**1. Introduction**

Generally, with the extensive screening of plants used in traditional medicine, evidence of their rational use in treating infections, diseases, inflammation and other disorders has been provided [1–3]. Herbal extracts have extensively health benefits, and indigenous medicinal plants have been used traditionally as a major source of drugs for the treatment of various illnesses, including osteoarthritis (OA), asthma, cancer, heart disease, tuberculosis, swollen ankles and hypertension [4–6]. Extracted compounds of medicinal plants are usually used as inputs in toxicology, phytochemicals, pharmaceuticals and other chemical industries [3–5, 7–9]. Stem cell therapies involving cartilage regeneration and several current 3D bioprinting processes involve the use of synthetic and natural biological molecules such as growth factors to improve their proliferation and differentiation [9–11]. There is an ongoing search in the science community for alternatives of these growth factors and the existing synthetic materials, due to reports on their numerous negative effects and complete failure in cartilage regeneration [3, 12–14]. Several medicinal plant extracts have been suggested to stimulate adult stem cell proliferation and thus regeneration of damaged or diseased tissues. Many Chinese herbs have been found to exert adipogenic, osteogenic and chondrogenic effects on human mesenchymal stem cells (hMSCs). Dried root of *Drynaria fortunei* contains flavonoid

and triterpenoid found to promote increased bone cell viability, intracellular total protein as well as alkaline and acid phosphates. Naringin, the major component of *Rhizoma drynariae* extract, enhanced the proliferation of BM-derived hMSCs by regulating β-catenin and AMP-activated protein kinase (AMPK) [15–17]. *Foeniculum vulgare* is traditionally used in the estrogenic activity to enhance milk secretion, in birth facilitation and for the alleviation of dysmenorrhea. *Foeniculum vulgare* extract has been found to promote the proliferation and differentiation of BM-derived hMSC into osteoblasts. Additionally, an ethanol extract of *Ferula gummosa* (an Iranian traditional medicine) was observed to enhance proliferation and differentiation of BM-derived hMSCs into osteocytes. [18]. Studies in this section elaborate on the possible mechanisms and beneficial effects of herbal remedies in the engineering of articular cartilage and regenerative medicine.
