Macrocyclic lactones, particularly the avermectins, have completely revolutionized the approaches aimed at control of parasites. These avermectins are the most widely used anti-parasitic drugs in veterinary field with sales exceeding one billion US dollars annually. However, before clinical usage, their safety evaluation in the animals is a major critical factor that must be considered. Many studies have reported the negative effects of avermectins like ivermectin, abamectin, doramectin, and eprinomectin on the host animals. These harmful effects arise from avermectins targeting GABA and glutamate-gated chloride channels present both in the parasites and the host animals. In this review, various modes of avermectins action along with the negative effects on the host like nephrotoxicity, hepatotoxicity, neurotoxicity, reproductive toxicity, and endocrine disruption were discussed in detail. Furthermore, other important issues like ecotoxicity, drug resistance, and drug residues in milk associated with avermectins usage were also discussed, which need special attention.

Protozoa, helminths and ectoparasites are the major groups of parasites distributed worldwide. Currently, these parasites are treated with chemotherapeutic antiprotozoal drugs, anti-helminthic and anti-ectoparasitic agents, but, with the passage of time, resistance to these drugs has developed due to overuse. In this scenario, nanoparticles are proving to be a major breakthrough in the treatment and control of parasitic diseases. In the last decade, there has been enormous development in the field of nanomedicine for parasitic control. Gold and silver nanoparticles have shown promising results in the treatments of various types of parasitic infections. These nanoparticles are synthesized through the use of various conventional and molecular technologies and have shown great efficacy. They work in different ways, that include damaging the parasite membrane, DNA (Deoxyribonucleic acid) disruption, protein synthesis inhibition and free-radical formation. These agents are effective against intracellular parasites as well. Other nanoparticles, such as iron, nickel, zinc and platinum, have also shown good results in the treatment and control of parasitic infections. It is hoped that this research subject will become the future of modern drug development. This review summarizes the methods that are used to synthesize nanoparticles and their possible mechanisms of action against parasites.

Oxidative stress is a key cause of gastrointestinal disorders, primarily stomach ulcers. Multiple intrinsic and extrinsic mechanisms caused the body to produce reactive oxygen species (ROS). The body's antioxidant defense system protects against these reactive species. When the degree of ROS production exceeds the normal range, the body's natural defense system fails to neutralize these dangerous free radicals, necessitating need foran exogenous source of natural antioxidants. Natural herbal remedies have been widely employed as antioxidants to relieve oxidative stress in gastric ulcers. Polyphenols, tannins, essential oils, flavonoids, notably quercetin, carotenoids, vitamin C, vitamin A, and minerals are among the molecules of immense interest in bioassays due to their significant antioxidant effects. In the present review, several natural anti-ulcer medicinal plants along with their antioxidative mechanism have been reported. Electronic databases including PubMed, Google Scholar and Scopus were explored to identify the antioxidant and gastroprotective potential of all the plants.