamate glycoside from Moringa oleifera Lam. seeds with a novel neuroprotective activity

Moringa oleifera (MO) known as the miracle tree is a famous nutritional source in many countries. In this study, the neuroprotective activity of MO seeds was investigated. Fractions of the 70% ethanol seed extract of MO were injected at a dose of 250 mg kg^-1  day^-1 to albino rats for 15 days, after-which induction of dementia was done using 100 mg/kg AlCl₃ over 30 days. Results revealed that all fractions ameliorated the effects of AlCl₃ where methylene chloride and ethyl acetate fractions, containing the major bioactive compound niazimicin (NZ), showed the best activities. Biological investigations proved NZ to be a highly potent neuroprotective drug lead as a first report, by causing a decrease in the levels of malondialdehyde, cholinesterase, nitric oxide (NO) and amyloid β by 47%, 34%, 53% and 59%, respectively, and increasing glutathione levels by 54%. Molecular docking studies suggested NZ neuroprotective effects to be mediated by inhibition of caspase-3 and inducible nitric oxide synthase enzymes. PRACTICAL APPLICATIONS: The current findings present the neuroprotective effect of Moringa oleifera seeds consumed as a food supplement and in daily diet. In addition, niazimicin is a promising lead for the development of novel agents against Alzheimer's disease as seen by the reported results.

Development and Validation of Novel Gas Chromatography (GC) and Thin Layer Chromatography (TLC) Densitometry Methods for the Quantification of Stigmasterol 3-O-β-D-Glucopyranoside (S3G) in Balanites Aegyptiaca Extract: Application to Newly Formulated Balanites Capsules

Balanites aegyptiaca is a commonly used antihyperglycemic in Egyptian folk medicine. The objective of the present study is to develop two chromatographic methods for standardizing the Balanites extract by quantification of its main component, stigmasterol 3-O-β-D-glucopyranoside (S3G). The first method is gas chromatography (GC) where nitrogen was adopted as the carrier gas. The second method was thin layer chromatography (TLC) densitometry where chromatographic separation was established on aluminum plates using chloroform; methanol was used as the mobile phase followed by a densitometric measurement at 254 nm. Validation of the proposed methods was applied per International Council for Harmonization (ICH) guidelines. Both methods were adopted for quantification of S3G in Balanites capsules. The standard calibration curve was established for S3G in the concentration range of 10–130 μg/mL and 0.5–7.5 μg/mL for the GC and TLC methods, respectively. A good linearity with a correlation coefficient of 0.999 was obtained for both methods. Furthermore, the mean percentage recovery was found to be 99.46% for GC and 100.67% for TLC. Good precision was achieved, with relative standard deviation values <1%, and finally, the limits of detection and quantification were 2.51 and 7.59 μg/mL for GC and 0.13 and 0.40 μg/mL for TLC, respectively.

Potential neuroprotective activity of Mentha longifolia L. in aluminum chloride-induced rat model of Alzheimer's disease

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder manifested by cognitive deterioration where the available treatments failed to delay its progression. The objective of this study was to investigate the neuroprotective activity in an aluminum chloride (AlCl₃ )-induced AD in vivo model and phytochemical profile of the traditional Egyptian herb Mentha longifolia (Ml). Male albino rats were injected with Ml fractions and essential oil for 15 days followed by AlCl₃ for 30 days. Oxidative stress and neuroinflammatory markers were measured namely: malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), and nuclear factor-κB (NF-κB). Furthermore, cholinesterase activity was tested and analysis of brain neurotransmitters using HPLC was performed. Results showed that methylene chloride and ethyl acetate fractions were able to reverse the AlCl₃ mediated MDA increase, GSH decrease and exhibited anticholinesterase activity. EaFr reversed the increased levels of NF-κB and NO. Ml fractions and oil counteracted the AlCl₃ effect on brain neurotransmitters. Forty metabolites were tentatively characterized in the bioactive fractions using UPLC-PDA-ESI-MS. 5,6,4'-trihydroxy-3',7,8-trimethoxy flavone was isolated from Ml as a first report, in addition to 5,6-dihydroxy-3',4',7,8-tetramethoxy flavone and rosmarinic acid. These findings suggest that Ml is a promising nutraceutical and source of lead compounds halting AD progression. PRACTICAL APPLICATIONS: The results presented in this paper unravels the neuroprotective effect of Mentha longifolia fractions and oil by acting as anti-inflammatory, antioxidant agents, and regulating the levels of neurotransmitters. This provides basic knowledge for the development of Ml as a source of lead compounds and a promising food supplement protective against Alzheimer's disease.

