Infertility is a globally recognized issue caused by different reproductive disorders. To date, various therapeutic approaches to restore fertility have been attempted including etiology-specific medication, hormonal therapies, surgical excisions, and assisted reproductive technologies. Although these approaches produce results, however, fertility restoration is not achieved in all cases. Advances in using stem cell (SC) therapy hold a great promise for treating infertile patients due to their abilities to self-renew, differentiate, and produce different paracrine factors to regenerate the damaged or injured cells and replenish the affected germ cells. Furthermore, SCs secrete extracellular vesicles (EVs) containing biologically active molecules including nucleic acids, lipids, and proteins. EVs are involved in various physiological and pathological processes and show promising non-cellular therapeutic uses to combat infertility. Several studies have indicated that SCs and/or their derived EVs transplantation plays a crucial role in the regeneration of different segments of the reproductive system, oocyte production, and initiation of sperm production. However, available evidence triggers the need to testify the efficacy of SC transplantation or EVs injection in resolving the infertility issues of the human population. In this review, we highlight the recent literature covering the issues of infertility in females and males, with a special focus on the possible treatments by stem cells or their derived EVs.

Pb, a major environmental pollutant, can bio-accumulate in different tissues of food animals. The present study was accomplished to investigate the presence of Pb residues in various tissues of Lohi sheep (n = 360) and its deleterious effects. The blood and tissue samples (kidney, liver, and muscles) were collected from a local slaughterhouse for 6 weeks and analyzed through flame atomic absorption sepectrophotometry. The Pb concentration was determined to be maximum in kidney samples, followed by liver, serum, and muscle. In our analysis, 82.78% of muscle samples showed Pb concentrations below the maximum permissible limit (1 mg/kg) by the Australia New Zealand Food Authority (ANZFA). While values of serum ALT, AST, ALP, and urea were within normal range. In all the samples, RBC, TLC, PCV, and Hb values were significantly lower than control (P<0.05). Based on the above results, Lohi sheep seems to be quite resistant to the deleterious effects of Pb; however, its edible offal and lean muscle could pose a serious risk to public health.