The sweet shrub Stevia rebaudiana Bertoni has been used throughout the world as a noncaloric biosweetener owing to its two major thermostable phytoconstituents - namely, stevioside and rebaudioside - which have recently been added to the European Union list of permitted sweeteners. A number of countries across the globe, such as Japan, China, Malaysia, Taiwan, Australia, Korea, etc., have approved the use of S. rebaudiana-based sweeteners in foods and beverages. However, several studies on this ancient plant have revealed many of its pharmacological properties, such as anticancer, antihypertensive, antibacterial, etc., and thus S. rebaudiana ought to be called a medicinal plant. As expected, in recent years, researchers have directed the focus toward S. rebaudiana and have been patenting their inventions. A number of review articles have been published on S. rebaudiana in relation to different aspects, but no one has reported on their patents published. Hence, it has become necessary to provide the up-to-date and collective information on studies conducted and patents on S. rebaudiana and its metabolites with respect to their commercial applications. A good number of patents and research articles have been published on S. rebaudiana. These patents and research articles of interest were divided on the basis of their pharmacological activity and pharmaceutical application, described and discussed below in this review article. Furthermore, the yearwise distribution of patents was presented as bar diagram.

In recent years, focus has been directed towards the development of drug delivery system using biologically active compounds derived from the natural sources. These formulations based on natural products have been reported to have significant activity and are advantageous over the conventional formulations in terms of solubility, enhanced bioavailability, increased pharmacological activity, stability and fewer side effects. Nowadays, people are switching to the natural products over synthetic compounds, which can be easily obtained from the locally available plants and can help in reducing public health costs. The present review aimed at highlighting the development of microspheres based on herbal actives formulations, in which biologically active compounds are delivered to the targeted site. It also summarizes the method of preparation, therapeutic activity and application of herbal formulations in various biomedical fields.

Objective The aim of this study was to isolate and identify heavy metal-resistant and antibiotics-resistant bacteria from contaminated samples (wastewater and soil) collected from different industrial areas in Egypt and determine their role in heavy metal removing. Materials and methods Samples were collected from Helwan and 10th of Ramadan city areas and enriched in culture broth containing 200, 100, and 10 ppm of arsenic (As), lead (Pb), and cadmium (Cd) as AsHNa ₂ O ₄·H ₂ O, Pb(NO ₃ ) ₂ , and CdSO ₄ , respectively. The highly resistant isolate (ST6) was selected and identified biochemically and also subjected to 16S rDNA sequencing. The growth parameters were optimized and the maximum tolerable concentration of the respective metals as well as the antibiotic resistance was determined. Result and conclusion After enrichment culture we isolated and purified 20 bacterial isolates resistant to the respective heavy metals As, Pb, and Cd. The morphological, biochemical, and phylogenetical characteristics of the most resistant bacterial isolates (ST6) were studied. The results showed that this isolate belongs to the species Pseudomonas stutzeri. The optimum temperature was 35°C, whereas the optimum pH was in the range of 6-7. Maximum tolerable concentration values for As, Pb, and Cd were 3500, 1750, and 50 ppm, respectively. Also, the isolate ST6 showed resistance against different antibiotics. The metal removal ability was 42.5, 57.1, and 52.9% of As, Pb, and Cd, respectively. It was concluded that the ST6 isolate was resistant and removed high concentrations of As, Pb, and Cd. Hence, this isolate may play a role in bioremediation processes of heavy metal in polluted areas.

Background Recently, much attention has been paid to the application of nanoemulsions (NEs) as drug delivery systems. Besides their high solubilization capacity, NEs are powerful carrier systems because of their thermodynamic stability, ease of preparation, and high absorption rates. Aim The present work focuses on the design of stable and dilutable NEs for intravenous administration of a potent antitumor benzimidazole derivative, a poorly water-soluble active ingredient. Materials and methods NEs were formulated using ethanol as cosurfactant and Tween 20, Acconon MCF, and Labrasol as surfactants using the oil with maximum drug solubilization. Selected NEs were evaluated for droplet size, zeta potential, morphology, in-vitro release profile, and physical stability. Results The results revealed the development of eight NEs composed of 10% oleic acid with an infinite dilution capacity. NE3, NE6, and NE8 having the highest surfactant to cosurfactant ratio (3: 1) showed the best drug solubilization capacity. The NE droplets appeared almost spherical, ranging from 28.21 to 153.00 nm, with narrow distribution and relatively high zeta potential. NEs demonstrated sustained release profiles, whereas increasing surfactant to cosurfactant ratio was accompanied by increased drug release. NEs showed excellent physical stability with no phase separation or change in particle size. Conclusion Our results suggest that NEs can be used as a promising intravenous delivery system.