Flavonol Glycosides: In Vitro Inhibition of DPPIV, Aldose Reductase and Combating Oxidative Stress are Potential Mechanisms for Mediating the Antidiabetic Activity of Cleome droserifolia

Diabetes is a major health problem that is associated with high risk of various complications. Medicinal plants hold great promise against diabetes. The traditional use of Cleome droserifolia as an antidiabetic agent was correlated to its flavonol glycosides content. In the current study, five major flavonol glycosides appeared on the RP-HPLC chromatogram of the aqueous extract namely; quercetin-3-O-β-d-glucosyl-7-O-α-rhamnoside (1), isorhamnetin-7-O-β-neohesperidoside (2), isorhamnetin-3-O-β-d-glucoside (3) kaempferol-4'-methoxy-3,7-O-α-dirhamnoside (4), and isorhamnetin-3-O-α-(4″-acetylrhamnoside)-7-O-α-rhamnoside (5). The inhibitory activities of these compounds were tested in vitro against several enzymes involved in diabetes management. Only the relatively less polar methoxylated flavonol glycosides (4, 5) showed mild to moderate α-amylase and α-glucosidase inhibitory activities. Compounds 1-4 displayed remarkable inhibition of dipeptidyl peptidase IV (DPPIV) enzyme (IC50 0.194 ± 0.06, 0.573 ± 0.03, 0.345 ± 0.02 and 0.281 ± 0.05 µg/mL, respectively) comparable to vildagliptin (IC50 0.154 ± 0.02 µg/mL). Moreover, these compounds showed high potential in preventing diabetes complications through inhibiting aldose reductase enzyme and combating oxidative stress. Both isorhamnetin glycoside derivatives (2, 3) exhibited the highest activities in aldose reductase inhibition and compound 2 (IC50 5.45 ± 0.26 µg/mL) was even more potent than standard quercetin (IC50 7.77 ± 0.43 µg/mL). Additionally, these flavonols exerted excellent antioxidant capacities through 2, 2-diphenyl-1-picrylhydrazil (DPPH) and ferric reducing antioxidant (FRAP) assays.

Targeting hydrogen sulphide signaling in breast cancer

Introduction

Hydrogen sulphide (H₂S) has been established as a key member of the gasotransmitters family that recently showed a pivotal role in various pathological conditions including cancer.

Objectives

This study investigated the role of H₂S in breast cancer (BC) pathogenesis, on BC immune recognition capacity and the consequence of targeting H₂S using non-coding RNAs.

Methods

Eighty BC patients have been recruited for the study. BC cell lines were cultured and transfected using validated oligonucleotide delivery system. Gene and protein expression analysis was performed using qRT-PCR, western blot and flow-cytometry. In-vitro analysis for BC hallmarks was performed using MTT, BrdU, Modified Boyden chamber, migration and colony forming assays. H₂S and nitric oxide (NO) levels were measured spectrophotometrically. Primary natural killer cells (NK cells) and T cell isolation and chimeric antigen receptor transduction (CAR T cells) were performed using appropriate kits. NK and T cells cytotoxicity was measured. Finally, computational target prediction analysis and binding confirmation analyses were performed using different software and dual luciferase assay kit, respectively.

