In vitro pharmacological screening of antioxidant, cytotoxic and enzyme inhibitory activities of Citrus aurantifolia Linn. Dried fruit extract

Bioactive Components and Their Activities from Different Parts of Citrus aurantifolia (Christm.) Swingle for Food Development

Citrus aurantifolia is part of the Rutaceae family and belongs to the genus Citrus. It is widely used in food, the chemical industry, and pharmaceuticals because it has a unique flavor and odor. It is nutrient-rich and is beneficial as an antibacterial, anticancer, antioxidant, anti-inflammatory, and insecticide. Secondary metabolites present in C. aurantifolia are what give rise to biological action. Flavonoids, terpenoids, phenolics, limonoids, alkaloids, and essential oils are among the secondary metabolites/phytochemicals discovered in C. aurantifolia. Every portion of the plant's C. aurantifolia has a different composition of secondary metabolites. Environmental conditions such as light and temperature affect the oxidative stability of the secondary metabolites from C. aurantifolia. The oxidative stability has been increased by using microencapsulation. The advantages of microencapsulation are control of the release, solubilization, and protection of the bioactive component. Therefore, the chemical makeup and biological functions of the various plant components of C. aurantifolia must be investigated. The aim of this review is to discuss the bioactive components of C. aurantifolia such as essential oils, flavonoids, terpenoids, phenolic, limonoids, and alkaloids obtained from different parts of the plants and their biological activities such as being antibacterial, antioxidant, anticancer, an insecticide, and anti-inflammatory. In addition, various extraction techniques of the compounds out of different parts of the plant matrix as well as the microencapsulation of the bioactive components in food are also provided.

Phytochemical Profiles, Antioxidant, Cytotoxic, and Anti-Inflammatory Activities of Traditional Medicinal Plants: Centaurea pichleri subsp. pichleri, Conyza canadensis, and Jasminum fruticans

Centaurea pichleri subsp. pichleri, Conyza canadensis, and Jasminum fruticans are traditionally used plants grown in Turkey. Methanol extracts were obtained from these plants and pharmacological activity studies and phytochemical analyses were carried out. To evaluate the phytochemical composition, spectrophotometric and chromatographic techniques were used. The extracts were evaluated for antioxidant activity by DPPH^●, ABTS^●+ radical scavenging, and FRAP assays. The cytotoxic effects of the extracts were investigated on DU145 prostate cancer and A549 lung cancer cell lines. The anti-inflammatory effects of extracts were investigated on the NO amount, TNF-α, IFN-γ, and PGE 2 levels in lipopolysaccharide-stimulated Raw 264.7 cells. The richest extract in terms of phenolic compounds (98.19 ± 1.64 mg_GAE/g_extract) and total flavonoids (21.85 ± 0.64 mg_CA/g_extract) was identified as C. pichleri subsp. pichleri methanol extract. According to antioxidant activity determinations, the C. pichleri subsp. pichleri extract was found to be the most active extract. Finally, the C. pichleri subsp. pichleri methanol extract was revealed to be the most effective inhibitor of viability in the cytotoxic activity investigation, and the extract with the best anti-inflammatory action. The findings point to C. pichleri subsp. pichleri as a promising source of bioactive compounds in the transition from natural sources to industrial uses, such as new medications, cosmeceuticals, and nutraceuticals.

Antihypertensive and Vasorelaxant Effects of Citrus aurantifolia Linn. Fruit: Proposed Mechanisms

Background

Citrus aurantifolia Linn. fruit, a natural dietary item, has long been used traditionally to treat hypertension in Pakistan. The current research work aims to explore the effect on blood pressure and its mechanisms.

Methods

The aqueous methanol extract of plant fruit was used to evaluate hypotensive/antihypertensive, vasorelaxation, and safety profiles. Moreover, the in vitro inhibitory effect of AMECA on phosphodiesterase was also evaluated.

Results

In hypotensive studies, extracts of Citrus aurantifolia fruit exhibited a concentration-dependent reduction in SBP, DBP, MAP, and heart rate. A similar effect has been observed on anesthetized rats, but the effects exerted by the extract were not altered significantly in the presence of L-NAME, atropine, captopril, and propranolol. Moreover, in coronary arteries, the extract significantly potentiated relaxations induced by cGMP- and cAMP-dependent relaxing agonists. When exposed to PDEs, the extract concentration dependently subdued cGMP-hydrolyzing activity of different PDEs with IC50 values of 40-130 μg/mL.

