Background: Herbal drug delivery is limited by poor solubility and bioavailability which can be overcome with suitable nanomaterials that will enhance their pharmacokinetics and performance. Objective: This study aimed to analyze the synthesis, characterization, and biological activities of silver nanoparticles (AgNPs) from three spices. Materials and Methods: AgNPs were prepared using 0.1 M silver nitrate and aqueous extracts of Allium sativum L. (garlic), Zingiber officinale Rosc. (ginger), and Capsicum frutescens L. (cayenne pepper). The AgNPs were characterized using ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Results: The AgNPs were formed within an hour of the reaction and showed maximum UV-Vis absorption in the 375–480 nm range. SEM and TEM revealed well-dispersed spherical particles with little agglomeration, average sizes of 3–6 nm, 3–22 nm, and 3–18 nm for garlic, ginger, and cayenne pepper, respectively. FTIR showed that amine, protein, phenolic, aromatic, and alkynes groups contributed to AgNP synthesis and XRD confirmed their crystalline and face-centered cubic nature. Antibacterial action of the AgNPs was in the following order: ginger (minimum inhibitory concentration [MIC] garlic> cayenne pepper (MIC 125 μg/mL). Antioxidant action showed cayenne pepper > ginger > garlic (inhibitory concentration 50% [IC50]: 40, 240, and 250 μg/mL, respectively) against 2,2-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) and garlic > cayenne pepper > ginger (IC50: <31.25, 40, and 120 μg/mL, respectively) against 1,1-diphenyl-2-picrylhydrazyl. Conclusion: Optimization of this green synthesis would support the production of AgNPs with great therapeutic potentials. Abbreviations used: AgNPs: Silver nanoparticles; UV-Vis: ultraviolet-visible; SEM: Scanning electron microscopy; TEM: Transmission electron microscopy; EDX: Energy dispersive X-ray; XRD: X-ray diffraction; FTIR: Fourier transform infrared; GaNPs: Garlic nanoparticles; GiNPs: Ginger nanoparticles; C.PeNPs: Cayenne pepper nanoparticles; FCC: Face centred cubic; SPR: Surface Plasmon resonance; ABTS-2: 2-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid); DPPH-1: 1-diphenyl-2-picrylhydrazyl.

Here we report the synthesis, characterization and biological properties of silver nanoparticles (AgNPs) using the extract from a spice blend. AgNPs were prepared using 0.1 mmol/L AgNO₃ solution and aqueous extract from a spice blend of garlic, ginger and cayenne pepper. The nanoparticles were characterized using ultraviolet–visible (UV-vis) spectroscopy, scanning and transmission electron microscopy (SEM and TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The AgNPs formed within an hour of the reaction with colour change from yellow to dark brown and maximum absorbance at 420 nm in the UV-vis spectrum. SEM revealed well dispersed particles with little agglomeration, and the presence of elemental silver was confirmed by EDX. TEM confirmed the formation of poly-dispersed, spherical-shaped NPs with size range of 6–28 nm. FTIR showed that amine, protein, phenolic, aromatic and alkyne groups contributed to AgNPs synthesis, and XRD confirmed their crystalline and face-centred cubic nature. Both Gram-negative and Gram-positive bacteria were susceptible to the spice blend AgNPs with MIC of 0.0625 at 62.5 µg/mL. The AgNPs exhibited greater inhibition on DPPH radical with IC₅₀ < 31.25 µg/mL, while it was 68.75 µg/mL for ABTS. The nanoparticles were not toxic against MDA-MB-231 breast cancer cell lines. These spice blend nanoparticles would support the production of AgNPs with significantly enhanced pharmacokinetic properties and greatly improved therapeutic performance.

Kedrostis africana, is a tuberous plant commonly used by traditional healers in the Eastern Cape Province of South Africa for the management of obesity. The aim of this study was to investigate the antiobesity and cytotoxic effects of Kedrostis africana extracts in vitro The α-amylase, α-glucosidase and lipase inhibitory activities of aqueous and ethanol extracts of Kedrostis africana tuber were investigated while the cytotoxic effects of these extracts were analyzed using Hoechst 33342 and propidium iodide (PI) dual staining in combination with Molecular Devices ImageXpress Micro XLS Widefield microscope for high content analysis on human cervical (HeLa) cell line. The ethanol extract exhibited the strongest inhibitory effect on pancreatic lipase (IC50 = 381.86 μg/ml) and on α-glucosidase (IC50 = 157.99 μg/mL) while the aqueous extract has strongest α-amylase (IC50 = 439.45 μg/ml). Both tuber extracts were found nontoxic at tested concentrations on HeLa cell lines as confirmed by the Hoechst 33342 and propidium iodide dual staining respectively. This study revealed that both the aqueous and ethanol tuber extract of K. africana exerts a certain degree of inhibitory effect on α-amylase, α-glucosidase and lipase and were also nontoxic to HeLa cell line at tested concentrations.

Objective: To evaluate the nutritional composition and elemental constituents of Kedrostis africana and their safety aspect. Methods: Proximate parameters (moisture, ash, crude fibre, crude fat, proteins, and carbohydrate and energy) were evaluated using ALASA methods, and elemental analysis by ICP-OES technique. Results: The results from nutritional analysis showed that the tuber used for this study had a low content of crude fat and high content of ash, crude protein, crude fibre, carbohydrate and energy having the recommended dietary allowances. The tuber was rich in major minerals Na, K, Ca and Mg, there was sufficient amount of trace elements Fe, Cu, and Zn while the anti-nutrients oxalate, phytate, alkaloids, and saponins were detected in amounts that are not harmful according to Food and Agriculture Organization/World Health Organization. Conclusions: The outcome of this study suggests that this wild plant has very good nutritional potentials to meet the recommended dietary allowance and it could be a cheap source of essential nutrients that may ameliorate most nutritional challenges and can contribute remarkably to the amount of nutrient intake in human and animal diet

The Opuntia spp. have been used in traditional medicine for many centuries. It is used in the management of diseases that involves oxidative stress, especially diabetes, obesity and cancer. Opuntia stricta (Haw) is one of the relatively unknown species in South Africa where it is regarded more as a weed. Because of this, not much is known about its chemical composition. To determine the chemical composition, antioxidant, anti-inflammatory, and cytotoxic activities of Opuntia stricta cladodes. The phytochemical composition of acetone, aqueous and ethanol extract of cladodes of Opuntia stricta (Haw), as well as the vitamins A, C and E of its dried weight cladodes and the antioxidant activities, were evaluated using standard in vitro methods. The anti-inflammatory and cytotoxic activities were evaluated using cell-based assays. The phytochemical composition and vitamins were determined spectrophotometrically, while the antioxidant activities were determined by DPPH, nitric oxide, hydrogen peroxide scavenging activity and phosphomolybdenum (total) antioxidant activity. Anti-inflammatory activity was determined using RAW 264.7 cells, while cytotoxicity was determined using U937 cells. The phytochemical composition showed a significant difference in the various extracts. The total phenolics were higher than other phytochemicals in all the extracts used. All the extracts displayed antioxidant activity, while most of the extracts showed anti-inflammatory activity. Only one extract showed cytotoxicity, and it was mild. The results show that the Opuntia stricta is rich in polyphenolic compounds and has good antioxidant activity as well as anti-inflammatory activities.