Results

The H₂S synthesizing enzymes, cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE), exhibited elevated levels in the clinical samples that correlated with tumor proliferation index. Knock-down of CBS and CSE in the HER2+ BC and triple negative BC (TNBC) cells resulted in significant attenuation of BC malignancy. In addition to increased susceptibility of HER2+ BC and TNBC to the cytotoxic activity of HER2 targeting CAR T cells and NK cells, respectively. Transcriptomic and phosphoprotein analysis revealed that H₂S signaling is mediated through Akt in MCF7, STAT3 in MDA-MB-231 and miR-155/ NOS2/NO signaling in both cell lines. Lastly, miR-4317 was found to function as an upstream regulator of CBS and CSE synergistically abrogates the malignancy of BC cells.

Conclusion

These findings demonstrate the potential role of H₂S signaling in BC pathogenesis and the potential of its targeting for disease mitigation.

Upregulation of MC4R and PPAR-α expression mediates the anti-obesity activity of Moringa oleifera Lam. in high-fat diet-induced obesity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

various extracts of Moringa oleifera Lam. leaves, were reported to possess antiobesity effect in experimental animals models, yet its active doses and mechanism of action are still unclear.

MATERIALS AND METHODS

The metabolic profiling of 70% ethanol extract of M. oleifera (MO) leaves was performed using HPLC-MS/MS analysis. The antiobesity activity of MO was tested in high fat diet induced obesity in rats at 200 and 400 mg/kg body weight orally for 1 month. Total cholesterol (TC), high density lipoproteins (HDL-C), low density lipoprotein-cholesterol (LDL-C), triglycerides (TGs), insulin resistance, insulin sensitivity, and adipose tissue index were monitored. In addition, fatty acid synthase (FAS) and HMG-CoA reductase mRNA from liver tissue, Peroxisome Proliferator-Activated Receptor alpha (PPARα) and Melanocortin-4 receptor (MC4R) RNA from adipose tissue were quantified using qRT-PCR. MO hard gelatin capsules (400 mg/capsule) were formulated and standardized using HPLC-RP analysis and tested on fifteen female participants, aged 45-55 with a BMI of 29-34 kg/m².

RESULTS

Thirteen metabolites were tentatively identified using HPLC-MS/MS analysis including flavonols, flavones and a phenolic acid. MO 400 showed a prominent effect on reducing the rats' final weights, % weight increase and adiposity index (P < 0.05). Glucose, insulin and HOMA-IR were significantly reduced and R-QUICKI was significantly increased by MO 400 (P < 0.001). Mean tissue level of leptin and vaspin were significantly reduced, adiponectin, omentin and GLUT-4 expression were increased significantly by MO 400 (P < 0.01). MO 400 significantly suppressed FAS and HMG-CoA reductase and increased mRNA expression of MC4R and PPAR-α (P < 0.01). Eight weeks administration of MO hard gelatin capsules to obese patients showed significant reduction of the average BMI, TC and LDL compared to the baseline values (p < 0.05).

CONCLUSION

Our results presented a scientific evidence for the traditional use of M. oleifera leaves as antiobesity herbal medicine.

Analgesic, Anti-Inflammatory, Cytotoxic Activity Screening and UPLC-PDA-ESI-MS Metabolites Determination of Bioactive Fractions of Kleinia pendula

Kleinia pendula (Forssk.) DC. is a prostrate or pendent dark green succulent herb found in the southwestern mountain regions of Saudi Arabia. The literature survey of the plant reveals a lack of phytochemical and pharmacological studies, although traditional uses have been noted. The objective of the present work was to assess the in vivo analgesic and anti-inflammatory activities, as well as, the in vitro cytotoxic potential of the fractions of Kleinia pendula, and correlate these activities to the plant metabolites. The methanolic extract of Kleinia pendula was subjected to fractionation with n-hexane, ethyl acetate, chloroform, n-butanol, and water. The fractions were screened for their analgesic and anti-inflammatory activities, as well as cytotoxic activity against breast, liver, and colon cancer cell lines. The n-hexane and chloroform fractions of Kleinia pendula showed significant cytotoxic activity against all three cancer cell lines tested. The ethyl acetate and chloroform fractions showed significant analgesic and anti-inflammatory activities. The metabolites in these three active fractions were determined using UPLC-PDA-ESI-MS. Thus, the analgesic and anti-inflammatory activities of the plant were attributed to its phenolic acids (caffeoylquinic acid derivatives, protocatechuic, and chlorogenic acids). While fatty acids and triterpenoids such as (tormentic acid) in the hexane fraction are responsible for the cytotoxic activity; thus, these fractions of Kleinia pendula may be a novel source for the development of new plant-based analgesic, anti-inflammatory, and anticancer drugs.