Objectives This work was designed to evaluate the therapeutic efficacy of Alectryon tomentosus F. Muell leaf extract against CCl ₄ -induced hepatic injury in albino rats and anti-HIV effect in vitro. Proximate analysis, phytochemical screening and assay of total flavonoid (TFC) and phenolic contents (TPC), were carried out according to standard methods. Materials and methods The TPC and TFC were estimated spectrophotometrically. The median lethal dose (LD ₅₀ ) of the total ethanol extract of A. tomentosus F. Muell leaves was evaluated. The effect on acute HIV-1 infectivity was measured with the syncytium formation assay using AZT (3΄-azido-3΄-deoxythymidine) as a positive control. Moreover, carbon tetrachloride-induced acute hepatic damage was used to evaluate the hepatoprotective effect of the leaves. Results and conclusion Proximate analysis of air-dried leaves of A. tomentosus F. Muell revealed 8.3% moisture content, 9.2% total ash, 0.48% water-soluble ash and 2.56% acid-insoluble ash. Preliminary phytochemical screening revealed that the dried powdered leaves of A. tomentosus F. Muell are rich in carbohydrates and/or glycosides, volatile constituents, sterols and/or triterpenes and tannins; however, flavonoids (free and combined) and coumarins are present in a lesser concentration. Alkaloids, saponins, cardiac glycosides and anthraquinones are absent. The evaluated TPC was 71.59 mg gallic acid equivalent/g dry weight, whereas TFC was 63.64 mg quercetin equivalent/g plant dry weight. The median lethal dose (LD ₅₀ ) of the total ethanol extract was found to be 9.2 g/kg body weight, indicating the safety of the leaves of the plant. In carbon tetrachloride-induced acute hepatic damage model, the methylene chloride extract showed the highest protection percentage as shown by reduction in the level of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels, followed by aqueous extract. These may be attributed to their phenolic and flavonoidal content. The anti-HIV-1 activity was assessed by evaluating syncytium formation. The results showed that the extract was minimally toxic and showed a weak anti-HIV-1 activity in comparison with AZT.

Objectives This work aimed to carry out a proximate analysis, phytochemical screening, and bioactivities evaluation of the nonflowering aerial parts of each of Cissus rotundifolia (Forssk.) Vahl. (Fam. Vitaceae) and S. cylindrica Bojer ex Hook. (Fam. Dracaenaceae) growing in Egypt. Materials and methods The total phenolic contents (TPC) and total flavonoid contents were estimated spectrophotometrically. The oral acute toxicity of each of the two plant extracts was evaluated. Analgesic activities of both plants were evaluated using hot plate and writhing test using indomethacin as a reference drug. Anti-inflammatory activities were evaluated using carrageenan-induced rat-paw edema. Antiulcerative activities were measured using indomethacin-induced ulcer in pyloric-ligated rats. Thioacetamide-induced acute hepatic encephalopathy was used to evaluate the hepatoprotective effects of the plants. Results and conclusion Proximate analysis of air-dried nonflowering aerial parts of each of C. rotundifolia and S. cylindrica yielded a moisture content of 7.95 and 7.52%, total ash of 8.35 and 9.83%, water-soluble ash of 3.96 and 2.94%, acid-insoluble ash of 2.14 and 3.42%, crude fiber content of 8.52 and 13.43%, and methanolic extractive value of 41 and 35%, respectively. Phytochemical analysis of C. rotundifolia extract indicated the presence of triterpenes, carbohydrates, and/or glycosides, tannins, flavonoids, coumarins, and saponins, whereas S. cylindrica extract showed the presence of sterols, carbohydrates, and/or glycosides, flavonoids, coumarins, and saponins. Total phenolic content of C. rotundifolia and S. cylindrica were 3.18 and 4.82 mg (GAE)/g, respectively, whereas total flavonoid contents of C. rotundifolia and S. cylindrica were 1.35 and 4.13 mg (QE)/g plant dry weight, respectively. Both extracts showed no toxicity up to 1 g/kg body weight. Both methanolic extracts showed significant central and peripheral analgesic effects. C. rotundifolia extract showed percentages of edema inhibition higher than or equal to the reference drug indomethacin in carrageenan-induced paw edema assay, whereas S. cylindrica extract showed percentages of edema inhibition less than that of the reference drug indomethacin. In the ulcer model induced by indomethacin, the groups pretreated with both plants received significant protection against ulcer formation. In the thioacetamide-induced acute hepatopathic encephalopathy model, rats treated with S. extract showed significant improvement in their plasma AST and ALT, whereas rats treated with C. rotundifolia extract showed increased levels of their ALT and AST.

