Annona muricata L. (Magnoliales: Annonaceae) is a tropical plant species known for its edible fruit which has some medicinal merits, but also some toxicological effects. This review focuses on the phytochemicals contents, bioactivity, biological actions and toxicological aspects of extracts and isolated compounds, as well as medicinal uses of A. muricata, with the objective of stimulating further studies on extracts and fruit pulp used for human consumption. Traditional medicinal uses of A. muricata have been identified in tropical regions to treat diverse ailments such as fever, pain, respiratory and skin illness, internal and external parasites, bacterial infections, hypertension, inflammation, diabetes and cancer. More than 200 chemical compounds have been identified and isolated from this plant; the most important being alkaloids, phenols and acetogenins. Using in vitro studies, extracts and phytochemicals of A. muricata have been characterized as an antimicrobial, anti-inflammatory, anti-protozoan, antioxidant, insecticide, larvicide, and cytotoxic to tumor cells. In vivo studies of the crude extracts and isolated compounds of A. muricata were shown to possess anxiolytic, anti-stress, anti-inflammatory, contraceptive, anti-tumoral, antiulceric, wound healing, hepato-protective, anti-icteric and hypoglycemic activities. In addition, clinical studies support the hypoglycemic activity of the ethanolic extracts of A. muricata leaves. Mechanisms of action of some pharmacological activities have been elucidated, such as cytotoxic, antioxidant, antimicrobial, antinociception and hypotensive activities. However, some phytochemical compounds isolated from A. muricata have shown a neurotoxic effect in vitro and in vivo, and therefore, these crude extracts and isolated compounds need to be further investigated to define the magnitude of the effects, optimal dosage, mechanisms of action, long-term safety, and potential side effects. Additionally, clinical studies are necessary to support the therapeutic potential of this plant

In recent years, a strong interest has emerged in hybrid composites and their potential uses, especially in chitosan–titanium dioxide (CS–TiO₂) composites, which have interesting technological properties and applications. This review describes the reported advantages and limitations of the functionalization of chitosan by adding TiO₂ nanoparticles. Their effects on structural, textural, thermal, optical, mechanical, and vapor barrier properties and their biodegradability are also discussed. Evidence shows that the incorporation of TiO₂ onto the CS matrix improves all the above properties in a dose-dependent manner. Nonetheless, the CS–TiO₂ composite exhibits great potential applications including antimicrobial activity against bacteria and fungi; UV-barrier properties when it is used for packaging and textile purposes; environmental applications for removal of heavy metal ions and degradation of diverse water pollutants; biomedical applications as a wound-healing material, drug delivery system, or by the development of biosensors. Furthermore, no cytotoxic effects of CS–TiO₂ have been reported on different cell lines, which supports their use for food and biomedical applications. Moreover, CS–TiO₂ has also been used as an anti-corrosive material. However, the development of suitable protocols for CS–TiO₂ composite preparation is mandatory for industrial-scale implementation.

In recent years, a strong interest has emerged in polysaccharide-hybrid composites and their potential applications, which have interesting functional and technological properties. This review summarizes and discusses the reported advantages and limitations of the functionalization of conventional and nonconventional polysaccharides by adding TiO₂ nanoparticles as a reinforcement agent. Their effects on the mechanical, thermal, and UV-barrier properties as well as their water-resistance are discussed. In general, the polysaccharide–TiO₂ hybrid materials showed improved physicochemical properties in a TiO₂ content-dependent response. It showed antimicrobial activity against bacteria (gram-negative and gram-positive), yeasts, and molds with enhanced UV-protective effects for food and non-food packaging purposes. The reported applications of functionalized polysaccharide–TiO₂ composites include photocatalysts (dye removal from aqueous media and water purification), biomedical (wound-healing material, drug delivery systems, biosensor, and tissue engineering), food preservation (fruits and meat), cosmetics (sunscreen and bleaching tooth treatment), textile (cotton fabric self-cleaning), and dye-sensitized solar cells. Furthermore, the polysaccharide–TiO₂ showed high biocompatibility without adverse effects on different cell lines, indicating that their use in food, pharmaceutical, and biomedical applications is safe. However, it is necessary to evaluate the structural changes promoted by the storage conditions (time and temperature) on the physicochemical properties of polysaccharide–TiO₂ hybrid composites to guarantee their stability during a determined time.

The biological properties of polyphenol (PP) depend on its bioaccessibility and bioavailability. Therefore, part of PP released from the food matrix in the gastrointestinal tract through enzymatic hydrolysis is at least partially absorbed. The aim of this study is to determine the bioaccessibility of PP associated with dietary fiber (DF) and the kinetics release of PP in mango (Mangifera indica L.) ‘Ataulfo’ by-products by an in vitro model. Soluble and insoluble DF values were 7.99 and 18.56% in the mango paste and 6.98 and 22.78% in the mango peel, respectively. PP associated with soluble and insoluble DF was 6.0 and 3.73 g GAE per 100 g in the paste and 4.72 and 4.50 g GAE per 100 g in the peel. The bioaccessibility of PP was 38.67% in the pulp paste and 40.53% in the peel. A kinetics study shows a release rate of 2.66 and 3.27 g PP min⁻¹ in the paste and peel, respectively. The antioxidant capacity of the paste increased as digestion reached a value of 2.87 mmol TE min⁻¹ at 180 min. The antioxidant capacity of the peel had its maximum (28.94 mmol TE min⁻¹) between 90 and 120 min of digestion; it started with a value of 2.58 mmol TE min⁻¹, and thereafter increased to 4.20 mmol TE min⁻¹ at 180 min. The major PPs released during the digestion of paste were gallic and hydroxybenzoic acids, while in the peel, they were hydroxycinnamic and vanillic acids. It was concluded that these phenolic compounds are readily available for absorption in the small intestine and exert different potential health benefits.