An acetylated derivative of vitexin halts MDA-MB-231 cellular progression and improves its immunogenic profile through tuning miR- 20a-MICA/B axis

The activating immune ligands, MICA/B, act as a "kill me" signal through the NKG2D receptor expressed on natural killer (NK) cells. Recently, the oncogenic miR-20a was found to mediate immune escape through repressing MICA/B levels in breast cancer (BC) cells. However, targeting miR-20a-MICA/B using natural compounds has rarely been investigated. Our group has successfully isolated 3'-O-acetylvitexin that showed cytotoxic effects against colon cancer cells but has never been evaluated in BC. Our aim is to investigate the effects of 3'-O-acetylvitexin on BC cell lines and to further elucidate its molecular mechanism of action.The results showed that 3'-O-acetylvitex depicted a more pronounced dose-dependent repression of TNBC cellular viability, colonogenicity and migration capacity than Vitexin. 3'-O-acetylvitexin treatment resulted in a marked dose-dependent repression of miR-20a with a concomitant dose-dependent increase in MICA/B expression. In conclusion, 3'-O-acetylvitexin might act as a promising therapeutic agent for TNBC patients.

The long noncoding RNA sONE represses triple-negative breast cancer aggressiveness through inducing the expression of miR-34a, miR-15a, miR-16, and let-7a

Triple-negative breast cancer (TNBC) represents an aggressive breast cancer subtype. Among young females, TNBC is the leading cause of cancer-related mortalities. Recently, long noncoding RNAs (lncRNAs) are representing a promising pool of regulators for tuning the aggressiveness of several solid malignancies. However, this still needs further investigations in TNBC. The main aim of this study is to unravel the expression pattern of sONE lncRNA and its mechanistic role in TNBC. Results showed that sONE is restrictedly expressed in TNBC patients; its expression level is inversely correlated with the aggressiveness of the disease. sONE acts as a posttranscriptional regulator to endothelial nitric oxide synthase (eNOS) and thus affecting eNOS-induced nitric oxide (NO) production from TNBC cells measured by Greiss reagent. Mechanistically, sONE is a potential tumor suppressor lncRNA in TNBC cells; repressing cellular viability, proliferation, colony-forming ability, migration, and invasion capacities of MDA-MB-231. Furthermore, sONE effects were found to be extended to affect the maestro tumor suppressor TP53 and the oncogenic transcription factor c-Myc. Knocking down of sONE resulted in a marked decrease in TP53 and increase in c-Myc and consequently altering the expression status of their downstream tumor suppressor microRNAs (miRNAs) such as miR-34a, miR-15, miR-16, and let-7a. In conclusion, this study highlights sONE as a downregulated tumor suppressor lncRNA in TNBC cells acting through repressing eNOS-induced NO production, affecting TP53 and c-Myc proteins levels and finally altering the levels of a panel of tumor suppressor miRNAs downstream TP53/c-Myc proteins.

A novel role of sONE/NOS3/NO signaling cascade in mediating hydrogen sulphide bilateral effects on triple negative breast cancer progression