Background and objectives Development of a novel compound containing a heterocyclic nucleus as an anticancer therapeutic agent is the most important focal point in medicinal chemistry. Programmed cell death or apoptosis is a fundamental phenomenon and plays a central role in immune regulation, embryogenesis, and general tissue homeostasis. Therefore, identification of novel potent, selective, and less toxic anticancer agents is one of the most crucial concerns. Materials and methods A series of 4-{1-[(4-acetyl-5-(substituted)-4,5-dihydro-1,3,4-oxadiazol-2-yl)methyl]-5-nitro-1H-benzimidazol-2-yl}benzonitrile 6 (I-IV) and novel 4-{5-substituted-1-[(4,5-disubstituted)-4,5-dihydro-1,3,4-oxadiazol-2-yl)methyl]-5-nitro-1H-benzimidazol-2-yl}benzonitrile 7 (V-XXXIII) derivatives were synthesized. Results and conclusion Nine of them were selected by the Department of Biotechnology Drug Discovery R&D, Century Pharmaceuticals Ltd, for evaluation of their in-vitro anticancer activity. Three of the investigated compounds, 7.X, 7.XIX , and 7.XXIV , displayed in-vitro anticancer activity in the primary assay. These compounds were selected for a full anticancer screening against a three-cell panel MTT assay, and they showed a nonselective broad spectrum antiproliferative activity against L929, HCT15, and Hep2 cancer cell lines. Compound 7.XIX showed antiproliferative activity, which can be comparable to that of 5-fluorouracil, methotrexate, and daunorubicin, and this compound has been identified as a promising lead compound.

Background and objective 2,6-Diketopiperazines are promising bioactive chemical entities in drug discovery. They could be considered a versatile template for the synthesis of a variety of scaffolds because of the presence of the reactive endocyclic nucleophilic imide group. It is worth mentioning that the 2,6-diketopiperazine system is embedded in the chemical skeleton of 6,9-diazaspiro-[4,5]decane-8,10-diones. The aim of the present work was to study both peripheral and central analgesic activities as well as the anti-inflammatory activity of 6-aryl-9-substituted-6,9-diazaspiro-[4,5]decane-8,10-diones 1-9 in different in-vivo experimental models. Materials and methods The test compounds 1-9 were evaluated for their analgesic activity in adult male Swiss albino mice using the writhing (12.5 and 25 mg/kg) and hot-plate (25 mg/kg) tests. Moreover, the anti-inflammatory activity was assessed for compounds 1-9 at dose 25 mg/kg (0.066-0.079 mmol/kg) by intraperitoneal administration using carrageenan-induced hind-paw edema assay in mice at 1, 2, and 3 h after carrageenan challenge and compared with diclofenac sodium at dose 10 mg/kg (0.031 mmol/kg) as the reference drug. Results and conclusion All compounds 1-9 showed significant inhibition of acetic acid induced writhing in the writhing test. Their percentage inhibition of abdominal writhing induced by acetic acid (peripheral effect) at doses of 12.5 mg/kg (0.033-0.039 mmol/kg) and 25 mg/kg (0.066-0.079 mmol/kg) ranged from 68.55 to 17.74% and from 88.71 to 53.23%, respectively. Compound 7 (R ₁ = H, R ₂ = CH ₂ CH ₂ Ph) demonstrated the highest writhing inhibition percentage at both dose levels (88.71 and 68.55%, respectively) and exhibited significantly lower number of writhes compared with diclofenac sodium as the reference standard. In the hot-plate test (central effect), compounds 2 (R ₁ = CH ₃ , R ₂ = CH ₂ COOH ₃ ) and 3 (R ₁ = 4-OCH ₃ , R ₂ = CH ₂ COOCH ₃ ) at doses of 0.076 and 0.072 mmol/kg, respectively (equivalent to 25 mg/kg), significantly raised the pain threshold and exhibited the best analgesic activity at 30 min. Both of them displayed nonsignificant difference from tramadol hydrochloride (0.095 mmol/kg, 25 mg/kg) at 30 min. In contrast, compounds 1 (R ₁ = H, R ₂ = CH ₂ COOH ₃ ) at dose 0.079 mmol/kg and 5 (R ₁ = CH ₃ , R ₂ = CH ₂ Ph) at dose 0.068 mmol/kg showed slight lower analgesic potency compared with 2 and 3 with significant difference from the reference drug. The most powerful anti-inflammatory effect in this series was demonstrated in 9-N-methyl acetate derivatives (1-3), where compound 1 (R ₁ = H, R ₂ = CH ₂ COOH ₃ ) at dose 0.079 mmol/kg exhibited 53.93% maximum protection (inhibition of edema size) at 3 h, compared with diclofenac sodium (0.0314 mmol/kg), which reached 60.40%. On the other hand, compounds 4-9 displayed 36.90-26.77% protection against carrageenan-induced edema.