Cancer is one of the leading causes of death globally. The development of drug resistance is the main contributor to cancer-related mortality. Cancer cells exploit multiple mechanisms to reduce the therapeutic effects of anticancer drugs, thereby causing chemotherapy failure. Natural products are accessible, inexpensive, and less toxic sources of chemotherapeutic agents. Additionally, they have multiple mechanisms of action to inhibit various targets involved in the development of drug resistance. In this review, we have summarized the basic research and clinical applications of natural products as possible inhibitors for drug resistance in cancer. The molecular targets and the mechanisms of action of each natural product are also explained. Diverse drug resistance biomarkers were sensitive to natural products. P-glycoprotein and breast cancer resistance protein can be targeted by a large number of natural products. On the other hand, protein kinase C and topoisomerases were less sensitive to most of the studied natural products. The studies discussed in this review will provide a solid ground for scientists to explore the possible use of natural products in combination anticancer therapies to overcome drug resistance by targeting multiple drug resistance mechanisms.

Many plants and herbs have been traditionally used in the Middle East and some are still used today to treat various diseases. Ammi visnaga, commonly known as khella, is a well-known example of a medicinal plant used traditionally in the region, and its pharmacological action has been scientifically explored in various studies. Preclinical and clinical studies immensely investigated its active phytochemicals, namely khellin and visnagin. The plant extract and active constituents of khella were found to have antispasmodic, anti-inflammatory, antimicrobial, and vasodilatory effects. Moreover, they proved efficacious in treating renal colic, urolithiasis, and urinary tract infections. They were also found beneficial in various topical applications such as wound healing, vitiligo, psoriasis, and poisonous bites management. However, it should be used with caution as it can lead to elevation of liver enzymes, photosensitive reactions, and oxytocic effect.

Burns are a type of skin injury that occurs due to close contact with a heat source or corrosive chemicals. The use of natural products to treat burns dates back to ancient civilizations. This chapter discusses naturally derived products from plants, animals and fungi sources. The natural origin, chemical composition, burn healing mechanisms, clinical studies, and used pharmaceutical formulation are also covered.