Hydrogen sulphide (H₂S) gas has been recognized as an intracellular mediator influencing an array of signaling pathways. Yet, the role of H₂S in cancer progression has been controversial. This study aims to unravel the role of exogenous H₂S in triple negative breast cancer (TNBC) and to further investigate any possible association of H₂S mediated actions with the endogenous production of nitric oxide (NO) gas. A wide concentration range of NaHS (20-2000 μM) and a variable reaction time (2-72 h) were probed. A bell-shaped impact of H₂S on TNBC cellular viability, proliferation, migration, invasion and colony forming ability was repeatedly observed in the aggressive TNBC cell lines, MDA-MB-231 but not in hormone receptor positive, MCF-7 cells. This bell-shaped effect was found to be shifted towards the left upon increasing the reaction time within the range of 2-24 h. However, this was totally opposed in case of continuous exposure (72 h) to exogenous H₂S. An inverted bell-shaped effect of H₂S on TNBC cellular growth, migration, proliferation and colony forming ability was shown. Moreover, this study provided the first evidence of a possible involvement of NO in mediating H₂S actions in TNBC. Such intricate cross-talk was found to be orchestrated by the novel lncRNA, sONE and its down-stream target NOS3 building up a novel axis, sONE/NOS3/NO, that was shown to play a pivotal role in plotting the bilateral effect of H₂S on TNBC progression. Finally, this study showed that low and continuous exposure of H₂S serves as a novel, selective and effective strategy in harnessing TNBC oncogenic profile through cGMP dependent and independent pathways where alterations of cell cycle regulatory proteins such as TP53 and c-Myc was observed. Moreover, NaHS could repress TNBC migration and invasion capacities through repressing the intracellular adhesion molecule, ICAM-1. In conclusion, this study provides an insight about the role of exogenous H₂S in TNBC cell lines highlighting a novel crosstalk between H₂S and NO orchestrated by sONE/NOS3 axis.

An in vivo study of Hypericum perforatum in a niosomal topical drug delivery system

The active compounds present in Hypericum perforatum L. (Hypericaceae) include hyperforin, hypericins and flavonoids, which are assumed to be responsible for the activity of the extract in the treatment of wounds and scars. The present study aimed to incorporate H. perforatum extract standardized to a known content of phloroglucinols, naphthodianthrones and polyphenolic compounds into an effective transdermal drug delivery system capable of entrapping both lipophilic and hydrophilic constituents in the form of niosomal gels for wound treatment. An 80% ethanol extract (HE) was prepared on a pilot scale using DIG-MAZ. An HPLC-DAD holistic profile was established for HE and was standardized to contain 3.4 ± 4 rutin, 1.1 ± 3 chlorogenic acid, 0.5 ± 2 quercitrin, 2.8 ± 2 hyperforin, and 0.51 ± 3% w/w total hypericins. Niosomes were prepared using the modified reverse phase evaporation technique (REV). The wound healing effect of the gel was tested on 16 adult mongrel dogs. A significant decrease in the inflammatory cell count (18.4 ± 5.3) was recorded in the niosomal gel 1.5% NaCMC-treated group at the 7th day post wounding. It induced a marked regression in the inflammatory phase and enhanced the early beginning of the proliferative phase of wound healing. After 21 days, it showed complete re-epithelization, formation of new matrix fibers and significant reduction in the wound size, compared to the control and the Panthenol® 2% cream treated groups. This is the first study of H. perforatum in a niosomal topical drug delivery system.

Randomized double-blinded pilot clinical study of the antidiabetic activity of Balanites aegyptiaca and UPLC-ESI-MS/MS identification of its metabolites

CONTEXT

Balanites aegyptiaca Del. (Zygophyllaceae) fruits are traditionally known for the treatment of hyperglycaemia. Several in vitro and in vivo studies proposed some mechanisms of action. However, clinical trials in human beings were never reported to date.

OBJECTIVES

To investigate the antidiabetic efficacy of the 70% ethanol extract of the pericarps of B. aegyptiaca (BE) within a nutritional intervention in elderly people.

MATERIALS AND METHODS

Ultra-performance electrospray ionization-mass spectroscopy (UPLC-ESI-MS/MS) analysis was used for metabolic profiling of BE which was incorporated in hard gelatine capsules (400 mg/day) and tested on 30 type 2 diabetes (T2D) Egyptian patients for 8 weeks. According to sex, age and body mass index participants were divided into two equivalent groups, placebo and treatment.