Conclusion

It is conceivable that extracts obtained from Citrus aurantifolia fruit produced hypotensive and antihypertensive effects in rats. The extract elicited endothelium-independent vasorelaxation, possibly by acting directly on smooth muscles of the coronary artery and by increasing cGMP and cAMP via nonselective inhibition of vascular PDEs.

Nanoemulsions Containing Megestrol Acetate: Development, Characterization, and Stability Evaluation

Many active pharmaceutical ingredients (API) are poorly soluble in water and their low oral bioavailability is a major hindrance to their potential use. Megestrol acetate (MGA) is insoluble in water and its oral absorption is limited and considerably affected by food. Nanoemulsions (NEs) can be used as effective oral drug delivery systems where the hydrophobic API is loaded into the oil phase. In this study, MGA-loaded NEs were prepared based on the spontaneous emulsification technique. The effects of different excipients such as ethanol, Tween 80, Lipoid E80, and medium-chain triglyceride (MCT) on the NEs characterization were investigated. The experimental results indicated that optimum MGA-loaded NEs (F20) were nanometer-sized droplets (166.9 ± 3.0 nm) with negative zeta potential (-12.2 ± 1.1 mV). The effect of polyvinylpyrrolidone (PVP) on characteristic properties of F20 was also evaluated. On the selected NEs, in vitro dissolution tests and stability studies in various mediums and storage conditions were performed. The encapsulation efficiency of NEs were > 99%. The overall droplet size of F20 and PVP-2 (PVP-coated NEs) remained relatively stable as the pH changed from 1.2 to 6.8. It was determined that F20 and PVP-2 remained stable at 4°C until 12 weeks and had higher cytotoxicity on MCF-7 cells. To conclude, droplet size, surface charge, and stability are important properties for NEs to have sufficient effectiveness. In this study, alternative oral NEs of low-solubility drug MGA were developed considering the above features.

Fruit, vegetables, and mushrooms for the preparation of extracts with α-amylase and α-glucosidase inhibition properties: A review

The inhibition of the α-amylase and α-glucosidase activity facilitates the maintenance of circulating glucose levels by decreasing the rate of blood sugar absorption. Existing enzyme inhibitors such as acarbose, miglitol, and voglibose are used for inhibiting the activity of these enzymes, however, alternative solutions are required to avoid the side-effects of using these drugs. The current study aims to review recent evidence regarding the in vitro α-amylase and α-glucosidase inhibition activities of extracts derived from selected fruit, vegetables, and mushrooms. The mechanisms of action of the extracts involved in the inhibition of both enzymes are also presented and discussed. Compounds including flavonoids, phenolic acids, anthocyanins, saponins, carotenoids, terpenes, sugars, proteins, capsaicinoids, fatty acids, alkaloids have been shown to have α-amylase and α-glucosidase inhibition activities. Harvesting period, maturity stage, sample preparation, extraction technique, and solvent type are parameters that affect the α-amylase and α-glucosidase inhibition activities of the extracts.

Anti-glycation effect and the α-amylase, lipase, and α-glycosidase inhibition properties of a polyphenolic fraction derived from citrus wastes

The advanced glycation end products (AGEs) constitute a wide variety of substances synthesized from interactions between amino groups of proteins and reducing sugars, which excess induces pathogenesis of chronic diseases. Brazil is the major producer of citrus, a low-cost source of hesperidin, which is a polyphenol recognized for its capacity to inhibit AGEs formation. This is the first work to evaluate the effects of a polyphenolic fraction derived from citrus wastes on the antiglycation and on the inhibition properties of digestive enzymes on the possibility to process these wastes in high value-added products. At concentrations of 10, 15 and 20 mg/mL inhibition of AGEs was higher than 60%. The extracts were able to inhibit by 76% the activity of pancreatic lipase and by 98% the activity of α-glucosidase. For the α-amylase the inhibition capacity was lower than 50%. Strong correlation was obtained among anti-glycation with polyphenolic content and antioxidant capacity.