RESULTS

Thirteen compounds were identified in BE using UPLC-ESI-MS/MS analysis among which five steroidal saponins, seven phenolic compounds and a sterol glucoside. At the end of the 8-week treatment, the treated group showed 26.88% decrease in 2 h postprandial plasma glucose relative to 2.6% increase in the placebo group, while fasting plasma glucose was reduced to 10.3%. Treatment with BE capsules for 8 weeks produced significant reduction in the plasma triglyceride, total cholesterol and low-density lipoprotein cholesterol by 9.0, 12.76 and 21.35%, respectively, with 29.8% increase in the high-density lipoprotein cholesterol. Plasma alanine transaminase and aspartate transaminase were reduced by 42.6 and 43.3%, respectively.

DISCUSSION AND CONCLUSION

Administration of the BE capsules to T2D resulted in significant improvements in the glycaemic markers and the lipid profile, without adverse effects or hypoglycaemia.

In vitro and in vivo antidiabetic potential of extracts and a furostanol saponin from Balanites aegyptiaca

CONTEXT

Balanites aegyptiaca Del. (Zygophyllaceae) fruits are well-known antidiabetic drug in Egyptian folk medicine. Nevertheless, its mechanism of action is still unclear.

OBJECTIVES

Searching for the possible mechanisms of action of the plant and identification of its bioactive compounds.

MATERIALS AND METHODS

A bio-guided protocol based on the evaluation of α-glucosidase (AG) and aldose reductase (AR) inhibitory activities was adopted to isolate the biologically active compounds from the methanol extract (MeEx). An in vivo antidiabetic study was conducted for the active extract, fraction and compound using streptozotocin-induced diabetic male albino Wistar rats at two dose levels (100 and 200 mg/kg.b/wt) for 2 weeks.

RESULTS

Three compounds were isolated and identified: a sterol, (1) stigmasterol-3-O-β-d-glucopyranoside; a pregnane glucoside, (2) pregn-5-ene-3β,16β,20(R)-trio1-3-O-β-d-glucopyranoside; a furostanol saponin, (3) 26-(O-β-d-glucopyranosyl)-22-O-methylfurost-5-ene-3β,26-diol-3-O-β-d-glucopyranosyl-(1 → 4)-[α-l-rhamnopyranosyl-(1 → 2)]-β-d-glucopyranoside. Only compound 3 possessed significant AG and AR inhibitory activities (IC₅₀ = 3.12 ± 0.17 and 1.04 ± 0.02 μg/mL, respectively), while compounds 1 and 2 were inactive. The in vivo antidiabetic study revealed that MeEx and furostanol saponin 3 possessed significant activities at a dose of 200 mg/kg through reducing the fasting plasma glucose level by 46.14% and 51.39%, respectively, as well as reducing the total cholesterol by 24.44% and 31.90%, respectively. Compound 3 also caused increment in insulin and C-peptide levels by 63.56% and 65%, respectively.

DISCUSSION AND CONCLUSIONS

We presented a scientific base for using Balanites aegyptiaca, and shed the light on one of its saponins, as an antidiabetic agent in fasting and postprandial hyperglycaemia along with the improvement of diabetic complications.

In vivo anti-inflammatory activity of caffeoylquinic acid derivatives from Solidago virgaurea in rats

CONTEXT

Solidago virgaurea L. (Asteraceae) is traditionally used as an anti-inflammatory for the treatment of various symptoms including cystitis. However, little is known concerning the constituents responsible for this activity and the mechanism of their action.

OBJECTIVE

To assess the anti-inflammatory activity of the phenolic-rich fraction of S. virgaurea aerial parts in rats, isolate and assess the activity of the major compounds present.

MATERIALS AND METHODS

An HPLC method was developed for the analysis of the phenolic-rich fraction (EtFr). The in vivo anti-inflammatory activity of the EtFr and four isolated compounds (at 25 and 50 mg/kg) were assessed in adult male rats using the carrageenan-induced rat paw oedema model. The levels of the pro-inflammatory cytokines (TNF-α and IL-1β) were measured using ELISA.

RESULTS

3,5-O-Dicaffeoylquinic acid (1), 3,4-O-dicaffeoylquinic acid (2), 3,4,5-O-tricaffeoylquinic acid (3) and 4,5-O-dicaffeoylquinic acid (4) were isolated from EtFr. Compound 3 (50 mg/kg) showed a highly significant activity in inhibiting the oedema volume after 3 h (88% of the activity of indomethacin at 10 mg/kg). The EtFr and the isolated compounds largely inhibited the excessive production of the inflammatory mediators TNF-α and IL-1β.

DISCUSSION AND CONCLUSION

This is the first report of 3,4,5-tri-O-caffeoylquinic acid (3) in Solidago species. The tricaffeoylquinic acid (3) showed a significantly higher activity than the other three dicaffeoylquinic acids (1, 2, 4) and indomethacin in reduction of TNF-α and IL-1β concentrations (8.44 ± 0.62 and 5.83 ± 0.57 pg/mL compared to 12.60 ± 1.30 and 52.91 ± 5.20 pg/mL induced by indomethacin, respectively).

Aldose reductase inhibition of a saponin-rich fraction and new furostanol saponin derivatives from Balanites aegyptiaca

BACKGROUND

Balanites aegyptiaca Del. (Zygophyllaceae) fruits are used to treat hyperglycemia in Egyptian folk medicine and are sold by herbalists in the Egyptian open market for this purpose. Nevertheless, the fruits have not yet been incorporated into pharmaceutical dosage forms. The identity of the bioactive compounds and their possible mechanisms of action were not well understood until now.

PURPOSE

Aldose reductase inhibitors are considered vital therapeutic and preventive agents to address complications caused by hyperglycemia. The present study was carried out to identify the primary compounds responsible for the aldose reductase inhibitory activity of Balanites aegyptiaca fruits.

STUDY DESIGN

The 70% ethanolic extract of Balanites aegyptiaca fruit mesocarp and its fractions were screened for inhibition of the aldose reductase enzyme. Bio-guided fractionation of the active butanol fraction was performed and the primary compounds present in the saponin-rich fraction (D), which were responsible for the inhibitory activity, were characterized. HPLC chromatographic profiles were established for the different fractions, using the isolated compounds as biomarkers.

METHODS

Aldose reductase inhibition was tested in vitro on rat liver homogenate. The butanol fraction of the 70% ethanolic extract was fractionated using vacuum liquid chromatography (VLC, RP-18 column). The most active sub-fraction D, which was eluted with 75% methanol, was subjected to preparative HPLC to isolate the bioactive compounds.

RESULTS

The butanol fraction displayed inhibitory activity against the aldose reductase enzyme (IC50 = 55.0 ± 6 µg/ml). Sub-fraction D exhibited the highest inhibitory activity (IC50 = 12.8 ± 1 µg/ml). Five new steroidal saponin derivatives were isolated from this fraction. The isolated compounds were identified as compound 1a/b, a 7:3 mixture of the 25R:25S epimers of 26-O-β-D-glucopyranosyl-furost-5-ene-3,22,26-triol 3-O-[α-L-rhamnopyranosyl-(1→3)- β-D-glucopyranosyl-(1→2)]- α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside; compound 2, 26-O-β-D-glucopyranosyl-(25R)-furost-5-ene-3,22,26-triol 3-O-[ β-D-glucopyranosyl-(1→2)]- α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside; compound 3, 26-O-β-D-glucopyranosyl-(25R)-furost-5,20-diene-3,26-diol 3-O-[α-L-rhamnopyranosyl-(1→3)- β-D-glucopyranosyl-(1→2)]- α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside; compound 4, 26-O-β-D-glucopyranosyl-(25R)-furost-5,20-diene-3,26-diol 3-O-[ β-D-glucopyranosyl-(1→2)]- α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside; and compound 5, which is the 25S epimer of compound 4, by using various spectroscopic methods [MS,1D and 2D NMR (HSQC, HMBC, DQF-COSY, HSQC-TOCSY)]. Compounds 1a/b, 2, 3, 4, 5 exhibited highly significant aldose reductase inhibitory activities (IC50 values were 1.9 ± 0.2, 1.3 ± 0.5, 5.6 ± 0.2, 5.1 ± 0.4, 5.1 ± 0.6 µM, respectively) as compared to the activity of the reference standard quercetin (IC50 = 6.6 ± 0.3 µM).

CONCLUSION

The aldose reductase inhibitory activity of Balanites fruits is due to the steroidal saponins present. HPLC chromatographic profiles of the crude butanol fraction and its 4 sub-fractions showed that the most highly bioactive fraction D contained the highest amount of steroidal saponins (75%) as compared to the 21% present in the original butanol fraction. The isolated furostanol saponins proved to be highly active in an in vitro assay.

Isolation of New Cytotoxic Metabolites from Cleome droserifolia Growing in Egypt

The sulforhodamine B (SRB) assay was used to assess the cytotoxicity of the aqueous (AqEx) and ethanolic (AlEx) extracts, respectively, of the aerial parts of Cleome droserifolia (Forssk.) Del. against two human cancer cell lines, breast (MCF7) and colon (HCT116) adenocarcinoma. AqEx exhibited higher cytotoxic activity, thus its four subfractions, namely n-hexane (HxFr), chloroform (ClFr), ethyl acetate (EtFr), and n-butanol (BuFr) fractions, were also tested. Purifi cation of the more active ClFr and EtFr yielded nine compounds. Six terpenoids, guai-7(11),8-diene (C1), 1-hydroxy-guai-3,10(14)-diene (C2), 18-hydroxydollabela- 8(17)-ene (C3), (24E)-stigmasta-5,8-dien-3β-ol (C4), teucladiol [1α,5β-guai-10(14)- ene-4β,6β-diol] (C5), and buchariol (4,10-epoxy-6α-hydroxyguaiane) (C6), were isolated from ClFr and three fl avonol glycosides, isorhamnetin-3-O-β-D-glucoside (F1), quercetin- 3`-methoxy-3-O-(4``-acetylrhamnoside)-7-O-α-rhamnoside (F2), and kaempferol-4`-methoxy- 3,7-O-dirhamnoside (F3), were isolated from EtFr. Compounds C3 and F2 are new in nature. The isolated compounds were identifi ed using various spectroscopic methods (UV, IR, 1H NMR,13C NMR, HMQC, HMBC, and COSY). Compounds C1, C3, F2, and F3 showed significant cytotoxic activities against the two tested cell lines comparable to those of the anticancer drug doxorubicin®. The new compound C3 was the most active as it had the lowest IC50 values, (1.9 ± 0.08) and (1.6 ± 0.09) μg/ml corresponding to 6.5 and 5.4 μM, against MCF7 and HCT116 cells, respectively

Fatty acid regulation of adenylyl cyclase Rv2212 from Mycobacterium tuberculosis H37Rv

Adenylyl cyclase Rv2212 from Mycobacterium tuberculosis has a domain composition identical to the pH-sensing isoform Rv1264, an N-terminal regulatory domain and a C-terminal catalytic domain. The maximal velocity of Rv2212 was the highest of all 10 mycobacterial cyclases investigated to date (3.9 micromol cAMP.mg(-1).min(-1)), whereas ATP substrate affinity was low (SC(50) = 2.1 mm ATP). Guanylyl cyclase side activity was absent. The activities and kinetics of the holoenzyme and of the catalytic domain alone were similar, i.e. in distinct contrast to the Rv1264 adenylyl cyclase, in which the N-terminal domain is autoinhibitory. Unsaturated fatty acids strongly stimulated Rv2212 activity by increasing substrate affinity. In addition, fatty acids greatly enhanced the pH sensitivity of the holoenzyme, thus converting Rv2212 to a pH sensor adenylyl cyclase. Fatty acid binding to Rv2212 was modelled by homology to a recent structure of the N-terminal domain of Rv1264, in which a fatty acid-binding pocket is defined. Rv2212 appears to integrate three cellular parameters: ATP concentration, presence of unsaturated fatty acids, and pH. These regulatory properties open the possibility that novel modes of cAMP-mediated signal transduction exist in the pathogen.